Obesity Paradox ? Post-PCI outcome of Overweight better than Leaner Counterparts

Obesity has been thought to be associated with increased PTCI procedure complication as well as decreased outcomes since long. Recently in a randomised trial impact of overweight moderate and morbid obesity on the outcomes of percutaneous coronary intervention was studied. Surprisingly it has been found that Obese and even overweight patients have better survival and fewer major adverse cardiovascular and bleeding events after PCI than their normal-weight or lean counterparts and the same has been termed as Obesity paradox of PTCI.

Dr Eric W Holroyd et al conducted the study 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.

The researchers studied the relationship between BMI and adverse outcomes in 345,192 participants in the British Cardiovascular Intervention Society registry who underwent PCI between 2005 and 2013.Out of all 3007 were classified as underweight (BMI <18.5 kg/m²) based on BMI, , 87,279 as normal weight (18.5–24.9 kg/m²), 146,517 as overweight (25–30 kg/m²), and 108,190 as obese (>30 kg/m²).The 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/m²) and adverse in-hospital outcomes and mortality.

It was found that 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/m², 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).

It was therefore concluded that 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.

The study was published in the July 10, 2017 issue of JACC: Cardiovascular Interventions.