Littérature scientifique sur le sujet « Cardiac RM »

Abstract Objective Remote monitoring (RM) of patients with cardiac rhythm management devices enables healthcare teams to effectively and efficiently monitor patients with heart problems without the requirement in-person patient visits. RM has been associated with safer and higher quality care but was not being used to its full potential in this setting. Cardiac rhythm management had observed an average implant rate of 295 devices per year over the past 13 years, resulting in a five-fold growth in patient follow-up in clinics. This increased demand was becoming unmanageable, with impacts on care quality. This study aimed to enhance the enrolment of eligible patients to RM. Design A pre-post design. Setting A 600-bed city centre teaching hospital in Dublin, Ireland. Participants Hospital staff and patients eligible for RM. Interventions Lean Six Sigma methods were used to develop patient education materials on RM and the clinic area was redesigned to enable RM enrolment and monitoring. Main outcomes measures Number of unscheduled attendances to clinic and RM enrolment. Results At baseline, the clinic was processing 102 RM follow-up checks with 140 unscheduled attendances on average per month. Following implementation, RM enrolment increased to 335 RM follow-up checks (194% increase), with 41 unscheduled attendances on average per month (70% decrease). These results were sustained one-year post-implementation. Conclusions These process changes have streamlined workflow by reducing the number of unscheduled attendances to clinic and increased the use of RM among the eligible patient population. This has meant safer, more timely responses to cardiac events and enhanced care quality.

INTRODUCTION:The reduction of healthcare costs and societal cost due to remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) has been demonstrated in several countries; however, to the best of our knowledge it does not exist for South Korea. This work aims at providing an estimation of the potential benefit of RM versus standard care (SC) of CIEDs in term of healthcare costs in South Korea, in order to provide additional substance to the currently ongoing societal debate about the value of telemedicine.METHODS:Healthcare resource consumption was taken from the results of the TARIFF study, a prospective, non-randomized, multicenter clinical trial designed in Italy to assess the economic benefits of RM follow-up in comparison with standard follow-up in 209 patients (107 SC, 102 RM). The main results demonstrated that RM reduced healthcare resource consumption by 54 percent from a healthcare services perspective (SC: EUR1,044.89±1,990.47 versus RM: EUR482.87±2488.10, p<.0001 (1).In order to perform a cost analysis from the perspective of the South Korean healthcare payer, the following unit costs were assigned to resources collected in TARIFF (hospitalizations, visits, examinations): fee-for-service tariffs, emergency tariffs and outpatient tariffs. Remote follow-up costs were considered as zero.RESULTS:From the perspective of the South Korean healthcare payer, the overall mean annual cost/patient in the RM group is 53 percent lower than in SC group (SC: EUR405,439±40,135 versus RM: EUR189,96±725,52, p<.0001) (SC: KRW 497,145±49,2137 versus RM: KRW 232,936±890,181, p<.0001). This is mainly due to a significant cost reduction in device-related hospitalizations, examination tests and visits in the follow-up period.CONCLUSIONS:RM of CIED patients is cost-saving from the perspective of the South Korean healthcare system. Introducing appropriate reimbursement for remote monitoring of CIED is not likely to change this result and should make RM sustainable for the provider and encourage widespread adoption of RM.

Follow-up of patients with cardiac implantable electronic devices is challenging due to the increasing number and technical complexity of devices coupled to increasing clinical complexity of patients. Remote monitoring (RM) offers the opportunity to optimise clinic workflow and to improve device monitoring and patient management. Several randomised clinical trials and registries have demonstrated that RM may reduce number of hospital visits, time required for patient follow-up, physician and nurse time, hospital and social costs. Furthermore, patient retention and adherence to follow-up schedule are significantly improved by RM. Continuous wireless monitoring of data stored in the device memory with automatic alerts allows early detection of device malfunctions and of events requiring clinical reaction, such as atrial fibrillation, ventricular arrhythmias and heart failure. Early reaction may improve patient outcome. RM is easy to use and patients showed a high level of acceptance and satisfaction. Implementing RM in daily practice may require changes in clinic workflow. To this purpose, new organisational models have been introduced. In spite of a favourable cost:benefit ratio, RM reimbursement still represents an issue in several European countries.

Background: The impact of cardiac rehabilitation on the number of alerts in patients with remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) is unknown. We compared alerts in RM and outcomes in patients with CIEDs undergoing hybrid comprehensive telerehabilitation (HCTR) versus usual care (UC). Methods: Patients with heart failure (HF) after a hospitalization due to worsening HF within the last 6 months (New York Heart Association (NYHA) class I-III and left ventricular ejection fraction (LVEF) ≤40%) were enrolled in the TELEREH-HF study and randomised 1:1 to HCTR or UC. Patients with HCTR and CIEDs received RM (HCTR-RM). Patients with UC and CIEDs were offered RM optionally (UC-RM). Data from the initial 9 weeks of the study were analysed. Results: Of 850 enrolled patients, 208 were in the HCTR-RM group and 62 in the UC-RM group. The HCTR-RM group was less likely to have alerts of intrathoracic impedance (TI) decrease (p < 0.001), atrial fibrillation (AF) occurrence (p = 0.031) and lower mean number of alerts per patient associated with TI decrease (p < 0.0001) and AF (p = 0.019) than the UC-RM group. HCTR significantly decreased the occurrence of alerts in RM of CIEDs, 0.360 (95%CI, 0.189–0.686; p = 0.002), in multivariable regression analysis. There were two deaths in the HCTR-RM group (0.96%) and no deaths in the UC-RM group (p = 1.0). There were no differences in the number of hospitalised patients between the HCTR-RM and UC-RM group (p = 1.0). Conclusions: HCTR significantly reduced the number of patients with RM alerts of CIEDs related to TI decrease and AF occurrence. There were no differences in mortality or hospitalisation rates between HCTR-RM and UC-RM groups.

