Prognostic significance of a clearly audible fourth heart sound detected a month after an acute myocardial infarction.

Patients (n = 181) with a myocardial infarction, with (n = 20) or without (n = 161) a clearly audible fourth heart sound detected 1 month after the onset of a myocardial infarction, were followed for 56.2 +/- 21.4 months for cardiac events (death, myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass surgery, worsening angina, or heart failure). The present study suggests that a clearly audible fourth heart sound detected 1 month after the onset of myocardial infarction increases the risk of adverse cardiac events.