Change of B-type natriuretic peptide after surgery and its association with rhythm status in patients with chronic severe mitral regurgitation.

BACKGROUND

B-type natriuretic peptide (BNP) is a useful biomarker of cardiac function in patients with mitral regurgitation (MR). However, the change in BNP in association with rhythm status after corrective surgery has not been studied.

METHODS

A total of 101 patients with chronic severe MR undergoing surgery were prospectively enrolled. BNP assays and echocardiographic studies were conducted before and 6 months after surgery. Patients were divided into 3 groups according to pre- and postoperative rhythm (sinus to sinus [SS], n = 61; atrial fibrillation [AF] to sinus [AS], n = 28; AF to AF [AA], n = 12).

RESULTS

BNP decreased only in the AS group 6 months after mitral surgery (from 218.0 ± 136.5 to 94.7 ± 85.1 pg/mL; P < 0.001) but not in the SS or AA groups (P for interaction = 0.001). However, changes of echocardiographic parameters after surgery were not different among the 3 groups. In the AA group, postoperative left ventricular (LV) end-diastolic dimension and left atrial volume were higher than the other groups. Significant determinants of BNP were the presence of AF and the higher pulmonary artery systolic pressure preoperatively (β = 0.767 and P = 0.001 for AF; β = 0.022 and P = 0.019 for pulmonary artery systolic pressure), and the lower LV ejection fraction postoperatively (β = -0.030; P = 0.011).

CONCLUSIONS

After surgical correction of chronic organic severe MR, BNP decreased only in patients with preoperative AF which was converted to sinus rhythm postoperatively. A reduction in BNP was not observed when rhythm status did not change. BNP activation was associated with the presence of AF and LV systolic dysfunction, suggesting its prognostic value.