Obesity paradox in patients with chronic total occlusion of coronary artery

Background: Obesity is associated with metabolic syndrome which increases further risk of coronary artery disease and adverse cardiovascular events. Impact of body mass index (BMI) on long-term outcome in patients with coronary chronic total occlusion (CTO) is less clear.

Method and results: From January 2005 to November 2020, a total of 1301 patients with coronary angiographic confirmed CTO were enrolled in our study. Patients were divided into two groups: low BMI group: 18-24.99 kg/m² and high BMI group ≥25 kg/m² . Clinical outcomes were 3-year all-cause mortality, 3-year cardiovascular mortality and 3-year non-fatal myocardial infarct. During the 3-year follow-up period, all-cause mortality was significantly higher in patients with low BMI group compared to those in high BMI groups (14% vs. 6%, p = .0001). Kaplan-Meier analysis showed patients with high BMI groups had significant better survival compared with those in low BMI group (p = .0001). In multivariate analysis, higher BMI was independently associated with decreased risk of 3-year all-cause mortality (Hazard ratio [HR]: 0.534; 95% confidence interval [CI]: 0.349-0.819, p = .004) after controlling for age, renal function, prior history of stroke, coronary artery bypass graft, co-morbidities with peripheral arterial disease, heart failure and revascularization status for CTO. In propensity-matched multivariate analysis, high BMI remained a significant predictor of 3-year all-cause mortality (HR, 0.525; 95% CI, 0.346-0.795, p = .002).

Conclusion: Higher BMI was associated with better long-term outcome in patients with coronary CTO.