Heart rate, pulse pressure and mortality in patients with myocardial infarction complicated by heart failure

To assess the relationship between heart rate (HR), pulse pressure (PP), and their association with mortality in a population of high-risk patients following acute myocardial infarction (MI).

We performed an analysis in 22,398 patients included in "The High-Risk Myocardial Infarction Database Initiative", a database of clinical trials evaluating pharmacologic interventions in patients with MI complicated by signs of heart failure (HF) or left ventricular dysfunction. We found an interaction between HR and PP. Based on median HR and median PP, patients were divided in four categories: (1) HR < 75 bpm and PP ≥ 50 mm Hg (reference), (2) HR < 75 bpm and PP < 50 mm Hg, (3) HR ≥ 75 bpm and PP ≥ 50 mm Hg, and (4) HR ≥ 75 bpm and PP < 50 mm Hg. The association between these categories and outcomes was studied using a Cox proportional hazard model.

After a median follow-up of 24 (18-33) months, 3561 (16%) patients died of all-causes and 3048 (14%) patients of cardiovascular (CV) causes. In multivariate analysis, patients from the fourth category had the highest risk of all-cause mortality (hazard ratio of 1.69; 95% CI: 1.53-1.86) and CV mortality (hazard ratio of 1.78; 95% CI: 1.60-1.97).

There is an interaction between HR and PP in patients with HF following MI, with the highest risk being conferred by a clinical status with both an elevated HR and a lower PP. These findings identify a high-risk population likely to require an aggressive diagnostic and management strategy.