RISK FACTORS FOR PREMATURE MYOCARDIAL INFARCTION: A SCOPING REVIEW

Abstract

Introduction Myocardial infarction remains a major cause of premature mortality and morbidity globally. Early onset or premature myocardial infarction (MI) is a further health and economic challenge, with significant impacts on a working age population. However, progress in preventing premature MI has remained largely static with challenges in understanding and managing risk factors for this specific phenotype. We sought to identify the most prevalent cardiovascular risk factors reported in different studies of premature MI cohorts, over time and geography. Methods We conducted a scoping review, with a literature search in Ovid Medline and Cochrane Library databases, identifying 3612 studies that contained key search terms including 'premature' and 'early onset'. Of these, 136 met the inclusion criteria, where the focus was on premature MI, regardless of study design, and included reporting of common cardiovascular risk factors. We used Pearson's correlation coefficient to examine the association between risk factors and the age cutoffs for premature MI. Results Among the studies reviewed, the most prevalent risk factor reported worldwide in cohorts of premature MI patients was smoking, ranging from 9.6%-96%. There were significant regional differences in the reported prevalence of risk factors within premature MI cohorts, with diabetes ranked highest in India, dyslipidaemia in Iran, and smoking in North America, Europe, and China. Over time, studies of premature MI patients, collectively reported a trend towards lower prevalence of smoking (80% 2011), but an increase in hypertension (27% 2021) and diabetes (6%2011), especially in the past decade. Finally, we noted a correlation between the age cut point definition of premature MI and risk factor prevalence, with hypertension (0.42) more prevalent in studies an using older age cut point for prematurity and family history (-0.26) more common in those with younger age cut points. Conclusion Among research studies reporting on characteristics of individuals with premature MI, we identified that smoking remains the most prevalent risk factor globally for this condition. We also noted important geographical variation and changes over time, reflecting known ethnic differences and emerging trends in risk factor prevalence globally. Finally, the observed differential association with age of event indicates the need to treat premature MI patients as a specific sub-phenotype of MI. These findings highlight the opportunity to tailor population level prevention efforts to reduce the burden of premature MI across the world.