BackgroundRemote monitoring (RM) of cardiac implantable electronic devices (CIEDs) is now the standard of care, but whether the demonstrated benefits of RM translate into improvements in heart failure (HF) management is controversial. This systematic review addresses the role of RM in patients with HF with a CIED.Methods and resultsA systematic search of the literature for randomised clinical trials in patients with HF and a CIED assessing efficacy/effectiveness of RM was performed using MEDLINE, PubMed and Embase. Meta-analysis was performed on the effects of RM of CIEDs in patients with HF on mortality and readmissions. Effects on implantable cardiac defibrillator (ICD) therapy, healthcare costs and clinic presentations were also assessed.607 articles were identified and refined to 10 studies with a total of 6579 patients. Implementation of RM was not uniform with substantial variation in methodology across the studies. There was no reduction in mortality or hospital readmission rates, while ICD therapy findings were inconsistent. There was a reduction in patient-associated healthcare costs and reduction in healthcare presentations.ConclusionRM for patients with CIEDs and HF was not uniformly performed. As currently implemented, RM does not provide a benefit on overall mortality or the key metric of HF readmission. It does provide a reduction in healthcare costs and healthcare presentations.PROSPERO REGISTRATION NUMBERCRD42019129270.

Abstract Aims Cardiac implantable electronic devices with device advisories have the potential of device malfunction. Remote monitoring (RM) of devices has been suggested to allow the identification of abnormal device performance and permit early intervention. We sought to describe the outcomes of patients with and without RM in devices subject to the Abbott Premature Battery Depletion (PBD) advisory with data from a Canadian registry. Methods and results Patients with an Abbott device subject to the PBD advisory from nine implantable cardioverter defibrillator (ICD) implanting centres in Canada were included in the registry. The use of RM was identified from baseline and follow-up data in the registry. The primary outcome was detection of PBD and all-cause mortality. A total of 2666 patients were identified with a device subject to the advisory. In all, 1687 patients (63.2%) had RM at baseline. There were 487 deaths during follow-up. At a mean follow-up of 5.7 ± 0.7 years, mortality was higher in those without a remote monitor compared with RM at baseline (24.7% vs. 14.5%; P &lt; 0.001). Pre-mature battery depletion was identified in 36 patients (2.1%) with RM vs. 7 (0.7%) without RM (P = 0.004). Time to battery replacement was significantly reduced in patients on RM (median 5 vs. 13 days, P = 0.001). Conclusion The use of RM in patients with ICD and cardiac resynchronization therapy under advisory improved detection of PBD, time to device replacement, and was associated with a reduction in all-cause mortality. The factors influencing the association with mortality are unknown and deserve further study.

The COVID-19 pandemic has had a profound impact on the organisation of health care in Italy, with an acceleration in the development of telemedicine. To assess the impact of the COVID-19 pandemic on the spread of remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) in Italy, a survey addressed to cardiologists operating in all Italian CIED-implanting centres was launched. A total of 127 cardiologists from 116 Italian arrhythmia centres took part in the survey, 41.0% of all 283 CIED-implanting centres operating in Italy in 2019. All participating centres declared to use RM of CIEDs. COVID-19 pandemic resulted in an increase in the use of RM in 83 (71.6%) participating centres. In a temporal perspective, an increase in the median number of patients per centre followed up by RM was found from 2012 to 2017, followed by an exponential increase from 2017 to 2020. In 36 participating centres (31.0%) a telehealth visits service was activated as a replacement for in-person outpatient visits (in patients with or without CIED) during the COVID-19 pandemic. COVID-19 pandemic has caused an acceleration in the use of RM of CIEDs and in the use of telemedicine in the clinical practice of cardiology.

