Marginalized Neighborhoods and Health Outcomes in Younger Myocardial Infarction Survivors

Importance: Neighborhood characteristics may be independently associated with survival after acute myocardial infarction (AMI). Objective: To examine the association of living in a marginalized neighborhood with mortality and care for younger AMI survivors (aged <65 years) in a universal health care system. Design, Setting, and Participants: Population-based retrospective cohort using clinical and administrative databases in Ontario, Canada. Participants were younger patients hospitalized for their first AMI who received invasive evaluation and survived to 7 days after discharge between April 1, 2010, and March 1, 2019. Statistical analysis was performed between May 27, 2022, and March 31, 2025. Exposures: Neighborhood marginalization, a metric comprising material deprivation, residential instability, and dependency. Main Outcomes and Measures: All-cause death, all-cause hospitalizations, and subsequent AMIs. Proportional hazards regression models were used to quantify the association of marginalization with outcomes over 3 years. Results: Among 65 464 AMI patients (median age, 56 [IQR, 50-61] years; 22.9% female), increasing neighborhood marginalization was associated with higher rates of mortality beginning 30 days after discharge and persisting over time. At 3 years, mortality rates ranged from 2.2% in the least marginalized neighborhood quintile (Q1) to 5.2% in the most marginalized (Q5). Adjusted hazard ratios for mortality over 3 years of follow-up were significantly higher in patients from marginalized neighborhoods and ranged from 1.13 (95% CI, 0.95-1.35) in Q2 to 1.52 (95% CI, 1.29-1.80) in Q5. Over 1 year, differences were observed between Q1 and Q5 in visits to primary care physicians (Q1, 96.1%; Q5, 91.6%) and cardiologists (Q1, 88.0%; Q5, 75.7%), as well as diagnostic testing. Conclusions and Relevance: In this cohort study of younger AMI survivors with universal health care, living in marginalized neighborhoods was associated with adverse outcomes. The observed differences in health service utilization among marginalized patients warrant further investigation to better understand the underlying structural and systemic factors.