Atrial fibrillation in hypertrophic cardiomyopathy: A turning point towards increased morbidity and mortality.

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmic event in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to identify the clinical impact and prognostic significance of AF on a large cohort of patients with HCM. METHODS: Echocardiographic and clinical correlates, risk factors for AF and thromboembolic stroke and the prognostic significance of AF were evaluated in 509 patients with an established diagnosis of HCM. RESULTS: A total of 119 patients (23.4%) were diagnosed with AF during the index evaluation visit. AF patients had a higher prevalence of stroke and presented with worse functional impairment. Left atrial diameter (LA size) was a common independent predictor of the arrhythmia (OR: 2.2, 95% CI 1.6-3.3) and thromboembolic stroke (OR: 1.6, 95% CI 1.01-2.40). AF was an important risk factor for overall mortality (HR=3.4, 95% CI: 1.7-6.5), HCM-related mortality (HR=3.9, 95% CI: 1.8-8.2) and heart failure-related mortality (HR=6.0, 95% CI: 2.0-17.9), even after adjusting for statistically significant clinical and demographic risk factors. However, AF did not affect the risk for sudden death. CONCLUSIONS: LA size is an independent predictor of both AF and thromboembolic stroke. Moreover, patients with AF, regardless of type, have significantly higher mortality rates than patients without AF.

Prognostic value of right ventricular diastolic function indices in hypertrophic cardiomyopathy.

AIMS: Despite the fact that the role of left ventricular diastolic dysfunction in hypertrophic cardiomyopathy (HCM) patients' prognosis has been established, the effect of increased right ventricular (RV) diastolic filling pressures still remains unclear. The purpose of this study was to determine the prognostic significance of transthoracic echocardiographic indices of RV diastolic function (tricuspid inflow and tricuspid annulus tissue Doppler imaging) in HCM patients. METHODS AND RESULTS: We followed up 386 patients diagnosed with HCM (aged 49.3 ± 17.2 years; 65% male) for a median period of 67 months (interquartile range 26-189 months). Primary endpoints were considered mortality due to heart failure (HF) (13 patients) and total cardiovascular (TC) mortality [HF, sudden cardiac death and its equivalents (35 patients)]. Patients presenting with an increased RV E/E(r) ratio (ratio of tricuspid in flow E wave to E(r) wave obtained by tissue Doppler imaging at the lateral tricuspid annulus) had a 1.6 times greater risk for HF mortality [hazard ratio (HR): 1.6, 95% confidence interval (CI): 1.1-2.4, P = 0.03] while patients with shortened tricuspid E wave deceleration time (DTE) had a 1.1 greater risk for SCD (HR: 1.1, 95% CI: 1.01-1.2, P = 0.03). Following ROC analysis, the optimal RV indices' cut-off values for the recognition of our study endpoints were assessed [E/E(r) = 6.88, sensitivity 75%, specificity 77.4%, area under curve (AUC) 0.847, P = 0.017 for HF mortality and DTE < 239 ms, sensitivity 62.5%, specificity 56.7%, AUC 0.642, P = 0.05 for TC mortality]. CONCLUSION: The establishment of RV restrictive physiology appears to have significant predictive value in HCM, regardless of the presence of other detrimental risk factors.