A synergistic impact of body mass index and gamma gap on heart failure and mortality rate among older patients with coronary artery disease: a prospective study with 10-year follow-up

Purpose: To examine the impact of body mass index (BMI) and gamma gap on heart failure and all-cause mortality among older patients with coronary artery disease (CAD) over a 10-year follow-up. Methods: A total of 987 consecutive CAD patients aged ≥60 years were categorized into four groups by BMI (high ≥25 kg/m² vs low) and gamma gap (high ≥30 g/L vs low). Results: Median age was 86 years. The highest heart failure proportion (46.2%) and mortality rate (84.4%) occurred in the low BMI/high gamma gap group; the lowest heart failure (18.9%) and mortality (62.9%) occurred in the high BMI/low gamma gap group. In fully adjusted models, low BMI/high gamma gap vs high BMI/low gamma gap was associated with higher odds of heart failure (HR 2.82, 95% CI 1.79–4.48) and higher mortality (HR 1.65, 95% CI 1.32–2.07). Conclusion: Low BMI combined with high gamma gap synergistically increases heart failure and mortality risk in older CAD patients; further research should explore mechanisms and potential nutritional/immunological interventions.