The obesity paradox revisited: Body mass index and long-term outcomes after PCI from a large pooled patient-level database

Aims: The aim of this study was to evaluate the relationship between body mass index (BMI) and outcomes in patients with coronary artery disease undergoing percutaneous revascularisation. Methods and results: In 13 randomised trials, 22,922 patients were stratified (in kg/m²) as underweight (BMI <18.5), normal weight (18.5 ≤BMI <25, used as reference), overweight (25 ≤BMI <30), and obese (Class I [30 ≤BMI <35], Class II [35 ≤BMI <40], or Class III [BMI ≥40]). The primary endpoint was allcause death at five years. Secondary endpoints were cardiac and non-cardiac death, target (TLR) and nontarget lesion revascularisation (NTLR), myocardial infarction (MI), and definite/probable stent thrombosis. Despite adjustment for multiple confounders, overweight and Class I obesity were associated with lower all-cause mortality versus normal weight (HR 0.83, 95% CI: 0.71-0.96, and HR 0.83, 95% CI: 0.69-0.96, respectively); however, non-cardiac death was the major contributor to this effect (HR 0.77, 95% CI: 0.63- 0.94 for overweight). Conversely, cardiac mortality was higher in severely obese individuals (HR 1.62, 95% CI: 1.05-2.51 for Class III obesity). Obesity was associated with higher rates of NTLR (HR 1.28, 95% CI: 1.04-1.58 for Class II obesity) but not with TLR, MI and stent thrombosis. Conclusions: Moderately increased BMI is associated with improved survival post PCI, mostly due to lower non-cardiac but not cardiac mortality.