Background Remote management is partially replacing routine follow-up in patients implanted with cardiac implantable electronic devices (CIEDs). Although it reduces clinical staff time compared with standard in-office follow-up, a new definition of roles and responsibilities may be needed to review remote transmissions in an effective, efficient, and timely manner. Whether remote triage may be outsourced to an external remote monitoring center (ERMC) is still unclear. Objective The aim of this health care quality improvement project was to evaluate the feasibility of outsourcing remote triage to an ERMC to improve patient care and health care resource utilization. Methods Patients (N=153) with implanted CIEDs were followed up for 8 months. An ERMC composed of nurses and physicians reviewed remote transmissions daily following a specific remote monitoring (RM) protocol. A 6-month benchmarking phase where patients’ transmissions were managed directly by hospital staff was evaluated as a term of comparison. Results A total of 654 transmissions were recorded in the RM system and managed by the ERMC team within 2 working days, showing a significant time reduction compared with standard RM management (100% vs 11%, respectively, within 2 days; P<.001). A total of 84.3% (551/654) of the transmissions did not include a prioritized event and did not require escalation to the hospital clinician. High priority was assigned to 2.3% (15/654) of transmissions, which were communicated to the hospital team by email within 1 working day. Nonurgent device status events occurred in 88 cases and were communicated to the hospital within 2 working days. Of these, 11% (10/88) were followed by a hospitalization. Conclusions The outsourcing of RM management to an ERMC safely provides efficacy and efficiency gains in patients’ care compared with a standard in-hospital management. Moreover, the externalization of RM management could be a key tool for saving dedicated staff and facility time with possible positive economic impact. Trial Registration ClinicalTrials.gov NCT01007474; http://clinicaltrials.gov/ct2/show/NCT01007474

Aim. To study the advantages of using a portable electrocardiographic (ECG) monitor in outpatients with paroxysmal atrial fibrillation (AF).Material and methods. We examined 88 patients (26 men, 62 women, mean age, 63 [57;68] years) with paroxysmal AF with an average frequency of arrhythmia episodes of 1,0 [0.3;3.75] per month. Forty three (49%) patients were included in the remote monitoring (RM) group using the ECG Dongle monitor, and 45 (51%) patients were included in the conventional monitoring (CM) group. Patients underwent scheduled examinations 2, 6 and 12 months after the start of therapy. Unscheduled consultations were carried out in case of AF recurrence. Patients from the RM group, using portable cardiac monitor, additionally self-registered ECG 1 time per week and in case of symptoms suggestive of AF. ECG strips were sent to the clinical investigator for analysis.Results. With the help of portable cardiac monitor, 2477 ECG strips were collected and analyzed: 2159 (87,2%) — sinus rhythm, 318 (12,8%) — AF and atypical atrial flutter. Forty four episodes of AF in 3 patients were asymptomatic. In addition, 211 (8,5%) sinus rhythm ECG strips were recorded by 13 patients with symptoms suggestive of AF. In the RM group, 7 (16%) patients were hospitalized due to recurrent AF, while in the CM group, 20 (44%) patients (p=0,004). The total number of emergency hospitalizations was 8 and 29 in the RM and CM groups, respectively. The number of patients who called an ambulance was significantly lower in the RM group: in the CM group, 37 calls for an ambulance were made by 22 patients, while in the RM group — 12 patients made 15 calls (p=0,044). The proportion of calls followed by hospitalization (40 vs 70%, p=0,043) was significantly lower in the RM group.Conclusion. Remote ECG monitoring using the ECG Dongle system is a useful way to monitor patients with paroxysmal AF, which make it possible to register asymptomatic AF episodes, differentiate the causes of palpitations, and significantly reduce the frequency of emergency calls and hospitalizations.

In the following review article, we present arguments for and against the use of postoperative troponin surveillance and preoperative natriuretic peptide testing. This article covers the evidence that informed the CCS 2016 perioperative guidelines and research published since then. This review is based on the debate held at the Canadian Society of Internal Medicine/American College of Physicians Rocky Mountain Chapter Annual Meeting (CSIM/ACP RM) held in October 2018 in Banff, Alberta. Resume Dans l'article de synthèse qui suit, nous présentons des arguments pour et contre l'utilisation de la surveillance postopératoire de la troponine et des tests préopératoires de peptides natriurétiques. Cet article porte sur les données probantes qui ont éclairé les lignes directrices périopératoires de la SCC 2016 et les recherches publiées depuis lors. Cet examen est fondé sur le débat qui a eu lieu à l'assemblée annuelle de la section des Rocheuses de la Société canadienne de médecine interne et de l'American College of Physicians (CSIM/ACP RM) tenue en octobre 2018 à Banff, en Alberta.

