Association of adherence to various dietary patterns with mortality among survivors of myocardial infarction: a prospective cohort study

Abstract

Background: Current dietary guidelines are largely based on evidence from the general population, and data on dietary patterns and survival after myocardial infarction (MI) remain limited. We evaluated post-MI adherence to multiple healthy dietary patterns, as well as changes in adherence from before to after MI diagnosis, in relation to mortality among MI survivors. Methods: We included 3,277 women from the Nurses’ Health Study and 2,618 men from the Health Professionals Follow-up Study who survived a non-fatal MI. The mean age at MI diagnosis was 68.2 (standard deviation, 10.2) years. Diet was assessed using validated food frequency questionnaires and updated every two to four years. We calculated post-MI adherence scores for eight healthy patterns: the Alternate Healthy Eating Index (AHEI), the Healthy Eating Index-2015 (HEI-2015), the Alternate Mediterranean Diet Score (AMED), the Dietary Approaches to Stop Hypertension (DASH), the healthful Plant-Based Diet Index (hPDI), the reversed empirical dietary inflammatory pattern (rEDIP), the reversed empirical dietary index for hyperinsulinemia (rEDIH), and the reversed empirical dietary index for insulin resistance (rEDIR). The main outcome was total mortality, with cardiovascular disease (CVD) mortality and recurrent non-fatal MI as secondary outcomes. Results: During 15.7 years of follow-up after MI, 3,858 deaths (65.4%) were documented, including 1,639 CVD deaths (42.5% of deaths). Comparing the highest with the lowest quintile, higher post-MI dietary scores were consistently associated with lower total mortality, with the hazard ratio (HR) of 0.67 (95% confidence interval [CI]: 0.60–0.74) for AHEI, 0.73 (0.65–0.81) for HEI-2015, 0.66 (0.59–0.75) for AMED, 0.77 (0.69–0.86) for DASH, 0.74 (0.66–0.83) for hPDI, 0.77 (0.68–0.86) for rEDIP, 0.73 (0.65–0.83) for rEDIR, and 0.71 (0.64–0.80) for rEDIH. Similar inverse associations were observed for CVD mortality and recurrent non-fatal MI. Improved AHEI adherence from before to after MI was associated with lower mortality (HR: 0.86; 95% CI: 0.76–0.97), whereas decreased adherence to most patterns was associated with higher mortality. Conclusions: Among individuals who survived MI, adherence to post-MI dietary patterns emphasizing higher diet quality was associated with better long-term survival. These findings support dietary guidance focusing on overall diet quality for the secondary prevention of deaths among MI survivors.