Myocardial fibrosis detected by cardiac CT predicts ventricular fibrillation/ventricular tachycardia events in patients with hypertrophic cardiomyopathy.

BACKGROUND: Myocardial fibrosis (MF) occurs in up to 80% of subjects with asymptomatic or mildly symptomatic hypertrophic cardiomyopathy (HCM) and can constitute an arrhythmogenic substrate for re-entrant, life-threatening ventricular arrhythmias in predisposed persons. OBJECTIVE: The aim was to investigate whether MF detected by delayed enhancement cardiac CT is predictive of ventricular tachycardia (VT) and fibrillation (VF) that require appropriate therapy by an implantable cardioverter defibrillator (ICD) in patients with HCM. METHODS: Twenty-six patients with HCM with previously (for at least 1 year) implanted ICD underwent MF evaluation by cardiac CT. MF was quantified by myocardial delayed enhanced cardiac CT. Data on ICD firing were recorded every 3 months after ICD implantation. Risk factors for sudden cardiac death in patients with HCM were evaluated in all patients. RESULTS: MF was present in 25 of 26 patients (96%) with mean fibrosis mass of 20.5 ± 15.8 g. Patients with appropriate ICD shocks for VF/VT had significantly greater MF mass than patients without (29.10 ± 19.13 g vs 13.57 ± 8.31 g; P = .01). For a MF mass of at least 18 g, sensitivity and specificity for appropriate ICD firing were 73% (95% CI, 49%-88%) and 71% (95% CI, 56%-81%), respectively. Kaplan-Meier curves indicated a significantly greater VF/VT event rate in patients with MF mass ≥18 g than in patients with MF <18 g (P = .02). In the Cox regression analysis, the amount of MF was independently associated with VF/VT in ICD-stored electrograms. CONCLUSION: The mass of MF detected by cardiac CT in patients with HCM at high risk of sudden death was associated with appropriate ICD firings.

Utilidade clínica da angiografia coronária e da ressonância nuclear magnética no diagnóstico da cardiomiopatia isquêmica / Clinical use of coronary angiography and magnetic resonance imaging in the diagnosis of ischemic cardiomyopathy

INTRODUÇÃO: O diagnóstico da cardiomiopatia isquêmica é frequentemente difícil. A angiografia coronária (AC) é limitada, por ser invasiva e de avaliação exclusivamente anatômica. A ressonância nuclear magnética cardíaca (RNM) com realce tardio pelo gadolínio (RTG) pode mensurar padrões de fibrose miocárdica ocasionados pela isquemia. Porém, o RTG pode não detectar isquemia que não resultou em fibrose. Assim, uma avaliação clínica meticulosa pelo cardiologista parece ser a maneira mais eficaz para definir o diagnóstico. O objetivo deste estudo foi avaliar a AC e o RTG como métodos complementares para o diagnóstico de cardiomiopatia isquêmica em pacientes com insuficiência cardíaca sistólica sem etiologia definida. MÉTODOS: Pacientes com insuficiência cardíaca sistólica, fração de ejeção do ventrículo esquerdo < 45% e etiologia indefinida após avaliação não invasiva inicial foram submetidos à AC e à RNM com RTG para definição etiológica. A análise dos casos por dois cardiologistas foi o padrão-ouro para o diagnóstico de cardiomiopatia isquêmica. RESULTADOS: Foram incluídos 24 pacientes. A sensibilidade para detecção de cardiomiopatia isquêmica foi de 0,45 para AC vs. 0,81 do RTG. A especificidade da AC foi de 1,0 vs. 0,84 do RTG. O valor preditivo positivo foi de 1,0 vs. 0,81, e o valor preditivo negativo foi 0,68 vs. 0,84 para AC e do RTG, respectivamente. A acurácia do RTG foi superior a da AC (0,83 vs. 0,75). CONCLUSÕES: O RTG foi mais sensível do que a AC na avaliação etiológica da disfunção ventricular, enquanto a AC foi mais específica. A definição de cardiomiopatia isquêmica utilizando cada um dos métodos em separado apresentou limitações.

