The N-terminal pro–B-type natriuretic peptide (NT-proBNP) ratio may improve prognosis in elderly patients with moderate to severe valvular heart disease (VHD), according to a study published in the Journal of American College of Cardiology.
In this study, 5983 elderly patients (mean age, 71.1±7.6 years) from mainland China with moderate or severe VHD were enrolled. Participants underwent echocardiography and their NT-proBNP levels were measured. VHDs in this cohort were: aortic stenosis (n=305), aortic regurgitation (n=581), mitral stenosis (n=189), mitral regurgitation (n=1594), tricuspid regurgitation (n=1034), or multivalvular heart disease (n=2280). The NT-proBNP ratio defined as the NT-proBNP level relative to the maximal normal NT-proBNP values specific to age and sex. The study’s primary outcome was all-cause mortality.
A total of 561 patients (9.4%) died by the 1-year follow-up. Increased NT-proBNP ratio was associated with mortality (overall adjusted hazard ratio [aHR], 1.99; 95% CI, 1.76-2.24; P <.001). There was a monotonic increase in relative hazards with greater NT-proBNP ratio for death for all VHDs included in the cohort except mitral stenosis (P <.001 for all).
A higher NT-proBNP ratio was associated with excess mortality for all VHD subtypes examined, with the strongest association observed for aortic stenosis (aHR, 10.5; 95% CI, 3.9-28.27; P <.001). In an analysis adjusted for age and sex, ln(NT-proBNP ratio), as a continuous variable, was found to be associated with mortality in aortic stenosis (aHR, 1.88; 95% CI, 1.44-2.46; P <.001), aortic regurgitation (aHR, 1.71; 95% CI, 1.40-1.91; P <.001), mitral regurgitation (aHR, 1.59; 95% CI, 1.41-1.79; P <.001), tricuspid regurgitation (aHR, 1.45; 95% CI, 1.24-1.69; P <.001), and multivalvular heart disease (aHR, 1.56; 95% CI, 1.42-1.71; P <.001).
Addition of the NT-proBNP ratio to a prediction algorithm that included traditional risk factors was found to improve outcome prediction (overall net reclassification index, 0.28; 95% CI, 0.24-0.34; P <.001; likelihood ratio test, P <.001). The NT-proBNP ratio was found to provide greater prognostic information compared with left ventricular ejection fraction.
Limitations of this study include the sole reliance on baseline NT-proBNP.
“NT-proBNP ratio is a reliable and incremental prognostic factor in various subtypes of VHD. It can potentially assist risk stratification and decision making as a pragmatic and versatile biomarker in elderly patients [with VHDs],” concluded the study authors.
Zhang B, Xu H, Zhang H, et al. Prognostic value of N-terminal pro-B-type natriuretic peptide in elderly patients with valvular heart disease. J Am Coll Cardiol. 2020;75(14):1659-1672.