The aim of this study was to study the electrophysiological and mechanical effects of the gap junction uncoupler 1-heptanol in the left ventricle (epicardial surface) of the artificially perfused Langendorff rabbit heart. Specifically, electrical restitution and the dispersion of repolarisation were studied. Methods. Using a single monophasic action potential (MAP) electrode, in the healthy and failing (coronary ligated) heart, the effect of 1-heptanol was studied on rate dependent changes in action potential duration. Dispersion of repolarisation was measured sequentially. A 32 MAP electrode array was developed to simultaneously record dispersion of repolarisation from the epicardial surface of the left ventricle of healthy hearts. Restitution was studied using an extrastimulus protocol that involved electrically stimulating the heart with 16 S1 stimuli (350ms intervals), and an extrastimulus S2. S1-S2 interval was increased progressively from 70 to 600ms. S1-S2 changes of 5ms were made between 70 and 150ms, 10ms between 150 and 350ms, and 50ms between 350 and 600ms. Protocols were run at 37°C, initially in Tyrode's solution, then after addition of 0.3mM 1-heptanol. Results. The single catheter study showed that failure significantly (P<0.05) prolongs MAP duration between cycle lengths of 250ms and 650ms. No base to apex changes, changes in dispersion of repolarisation or ventricular fibrillation thresholds were observed. 1-Heptanol, at cycle lengths above 350ms, significantly (P<0.05) decreased MAP duration in failing and healthy hearts. 1-Heptanol however did not alter the dispersion of repolarisation or ventricular fibrillation threshold in healthy and failing hearts. The last SI MAP in the 16 beat train and the S2 MAP obtained using the 32 electrode array were analysed at 90% repolarisation (MAPD90). S2 MAPD90 increased with S I-S2 interval up to -180ms but decreased at longer intervals. 0.3mM l-heptanol exacerbated this negative slope in the restitution curve from (mean±SEM) -0.031±O.004 in Tyrode's compared to -O.063±O.005 in O.3mM 1-heptanol (PO.05) in the presence of O.3mM l-heptanol. Conduction delay was increased from (mean±SEM) 44.2±0.82ms to 49.2±O.87ms (P0.05) and caused a significant conduction slowing from (mean±SEM) 45.50±2.I2ms in Tyrode to 55.11±2.82ms in carbenoxolone (P<0.05). Carbenoxolone has an inconsistent effect on single cell fractional shortening and Ca2+ handling. Conclusions. The biphasic relationship and the increased dispersion of repolarisation in the presence of 0.3mM I-heptanol may have implications for the development of alternans and/or arrhythmias (Gilmour and Chialvo, 2000). The cause of the negative slope is as yet unknown. but it is likely that it is an effect on the single cell rather than gap junction uncoupling.

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Outra
The use of Magnetic Resonance Imaging (MRI) as a diagnostic imaging has grown every year due to its great benefits. MRI is a noninvasive test and decisiveness for diagnosis of various diseases and is widely used around the world. With the extension of human longevity, it is increasingly necessary to use new technologies for diagnosis and treatment of diseases. It is known that with increasing age, the individual develops certain diseases that require surgical correction resulting often the implant fixtures as, Cardiac Implantable Electronic Devices (DCEIs). Even though technologies that broke paradigms and transformed lives, extending life expectancy and facilitating diagnoses that were previously impossible and bad, these two medical advances were antagonists until recently, strictly forbidden and that patients with DCEI do use the examination RM due to the interference that this test could cause the DCEI and so harm the health of the patient. As this diagnostic imaging technology cannot be applied to most existing implants, it may be necessary to use alternatives with side effects or less valuable diagnostic information. Because it is an important and necessary for the progress of medical diagnostic advance, the potential risks and the influence of MRI on pacemakers have become research topic over the last ten years. As a result, we acquired a comprehensive understanding of the associated problems. This understanding and solutions to these problems have been integrated in the development of secure devices for MRI (MRI Pro). The objectives of this study were to determine if there is interference DCEI the image generated by Thoracic MRI and thus to understand their influence on the outcome of the review, and determine whether there were significant changes in the operation of this DCEI. Thoracic MRI was performed in 20 patients with DCEIs. The generated image, artifacts and pre and post test parameters were analyzed and compared; coming to the conclusion that Thoracic MRI in patients with DCEIs Pro MRI can be performed safely without changing the operation of the devices and without damaging the image of RM, since some rules and conditions are followed.
O uso da Ressonância Magnética (RM) como método de diagnóstico por imagem tem crescido a cada ano devido aos seus grandes benefícios. A RM é um exame não-invasivo e de caráter decisivo para diagnóstico de diversas doenças, sendo largamente usado ao redor do mundo. Com o prolongamento da longevidade humana, se faz cada vez mais necessário o uso de novas tecnologias para diagnóstico e tratamento de patologias. Sabe-se que com o avanço da idade, o indivíduo desenvolve certas doenças que necessitam correção cirúrgica acarretando, muitas vezes, o implante de dispositivos elétricos como, Dispositivos Cardíacos Eletrônicos Implantáveis (DCEIs). Mesmo sendo tecnologias que romperam paradigmas e transformaram vidas, prolongando a expectativa de vida e facilitando diagnósticos que antes eram impossíveis e duvidosos, esses dois avanços da medicina eram antagonistas até pouco tempo atrás, sendo terminantemente proibido que pacientes portadores de DCEI fizessem uso do exame de RM devido as interferências que este exame poderia causar no DCEI e assim prejudicar a saúde do paciente. Como essa tecnologia de diagnóstico por imagem não pode ser aplicada na maioria dos implantes existentes, pode ser necessário recorrer a alternativas com efeitos colaterais ou informações diagnósticas menos valiosas. Por se tratar de um avanço importante e necessário para o progresso da medicina diagnóstica, os riscos em potenciais e a influência do exame de RM sobre os marcapassos se tornaram tema de pesquisa no decorrer dos últimos dez anos. Como resultado foi adquirido um entendimento abrangente dos problemas associados. Este entendimento e as soluções para esses problemas foram integradas no desenvolvimento de dispositivos seguros para o exame de RM (Pro MRI). Os objetivos deste estudo foram determinar se existe interferência do DCEI na imagem gerada pela RM de Tórax e assim entender sua influência no resultado final do exame, e determinar se ocorreram alterações significativas no funcionamento desses DCEI. Foram realizados exames de RM de Tórax em 20 portadores de DCEIs. A imagem gerada, os artefatos e os parâmetros pré e pós exame foram analisados e comparados, chegando-se à conclusão de que o exame de RM de Tórax em portadores de DCEIs Pro RMI pode ser realizado com segurança, sem alterar o funcionamento dos dispositivos e sem prejudicar a imagem da RM, desde que algumas regras e condições sejam seguidas corretamente.

