Improvement of Serum NT-ProBNP Predicts Improvement in Cardiac Function and Favorable Prognosis After Cardiac Resynchronization Therapy for Heart Failure

Abstract

Background Cardiac resynchronization therapy (CRT) is now an established therapy for patients with advanced heart failure with electromechanical delay, although nonresponders have been observed. Because natriuretic peptides are relevant markers to reflect the severity of heart failure and filling pressure of cardiac chambers, it may be helpful to assess the efficacy of CRT. Methods and Results Forty-two patients with heart failure with QRS of >120 msec were recruited; their serial N-terminal pro–B-type natriuretic peptide (NT-proBNP) levels were measured at baseline and at 1 and 3 months after CRT. There was a reduction in NT-proBNP level 1 month after CRT (2655 ± 2242 pg/mL vs 2149 ± 2033 pg/mL; P = .03), which was further reduced at 3 months (1473 ± 1786 pg/mL; P < .001 vs baseline). The reduction of NT-proBNP correlated with the change of left ventricular (LV) end-systolic volume ( r = 0.53; P = .001) or LV ejection fraction ( r = −0.49; P = .002) and with improvement in exercise capacity after CRT for 3 months ( r = 0.50; P = .002). The patients were classified by the degree of reduction in NT-proBNP as group 1 (reduction of ≥50% vs baseline; n = 19) and group 2 (reduction of <50% vs baseline; n = 23). The degree of LV reverse remodeling (–31.8 ± 24.7 mL vs −12.6 ± 19.2 mL; P = .007) and gain in LV ejection fraction (+12.5% ± 8.8% vs +4.6% ± 5.8%; P = .002) were significantly better in group 1 than group 2. Both the all-cause mortality rate (Log-rank χ 2 = 4.01; P = .04) and the composite end-point of mortality rate or hospitalization rate for cardiovascular causes (Log-rank χ 2 = 4.31; P = .02) were significantly lower in group 1 than in group 2. Conclusion Serial monitoring of NT-proBNP may be helpful to predict a favorable outcome after CRT. Those who had a reduction of NT-proBNP level of ≥50% were more likely to exhibit a favorable response.