Correlates and Prognostic Value of NT-proBNP in Post-Acute Coronary Syndrome Patients with Preserved Left Ventricular Ejection Fraction

Patients with Acute Coronary Syndrome (ACS) with preserved Left Ventricular Ejection Fraction (LVEF) have an incidence of adverse outcomes despite the previously presumed benign prognosis.

We hypothesized that NT-pro-BNP could help refine the risk stratification of these patients.

In this observational retrospective study, laboratory and clinical data were collected from 232 consecutive patients with ACS and preserved LVEF (> 50%) and no previous history of Heart Failure (HF) at hospital discharge. Associations between NT-proBNP and the composite outcome of HF hospitalization, HF diagnosis de novo, and all-cause mortality were assessed by univariate and multivariable Cox models. Statistical analyses were performed using Stata software, version 12.1 and a two-sided P-value < 0.05 was considered to be statistically significant.

The NT-proBNP median was 408 [IQR 177-853] pg/mL. Patients with increased NT-proBNP were older and were more likely to be female (P = 0.013), be non-smoker (P = 0.039), have worse renal function (P < 0.001), and have lower hemoglobin concentration (P < 0.001). They had more ST-Elevation Myocardial Infarction (STEMI) and evolved with higher Killip classes (P < 0.001). Increased NT-proBNP levels were also associated with higher peak values of Creatinine Kinase (CK) and troponin (r = 0.36, P < 0.001 and r = 0.37, P < 0.001), higher left ventricular mass (P = 0.021), larger left atria (P = 0.013), and higher prevalence of regional LV hypocontractility (P = 0.012 to P = 0.090). During the 4.2 [2.1-5.4] years of follow-up, the composite outcome occurred in 19 patients. After adjusting for age, sex, and Killip class, NT-proBNP was not associated with the composite outcome (HR = 1.18; 95% CI: 0.78 - 1.78).

Post-ACS patients with preserved LVEF and increased levels of NT-proBNP were older, had more comorbidities, and presented with a more severe myocardial infarction. However, NT-proBNP levels measured during ACS hospitalization did not predict the clinical adverse outcomes.