Recovery of left ventricular function and sleep apnoea after acute myocardial infarction.

In both studies the natural course of polysomnographically assessed sleep apnoea was observed within the first months after acute coronary syndrome [2] and acute myocardial infarction [1]. At baseline, average left ventricular function was mildly impaired in both study populations (left ventricular ejection fraction (LVEF) 47¡10% [2] and 44¡2% [1]). Importantly, in the study by SCHIZA et al. [2] patients with large myocardial infarctions were systematically excluded (LVEF ,40%), resulting in a patient population without major impairment of left ventricular function and a smaller range of severity of heart failure. Both studies found a very high prevalence of sleep apnoea within the first days after the acute coronary event (apnoea/hypopnoea index (AHI) o10 per hour: 54% [2] and AHI o15 per hour: 55% [1]) and a decrease of AHI over time after the coronary event, which was mainly due to a reduction in obstructive apnoeas and hypopnoeas [1, 2].