Association of the body mass index with outcomes in elderly patients (≥80 years) undergoing percutaneous coronary intervention

BACKGROUND The obesity paradox has been recognized in patients with cardiovascular disease. The association between obesity and outcomes in elderly patients undergoing percutaneous coronary intervention (PCI) has not been investigated, yet. METHODS A total of 990 elderly (≥80 years) patients undergoing PCI at our institution between January 2009 and December 2017 and with available data on body mass index (BMI) were divided according to BMI tertiles (lowest BMI tertile: ≪24.1 kg/m$^{2}$, middle BMI tertile: 24.1-27.2 kg/m$^{2}$, and highest BMI tertile: ≫27.2 kg/m$^{2}$). The primary endpoint was all-cause mortality at a median follow-up of 233 [34-862] days. RESULTS All-cause mortality was 11.2%, 7.6%, and 5.8% in the lowest, the middle, and the highest BMI tertiles (Log Rank p = 0.008). Belonging to the lowest BMI tertile was associated with an increased risk of all-cause mortality (HR 2.14, 95% CI 1.23-3.73, p = 0.007), and associations remained significant after multivariable adjustments (adjusted HR 1.92, 95% CI 1.05-3.52, p = 0.03). While belonging to the lowest BMI tertile was independently associated with an increased all-cause mortality in patients with acute coronary syndromes (HR 2.32, 95% CI 1.24-4.35, p = 0.009; adjusted HR 2.40, 95% CI 1.19-4.84, p = 0.01), relations were not significant in patients with stable coronary artery disease (HR 1.32, 95% CI 0.38-4.56, p = 0.67; adjusted HR 0.80, 95% CI 0.21-3.05, p = 0.75). CONCLUSIONS In elderly (≥80 years) patients undergoing PCI, belonging to the lowest BMI tertile was associated with an increased mortality, mainly in acute coronary syndromes. Hence, the BMI should be incorporated into the risk stratification of elderly patients with coronary artery disease