10-year survival in coronary artery bypass grafting surgery patients in Tehran heart center, coronary outcome measurement study: Predictive power of dietary inflammatory index and dietary antioxidant quality

Objectives: There is a higher rate of mortality from cardiovascular disease (CVD) in Iran and the mortality rate increases even after coronary artery bypass grafting (CABG). The aim of this study was to evaluate the association between mortality and survival in patients 10 y after CABG, using the dietary inflammatory index (DII) and dietary antioxidant indices.

Methods: In the current prospective cohort study, 450 patients with CVD who were referred to the Tehran Heart Center and who underwent an isolated CABG during the 6-mo period between April and September 2006 were enrolled. Anthropometric measurements and clinical assessments were performed. Biochemical assay, including hemoglobin A1c, serum lipids, creatinine, blood urea nitrogen, lipoprotein(a), albumin, and C-reactive protein, were also measured. DII, dietary antioxidant quality (DAQ) scores, and dietary Mediterranean quality index (MEDQI) were measured using the data obtained from a semi-quantitative food frequency questionnaire. Survival analysis was performed using the Kaplan-Meir method followed by log-rank test. The association between all-cause mortality and study parameters was performed with Cox proportional hazard model.

Results: According to the present results, older ages, male sex, lower educational attainment, opium use, previous history of diabetes and myocardial infarction, and higher hematocrit and creatinine concentrations were associated with higher mortality rates. Among nutritional indices, a high inflammatory diet was a positive predictor of mortality, whereas a higher DAQ score was a negative predictor (P < 0.05). No association was found between the MEDQI score and mortality rate among patients.

Conclusion: According to the present findings, a diet high in inflammatory foods and low in antioxidant content is a potent predictor of mortality 10 y post-CABG. Therefore, reducing the inflammatory potential of the diet and improving its antioxidant content will be a preventive strategy for reducing mortality after CABG.