Aims: Multiple studies have focused on the relationship of body anthropometric measures with clinical events in ST-elevation myocardial infarction (STEMI) patients, highlighting the 'obesity paradox'. However, the relative prognostic importance of these measures over other baseline variables is less known.
Method and results: We performed a retrospective analysis of 94,108 STEMI patients from seven clinical trials evaluating various reperfusion strategies to study the relationship and prognostic importance of height, weight, body mass index (BMI), and body surface area (BSA) with 30-day death and in-hospital cardiogenic shock, major bleeding, and stroke. Main outcome measures of interest included 30-day death and in-hospital cardiogenic shock, major bleeding, and stroke. Weight, BMI, and BSA were inversely and independently related to all clinical events. Despite being statistically significant (P<0.0001), the prognostic information contributed by weight beyond that conferred by baseline clinical factors was minimal (<1% of total prognostic information) making it of limited clinical relevance for predicting 30-day death and cardiogenic shock. In contrast, weight accounted for 8.4% and 4.3% of the prognostic information in the logistic regression models for major bleeding and for stroke. BMI or BSA added little incremental value over simple measure of weight.
Conclusion: Although statistically significantly related to most outcomes in patients with STEMI including death and shock, body weight provided clinically relevant prognostic information only for the risk of major bleeding and of stroke. Furthermore, BMI or BSA contributed little incremental prognostic information beyond that provided by weight alone. Thus, the existing large body of information concerning the strong prognostic importance of anthropometric measures with outcomes after STEMI should be interpreted in the context of other more important risk factors.