BACKGROUND: To determine whether differential all-cause hospital readmission exists for men and women 2 years after percutaneous coronary intervention (PCI) treatment for acute coronary syndrome (ACS), and to identify potential autonomic and psychological pathways contributing to this association. METHODS: Four hundred and sixteen (416) patients admitted with ACS were recruited from coronary care wards. Participants attended the study centre at one (T0) and 12 (T1) months following discharge. Heart rate variability (HRV) was used to assess autonomic functioning measured via a three-lead electrocardiogram. Psychological variables of interest (pathological worry, depression and phobic anxiety) were measured using validated self-report questionnaires. Percutaneous coronary intervention treatment data were collected from hospital records. The primary outcome was 2-year all-cause hospital readmission (yes/no). Logistic regression modelling using both complete case analysis and multiple imputation analysis was applied. RESULTS: Men who received PCI had a significant reduction in the odds of being rehospitalised over the following 2 years, relative to women who did not (OR=0.45, 95% CI=0.20, 0.98). No other group benefited to this extent. Adjustment for age, ACS severity and Very Low Frequency (VLF) Power appeared to strengthen the association in both the complete case analysis and multiple imputation analysis models. The inclusion of depression and worry also marginally explained these associations in the multiple imputation analysis model. CONCLUSIONS: Men who receive PCI after ACS were less likely to be readmitted to hospital over the following 2 years than their female counterparts. The small sample size of women and observational study design limit interpretation of the findings. However, heart rate variability, specifically VLF power, requires further investigation as a driver of such sex-specific outcomes.