Defining obesity with both BMI, WC leads to better long-term risk assessment after revascularization

Using the combination of body mass index (BMI) and waist circumference (WC) as measures of body composition seems to be a more appropriate indicator of the long-term risks obesity poses to patients with left-main coronary artery disease (LMCAD) or three-vessel disease (3VD) who have undergone coronary revascularization, a recent study has found.

Researchers conducted a posthoc analysis of the SYNTAX Extended Survival trial, including 1,799 and 1,587 patients with available BMI and WC data, respectively. Participants were then divided into high and low groups for each body composition measure.

Ultimately, four subgroups emerged: low BMI/low WC (n=344), low BMI/high WC (n=58), high BMI/low WC (n=538), and high BMI/high WC (n=647).

The 10-year mortality risk was significantly higher in patients low BMI/low WC (adjusted hazard ratio [HR], 1.65, 95 percent confidence interval [CI], 1.09–2.51) and high BMI/high WC (adjusted HR, 1.59, 95 percent CI, 1.11–2.27) compared to those with high BMI/low WC.

Notably, the group with low BMI/high WC saw the highest 10-year death risk, which was increased by nearly threefold (adjusted HR, 2.74, 95 percent CI, 1.12–6.69) relative to patients with high BMI/low WC.

The present findings suggest that “the ‘obesity paradox’ following coronary revascularization would be driven by low long-term mortality risk of the high BMI/Low WC group,” the researchers said. “Body composition should be assessed by the combination of BMI and WC in the appropriate evaluation of the long-term risk of obesity in patients with LMCAD or 3VD.”