Natural History of Patients Postacute Coronary Syndrome Based on Heart Failure Status.

The natural history of patients hospitalized for acute coronary syndrome (ACS) with pre-existing versus (vs) de novo heart failure (HF) has not been previously reported over an extended duration of follow-up. The IMPROVE-IT trial enrolled 18,144 patients hospitalized for ACS and randomized them to combination simvastatin (40 mg)/ezetimibe (10 mg) vs simvastatin (40 mg). Subjects were divided into 3 groups: pre-existing HF (i.e., defined by past medical history), de novo HF (i.e., defined by Killip class II or greater during index admission), and no HF. The final analytical cohort included 14,792 patients (82%) with HF status recorded at baseline. In total, 790 patients (5.3%) reported a pre-existing diagnosis of HF and 1374 patients (9.3%) experienced de novo HF. Patients with pre-existing or de novo HF were older, more likely to be woman, and had a greater prevalence of atrial fibrillation and diabetes mellitus. The incidences of death/HF-hospitalizations at 5 years were 32%/20% for pre-existing HF, 18%/7% for de novo HF, and 8%/3% for no HF. After adjusting for potential confounders, a history of pre-existing or de novo HF was independently associated with increased risk of death (pre-existing HF: hazard ratio [HR] 1.93, 95% confidence interval [CI] 1.68 to 2.22, p < 0.001; de novo HF: HR 1.51, 95% CI 1.33 to 1.72, p < 0.001) and hospitalizations for HF (pre-existing HF: HR 2.96, 95% CI 2.36 to 3.71, p < 0.001; de novo HF: HR 1.88, 95% CI 1.49 to 2.38, p < 0.001). There was no interaction among baseline HF status (i.e., pre-existing or de novo), lipid lowering therapy (i.e., simvastatin/ezetimibe vs simvastatin alone), and clinical outcomes. In conclusion, patients hospitalized for ACS with pre-existing or de novo HF were older and had a greater burden of medical co-morbidities. In conclusion, HF was independently associated with increased risk of long-term morbidity and mortality with the pre-existing HF cohort demonstrating the highest overall risk.