BACKGROUND: L'identificazione di marcatori affidabili associati a eventi dopo una miocardite acuta (AM) è clinicamente rilevante per pianificare un futuro follow-up. Abbiamo cercato di chiarire la performance prognostica dei marcatori di risonanza magnetica cardiaca (CMRI) precedentemente descritti, tra cui l'aumento tardivo del gadolinio settale (LGE), rispetto all'evidenza della frazione di eiezione ventricolare sinistra (LVEF) <50% sulla CMRI basale, rispetto alla presentazione clinica complicata (CCP) della AM (definita come la presenza di aritmie ventricolari sostenute [SVT] o LVEF <50% al primo ecocardiogramma di presentazione fulminante). METODI: Abbiamo valutato 248 pazienti AM con insorgenza di sintomi cardiaci <30 giorni prima del ricovero, aumento della troponina e CMRI coerente con la diagnosi di miocardite (tempo mediano dal ricovero alla CMRI di 6 giorni). I pazienti sono stati raccolti retrospettivamente tra febbraio 2006 e aprile 2019 da 6 ospedali Lombardi con un follow-up mediano di 1708 giorni (primo - terzo quartile [Q1-Q3], 1000-2751). Abbiamo valutato la performance prognostica di LGE settale vs. LVEF<50% su CMRI vs. CCP. RISULTATI: La popolazione dello studio aveva un'età mediana di 34 anni (Q1-Q3: 23-41) con una prevalenza maschile dell'87,1% e una LVEF mediana del 61% (Q1-Q3, 55-66%) alla CMRI basale. Tredici pazienti (5,2%) hanno sperimentato almeno un evento cardiaco maggiore (tra cui morte cardiaca, trapianto di cuore (N=1), arresto cardiaco resuscitato (N=3), SVT (N=5), o ricovero per insufficienza cardiaca (N=5). Tra questi 13 pazienti, 10 (76,9%) avevano LGE settale, 8 (61,5%) avevano LVEF<50%, su CMRI, e 12 (92,3%) avevano un CCP. La migliore performance per questi marcatori prognostici era il valore predittivo negativo (NPV) che variava tra 0,98 e 0,99 per CCP, mentre il valore predittivo positivo era basso, tra 0,14 e 0,25 per LVEF<50%. CONCLUSIONI: Abbiamo confermato che il tasso di eventi cardiaci maggiori dopo una AM è relativamente basso, e LGE settale, LVEF<50% su CMRI, e CCP sono significativamente associati agli eventi nel follow-up. Il risultato più rilevante è l'alto NPV di questi marcatori per identificare i pazienti senza eventi dopo una AM. Questa osservazione può aiutare i medici a monitorare i pazienti dopo una AM ed impostare un corretto monitoraggio nel follow-up sulla base di tali dati all'esordio.
BACKGROUND: Identifying reliable markers associated with events after acute myocarditis (AM) is clinically relevant to planning a future follow-up. We aimed to clarify the prognostic performance of previously described cardiac magnetic resonance imaging (CMRI) markers including septal late gadolinium enhancement (LGE), versus evidence of left ventricular ejection fraction (LVEF)<50% on baseline CMRI, vs. complicated clinical presentation (CCP) of AM (defined as the presence of sustained ventricular arrhythmias [SVT] or LVEF <50% on the first echocardiogram of fulminant presentation). METHODS: We assessed 248 AM patients with onset of cardiac symptoms <30 days before admission, increased troponin, and CMRI consistent with myocarditis (median time from admission to CMRI of 6 days). The patients were retrospectively collected between February 2006 and April 2019 from 6 hospitals with a median follow-up of 1708 days (first to third quartile [Q1-Q3], 1000-2751). We assessed the prognostic performance of septal LGE vs. LVEF<50% on CMRI vs. CCP. RESULTS: The study population had a median age of 34 years (Q1-Q3: 23-41) with a male prevalence of 87.1% and a median LVEF of 61% (Q1-Q3, 55-66%) on baseline CMRI. Thirteen patients (5.2%) experienced at least one major cardiac event (including cardiac death, heart transplantation (N=1), aborted cardiac death (N=3), SVT (N=5), or heart failure hospitalization (N=5). Among these 13 patients, 10 (76.9%) had septal LGE, 8 (61.5%) had LVEF<50%, on CMRI, and 12 (92.3%) had a CCP. The best performance for these prognostic markers was the negative predictive value (NPV) ranging between 0.98 and 0.99 for CCP, while predictive value was low, ranging between 0.14 and 0.25 for LVEF<50%. CONCLUSIONS: We confirmed that the rate of major cardiac events after an AM is relatively low, and septal LGE, LVEF<50% on CMRI, and CCP are significantly associated with events. The most relevant finding is the high NPV of these markers to identify patients without events after an AM. This observation can help clinicians to monitor the patients after an AM, in fact, patients without these markers had an uneventful follow-up.

