To compare receipt of guideline-informed myocardial infarction (MI) care by mental disorder and assess how the COVID-19 pandemic affected associations.

A population-based cohort study using linked electronic health records.

England, November 2019 to February 2023.

131 075 adults with non-ST-elevation MI (NSTEMI) and 79 045 adults with ST-elevation MI (STEMI) were identified from the Myocardial Ischaemia National Audit Project, and their prior diagnoses of mental disorder were ascertained from linked hospitalisation and primary care records.

We compared guideline-informed care standards for each of NSTEMI and STEMI between people with schizophrenia, bipolar disorder or depression versus those without any of these disorders. We used logistic regression to adjust for confounders and investigate differences over time.

Mental disorder disparities were more evident for NSTEMI than STEMI. Following NSTEMI, people with a mental disorder had lower odds of angiography eligibility and receipt, cardiac ward admission and cardiac rehabilitation referral. ORs (95% CIs) ranged from 0.25 (0.20 to 0.31) for angiography receipt for schizophrenia to 0.92 (0.89 to 0.96) for cardiac ward admission for depression. Following STEMI, people with bipolar disorder were less likely to meet the 150 min call-to-balloon target (OR 0.72; 95% CI 0.55 to 0.93), and people with schizophrenia were less likely to receive rehabilitation referral (OR 0.38; 95% CI 0.23 to 0.61) or indicated secondary prevention medication (OR 0.46, 95% CI 0.27 to 0.77). There was no clear evidence that the COVID-19 pandemic affected disparities.

People with a mental disorder are less likely to receive guideline-informed MI care, with disparities greatest following NSTEMI and for people with schizophrenia.