Increased inflammatory proteins in patients with severe obesity is associated with persistent myocardial dysfunction one year after bariatric surgery. The FatWest study

Abstract

Abstract Background Over half of patients with severe obesity have subclinical cardiac dysfunction and about 40% maintain impaired left ventricular (LV) mechanics one year after bariatric surgery despite impressive weight reduction. Purpose To investigate whether measurement of serum markers of chronic inflammation before bariatric surgery can help identify patients with persistent postoperative cardiac dysfunction. Methods In the prospective FatWest (Bariatric Surgery on the West Coast of Norway) study 75 patients with severe obesity (44±9 years, 72% women, body mass index [BMI] 41.5±4.7 kg/m², 56% with hypertension) underwent echocardiography before and 1 year after Roux-en-Y gastric bypass surgery. We assessed LV mechanics in the radial and longitudinal direction by the midwall shortening (MWS) and global longitudinal strain (GLS). Myocardial oxygen (O2) demand was derived from the LV mass-wall stress-heart rate product. Inflammation was assessed by high-sensitive C-reactive protein, serum amyloid A and calprotectin in biobank samples. Results Preoperatively, patients with low MWS (45% of the group) had increased high-sensitive C-reactive protein, total calprotectin, and several amyloid A isoforms, and patients with high myocardial O2 demand (20%) had high total calprotectin (all p<0.05). In the whole study population, bariatric surgery induced a significant improvement in both BMI (12.6±3.7 kg/m²), GLS (4.74±5.20%), myocardial O2 demand and inflammatory proteins (Figure A, all p<0.001). However, there were no significant improvement in MWS, and 33% of patients still had low MWS at the 1-year control. In logistic regression analyses, after adjustment for sex, BMI and hypertension, increased preoperative serum total calprotectin was independently associated with high myocardial O2 demand both pre- and postoperatively (Nagelkerke R² 0.47 and 0.51, p<0.05). In similar analyses, higher preoperative serum total amyloid A was related to low MWS and high myocardial O2 demand 1 year after surgery (Nagelkerke R² 0.55 and 0.51, p<0.05). A simple preoperative risk score based on sex, hypertension, biplane ejection fraction, and serum total amyloid A above 4.0 mg/ml predicted low 1-year MWS with 79% sensitivity and 75% specificity at a value of 1.75 in Receiver Operating Characteristic (ROC) analysis (AUC 0.80, p<0.001) (Figure B). Low GLS was not predicted by inflammatory biomarkers at any timepoint. Conclusion Increased serum concentration of inflammatory proteins in patients with severe obesity is linked to persistently elevated myocardial O2 demand and impaired LV midwall mechanics 1 year after bariatric surgery.Figure AFigure B