Abstract P276: Discordance Between Changes in NT-proBNP and Cardiac Function Following Bariatric Surgery

Abstract

Background: The N-Terminal of pro-B-type natriuretic peptide (NT-proBNP) is a potent biomarker for heart failure (HF), reflecting left ventricular dilation and stress. The association among obesity, HF, and NT-proBNP is complex, with paradoxically lower levels of NT-proBNP in obese individuals, despite their elevated HF risk. Furthermore, a few studies have reported decreased HF risk, but also increases in NT-proBNP, after weight loss via bariatric surgery. However, studies have not simultaneously evaluated changes in NT-proBNP and cardiac function after bariatric surgery. Hypothesis: There will be discordance between improvements in cardiac filling pressures (as reflected by E/e’) and increases in NT-proBNP with weight loss following bariatric surgery. Methods: We conducted a single-center analysis of participants in the BARI-Heart Study who underwent bariatric surgery and attended study visits 3-6 months and 2 weeks before surgery, and 6 and 12 months after surgery. We examined pre- and post-surgery changes in NT-proBNP and in echocardiographic measures of cardiac function. We also assessed the correlation between NT-pro-BNP and E/e’, at 2 weeks pre- and 6 months post-surgery. Results: Among 71 BARI-Heart participants (mean age 45 years, 74% female, 87% white, mean BMI 47.0 kg/m 2 ), there were no significant pre-surgery changes in BMI, NT-proBNP, or E/e’. By 6-12 months, there were marked reductions in BMI and significant increases in NT-proBNP, but decreases in E/e’ ( Figure ). Changes from surgery to the 6 month visit in NT-proBNP and E/e’ were associated (r=0.295; p=0.02). There was a tendency towards stronger correlations between NT-proBNP and E/e’ post- (r= 0.436; p<0.001) versus pre-surgery (r = 0.209; p=0.09). Conclusions: Weight loss is associated with increases in NT-proBNP despite reduced LV filling pressures, suggesting a non-cardiac etiology underlying increases in NT-proBNP after weight loss. The interpretation of NT-proBNP for cardiac dysfunction may change with decreasing adiposity.