Heart failure after myocardial infarction: Prevalence of preserved left ventricular systolic function in the community

Background: Studies have reported that a large proportion of the cases of congestive heart failure (CHF) with mixed etiologies have preserved left ventricular systolic function. Whether this is the case in subjects with CHF after myocardial infarction (MI) is not known. This study was undertaken to examine the prevalence and characteristics associated with CHF in patients who had preserved ejection fraction (LVEF) after MI. Methods: Clinical characteristics and LVEF were ascertained in a population-based cohort of patients with CHF after incident MI in Olmsted County, Minn. All MIs were validated by use of standardized epidemiological criteria, and all episodes of CHF were validated by use of Framingham criteria. Results: Between 1979 and 1994, 1658 patients had an MI, and 644 of these patients (38%) had CHF during 7.4 ± 5.4 years of follow-up. Of these patients, 395 (61%) underwent LVEF assessment. Preserved LVEF (ie, ≥50%) was present in 30% of cases, and this proportion did not change with time. The proportion of women with CHF and preserved LVEF (37%) was greater than the proportion of men (23%, P = .002). The positive association between female sex and preserved LVEF remained significant after adjustment (odds ratio 1.97, 95% Cl 1.26-3.07, P = .003). The highest tertile of peak creatinine phosphokinase level was negatively associated with preserved LVEF (odds ratio 0.51, 95% Cl 0.29-0.89). Conclusion: A notable proportion of cases of CHF after MI have preserved LVEF. This underscores the burden of CHF with preserved LVEF in a well-defined group of patients with documented coronary disease. CHF with preserved LVEF after MI is associated with female sex and smaller MI size.