Tese de mestrado integrado em Engenharia Biomédica e Biofísica (Sinais e Imagens Médicas), Universidade de Lisboa, Faculdade de Ciências, 2021
O líquido cefalorraquidiano (LCR) tem um papel essencial na drenagem dos resíduos resultantes do metabolismo cerebral e o constante movimento a que este fluido está sujeito é vital para manter a homeostasia do cérebro. Com feito, alterações neste movimento, geralmente associadas com o envelhecimento ou com doença, levam a perturbações fisiológicas, como a doença de Alzheimer ou a hidrocefalia. Por esta razão, é fundamental consolidar e aprofundar o conhecimento referente a este fluido, nomeadamente perceber como varia a sua velocidade e deslocamento, pois só desta forma será possível desenvolver e aperfeiçoar a prevenção e tratamento destas perturbações. Com efeito, este fluido está em constante movimento e o seu comportamento está intimamente ligado ao ciclo cardíaco. Apesar de estudos anteriores sobre a velocidade e o deslocamento do líquido cefalorraquidiano através de métodos de Ressonância Magnética (RM), ainda não existe uma descrição completa sobre o comportamento deste fluido. O objetivo principal deste estudo, consistiu em obter uma descrição detalhada da velocidade e do deslocamento do LCR através da aquisição de imagens de ressonância magnética obtidas com contraste de fase, um método de referência no que toca ao estudo da velocidade de fluidos No entanto, utilizar RM de contraste de fase para adquirir velocidades mais baixas, como as do LCR, requer tempos de aquisição mais longos e, consequentemente, as imagens obtidas estão mais sujeitas a distorções. Assim, a segunda parte deste projecto partiu dos resultados de deslocamento obtidos através da RM com contraste de fase para otimizar os parâmetros de uma segunda sequência de MR. Esta sequência é relativamente recente e possibilita o estudo do deslocamento sub-milimétrico do LCR associado ao movimento do cérebro através da aplicação de gradientes sucessivos (DENSE). Porém, é necessária uma escolha rigorosa dos parâmetros utilizados de forma a obter resultados que retratem o deslocamento do LCR de uma forma rigorosa e exata. Na primeira parte deste projecto, quatro voluntários foram estudados utilizando RM com contraste de fase, entre outubro de 2019 e fevereiro de 2020, em concordância com as diretrizes éticas da University Medical Center em Utrecth, Países Baixos. As aquisições foram realizadas utilizando um scanner de RM Philips 7 T e dois tipos de contraste foram utilizados: contraste de fase com 1mm de resolução isotrópica e com uma codificação de velocidade de 5m/s, e imagens 3D com ponderação em T1 com 1mm de resolução isotrópica. As imagens foram obtidas para três orientações distintas: anterior posterior, inferior-superior, e direita-esquerda. Na segunda parte deste projecto, dois voluntários foram estudados, de janeiro a fevereiro de 2020, utilizando seis contrastes: contraste de fase com 1mm de resolução isotrópica, e imagens 3D com ponderação em T1 com 1mm de resolução isotrópica, uma sequência básica DENSE com 2mm de resolução isotrópica, uma sequência básica DENSE com 3mm de resolução isotrópica, uma sequência DENSE com uma preparação T2 com 3mm de resolução isotrópica e, finalmente, uma sequência DENSE com tempo de eco prolongado com 3mm de resolução isotrópica. No entanto, e ao contrário das imagens adquiridas na primeira parte deste projecto, as imagens da segunda parte foram obtidas apenas para a orientação inferior-superior. Todas as imagens adquiridas no decorrer desta dissertação foram obtidas com gating cardíaco. O gating cardíaco foi realizado através da utilização de um eletrocardiograma e de um oxímetro de pulso de modo a relacionar o evolução da velocidade e do deslocamento com o ciclo cardíaco. Neste projecto foi também desenvolvida uma pipeline que permite que a partir das imagens adquiridas seja possível estudar a velocidade e o deslocamento do LCR. Esta pipeline inclui diversos passos. O primeiro passo consistiu em realinhar e co-registar as imagens obtidas de forma a permitir uma análise voxel a voxel. Seguidamente, as imagens foram segmentas em três tipos de tecidos: LCR, substância cinzenta, e substância branca. Adicionalmente, as primeiras etapas foram realizadas através da utilização de toolboxs disponíveis no MATLAB como o SPM e o CAT12. Posteriormente, os artefactos presentes nas imagens, tais como as correntes-eddy, foram corrigidos. No decorrer deste projecto diversas regiões foram analisadas e foram divididas em dois grupos: regiões do sistema ventricular, nas quais se incluíram os ventrículos laterais, o terceiro e quarto ventrículo, o aqueduto de Sylvius e a Cisterna Magna; e regiões mais abrangentes, como a região anterior e posterior do cérebro. Estas áreas do cérebro foram selecionadas através da segmentação das imagens anatómicas. Finalmente, a velocidade de cada uma destas regiões foi extraída e integrada ao longo do ciclo cardíaco de maneira a calcular o deslocamento do LCR. Os resultados obtidos relativamente à velocidade mostraram consistência para os quatro voluntários deste projecto. Verificou-se que as regiões do sistema ventricular demonstram valores de velocidade consideravelmente mais elevados do que as regiões mais abrangentes. Com efeito, a região que apresentou valores absolutos de velocidade mais elevados foi o aqueducto de Sylvius. Adicionalmente, verificou-se que as velocidades são superiores na orientação caudal-cranial e inferiores na orientação direita-esquerda. Concluiu-se também que o valor de velocidade escolhido não foi o mais indicado para as regiões mais abrangentes pois a velocidade destas regiões é significativamente inferior e, desta forma, poderá ter existido perda de sinal do LCR. Posteriormente, ao integrar a velocidade obtida através da RM com contraste fase obtiveram-se mapas de deslocamento para as mesmas regiões cerebrais. Estes resultados mostraram-se consistentes e, tal como anteriormente observado, o deslocamento é consideravelmente superior para as regiões do sistema ventricular. A região inferior do cérebro foi a que apresentou valores de deslocamento mais elevados, o que pode ser justificado pelo facto desta região se encontrar mais próxima do coração e, desta maneira, o LCR ser ejetado das regiões que ocupa com maior velocidade. Adicionalmente, verificou-se que as maiores alterações do deslocamento ocorrem imediatamente após a sístole cardíaca. Seguidamente, foi possível, a partir dos valores de deslocamento obtidos, determinar um valor ótimo para a sensibilidade, relativamente ao deslocamento, da sequência DENSE. Contrariamente à primeira parte deste projecto, os resultados obtidos utilizando as sequências DENSE dizem respeito exclusivamente às regiões mais abrangentes. De facto, esta exclusão das regiões do sistema ventricular foi causada pela baixa resolução das imagens obtidas que, desta forma, não permitiram uma segmentação de áreas tão reduzidas com fiabilidade razoável. Os resultados desta análise mostram que a sequência utilizada cujos resultados de deslocamento se assemelham mais aos resultados obtidos através do contraste de fase foi a sequência que utilizou a preparação T2. Por oposição, as sequências básicas utilizadas mostraram semelhança reduzida com o método de comparação. Esta diferença observada foi justifica pela baixa resolução das imagens adquiridas, o que contribui para que não fosse possível eliminar o efeito de volume parcial. Adicionalmente, concluiu-se que o valor de sensibilidade para o deslocamento utilizado não foi o correto para estas regiões e, desta forma, houve perda de sinal adquirido justificando assim às diferenças encontradas entre os dois métodos. Concluindo, esta dissertação cumpriu o objetivo principal proposto, nomeadamente fazer uma descrição completa e quantificar a evolução da velocidade e do deslocamento do líquido cefalorraquidiano ao longo do ciclo cardíaco. Adicionalmente, o método de RM com contraste de fase mostrou ser um método fiável para o estudo do comportamento do LCR mesmo em regiões com velocidades mais lentas. Os resultados de deslocamento obtidos através da utilização do método DENSE permitiram confirmar o potencial desta técnica para medir deslocamentos sub-milimétricos. No entanto, este método ainda necessita de ser otimizado de forma a ser uma alternativa viável ao contraste de fase. Finalmente, os resultados obtidos neste estudo permitem que estudos futuros utilizem os valores máximos de cada região obtida de forma a otimizar futuras sequências.
Cerebrospinal fluid (CSF) plays an essential role in the drainage of cerebral waste, and its continuous motion is vital to maintain the brain’s homeostasis. Variations in this motion, associated with aging and disease, are observed in physical and physiological disorders, such as Alzheimer’s Disease. Therefore, a deep understating of this fluid motion, such as its velocity and displacement, is fundamental to strengthen our knowledge of these diseases and might be vital to their prevention and treatment. Despite previous studies reporting CSF velocity and displacement using magnetic resonance imaging techniques, a complete picture of this fluid motion has not yet been obtained. The aim of this study was to, first and foremost, obtain a general picture of CSF velocity and displacement using Phase Contrast (PC) MRI, a method of reference for velocity acquisition. Furthermore, this sequence was also used to optimize the parameters for an MRI technique called Displacement Encoding with Stimulated Echoes (DENSE), a sequence that was modified in order to be capable of measuring small displacements. Four healthy subjects were studied using whole-brain ultra-high field (UHF) MRI at 7 Tesla (T). The volunteers were scanned using two different MRI imaging sequences: Phase Contrast MRI at 1 mm isotropic resolution and 3D T1-weighted (T1w) at 1 mm isotropic resolution. Additionally, two healthy subjects were scanned using PC and four different DENSE acquisitions. Firstly, two basic DENSE sequences with 2mm and 3mm isotropic resolution were acquired. Next, a DENSE acquisition with a T2 prepared magnetization, and a DENSE sequence with a long echo time were acquired to avoid confounding effects from partial volume between tissue and CSF. The image processing pipeline included coregistration, segmentation, eddy current correction. Moreover, mean velocity and displacement maps were calculated for regions of interest previously selected. The results in this study obtained from the PC acquisitions show consistent velocity and displacement values across all subjects. Furthermore, CSF shows higher values for the ventricular regions, such as the aqueduct, and predominant motion in the anterior and feet direction. Comparatively, regions in the periphery of the brain display slower velocities and smaller displacements. The displacement values obtained with PC were used to optimize the displacement sensitivity used in the DENSE acquisition. The DENSE sequence acquired with a T2 magnetization preparation showed the most consistent results when compared to the Phase Contrast. In conclusion, this project managed to study and quantify CSF behavior in the brain, which allows for the optimization of future sequences that desire a more detailed study of this fluid’s in specific brain regions.

