Risk of sudden death in heart failure patients

Sudden death is one of the more important cause of mortality in patients with chronic heart failure. The highest risk occurs among patients with less severe functional impairment, whereas patients in NYHA class IV usually die of progression of heart failure. Predictors of sudden death have been evaluated. Nevertheless, current methods of risk stratification for sudden death are still inadequate, especially in patients with advanced heart failure. Low left ventricular ejection fraction is widely used for the risk stratification, but it lacks of sensitivity and specificity in distinguishing patients with an increased arrhythmic mortality from those with an increased mortality due to pump failure. Unsustained ventricular tachycardia and inducibility at electrophysiological study may help identifying high-risk patients, requiring more aggressive therapy, as the ICD implantation. Heart rate variability and baroreflex sensitivity analysis have been utilized to obtain information on autonomic modulation, but with uncertain conclusion on the identification of high-risk patients. Increased QT dispersion, the presence of T-wave alternans and abnormal signal-averaged electrocardiography have also been proposed, but, up-to-now, any of these parameters showed a strong predictor power. In conclusion, our capability to identifying heart failure patients at risk for arrhythmic death is still far from being satisfactory.