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

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.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 all-cause death at five years. Secondary endpoints were cardiac and non-cardiac death, target (TLR) and non-target 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.Moderately increased BMI is associated with improved survival post PCI, mostly due to lower non-cardiac but not cardiac mortality.