Tiago Senra

Dipyridamole stress and rest transmural myocardial perfusion ratio evaluation by 64 detector-row computed tomography

BACKGROUND Myocardial stress CT perfusion (CTP) can detect myocardial ischemia. OBJECTIVE We evaluated the transmural perfusion ratio (TPR) of dipyridamole stress CTP to detect significant coronary stenosis (>70%) defined by quantitative invasive coronary angiography (ICA). METHODS Twenty-six patients (61.6 ± 8.0 years old; 14 males), without prior myocardial infarction, with positive single-photon emission computed tomography (SPECT; <2 months) and clinical indication for ICA, underwent a customized multidetector-row CT (MDCT) protocol with rest/stress myocardial perfusion evaluation and coronary CT angiography. TPR was defined as mean subendocardial divided by mean subepicardial attenuation and quantified on rest and stress MDCT images. Abnormal TPR was defined as 2 SDs below the mean rest TPR. RESULTS All 26 patients completed the CT protocol with no adverse events. Rest TPR was measured in all patients with a mean of 1.06 ± 0.11, and abnormal TPR was considered <0.85. For 6 patients with normal coronary arteries by ICA, the mean TPR of territories with a previous positive perfusion defect in SPECT was 1.02 ± 0.18 (95% CI, 0.86-1.18; n = 6), and mean TPR of territories without perfusion defect in SPECT was 1.03 ± 0.09 (95% CI, -0.95 to 1.11; n = 12; P = 0.83). Mean stress TPR in territories with positive SPECT and significant coronary artery disease by quantitative ICA was 0.71 ± 0.13 (95% CI, -0.64 to 0.77) and in the remote myocardial was 1.01 ± 0.09 (95% CI, -0.96 to 1.06; P < 0001). In these territories, a significant Pearsons correlation was observed (r = -0.74, P < 0.001). CONCLUSION TPR has a good correlation with SPECT and ICA to detect significant coronary stenosis.

Myocardial fibrosis in patients with hypertrophic cardiomyopathy and high risk for sudden death

FUNDAMENTO: A estratificacao de risco para morte subita na cardiomiopatia hipertrofica (CMH), continua a ser um verdadeiro desafio devido a grande heterogeneidade da sua apresentacao, em que a maioria dos individuos permanecem assintomaticos por toda sua vida e outros apresentam a morte subita como primeiro sintoma. Recentes trabalhos vem sugerindo que a fibrose miocardica pode constituir-se em um importante substrato para as arritmias ventriculares malignas, responsaveis pela morte subita nesta doenca. OBJETIVO: Avaliacao da prevalencia e quantificacao da fibrose miocardica (FM), em pacientes com CMH com alto risco ou recuperados de morte subita, portadores de cardiodesfibrilador implantavel (CDI). METODOS: Vinte e oito pacientes com CMH portadores de CDI foram submetidos a tomografia computadorizada com multiplos detectores, para realizacao da tecnica de realce tardio, e avaliacao da fibrose miocardica. RESULTADOS: 96% dos pacientes apresentavam fibrose miocardica (20,38 ± 15,55 gramas) correspondendo a 15,96 ± 10,20% da massa miocardica total. A FM foi significativamente mais prevalente que os demais fatores de risco classicos para morte subita. CONCLUSAO: Concluimos que existe uma alta prevalencia de fibrose miocardica em pacientes com cardiomiopatia hipertrofica de alto risco ou recuperados de morte subita, como neste grupo - portadores de cardiodesfibrilador implantavel. A maior prevalencia da fibrose miocardica comparada aos fatores de risco de pior prognostico levantam a hipotese de que a fibrose miocardica possa ser um importante substrato potencialmente necessario na genese das arritmias desencadeadoras da morte subita.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 diseases 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.