BACKGROUND: The diagnosis of ischemic cardiomyopathy is frequently difficult. Coronary angiography (CA) is limited because it is invasive and the evaluation is exclusively anatomic. Cardiac magnetic resonance imaging (MRI) with late gadolinium enhancement (LGE) measures patterns of myocardial fibrosis caused by ischemia. However, LGE does not detect ischemia that does not result in fibrosis. Thus, a thorough clinical evaluation by a cardiologist seems to be the most effective option for diagnosis. The aim of this study was to evaluate CA and LGE as complementary methods for the diagnosis of ischemic cardiomyopathy in patients with systolic heart failure of unknown etiology. METHODS: Patients with systolic heart failure, left ventricle ejection fraction < 45% and unknown etiology after initial non-invasive evaluation were submitted to CA and MRI with LGE to define the etiology of the disease. Patient evaluation by two cardiologists was the gold standard for the diagnosis of ischemic cardiomyopathy. RESULTS: Twenty-four patients were included. The sensitivity to detect ischemic cardiomyopathy was 0.45 for CA vs. 0.81 for LGE. The specificity was 1.0 for CA vs. 0.84 for LGE. The positive predictive value was 1.0 vs. 0.81 and the negative predictive value was 0.68 vs. 0.84 for CA and LGE, respectively. LGE accuracy was superior to CA accuracy (0.83 vs. 0.75). CONCLUSIONS: LGE was more sensitive than CA to evaluate the etiology of ventricular dysfunction, whereas CA was more specific. The diagnosis of ischemic cardiomyopathy using each one of the methods separately presented limitations.

Fibrose miocárdica em pacientes com cardiomiopatia hipertrófica com alto risco para morte súbita cardíaca / Myocardial fibrosis in patients with hypertrophic cardiomyopathy and high risk for sudden death

FUNDAMENTO: A estratificação de risco para morte súbita na cardiomiopatia hipertrófica (CMH), continua a ser um verdadeiro desafio devido à grande heterogeneidade da sua apresentação, em que a maioria dos indivíduos permanecem assintomáticos por toda sua vida e outros apresentam a morte súbita como primeiro sintoma. Recentes trabalhos vêm sugerindo que a fibrose miocárdica pode constituir-se em um importante substrato para as arritmias ventriculares malignas, responsáveis pela morte súbita nesta doença. OBJETIVO: Avaliação da prevalência e quantificação da fibrose miocárdica (FM), em pacientes com CMH com alto risco ou recuperados de morte súbita, portadores de cardiodesfibrilador implantável (CDI). MÉTODOS: Vinte e oito pacientes com CMH portadores de CDI foram submetidos à tomografia computadorizada com múltiplos detectores, para realização da técnica de realce tardio, e avaliação da fibrose miocárdica. RESULTADOS: 96 por cento dos pacientes apresentavam fibrose miocárdica (20,38 ± 15,55 gramas) correspondendo a 15,96 ± 10,20 por cento da massa miocárdica total. A FM foi significativamente mais prevalente que os demais fatores de risco clássicos para morte súbita. CONCLUSÃO: Concluímos que existe uma alta prevalência de fibrose miocárdica em pacientes com cardiomiopatia hipertrófica de alto risco ou recuperados de morte súbita, como neste grupo - portadores de cardiodesfibrilador implantável. A maior prevalência da fibrose miocárdica comparada aos fatores de risco de pior prognóstico levantam a hipótese de que a fibrose miocárdica possa ser um importante substrato potencialmente necessário na gênese das arritmias desencadeadoras da morte súbita.

BACKGROUND: The stratification of risk for sudden death in hypertrophic cardiomyopathy (HCM) continues to be a true challenge due to the great heterogeneity of this disease's presentation, as most individuals remain asymptomatic during their entire lives and others present sudden death as first symptom. Recent studies have suggested that myocardial fibrosis may represent an important substrate for the malignant ventricular arrhythmias, that are responsible for the cases of sudden death related to this disease. OBJECTIVE: To assess the prevalence and quantification of myocardial fibrosis (MF) in hypertrophic cardiomyopathy (HCM) patients with implantablecardioverter - defibrillator (ICD) indicated due to their high risk or recovered from cardiac sudden death. METHODS: Twenty-eight HCM patients with ICD were submitted to multidetector computed tomography to assess myocardial fibrosis by delayed enhancement technique. RESULTS: Myocardial fibrosis was present in 96 percent of these HCM patients with (20.38 ± 15.55 g) comprising 15.96 ± 10.20 percent of the total myocardial mass. MF was observed in a significantly higher prevalence as compared to other classical risk factors for sudden death. CONCLUSION: It is possible to conclude that there is a high prevalence of myocardial fibrosis in hypertrophic cardiomyopathy patients with high-risk or recovered from cardiac sudden death, like those with clinical indication to implantable cardioverter -defibrillator. The higher prevalence of myocardial fibrosis in comparison to classical risk factors of worse prognosis raise the hypothesis that the myocardial fibrosis may be an important substrate in the genesis of lifethreatening arrhythmias in these high risk HCM population.

