Better diet quality and decreased mortality among myocardial infarction survivors

Abstract

Importance: Information about diet after myocardial infarction (MI) and mortality is limited, despite the growing number of MI survivors in the United States.

Objective: To examine the association of post-MI dietary quality and changes from pre- to post-MI with all-cause and cardiovascular mortality among MI survivors.

Design, setting, and participants: We included 2258 women from the Nurses' Health Study and 1840 men from the Health Professionals Follow-up Study. Participants had survived an initial MI during the study follow-up period and completed the pre- and post-MI food frequency questionnaire. Diet quality was measured using Alternative Healthy Eating Index 2010 (AHEI2010), which consists of food and nutrients associated with the risk of chronic disease reported in the literature. We adjusted for medication use, medical history, and lifestyle risk factors using Cox proportional hazards regression models.

Main outcomes and measures: All-cause and cardiovascular mortality.

Results: During follow-up, we confirmed 682 all-cause deaths for women and 451 for men. The median survival time after the initial MI onset was 8.7 years for women and 9.0 years for men. When the results were pooled, the adjusted hazard ratio (HR) was 0.76 (95% CI, 0.60-0.96) for all-cause mortality and 0.73 (95% CI, 0.51-1.04) for cardiovascular mortality, comparing the extreme quintiles of post-MI AHEI2010. A greater increase in the AHEI2010 score from pre- to post-MI was significantly associated with lower all-cause mortality (pooled HR, 0.71; 95% CI, 0.56-0.91) and cardiovascular mortality (pooled HR, 0.60; 95% CI, 0.41- 0.86), comparing the extreme quintiles. The adjusted HRs associated with post-MI AHEI2010 were 0.73 (95% CI, 0.58-0.93) for all-cause mortality and 0.81 (95% CI, 0.64-1.04) for cardiovascular mortality when the alcohol component was excluded.

Conclusions and relevance: Myocardial infarction survivors who consume a higher-quality diet, which has been associated with a lower risk of coronary heart disease in primary prevention, have lower subsequent all-cause mortality.

Figure 1

Legend: Components of the Alternative Healthy Eating Index 2010 score post-MI and changes from pre- to post-MI period among MI survivors Footnote: Scores were age-standardized. Higher score represents higher diet quality, therefore means less consumption for red meat, sugar sweetened beverage, trans fat, and sodium component. For changes in AHEI2010 from pre- to post-MI, positive number represents improvement in diet quality while negative number refers to decrease of diet quality. For each 11 component of AHEI2010, a maximum score of 10 was given for: red meat and processed meat (< 1 servings/day), nuts and legume (1 servings/day), sugar-sweetened beverages and fruit juice (< 1 servings per month), total vegetables (> 5 servings/day), total fruit (> 4 servings/day), polyunsaturated fat (> 10% energy), trans fat (< 0.5% energy), alcohol (women:0.5 – 1.5 drinks/day, men:1.5 – 2.5 drinks/day), long-chain (n-3) fats (EPA+DHA), 250 mg/day), whole grains (women: 75 g/day, men: 90 g/day), sodium (lowest decile, mg/d). A minimum score of 0 was given for: red meat and processed meat (≥ 1.5 servings/day), nuts and legume (0 servings/day), sugar-sweetened beverages and fruit juice (≥ 1 servings per day), total vegetables (0 servings/day), total fruit (0 servings/day), polyunsaturated fat (≤ 2% energy), trans fat (≥ 4% energy), alcohol (women: 0 or > 2.5 drinks/day, men: 0 or > 3.5 drinks/day), long-chain (n-3) fats (EPA+DHA), 0 mg/day), whole grains (0 g/day), sodium (highest decile, mg/d).

Figure 2

Legend: Adjusted survival curve comparing MI survivors in the highest quintile of Alternative Healthy Eating Index 2010 score vs. those in the lowest quintile. (Quintile 5^th vs. 1^st) Footnote: Adjusted survival curve adjusted for: time since MI onset, age at diagnosis (continuous), calendar year (questionnaire cycle, continuous, 2-year period), total caloric intake (quintiles of Kcal), physical activity (simple updated, quintiles of metabolic equivalents/week), aspirin use (yes or no), diabetes(yes or no), high blood pressure(yes or no), lipid lowering medication use(yes or no), currently married (yes or no), body mass index (<21, 21–22.9, 23–24.9, 25–27.4, 27.5–29.9, >30 kg/m²), coronary artery bypass surgery (CABG, yes or no) and pre-MI score (quintiles). For women, additionally adjusted for post-menopausal hormone use status (pre-menopause, post-menopausal hormone never user, post-menopausal hormone current user, post-menopausal hormone past user), and smoking (never smoker or missing, past smoker, current smoker 1–14 cigarettes/day, current smoker 15–24 cigarettes/day, current smoker 25+ cigarettes/day). For men, additionally adjusted for heart failure (yes or no), left ventricular ejection fraction (≥40%, <40%, or missing), acute therapy during hospitalization (received either angioplasty or thrombolytics, or none), and smoking (never smoker or missing, past smoker, current smoker <15 cigarettes/day, current smoker 15+ cigarettes/day).