Greater Body Mass Index Predicts Valve Function Following Transcatheter Pulmonary Valve Replacement In Adults With Tetralogy Of Fallot

Introduction: After the initial surgical repair of tetralogy of Fallot (rTOF), right ventricular outflow tract dysfunction is common, with pulmonary stenosis (PS), regurgitation, or both. Obese adults with rTOF have worse biventricular systolic function, and greater post-operative pulmonary valve replacement morbidity than non-obese patients. Transcatheter PVR (TPVR) is used increasingly, though no studies have examined the impact of body mass index (BMI) on morbidity and hemodynamics in adults with rTOF and subsequent TPVR. Hypothesis: BMI affects outcomes of transcatheter PVR in adults with TOF. Methods: This was a 10 yr, single center, retrospective review of adults (>18 yo) with rTOF who underwent TPVR. The cohort was split into 2 groups based on BMI at time of TPVR. Group A (Grp A): normal and overweight (BMI <30), group B (Grp B): obese (BMI ≥30). Pre and post-TPVR echocardiogram, cardiac MRI, and catheterization data were reviewed. Results: There were 81 adults, 42 (52%) normal, 18 (22%) overweight (Grp A) and 21 (26%) obese (Grp B). Mean follow up was 6.4 + 3.1 yrs. With most recent post-TPVR echocardiogram, there was no significant difference in LV or RV size and function across groups. Compared to Grp A, Grp B patients were more likely to develop any degree of PS (mild, moderate, or severe) following TPVR (69% vs 94%, respectively, p = 0.032). An ROC curve analysis demonstrated BMI ≥ 26.3 had a low sensitivity (45%), but good specificity (89%) for predicting PS post TPVR. There was no difference between groups requiring re- intervention for PVR. Conclusion: This is the first study to show greater BMI affects valve function in adults with rTOF following TPVR. BMI >26 was associated with a greater risk of PS in follow up echocardiograms after TPVR. Obesity is an epidemic in the US and patient prosthesis mismatch may be an issue when considering TPVR. Further studies are indicated to determine the long-term effects of BMI on TPVR and the need for re-intervention in adults with TOF.