[Myocardial fibrosis in patients with hypertrophic cardiomyopathy and high risk for sudden death]. / Fibrose miocárdica em pacientes com cardiomiopatia hipertrófica com alto risco para morte súbita cardíaca.

BACKGROUND: The stratification of risk for sudden death in hypertrophic cardiomyopathy (HCM) continues to be a true challenge due to the great heterogeneity of this disease's presentation, as most individuals remain asymptomatic during their entire lives and others present sudden death as first symptom. Recent studies have suggested that myocardial fibrosis may represent an important substrate for the malignant ventricular arrhythmias, that are responsible for the cases of sudden death related to this disease. OBJECTIVE: To assess the prevalence and quantification of myocardial fibrosis (MF) in hypertrophic cardiomyopathy (HCM) patients with implantablecardioverter - defibrillator (ICD) indicated due to their high risk or recovered from cardiac sudden death. METHODS: Twenty-eight HCM patients with ICD were submitted to multidetector computed tomography to assess myocardial fibrosis by delayed enhancement technique. RESULTS: Myocardial fibrosis was present in 96% of these HCM patients with (20.38 +/- 15.55 g) comprising 15.96 +/- 10.20% of the total myocardial mass. MF was observed in a significantly higher prevalence as compared to other classical risk factors for sudden death. CONCLUSION: It is possible to conclude that there is a high prevalence of myocardial fibrosis in hypertrophic cardiomyopathy patients with high-risk or recovered from cardiac sudden death, like those with clinical indication to implantable cardioverter -defibrillator. The higher prevalence of myocardial fibrosis in comparison to classical risk factors of worse prognosis raise the hypothesis that the myocardial fibrosis may be an important substrate in the genesis of lifethreatening arrhythmias in these high risk HCM population.

Regression of coronary artery outward remodeling in patients with non-ST-segment acute coronary syndromes: a longitudinal study using noninvasive magnetic resonance imaging.

BACKGROUND: The association of plaques with outward arterial remodeling and acute coronary syndromes (ACS) has been mostly investigated by cross-sectional intravascular ultrasound studies. Magnetic resonance imaging (MRI) has made it possible to noninvasively assess the coronary vessels of patients with chronic coronary artery disease, but no study has been done in patients with ACS. We sought to serially investigate changes in coronary vessel walls of patients with ACS using noninvasive serial MRI. METHODS: A total of 42 segments of coronary arteries from 22 patients presenting with non-ST-segment elevation ACS were studied at baseline in the acute phase and at 6 months after stabilization and optimization of medical therapy. Patients received routine medical treatment during this period with control of risk factors. Vessel wall area, maximum wall thickness, mean wall thickness, and lumen area were analyzed longitudinally using MRI. RESULTS: Vessel wall area (38.8 +/- 20.0 vs 27.7 +/- 10.4 mm2; P = .001), maximum wall thickness (2.9 +/- 0.7 vs 2.5 +/- 0.6 mm; P < .001), and mean wall thickness (2.0 +/- 0.7 vs 1.6 +/- 0.5 mm; P < .001) were significantly reduced at 6 months compared with baseline, whereas lumen area did not show significant changes (11.5 +/- 4.8 vs 10.9 +/- 5.0 mm2; P = .52). The wall/lumen ratio was significantly reduced from 3.7 +/- 1.7 to 2.9 +/- 1.3 (P = .01), suggesting a regression of outward remodeling. CONCLUSION: Patients with ACS have increased coronary vessel wall thickness and area that can regress with stabilization and medical therapy over the period of 6 months. Magnetic resonance imaging can detect and serially follow these changes, monitoring coronary vascular remodeling from the acute to the chronic phase of the disease.

[Prevailing right ventricular myocardiopathy for previous myocarditis or arrhythmogenic dysplasia?]. / Miocardiopatia preponderante de ventrículo direito por miocardite prévia ou por displasia arritmogênica?

