Myocardial Infarction in Heart Failure With Preserved Ejection Fraction: Pooled Analysis of 3 Clinical Trials

OBJECTIVES:

The authors investigated the relationship between past or incident myocardial infarction (MI) and cardiovascular (CV) events in heart failure with preserved ejection fraction (HFpEF).

BACKGROUND:

MI and HFpEF share some common risk factors. The prognostic significance of MI in patients with HFpEF is uncertain.

METHODS:

The authors pooled data from 3 trials-CHARM Preserved (Candesartan Cilexietil in Heart Failure Assessment of Reduction in Mortality and Morbidity), I-Preserve (Irbesartan in Heart Failure With Preserved Systolic Function), and the Americas region of TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist) (N = 8,916)-and examined whether MI before or following enrollment independently predicted CV death and heart failure (HF) hospitalization.

RESULTS:

At baseline, 2,668 patients (30%) had history of MI. Prior MI was independently associated with greater risk of CV death (4.7 vs. 3.5 events/100 patient-years [py], adjusted hazard ratio [HR]: 1.42 [95% confidence interval (CI): 1.23 to 1.64]; p < 0.001). Excess sudden death drove this difference (1.9 vs. 1.2 events/100 py, adjusted HR: 1.55 [95% CI: 1.23 to 1.97]; p < 0.001). There was no difference in HF hospitalization (5.9 vs. 5.5 events/100 py, adjusted HR: 1.05, 95% CI: 0.92 to 1.19) or HF death by prior MI. During follow-up, MI occurred in 336 patients (3.8%). Risk of CV death increased 31-fold in the first 30 days after first post-enrollment MI, and remained 58% higher beyond 1 year after MI. Risk of first or recurrent HF hospitalization increased 2.4-fold after MI.

CONCLUSIONS:

Prior MI in HFpEF is associated with greater CV and sudden death but similar risk of HF outcomes. Patients with HFpEF who experience MI are at high risk of subsequent CV death and HF hospitalization. These data highlight the importance of primary and secondary prevention of MI in patients with HFpEF.