Fibrose miocárdica em pacientes com cardiomiopatia hipertrófica com alto risco para morte súbita cardíaca

FUNDAMENTO: A estratificacao de risco para morte subita na cardiomiopatia hipertrofica (CMH), continua a ser um verdadeiro desafio devido a grande heterogeneidade da sua apresentacao, em que a maioria dos individuos permanecem assintomaticos por toda sua vida e outros apresentam a morte subita como primeiro sintoma. Recentes trabalhos vem sugerindo que a fibrose miocardica pode constituir-se em um importante substrato para as arritmias ventriculares malignas, responsaveis pela morte subita nesta doenca. OBJETIVO: Avaliacao da prevalencia e quantificacao da fibrose miocardica (FM), em pacientes com CMH com alto risco ou recuperados de morte subita, portadores de cardiodesfibrilador implantavel (CDI). METODOS: Vinte e oito pacientes com CMH portadores de CDI foram submetidos a tomografia computadorizada com multiplos detectores, para realizacao da tecnica de realce tardio, e avaliacao da fibrose miocardica. RESULTADOS: 96% dos pacientes apresentavam fibrose miocardica (20,38 ± 15,55 gramas) correspondendo a 15,96 ± 10,20% da massa miocardica total. A FM foi significativamente mais prevalente que os demais fatores de risco classicos para morte subita. CONCLUSAO: Concluimos que existe uma alta prevalencia de fibrose miocardica em pacientes com cardiomiopatia hipertrofica de alto risco ou recuperados de morte subita, como neste grupo - portadores de cardiodesfibrilador implantavel. A maior prevalencia da fibrose miocardica comparada aos fatores de risco de pior prognostico levantam a hipotese de que a fibrose miocardica possa ser um importante substrato potencialmente necessario na genese das arritmias desencadeadoras da morte subita.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 diseases 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.

Treatment of patients with aortic atherosclerotic disease with paclitaxel-associated lipid nanoparticles

OBJECTIVE: The toxicity of anti-cancer chemotherapeutic agents can be reduced by associating these compounds, such as the anti-proliferative agent paclitaxel, with a cholesterol-rich nanoemulsion (LDE) that mimics the lipid composition of low-density lipoprotein (LDL). When injected into circulation, the LDE concentrates the carried drugs in neoplastic tissues and atherosclerotic lesions. In rabbits, atherosclerotic lesion size was reduced by 65% following LDE-paclitaxel treatment. The current study aimed to test the effectiveness of LDE-paclitaxel on inpatients with aortic atherosclerosis. METHODS: This study tested a 175 mg/m2 body surface area dose of LDE-paclitaxel (intravenous administration, 3/3 weeks for 6 cycles) in patients with aortic atherosclerosis who were aged between 69 and 86 yrs. A control group of 9 untreated patients with aortic atherosclerosis (72-83 yrs) was also observed. RESULTS: The LDE-paclitaxel treatment elicited no important clinical or laboratory toxicities. Images were acquired via multiple detector computer tomography angiography (64-slice scanner) before treatment and at 1-2 months after treatment. The images showed that the mean plaque volume in the aortic artery wall was reduced in 4 of the 8 patients, while in 3 patients it remained unchanged and in one patient it increased. In the control group, images were acquired twice with an interval of 6-8 months. None of the patients in this group exhibited a reduction in plaque volume; in contrast, the plaque volume increased in three patients and remained stable in four patients. During the study period, one death unrelated to the treatment occurred in the LDE-paclitaxel group and one death occurred in the control group. CONCLUSION: Treatment with LDE-paclitaxel was tolerated by patients with cardiovascular disease and showed the potential to reduce atherosclerotic lesion size.

Análise da incidência e preditores clínicos e ecocardiográficos do refluxo paraprotético aórtico após o implante de prótese aórtica transcateter

INTRODUCAO: A incidencia de refluxo paraprotetico (RPP) parece maior entre os pacientes submetidos a implante de protese aortica transcateter e sua potencial associacao com aumento da mortalidade tardia tem suscitado preocupacao na comunidade cientifica. Nosso objetivo foi avaliar a incidencia e o impacto clinico e estabelecer preditores do RPP em nossa casuistica. METODOS: Entre julho de 2009 e fevereiro de 2013, 112 pacientes foram submetidos a implante de protese aortica transcateter. O grau do RPP pos-procedimento foi avaliado segundo os criterios do VARC 2. Dividiu-se a populacao em grupo RPP ausente/RPP discreto e grupo RPP moderado/RPP grave. RESULTADOS: A media da idade foi de 82,5 ± 3,9 anos, 58,9% eram do sexo feminino e o EuroSCORE logistico foi de 23,6 ± 13,4. Houve queda do gradiente sistolico medio (54,7 ± 15,3 mmHg vs. 11,7 ± 4 mmHg; P < 0,01) e ganho da area valvar aortica (0,66 ± 0,15 cm2 vs. 1,8 ± 0,3 cm2; P < 0,01). Ao final do procedimento, 46,4% nao apresentaram RPP, e RRP discreto ou moderado foi observado em 42% e 11,6% dos pacientes. Nenhum paciente apresentou RPP grave. A analise multivariada identificou sexo masculino [odds ratio (OR) 5,85, intervalo de confianca (IC] 1,29-26,7; P = 0,022), valvoplastia aortica percutânea previa (OR 18,44, IC 2,30-147,85; P = 0,006), fracao de ejecao < 35% (OR 4,160, IC 1,014-17,064; P = 0,048) e presenca de hipertensao pulmonar grave (OR 7,649, IC 1,86-31,51; P = 0,005) como preditores independentes de RPP moderado/grave. CONCLUSOES: A incidencia de RPP moderado/grave foi baixa e comparavel a de outras casuisticas. Sexo masculino, antecedente de valvoplastia aortica percutânea previa, presenca de hipertensao pulmonar grave e disfuncao ventricular esquerda grave foram preditores independentes dessa complicacao.

