Sudden cardiovascular death following myocardial infarction: The importance of left ventricular systolic dysfunction and congestive heart failure

Background To study the prognostic information of congestive heart failure (CHF) and left ventricular systolic dysfunction regarding sudden and non-sudden cardiovascular death (SCD and non-SCD) in patients with acute myocardial infarction (MI), as this may indicate the potential benefit of implantable defibrillators. Methods Data from consecutive patients with acute MI screened in 1990–92 for the TRAndolapril Cardiac Evaluation (TRACE) study were entered into a registry. A total of 5502 patients were alive 30 days after the MI and were followed for up to 4 years with respect to cause of death. SCD was defined as cardiovascular death within 1 h of onset of symptoms. An echocardiography was performed 1–6 days after the admission and evaluated centrally using the wall motion index (WMI). Results Half of the patients had CHF and 17% of the patients had WMI ≤1.0 (corresponding to an ejection fraction ≤0.30). During follow-up 431 patients died from SCD and 606 from non-SCD. The risk ratios for SCD and non-SCD associated with WMI ≤1.0 were 3.17 and 2.95, transient CHF 2.01 and 1.46, and permanent CHF 3.71 and 4.42, respectively. No risk factor was a specific marker of SCD or non-SCD. The 3-year probability of SCD was 7.9% for patients with transient CHF, 13.3% for permanent CHF, and 15.5% for WMI ≤1.0. Conclusions CHF and low WMI identify a relevant proportion of patients with MI who are at high absolute risk of SCD. This study indicates the relevance of defibrillators in consecutive post-MI patients with left ventricular dysfunction or clinical signs of heart failure.