Mid-regional pro-atrial natriuretic peptide for the early detection of non-acute heart failure

Diagnosing non-acute heart failure (HF) remains challenging, notably in the early stages of the syndrome. The diagnostic value of mid-regional pro-atrial natriuretic peptide (MR-proANP) has been proven in acute onset HF, but its role in early non-acute HF is unknown. We aimed to determine the diagnostic value of MR-proANP in suspected non-acute HF.

In total, 721 people suspected of non-acute HF in primary care underwent standardised diagnostic work-up including chest X-ray, electrocardiogram, N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurement and echocardiography. Of these, 245 people underwent additional MR-proANP measurements. The outcome of HF was assessed by an expert panel comprised of two cardiologists and one expert physician, who used all available diagnostic information including echocardiography, but were blinded to biomarker results. Of the 245 people (mean age 71.0 years, 62.9% female), 72 (29.4%) were diagnosed with HF. The c-statistics of MR-proANP and NT-proBNP as single diagnostic test were 0.77 [95% confidence interval (CI) 0.70-0.84] and 0.79 (95% CI 0.73-0.86), respectively. The cut-point with the highest accuracy for MR-proANP was 120 pmol/L [sensitivity/specificity/positive predictive value (PPV)/negative predictive value (NPV) 0.72, 0.69, 0.46, and 0.86, respectively], and the best exclusionary cut-point was 40 pmol/L (sensitivity/specificity/PPV/NPV 0.99, 0.06, 0.30, and 0.92, respectively). After addition of MR-proANP on top of a previously validated clinical model, the c-statistic rose from 0.82 (95% CI 0.76-0.88) to 0.86 (95% CI 0.80-0.92), and with the addition of NT-proBNP to 0.87 (95% CI 0.81-0.92). No sex interactions between the biomarkers and HF were found in the multivariable models.

MR-proANP provides added diagnostic value in suspected non-acute HF, similar to NT-proBNP.