Trabalho final de mestrado integrado em Medicina (Cardiologia), apresentado á Faculdade de Medicina da universidade de Coimbra
A caquexia cardíaca representa a fase final da insuficiência cardíaca avançada, sendo caracterizada pelo desenvolvimento de alterações neurohormonais, inflamatórias e metabólicas, que contribuem para a deterioração física nestes doentes. A insuficiência cardíaca é um estado catabólico complexo que conduz a insulinorresistência, constituindo o maior factor de risco para o desenvolvimento de diabetes mellitus tipo 2. Neste estudo pretendeu-se estudar as alterações do metabolismo glucídico em doentes com insuficiência cardíaca avançada, associada ou não a diabetes de início recente. Nos não diabéticos, de forma a avaliar o metabolismo glucídico, recorreu-se à prova de tolerância à glucose oral. Foram também utilizadas técnicas de espectroscopia por ressonância magnética nuclear para avaliar o nível de produção endógena de glicose após jejum prolongado, o contributo relativo da glucogenólise e gluconeogénese para a produção endógena de glucose e, nos não diabéticos, a sua correlação com o resultado da prova de tolerância à glucose oral. A ficha lipídica foi também avaliada. Os resultados deste estudo sugerem que os doentes portadores de insuficiência cardíaca avançada têm, na sua maioria, importantes alterações do metabolismo glucídico e lipídico e que nos não diabéticos existe uma boa correlação entre a magnitude dessas alterações e os resultados da prova de tolerância à glucose oral.
Cardiac cachexia represents the endpoint of advanced heart failure and is characterized by the development of neurohormonal, inflammatory and metabolic abnormalities, which together contribute to the body wasting in these patients. 3 Heart failure is a complex catabolic state that increases insulin resistance, which constitutes the main risk factor for the development of type 2 diabetes. This study evaluates the abnormalities of glucose metabolism in patients with advanced heart failure, associated or not with recent onset diabetes. In non-diabetic patients an oral glucose tolerance test was performed, to evaluate glucose metabolism. Nuclear magnetic resonance spectroscopy was used to evaluate the endogenous glucose production in fasting state, the relative contribution of glycogenolysis and gluconeogenesis for glucose production, and in patients without diabetes, his correlation with the oral glucose tolerance test result. Lipid profile abnormalities were also evaluated. This study suggests that patients with advanced heart failure have, in his majority, important glucose and lipid metabolic abnormalities, and in non-diabetics there is a good correlation between the magnitude of these changes and oral glucose tolerance test results

