Timing of heart failure after ST-segment elevation myocardial infarction and its association with long-term mortality

Background Heart failure (HF) is a serious but common complication after ST-segment elevation myocardial infarction (STEMI).1 Previous studies have shown that the risk of hospitalization for HF is highest within the first year after STEMI but remains substantial beyond one year.2 HF occurring shortly after STEMI likely reflects the direct consequence of the infarction, whereas late-onset of HF may reflect progression in disease.3 This study aims to assess the long-term prognostic impact associated with timing of hospitalization for HF after STEMI. Methods This study included patients from the DANAMI-3 trial who were followed up to 10 years. Main exposure was hospitalization for HF ≤1 year after STEMI (early HF) while hospitalization for HF >1 year (late HF) were explored in secondary analyses. Logistic regression was applied to determine predictors for early and late HF hospitalization. Cox proportion hazard models were applied to evaluate the association between timing of HF hospitalization and mortality. HF was modeled as a time-dependent exposure in Cox regression analyses. Follow-up began at the index STEMI hospitalization, with patients contributing person-time to the unexposed group until first HF hospitalization and to the exposed group thereafter. Results A total of 2217 patients were included; 227 were admitted with HF of whom 56 (25%) had early HF and 171 (75%) had late HF. Age, hypertension, congestive HF, heart rate, and Killip class>1 were independent predictors of early HF hospitalization. Both early-HF and late-HF significantly increased the risk of all-cause mortality compared to patients with no HF (early HF: adjusted HR 2.07, 95% CI 1.44-2.98; late HF: adjusted HR 5.19, 95% CI 4.06-6.63; both p<0.001). Among patients who were hospitalized for HF, mortality risk differed by timing with early HF associated with a significantly lower risk of all-cause mortality compared to patients with late HF (adjusted HR: 0.51, 95% CI: 0.32-0.78, p<0.001). Conclusion Both early and late HF hospitalization after STEMI were independently associated with increased 10-year all-cause mortality compared with patients without HF. However, among patients who were hospitalized for HF, early HF was associated with a lower mortality risk compared with late HF.