Sex differences in heart failure hospitalisation risk following acute myocardial infarction.

ABSTRACT

OBJECTIVE: We evaluated the sex differences in 6-month heart failure (HF) hospitalisation risk in acute myocardial infarction (AMI) survivors. METHODS: For this retrospective cohort analysis, adult survivors of an AMI between January and June 2014 were identified from the US Nationwide Readmissions Database. The primary outcome was a HF hospitalisation within 6 months. Secondary outcomes were fatal HF hospitalisation and the composite of index in-hospital HF or 6-month HF hospitalisation. RESULTS: Of 237 549 AMI survivors, females (37.9%) were older (70±14 years vs 65±13 years; p<0.001), had a higher prevalence of cardiac comorbidities and a lower revascularisation rate compared with males. The primary outcome occurred in 12 934 patients (5.4%), at a 49% higher rate in females (6.8% vs 4.6% in males, p<0.001), which was attenuated to a 19% higher risk after multivariable adjustment. Findings were consistent across subgroups of age, AMI type and major risk factors. In the propensity-matched time-to-event analysis, female sex was associated with a 13% higher risk for 6-month HF readmission (6.4% vs 5.8% in males; HR 1.13, 95% CI 1.05 to 1.21, p<0.001), and the increased risk was evident early on after the AMI. Fatal HF rate was similar between groups (4.7% vs 4.6%, p=0.936), but females had a higher rate of the composite HF outcome (36.2% vs 27.5%, p<0.001). CONCLUSION: In a large all-comers AMI survivors' cohort, females had a higher HF hospitalisation risk that persisted after adjustment for baseline risk differences. This was consistent across several clinically relevant subgroups and was evident early on after the AMI.