Relationship between NT-proBNP and myocardial deformation in obese patients with acute myocardial infarction

Abstract

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): This research was funded by “Iuliu Haţieganu” University of Medicine and Pharmacy, Dept. of Cardiology, Cluj-Napoca, Romania, grant number 1529/66/18.01.2019. Introduction In addition to promoting coronary artery disease, obesity increases the risk of cardiovascular complications. The obesity paradox, however, refers to the observation that a high body mass index (BMI) may be protective of outcomes following an acute myocardial infarction (AMI). In patients with AMI, both NT-proBNP and novel echocardiographic markers (global longitudinal strain - GLS) provide additional information; nevertheless, there is limited research on the association between these parameters and obesity in this clinical setting. Material and methods This was a prospective study that included 55 patients admitted with AMI and preserved or mildly reduced LVEF (>40%), which all underwent successful percutaneous revascularization. At 48 hours after PCI, echocardiography was performed using a Vivid E95 scanner and the automated function-imaging (AFI) tool was used to determine GLS. NT-proBNP was measured using ELISA. All patients were divided into two groups according to their BMI (group 1 included 18 patients with normal BMI<25 kg/m2, and group 2 included 37 obese patients, with a BMI>30 kg/m2). Results The mean age of the patients was of 66±14 years, 58% were male and 65.5% had STEMI. Other than obesity, there was no difference between groups in the other cardiovascular risk factors (smoking, dyslipidemia, arterial hypertension, diabetes, age, gender). In both groups, the anterior descending coronary artery was the most frequent culprit vessel (44% vs. 40%, p=0.9). The majority of the patients had single- or two- vessel coronary artery disease (72% vs. 73%), but there were no differences between groups (p=0.74). The values of NT-proBNP were significantly lower in the obese group (300 [117-713] vs. 756 [450-1800] pg/mL, p=0.02). However, regarding the echocardiographic evaluation of myocardial function, there was no difference between the values of GLS (-10.5% vs. -10.8%, p=0.77) or LVEF (56.7% vs. 49.2%, p=0.27) among groups. GLS showed a stronger correlation to NT-proBNP values in the normal weight group (r=0.63) than in the obese group (r=0.27). Conclusion Despite the fact that increased BMI is linked to lower values of NT-proBNP following AMI, non-obese patients do not demonstrate more impaired myocardial longitudinal function. These findings might offer more insights on the perspectives of obese AMI patients.