Effect of B-Type Natriuretic Peptide Level on Long-Term Outcome in Patients With End-Stage Heart Failure

Abstract

Previous studies have demonstrated elevated B-type natriuretic peptide (BNP) level indicates a poor outcome in patients with heart failure (HF). However, some patients with end-stage HF presented with low BNP level and the impact of the nearly "normal" BNP level on long-term outcome is not well understood. Our study aimed to evaluate the association of BNP level with long-term outcome in 218 consecutive patients with dilated cardiomyopathy and end-stage HF. Sixty-two patients (28%) presented with admission BNP level ≤400 pg/ml. During a median follow-up period of 20months (4 to 26months), the all-cause mortality rate in patients with BNP ≤400 pg/ml was higher than in patients with BNP >400 pg/ml (76% vs 48%, p <0.001). Patients were then divided into 5 groups according to the BNP level (≤400, 401 to 1,000, 1,001 to 2,000, 2,001 to 3,000, and >3,000 pg/ml), the all-cause mortality were 76%, 41%, 40%, 49%, and 75%, respectively (p <0.001). After multivariate adjustment, both BNP ≤400 and >3,000 pg/ml were independently associated with increased risk of all-cause mortality (hazard ratios 1.87, 95% CI 1.02 to 3.42, p= 0.043 and hazard ratio 2.31, 95% CI 1.16 to 4.60, p= 0.018, respectively). In conclusion, our present study demonstrated a "U-like" shape between BNP level and all-cause mortality in end-stage HF, and the seemingly "normal" BNP level might also be a risk factor for poor outcome. Low BNP level may be a reflection of impaired neurohormonal response or altered metabolism of BNP and is associated with increased risk of poor outcome.