A clinical case of a 10-year-old male patient is reported. His dilated and prevailing right ventricular myocardiopathy shows diagnostic difficulties between previous myocarditis etiology and arrhythmogenic dysplasia. As the elements are not pathognomonic of one or other cause, the increase of cardiac enzymes in subacute stage maybe tends to the supposition of previous myocarditis. Hence, the questioning that many cases labeled as arrhythmogenic dysplasia can truly correspond to the possibility of evolutional myocarditis. The controversial clinic management is disputable.

Miocardiopatia preponderante de ventrículo direito por miocardite prévia ou por displasia arritmogênica? / Prevailing right ventricular myocardiopathy for previous myocarditis or arrhythmogenic dysplasia?

É relatado o caso clínico de um paciente do sexo masculino com 10 anos de idade, cuja miocardiopatia dilatada e preponderante de ventrículo direito apresenta dificuldades diagnósticas entre a etiologia de miocardite prévia e a displasia arritmogênica. Como os elementos não são patognomônicos de uma ou de outra causa, a elevacão de enzimas cardíacas na fase subaguda talvez incline para a suposicão de miocardite prévia. Daí, o questionamento de que muitos casos rotulados como displasia arritmogênica poderem, verdadeiramente, corresponder à possibilidade de miocardite evolutiva. A controvertida conduta clínica é discutida.

[Vascular prosthesis infection in thoracic aorta surgery: review of the experience and a case report illustrating treatment with an unconventional technique]. / Infecção de prótese vascular em cirurgia da aorta torácica: revisão da experiência e relato de caso tratado por técnica não convencional.

We report the case of a 37-year-old-female patient who had undergone a Bentall procedure at our service and returned with intense chest pain and acute aortic dissection type III, which was diagnosed and clinically treated. One year after this episode, this dissection expanded, and the patient underwent surgery with interposition of a Dacron graft in the descending aorta. In the immediate postoperative period, the patient experienced left bronchopneumonia and was discharged afebrile and in good condition. One month after discharge, she returned with fever and toxemia. Pleural empyema was diagnosed, and she underwent an exploratory thoracotomy that did not confirm this diagnosis, but revealed intense effusion thickening. Four months after the exploratory thoracotomy, Klebsiella pneumoniae and Enterobacter sp were isolated in a blood culture. Magnetic resonance imaging revealed shapes compatible with perigraft infection. With this clinical and laboratory picture, graft removal was indicated as was axillo-bifemoral grafting. Surgery was successfully performed, the patient was discharged in good condition, and remains well after a 57-month follow-up without complications. The methods used for diagnosis and treatment of prosthesis infection in thoracic aorta surgery are discussed.

Infecção de prótese vascular em cirurgia da aorta torácica: revisão da experiência e relato de caso tratado por técnica não convencional / Vascular prosthesis infection in thoracic aorta surgery: review of the experience and a case report illustrating treatment with an unconventional technique

Relatamos o caso de uma paciente de 37 anos de idade, que há cinco anos havia sido submetida à operação de Bental-de Bono em nosso serviço e retornou com dor de forte intensidade no toráx, sendo diagnosticada dissecção aguda de aorta do tipo III e tratada clinicamente. Um ano após esse episódio houve expansão dessa dissecção e a paciente foi submetida à cirurgia com interposição de prótese de dacron em aorta descendente. No pós-operatório imediato houve broncopneumonia esquerda e a paciente recebeu alta em boas condições e afebril. Após um mês da alta, retornou com febre e toxemia. Com diagnóstico de empiema pleural, foi submetida à toracotomia exploradora que não confirmou esse diagnóstico, havendo apenas intenso espessamento pleural. Quatro meses após a toracotomia exploradora, foram isolados Klebsiella pneumoniae e Enterobacter sp na hemocultura. A ressonância magnética revelou imagens compatíveis com infecção peri-prótese. Com esse quadro clínico e laboratorial foi indicada a remoção do enxerto e derivação axilo-bifemoral. A operação foi realizada com sucesso, a paciente recebeu alta em boas condições e continua fazendo controle ambulatorial e, atualmente, encontra-se com 57 meses de evolução sem complicações. São discutidos os métodos empregados para o diagnóstico e tratamento da infecçào de prótese na cirurgia da aorta torácica.