Low-normal or excessive body mass index: Newly identified and powerful risk factors for death and other complications with percutaneous coronary intervention

Recognized risk factors account for only a small portion of the variance in the 4% to 10% incidence of major ischemic events associated with percutaneous coronary intervention. Body mass index (BMI) (body weight in kg/[height in m](2)) is a clinically useful estimate of body fat and has been shown to correlate with mortality from several causes, We sought to evaluate the effect of BMI as a potential risk factor for the complications of percutaneous coronary intervention in 3,571 consecutive percutaneous coronary intervention patients treated at a single referral center. Patients were prospectively divided into the nonobese (BMI less than or equal to 25), mildly obese (BMI 26-35), and very obese (BMI >35), based on accepted definitions. Multiple logistic regression analyses were used to determine the correlates of major complications from 25 candidate variables, including BMI less than or equal to 25 (n = 614 patients) and BMI >35 (n = 275 patients), recorded prospectively in a relational database. Death occurred in 2.8% of the BMI less than or equal to 25 group, in 3.7% of the BMI >35 group, and in 0.9% of the BMI 26-34 group (p <0.001), but there was no difference in the incidence of other ischemic events. Blood product transfusion was required in 12% of the BMI less than or equal to 25 group, in 7% of the BMI 25-34 group, and in 8% of the BMI >35% group (p = 0.003). Multivariate analysis, after adjustment for other significant correlates, demonstrated that both BMI less than or equal to 25 (odds ratio [OR] = 2.7, p = 0.005) and BMI >35 (OR = 7.4, p <0.001) were independent correlates of death. Low-normal or high BMI is a newly described and powerful risk factor for in-hospital death after percutaneous coronary intervention.