Circulating secretoneurin concentrations predict cardiovascular death in ambulatory patients with heart failure

Abstract Background Secretoneurin (SN) is a novel biomarker, which predicts cardiovascular (CV)-related mortality in patients with acute dyspnea and sepsis. Higher SN concentrations have also been found associated with all-cause death in outpatients with heart failure (HF), but whether SN primarily reflects cardiovascular (CV)-related mortality in HF outpatients is not known. Objectives To evaluate the relation between SN concentrations and CV- & non-CV death in ambulatory patients with HF. Methods We studied 184 consecutive patients who attended our HF clinic for routine follow up and had stored blood samples available for SN analysis. SN concentrations were measured with a CE-marked SN ELISA assay. We assessed the associations between SN concentrations and CV & non-CV death. Mortality was ascertained using medical records, autopsy reports and death certificates, and CV deaths included sudden cardiac deaths or mortality due to myocardial infarction, HF or stroke. We assessed association with CV & non-CV death by Kaplan-Meier curves and by Cox proportional hazard regression analysis. Results Median age was 76 years (range: 38-94 years) and two thirds were male. Sixty-three percent had HF with reduced ejection fraction, 22% had NYHA III/IV symptoms and median NT-proBNP was 1079 (interquartile range: 462-2347) ng/L. Median SN level was 60 (range: 21-134) pmol/L. In multivariable linear regression analysis, impaired renal function and lower body-mass index were significantly associated with increasing (log)SN concentration. During median follow up of 540 days, there were 18 CV deaths, including 15 HF deaths, and 7 non-CV deaths. A higher SN concentration was associated with higher risk of CV death, while we did not find statistically significant association between SN concentrations and non-CV deaths (Figure). Patients with SN concentration in the top tertile had 15-fold increased risk of CV death compared to patients with SN concentration in the lowest tertile. In multivariable Cox regression analysis that adjusted for age, NYHA functional class, frailty status, increasing SN concentrations were independently associated with CV death: hazard ratio per logSN (95% CI): 3.01 (1.02-8.90), p=0.04. Conclusion In ambulatory patients with HF, circulating SN concentrations were predictive of CV death. Higher SN concentrations in ambulatory HF patients seemed to be linked to impaired renal function and lower body-mass index. Figure: Kaplan Meier curves illustrating the relation between SN tertiles and (A) CV mortality (B) Non-CV mortality.