[Arrhythmia risk stratification based on clinical and functional data].

Abstract

The term "sudden death" indicates a natural and rapid death, an unexpected event in patients with high mortality rates such as those with heart failure. Sudden death in patients with heart failure is responsible for some of 40% of all deaths. A detailed clinical evaluation in patients with heart failure is extremely helpful for risk stratification. Although sex has been shown to have no prognostic relevance, heart failure due to coronary artery disease is associated with a higher mortality rate when compared to other etiologies. Left ventricular ejection fraction is the independent risk factor with the highest predictive value of survival. However, in patients with heart failure, except for the advanced stages, sudden death shows an incidence comparable with that of progressive pump failure. Like left ventricular ejection fraction, even the functional classifications of heart failure (such as NYHA) are to be considered as a non-specific marker of overall mortality. In fact, despite the close relation between advanced disease stages and a higher mortality rate, a large overlap has been demonstrated for the intermediate classes. The noninvasive assessment of oxygen consumption during cardiopulmonary exercise testing has been recognized as an independent risk factor and patients with a peak oxygen consumption < 10 ml/kg/min should be recommended for cardiac transplantation. In these patients no clear relation with an increased risk of sudden death has been demonstrated. In conclusion, the commonly employed clinical-functional indexes (left ventricular ejection fraction, functional classifications, peak oxygen consumption during cardiopulmonary testing) are significant predictors of overall mortality, however they are useless in the risk stratification for death due to fatal arrhythmias.