In Patients with CAD, How Does Obesity Impact Risk of Cardiovascular Events?

In a study, researchers utilized the ADVANCE Registry to investigate the relationship between body mass index (BMI) and adverse cardiovascular events in patients with coronary artery disease (CAD). These findings were presented at the Transcatheter Cardiovascular Therapeutics (TCT) 2021 Annual Meeting.

BMI and CAD Outcomes

The researchers sought to understand “whether patients with CAD and higher BMI may have better outcomes, suggesting an ‘obesity paradox,’” they wrote.

The ADVANCE Registry was developed to evaluate fractional flow reserve (FFR) derived from computed tomography (CT) to assess coronary CT angiogram (CCTA) results in patients with CAD.

For this study, the researchers queried ADVANCE data and identified 2,166 patients with BMI <25 kg/m² (control), 1,883 with BMI 25-29.9 kg/m² (overweight), and 965 with BMI ≥30 kg/m² (obese). Baseline characteristics, comorbidities, and Updated Diamond and Forrester scores were compared between groups, and CCTA findings and FFR-CT positivity (≤0.8) were evaluated. To compare clinical outcomes between groups, the team used an adjusted Cox proportional hazards model with the BMI <25 group as the reference. They adjusted for confounders including age, sex (female), diabetes, hypertension, hyperlipidemia, tobacco, BMI as continuous variable, and prior percutaneous coronary intervention.

The authors noted that cardiovascular adverse outcomes were comparable between obese and non-obese patients. The risk of all-cause mortality relative to the BMI <25 cohort was elevated for both the overweight and obese groups (adjusted hazard ratio [HR]=1.55 and 5.65, respectively); however, neither of these associations were statistically significant (P=0.52 and 0.13, respectively). Similarly, the researchers did not find statistically significant differences in rates of cardiovascular-related death, non-fatal myocardial infarction, and unplanned revascularization between the overweight and obese groups compared with the control (all P>0.21).

Echocardiogram Results

Patients who were obese were more likely to have non-obstructive CAD compared to controls and overweight patients when measured on CCTA (P<0.01). However, the researchers noted that obese and non-obese patients demonstrated a similar degree of hemodynamically significant CAD when measured on FFR-CT.

“Hemodynamic significance, rather than anatomic stenosis, may be a better predictor of cardiovascular outcomes among patients with obesity,” the authors commented.

According to the researchers, the study was limited by “biases inherent to an observational analysis.”

Reference: Lowenstern A, et al. TCT 303: The Influence of Obesity on Coronary Artery Disease and Clinical Outcomes in the ADVANCE Registry. Presented at TCT 2021, Orlando, FL, Nov. 4–6, 2021.