Myocardial Dysfunction with Delayed Post-chemotherapy Enhancement Assessed in 3 Tesla Cardiac Magnetic Resonance imaging

Cardiomyopathy induced by myocardial fibrosis resulting from the use of doxorubicin and daunorubicin occurs in about 3% of patients, is dose-dependent, affects all age groups and is often irreversible.1 Cardiotoxicity can be acute, subacute or chronic.4 Acute or subacute cardiotoxicity is characterized by sudden changes in ventricular repolarization, changes in the Q-T interval, supraventricular and ventricular arrhythmias, acute coronary syndromes, pericarditis and myocarditis, usually observed from the onset up to 14 days after completion of treatment.4 The chronic cardiotoxicity can be differentiated into two types, according to the onset of clinical symptoms. The first subtype occurs within one year after the end of chemotherapy and the second usually occurs one year after the completion of chemotherapy. The most typical manifestation of chronic cardiotoxicity is systolic or diastolic ventricular dysfunction that may lead to congestive heart failure and cardiovascular death.4,5 The emergence of cardiovascular complications can determine interruption of chemotherapy, jeopardizing the cure or adequate control of cancer.6,7 It is worth noting that heart failure has a worse prognosis than many cancers and may seriously compromise the patient’s progress in treatment.8 The classical cardiotoxic effects are cumulative and are related to the dose, infusion rate, combination of drugs and hepatic and renal failure. In theory, any chemotherapeutic agent has the potential to cause toxicity. The cardiotoxicity of anthracyclines (doxorubicin, epirubicin and idarubicin) is characterized by a decline in left ventricular ejection fraction, occurs in 5% to 25% of the cases, begins with the first doses, and is related to cumulative dose, especially with doses above 400 mg/m2 of body surface.9 At this dose, there is a permanent myocardial damage characterized by myocyte apoptosis, resulting in fibrosis and loss of heart function.3

Delayed Enhancement Assessment of Pulmonary Veins Using 3 Tesla Magnetic Resonance Imaging after Atrial Fibrillation Ablation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinical practice. Epidemiological data show that AF is associated with significant morbidity and mortality, resulting in high medical and hospital costs.1 The dismay generated by the modest impact of antiarrhythmic agents in the natural history of AF motivated the development of non-pharmacological methods aimed at curative treatment of this arrhythmia. In this context, over the past decade, catheter ablation with percutaneous techniques evolved considerably and has become a therapeutic option for selected patients with AF.2 Imaging methods, such as intracardiac echocardiography and electroanatomic mapping have been increasingly incorporated to increase the efficiency and safety of the method. The efficiency of ablation has been discussed in recent years to evidence factors that contribute to the recurrence rates of AF. Failure of the procedure is often attributed to resumed conduction between the pulmonary veins and the left atrium due to incomplete ablation of ectopic foci.3 Cardiac magnetic resonance (CMR) with delayed enhancement technique is a noninvasive imaging modality used to view areas of fibrosis. In the context of AF, it may be adapted to identify fibrosis induced by radiofrequency waves on the left atrial wall and in the pulmonary vein ostia after ablation of AF. The fibrotic regions present increased signal intensity on delayed enhancement due to the slow gadolinium washout in the injured tissue. In this scenario, initial studies suggest that CMR with evaluation of atrial fibrosis using the delayed enhancement technique can provide important information about the radiofrequency ablation sites, potentially identifying incomplete isolations and preexisting areas of atrial fibrosis that may result in a higher AF recurrence rate after the procedure.4

