Increased risk of sudden and non-sudden cardiovascular death in patients with atrial fibrillation/flutter following acute myocardial infarction.

AIMS: Atrial fibrillation (AF) is a common complication in patients with acute myocardial infarction and is associated with an increase in the risk of death. The excess mortality associated with AF complicating acute myocardial infarction has not been studied in detail. Observations indicate that AF facilitates induction of ventricular arrhythmias, which may increase the risk of sudden cardiovascular death (SCD). A close examination of the mode of death could potentially provide useful knowledge to guide further investigations and treatments. METHODS AND RESULTS: We analysed the relation between AF/atrial flutter (AFL) and modes of death in 5983 consecutive patients discharged alive after an acute myocardial infarction screened in the TRAndolapril Cardiac Evaluation registry. This cohort of patients with an enzyme-verified acute myocardial infarction was admitted to 27 centres in 1990-92. Survival status was obtained 2 years after screening of the last patient. An independent endpoint committee assessed the modes of death. Left ventricular ejection fraction was determined in all the screened patients and information about presence or absence of AF/AFL was prospectively collected. Sustained or paroxysmal AF/AFL was observed in 1149 patients (19%) during hospitalization. During follow-up, 1659 patients (34%) died: 482 (50%) patients with AF/AFL and 1177 (30%) patients without AF/AFL, P<0.001. SCD occurred in 536, non-SCD occurred in 725, and 398 died of non-cardiovascular causes (includes 142 unclassifiable cases). The adjusted risk ratio of AF/AFL for total mortality was 1.33 (95% CI: 1.19-1.49; P<0.0001) and the risk ratio for SCD was 1.31 (95% CI: 1.07-1.60; P<0.009). The adjusted risk ratio of AF/AFL for non-SCD was 1.43 (95% CI: 1.21-1.70; P<0.0001). CONCLUSION: The excess mortality observed in patients with AF/AFL following acute myocardial infarction is due to a significant increase in both SCD and non-SCD.

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 < or =1.0 (corresponding to an ejection fraction < or =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 < or =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 < or =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.

Heart rate versus heart rate variability in risk prediction after myocardial infarction.

INTRODUCTION: The aim of this study was to evaluate and compare heart rate and heart rate variability (HRV) in risk prediction after acute myocardial infarction (MI) and to evaluate the effect of beta-blocker treatment on the prognostic performance of heart rate and HRV. METHODS AND RESULTS: Three hundred sixty-six patients underwent 24-hour Holter recording 1 to 6 days after an MI. HRV was expressed as the standard deviation of all normal-to-normal intervals. Left ventricular systolic function was evaluated using the wall motion index. Half of the patients were taking a beta-blocker at the time of Holter recording. Mean follow-up was 44 months (median 34) after MI. By the end of follow-up, 82 patients had died. Mortality at 1 and 3 years was 12.5% and 22.6%, respectively. HRV, heart rate, wall motion index, number of ventricular premature beats per hour, and ventricular tachycardia were all significantly (P < 0.05) associated with mortality in univariate analysis, independent of beta-blocker therapy. In multivariate Cox analysis, only heart rate, wall motion index, number of ventricular premature beats per hour, and age had independent prognostic value (P < 0.001). In any model, including heart rate, HRV had no predictive value. CONCLUSION: The prognostic information of HRV is contained completely in heart rate, which carries prognostic information further than that of HRV. This result was independent of beta-blocker treatment.