The Obesity Paradox in Patients with Significant Tricuspid Regurgitation: Effects of Obesity on Right Ventricular Remodeling and Long-Term Prognosis

Background: Obesity may cause right ventricular (RV) remodeling due to volume overload. However, obesity is also associated with better prognosis compared with normal weight in patients with various cardiac diseases. The aim of this study was to assess the impact of obesity on RV remodeling and long-term prognosis in patients with significant (moderate and severe) tricuspid regurgitation (TR).

Methods: A total of 951 patients with significant TR (median age, 70 years; interquartile range, 61-77 years; 50% men) were divided into three groups according to body mass index (BMI): normal weight (BMI 18.5-24.9 kg/m²), overweight (BMI 25-29.9 kg/m²), and obese (BMI ≥ 30 kg/m²). Patients with congenital heart disease, peripheral edema, active endocarditis, and BMI < 18.5 kg/m² were excluded. RV size and function for each group were measured using transthoracic echocardiography and compared with reference values of healthy study populations. The primary end point was all-cause mortality. Event rates were compared across the three BMI categories.

Results: Four hundred seventy-six patients (50%) with significant TR had normal weight, 356 (37%) were overweight, and 119 (13%) were obese. RV end-diastolic and end-systolic areas were larger in overweight and obese patients compared with normal-weight patients. However, no differences in RV systolic function were observed. During a median follow-up period of 5 years, 358 patients (38%) died. Five-year survival rates were significantly better in overweight and obese patients compared with patients with normal weight (65% and 67% vs 58%, respectively, P < .001 and P = .005). In multivariate analysis, overweight and obesity were independently associated with lower rates of all-cause mortality compared with normal weight (hazard ratios, 0.628 [95% CI, 0.493-0.800] and 0.573 [95% CI, 0.387-0.848], respectively).

Conclusions: In patients with significant TR, overweight and obese patients demonstrated more RV remodeling compared with patients with normal weight. Nevertheless, a higher BMI was independently associated with better long-term survival, confirming the obesity paradox in this context.