Impacto da Curva de Aprendizado na Seleção de Pacientes e nos Resultados Clínicos do Implante por Cateter de Prótese Aórtica

Introducao: O implante por cateter de protese aortica (TAVI, do ingles transcatheter aortic valve implantation) constitui tratamento alternativo para pacientes com estenose aortica de alto risco cirurgico ou inoperaveis. Para adquirir competencia, o grupo multidisciplinar deve receber treinamento especifico e acumular experiencia na execucao do TAVI. Contudo, sua curva de aprendizado nao esta bem estabelecida. Nosso objetivo foi analisar o impacto da curva de aprendizado na selecao de pacientes, nos aspectos tecnicos e nos resultados clinicos do TAVI. Metodos: Estudo observacional e prospectivo dos primeiros 150 pacientes submetidos a TAVI por via femoral, entre janeiro de 2009 e dezembro de 2013 divididos em tercis (n = 50) de acordo com a data do procedimento. Os desfechos foram definidos conforme os criterios Valve Academic Research Consortium-2 (VARC-2). Resultados: A idade foi de 82,5 ± 6,7 anos, sendo 44% homens e 75% em classe NYHA III/IV. O EuroSCORE (24,2 ± 13% vs. 21,2 ± 10,8% vs. 23,4 ± 14,3%) e o STS Score (5,9 ± 2,9% vs. 6,7 ± 4,3% vs. 5,8 ± 3,1%) foram similares entre os grupos. Observou-se reducao gradativa nos tempos do procedimento (107,2 ± 48,1 minutos vs. 90,3 ± 42,2 minutos vs. 76,6 ± 37,7 minutos; p < 0,01) e de fluoroscopia (31,3 ± 9,6 minutos vs. 25,4 ± 8,7 minutos vs. 17,2 ± 6,2 minutos; p = 0,01), e no volume de contraste (145,5 ± 70,9 mL vs. 123,2 ± 87,8 mL vs. 101,1 ± 50 mL; p = 0,01). A mortalidade reduziu-se de forma progressiva (20% vs. 10% vs. 4%; p = 0,047), e menores taxas de sangramentos e de refluxo paraprotetico de grau moderado/grave foram observadas no terceiro tercil (14% e 4%, respectivamente). Nao ocorreram casos de reintervencao, acidente vascular cerebral e nem outros eventos clinicos entre a alta hospitalar e o 30o dia pos-implante. Conclusoes: A competencia para o TAVI aumentou progressivamente com o numero de pacientes tratados, associando-se a melhores desfechos clinicos.

Fibrosis miocárdica en pacientes con cardiomiopatía hipertrófica con alto riesgo para muerte súbita cardíaca

FUNDAMENTO: A estratificacao de risco para morte subita na cardiomiopatia hipertrofica (CMH), continua a ser um verdadeiro desafio devido a grande heterogeneidade da sua apresentacao, em que a maioria dos individuos permanecem assintomaticos por toda sua vida e outros apresentam a morte subita como primeiro sintoma. Recentes trabalhos vem sugerindo que a fibrose miocardica pode constituir-se em um importante substrato para as arritmias ventriculares malignas, responsaveis pela morte subita nesta doenca. OBJETIVO: Avaliacao da prevalencia e quantificacao da fibrose miocardica (FM), em pacientes com CMH com alto risco ou recuperados de morte subita, portadores de cardiodesfibrilador implantavel (CDI). METODOS: Vinte e oito pacientes com CMH portadores de CDI foram submetidos a tomografia computadorizada com multiplos detectores, para realizacao da tecnica de realce tardio, e avaliacao da fibrose miocardica. RESULTADOS: 96% dos pacientes apresentavam fibrose miocardica (20,38 ± 15,55 gramas) correspondendo a 15,96 ± 10,20% da massa miocardica total. A FM foi significativamente mais prevalente que os demais fatores de risco classicos para morte subita. CONCLUSAO: Concluimos que existe uma alta prevalencia de fibrose miocardica em pacientes com cardiomiopatia hipertrofica de alto risco ou recuperados de morte subita, como neste grupo - portadores de cardiodesfibrilador implantavel. A maior prevalencia da fibrose miocardica comparada aos fatores de risco de pior prognostico levantam a hipotese de que a fibrose miocardica possa ser um importante substrato potencialmente necessario na genese das arritmias desencadeadoras da morte subita.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 diseases 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.