Background: Apelin is a potent endogenous inotropic peptide with a major role in counteracting the aldosterone and angiotensin II and their negative effects on the cardiovascular system. The exact role of apelin in the patho-physiology of this disease is not well understood. We aimed to investigate the possible associations of apelin-13 with clinical and paraclinical characteristics in HF patients as well as studying its dynamics during the course of the heart failure.
Method: We performed a prospective observational cohort single-center study. We compared the baseline serum levels of apelin-13 and NT-proBNP level in 53 heart failure patients (acute heart failure, chronic compensated heart failure and chronic decompensated heart failure). We divided the patients according to the apelin-13 level: above and below the median, and we analyzed the relationship between serum apelin-13 and the clinical, echocardiographic, electrocardiographic and biological parameters. Twenty patients were followed-up (after an average time interval of 9 months), investigating the same parameters.
Results: The median of apelin-13 was 495pg/mL (IQR 276-845pg/mL). We found strong, negative correlation between the serum levels of apelin-13 and NT-proBNP (Spearman rho= −0.83, p<0.001). For the reassessed patients the median apelin level was significantly higher at follow-up (460 pg/mL, IQR 342-871 pg/mL) as compared with the baseline level (395 pg/mL, IQR 270-603 pg/mL), p=0.019, and maintained the negative correlation with NT-proBNP level (Spearman’s rho −0.7, p<0.001. The Low Apelin-13 group have higher NT-proBNP levels and also contains all the patients in NYHA IV class heart failure, 71% of the acute HF patients, and 7 of 8 patients who died before follow-up.
Conclusion: Apelin-13 was negatively correlated with NT-proBNP. The Low Apelin-13 group contained the majority of the patients with a negative outcome (death before follow-up), most of the patients who presented with acute HF and all the patients in NYHA IV class.