I più recenti sviluppi tecnologici hanno permesso l'applicazione dell'Imaging di Risonanza Magnetica in ambito cardiaco. La Risonanza Magnetica Cardiaca fornisce in modo non invasivo e riproducibile informazioni di tipo morfologico, qualitativo e quantitativo; l’utilizzo del mezzo di contrasto a base di gadolinio permette di ottenere informazioni su impregnazione, perfusione e vitalità miocardica. Tecniche di mappatura parametrica dei tempi di rilassamento T1 e T2 consentono rispettivamente una quantificazione della fibrosi miocardica, sia focale che diffusa, e dell’edema miocardico tipico della patologia miocardica acuta, ischemica ed infiammatoria. Tra le possibili applicazioni il dottorando ha in particolare valutato il ruolo della Risonanza Magnetica Cardiaca con LGE (late gadolinium enhancement) e sequenze T1 mapping in pazienti con prolasso della valvola mitrale, comune valvulopatia associata ad un aumentato rischio di complicanza aritmiche e morte cardiaca improvvisa. The most recent technological developments have allowed the application of Magnetic Resonance Imaging in the cardiac environment. Cardiac Magnetic Resonance provides morphological, qualitative and quantitative information in a non-invasive and reproducible way; the use of gadolinium-based contrast agent allows obtaining information on enhancement, perfusion and myocardial vitality. Parametric mapping techniques of relaxation times T1 and T2 respectively allow a quantification of myocardial fibrosis, both focal and diffuse, and of myocardial edema typical of acute myocardial pathology, ischemic and inflammatory. Among the possible applications the student has evaluated the role of Cardiac Magnetic Resonance with LGE (late gadolinium enhancement) and T1 mapping sequences in patients with mitral valve prolapse, a common valvular disease associated with an increased risk of arrhythmic complication and sudden cardiac death.