Burden of risk factors in women and men with unrecognized myocardial infarction: a systematic review and meta-analysis

Unrecognized myocardial infarction (MI) is an MI that remains undetected in the acute phase and is associated with an unfavourable prognosis. With this systematic review and meta-analysis, we evaluated the burden of cardiovascular risk factors in individuals with unrecognized MI. We searched general population-based cohort studies diagnosing unrecognized MI by electrocardiogram or myocardial imaging up to 24 November 2023. Pooled mean differences (MDs) or risk ratios (RRs) with 95% confidence intervals (CIs) were determined, and random-effects meta-analyses were performed. Fourteen cohort studies were included involving 200 450 individuals (mean age 62.8 ± 9.9 years, 56.0% women), among which 4322 (2.2%) experienced unrecognized MI (mean age 66.3 ± 8.2 years, 47.8% women) and 4653 (2.1%) recognized MI (mean age 68.5 ± 7.3 years, 33.8% women). Compared to individuals without MI, those with unrecognized MI had higher body mass index (MD 0.27, 95% CI 0.16–0.39) and systolic blood pressure (MD 4.48, 95% CI 2.81–6.15) levels, and higher prevalence of hypertension (RR 1.27, 95% CI 1.06–1.51) and diabetes mellitus (RR 1.67, 95% CI 1.36–2.06). Furthermore, individuals with unrecognized MI had lower prevalence of hypertension (RR 0.92, 95% CI 0.88–0.97) and diabetes mellitus (RR 0.80, 95% CI 0.70–0.92). Individuals with unrecognized MI are characterized by a substantial burden of metabolic risk factors. Our findings suggest insufficient recognition and management of cardiovascular risk factors among individuals with unrecognized MI.