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.