[Value of Doppler-echocardiography in the prognosis and follow up of hypertrophic myocardiopathy]

Implantable Cardioverter-defibrillator Therapy for Hypertrophic Cardiomyopathy: Usefulness in Primary and Secondary Prevention

INTRODUCTION AND OBJECTIVES

Hypertrophic cardiomyopathy is a frequent cause of sudden death. Clinical practice guidelines indicate defibrillator implantation for primary prevention in patients with 1 or more risk factors and for secondary prevention in patients with a history of aborted sudden death or sustained ventricular arrhythmias. The aim of the present study was to analyze the follow-up of patients who received an implantable defibrillator following the current guidelines in nonreferral centers for this disease.

METHODS

This retrospective observational study included all patients who underwent defibrillator implantation between January 1996 and December 2012 in 3 centers in the province of Barcelona.

RESULTS

The study included 69 patients (mean age [standard deviation], 44.8 [17] years; 79.3% men), 48 in primary prevention and 21 in secondary prevention. The mean number of risk factors per patient was 1.8 in the primary prevention group and 0.5 in the secondary prevention group (P=.029). The median follow-up duration was 40.5 months. The appropriate therapy rate was 32.7/100 patient-years in secondary prevention and 1.7/100 patient-years in primary prevention (P<.001). Overall mortality was 10.1%. Implant-related complications were experienced by 8.7% of patients, and 13% had inappropriate defibrillator discharges.

CONCLUSIONS

In patients with a defibrillator for primary prevention, the appropriate therapy rate is extremely low, indicating the low predictive power of the current risk stratification criteria.

Do myocardial perfusion SPECT and radionuclide angiography studies in adult patients with hypertrophic cardiomyopathy have prognostic implications?

BACKGROUND

Some myocardial perfusion single photon emission computed tomography (SPECT) and radionuclide ventriculography studies have suggested that the presence of regional perfusion defects and diastolic abnormalities could have prognostic implications in patients with hypertrophic cardiomyopathy (HC). The aim of this prospective study was to analyze the prognostic value of these techniques in adult patients with HC.

METHODS AND RESULTS

One hundred one patients with HC (44 women; mean age, 54 +/- 16 years; 55% obstructive) were prospectively studied by means of myocardial perfusion SPECT and radionuclide angiography. Of these patients, 55 (54.4%) had an abnormal myocardial perfusion SPECT study: 28 (27.7%) had fixed defects and 41 (40.6%) had reversible defects; 15 (14.8%) of these patients had both types of defect. Of the patients, 16% had left ventricular ejection fraction lower than 60%, 25.7% had an abnormal peak filling rate, and 51% had an abnormal time to peak filling rate. During 5.6 +/- 2.7 years of follow-up, 13 patients (12.8%) died (heart failure 8 and sudden death in 5) and 14 had one or more severe complications develop (syncope in 6, angina III-IV in 4, dyspnea III-IV in 10, and acute myocardial infarction in 3). The summed difference score was higher in patients with cardiac death (2.2 +/- 2.3 vs 1.1 +/- 1.3, P = .008), and fixed defects were more prevalent in patients with severe complications (57% vs 21%, P = .01). In the Kaplan-Meier survival plot analysis, severe complications were more likely in patients with fixed defects (P = .01) or ejection fraction lower than 60% ( P = .01).

CONCLUSIONS

Prognostic information from myocardial perfusion SPECT and radionuclide angiography has limited clinical significance with regard to cardiac death in adult patients with HC. However, the presence of fixed defects and lower ejection fraction in these patients has an adverse prognostic meaning for severe complications.

Miocardiopatía hipertrófica en el adulto. Curso clínico y factores pronósticos de 119 pacientes

BACKGROUND AND OBJECTIVE

The purpose of this study was to characterize adult patients with hypertrophic cardiomyopathy (HCM), to compare their mortality with that of the general population and to establish a prognosis based on clinical and noninvasive techniques.

PATIENTS AND METHOD

One hundred nineteen consecutive patients (60 women, mean: 52 [12] years) with HCM were prospectively studied by ECG, Holter, echo-Doppler, exercise testing, myocardial perfusion SPET and radionuclide ventriculography. Prognostic variables included clinical data and parameters derived from these noninvasive techniques.

RESULTS

During a mean follow-up of 10 [6.7] years, 7 patients (5.8%) died of cardiovascular causes (4 cardiac failure and 3 sudden death). The annual mortality rate was 0.6% and the actuarial survival curve for patients with HCM was significantly worse compared with the expected survival curve derived from the general population after adjustment for age and sex (p = 0.008). The presence of atrial fibrillation (p = 0.04), moderate or severe mitral regurgitation (p = 0.02), dynamic gradient > 50 mmHg (p = 0.02), left atrial diameter > 45 mm (p = 0.02), and interventricular septal thickness > 25 mm (p = 0.04) were all predictive of mortality.

CONCLUSIONS

The mortality rate of adult patients with HCM is significantly higher than that expected for the general population and heart failure and sudden death are almost evenly distributed as a cause of death in these patients. Atrial fibrillation, magnitude of mitral regurgitation, dynamic gradient, left atrial dilatation and interventricular septal thickness are the main predictors of death.

[Functional assessment of patients with hypertrophic cardiomyopathy by maximal oxygen consumption]

INTRODUCTION AND OBJECTIVES

Differences between anatomical severity and clinical manifestations are frequent in patients with hypertrophic cardiomyopathy. Our objective was to assess functional capacity in a consecutive group of patients with hypertrophic cardiomyopathy measuring exercise aerobic parameters, as well as clinical and echocardiographic variables.

PATIENTS AND METHOD

We studied 98 consecutive patients with hypertrophic cardiomyopathy. All patients underwent both echocardiographic and cardiopulmonary exercise testing. The control group consisted of 22 untrained persons. We studied exercise capacity by analyzing maximal oxygen consumption and aerobic functional capacity, among other variables.

RESULTS

Patients with hypertrophic cardiomyopathy attained significantly lower maximal oxygen consumption values than controls (24.1 5.9 vs 36.4 5.9 ml/kg/min; p = 0.0001). Maximal aerobic capacity was significantly different among patients with NYHA functional capacity class I, II or III (78.9 13.5%; 71.9 14.7%; 63.9 15.7%; p = 0.009). However, considerable overlap was found between groups in maximal aerobic capacity. Functional impairment was greater in patients with left ventricular thickness > 20 mm, ejection fraction < 50%, left atrial dimension > 45 mm and pseudonormal or restrictive transmitral flow pattern.

CONCLUSIONS

Patients with hypertrophic cardiomyopathy show significant functional impairment, which is difficult to detect from their clinical manifestations. Optimal assessment requires cardiopulmonary exercise testing.

[Cardiogenic shock due to dynamic left ventricular outflow tract obstruction as a mechanical complication of acute myocardial infarction]

We report the clinical case of a 77-years-old woman with cardiogenic shock caused by dynamic left ventricular outflow tract (LVOT) obstruction that appeared after anterior acute myocardial infarction. Dynamic LVOT obstruction has been reported in various circumstances aside from hypertrophic obstructive cardiomyopathy, such as acute myocardial infarction. In a patient with cardiogenic shock and a heart murmur after acute myocardial infarction, an acute mechanical complication, ventricular septal defect, and acute mitral regurgitation must be ruled out because the treatment of these conditions differs completely. We describe the diagnostic and therapeutic measures used in the diagnosis and treatment of this complication.