Diagnostic-mortality discordance in ischaemic heart disease among patients with schizophrenia: a systematic review and meta-analysis

Background Schizophrenia patients experience a 14·5-year life expectancy reduction, yet the link between cardiovascular risk prediction, ischaemic heart disease (IHD) diagnosis, and mortality remains fragmented. We synthesised evidence across the full continuum of IHD risk, morbidity, and mortality in schizophrenia patients to identify gaps in clinical recognition and prevention. Methods This systematic review and meta-analysis searched PubMed, Embase, and Cochrane Library from database inception to June 17, 2026, for observational studies reporting IHD risk scores, incidence, prevalence, or mortality in schizophrenia populations. We pooled estimates with random-effects meta-analyses, using Robust Bayesian Meta-Analysis to assess bias. The study followed PRISMA and was registered with PROSPERO, CRD42023412510. Findings We identified 62 studies (North America, Europe, Asia, and Oceania); 33 contributed to meta-analysis. Schizophrenia patients have elevated IHD mortality compared to general population (standardised mortality ratio [SMR] 2·26, 95% CI 1·85–2·76; p<0·001; I²=98·5%). By contrast, IHD diagnostic incidence showed a weaker association across measures (hazard ratio 1·40, 95% CI 1·00–1·97; p=0·052), revealing an IHD diagnostic–mortality discordance. Elevated IHD mortality held in females (SMR 2·57, 2·00–3·29) and males (SMR 2·25, 1·84–2·75); within-study comparisons concentrated the relative IHD mortality burden in younger adults (<50 years) with conventionally low risk scores. Interpretation The contrast between elevated IHD mortality and weak IHD diagnostic associations suggests systematic under-recognition of IHD in schizophrenia. Routine cardiovascular screening and low diagnostic thresholds for ischaemic symptoms are warranted for all schizophrenia patients, particularly younger adults and women, in whom conventional risk tools may underestimate risk.