The Relationship of Body Mass Index to Percutaneous Coronary Intervention Outcomes: Does the Obesity Paradox Exist in Contemporary Percutaneous Coronary Intervention Cohorts? Insights From The British Cardiovascular Intervention Society Registry

Objectives: The aims of this study were to examine the relationship between body mass index (BMI) and clinical outcomes following percutaneous coronary intervention (PCI) and to determine the relevance of different clinical presentations requiring PCI to this relationship.

Background: Obesity is a growing problem, and studies have reported a protective effect from obesity compared with normal BMI for adverse outcomes after PCI.

Methods: Between 2005 and 2013, 345,192 participants were included. Data were obtained from the British Cardiovascular Intervention Society registry, and mortality data were obtained through the U.K. Office of National Statistics. Multiple logistic regression was performed to determine the association between BMI group (<18.5, 18.5 to 24.9, 25 to 30 and >30 kg/m) and adverse in-hospital outcomes and mortality.

Results: At 30 days post-PCI, significantly lower mortality was seen in patients with elevated BMIs (odds ratio [OR]: 0.86 [95% confidence interval (CI): 0.80 to 0.93] 0.90 [95% CI: 0.82 to 0.98] for BMI 25 to 30 and >30 kg/m, respectively). At 1 year post-PCI, and up to 5 years post-PCI, elevated BMI (either overweight or obese) was an independent predictor of greater survival compared with normal weight (OR: 0.70 [95% CI: 0.67 to 0.73] and 0.73 [95% CI: 0.69 to 0.77], respectively, for 1 year; OR: 0.78 [95% CI: 0.75 to 0.81] and 0.88 [95% CI: 0.84 to 0.92], respectively, for 5 years). Similar reductions in mortality were observed for the analysis according to clinical presentation (stable angina, unstable angina or non-ST-segment elevation myocardial infarction, and ST-segment elevation myocardial infarction).

Conclusions: A paradox regarding the independent association of elevated BMI with reduced mortality after PCI is still evident in contemporary U.K. practice. This is seen in both stable and more acute clinical settings.