Growth-differentiation factor-15 improves reclassification for the diagnosis of heart failure with normal ejection fraction in morbid obesity

This study aimed to examine the incremental value of growth-differentiation factor-15 (GDF-15) to N-terminal pro brain natriuretic hormone (NT-proBNP) levels for the diagnosis of left ventricular diastolic dysfunction (LVDD) and possible heart failure (HF) in morbidly obese patients. We analysed data from 207 obese subjects [body mass index (BMI) 41 8 kg/m(2)] with normal ejection fraction, LVDD, and symptoms and/or signs of HF (referred to as oLVDD with possible HF', n 88) and with normal left ventricular function (n 119) before participating in a medical weight loss programme, in addition to the study of healthy lean subjects (n 51). Median NT-proBNP (interquartile range) for obese subjects with oLVDD and possibe HF' and with normal LV function was 52 (2996) and 42 (2566) pg/mL, respectively (P 0.12). There was no correlation of NT-proBNP with parameters of left ventricular filling pressure, i.e. E/E (r(2) 0.002, P 0.63) or E velocity (r(2) 0.02, P 0.24). In contrast, GDF-15 was 665 (496926) with oLVDD and possible HF' and 451 (392 679) pg/mL without (P 0.0001). GDF-15 was significantly correlated to E/E, E velocity, E/A ratio, isovolumetric relaxation time, duration of reversed pulmonary vein atrial systolic flow, and left atrial size. The area under the receiver operating characteristic curve that defines LVDD with possible HF was 0.56 for NT-proBNP and 0.74 for GDF-15 (P 0.0001). The addition of GDF-15 to a multivariate predicition model increased the net reclassification improvement (NRI) by 9 (P 0.022). In morbidly obese individuals, GDF-15 levels seem to better correlate with diastolic dysfunction than NT-proBNP levels. GDF-15 significantly improves reclassification for the diagnosis of oLVDD with possible HF' and, thus, adds incremental value to NT-proBNP.