Brain natriuretic peptide - A reliable parameter for the effectiveness of cardiac resynchronization therapy after coronary artery bypass grafting

Abstract

Objectives: Brain natriuretic peptide (BNP) is a valuable marker in heart failure and its therapy, for example cardiac resynchronization therapy (CRT). So far, one finding which is indicative for CRT is dyssynchronity of ventricular contraction obtained by echocardiography. The aim of this study was to show that BNP is also a helpful marker to help decide whether CRT is useful for patients after CABG. Methods: Forty-two patients with a poor ejection fraction (<35%) underwent elective CABG. Twenty-eight of them received permanent biventricular stimulation for seven days after surgery. Before and on the first, third, seventh and tenth day after surgical treatment, the following parameters were established: left ventricular function obtained by transthoracic echocardiography, myocardium-specific enzymes (such as CK and CKMB), ECG and BNP. Results: There was a very good correlation between the preoperative ejection fraction and BNP (r2 = 0.98, P < 0.005). Patients who had received CRT after CABG had BNP levels similar to preoperative data on postoperative day 7. This decrease of the BNP values in the CRT-group is in accord with an increased left ventricular function as obtained by echocardiography. The control group, which had not received CRT, showed significantly higher BNP levels. Conclusions: Therefore, we conclude that BNP is a good marker to evaluate CRT in patients undergoing CABG. An extraordinary rise of the BNP level should lead to early therapeutic consequences like CRT. The significantly lower BNP level of the patients with heart failure who received CRT indicates a better prognosis.