Changes in Serum NT-Pro BNP and Left Atrial BNP Levels after Percutaneous Transvenous Mitral Commissurotomy in Sinus Rhythm Versus Atrial Firilation.

INTRODUCTION: Natriuretic peptides are secreted from the heart in response to increased wall stress. Their levels are expected to be increased in patients with mitral stenosis (MS) due to high left atrium (LA) pressure and pulmonary artery pressure (PAP). Percutaneous transvenous mitral commissurotomy (PTMC) if successful is pursued by a rapid decrease in LA pressure and subsequent decrease in pulmonary artery pressure. The concurrent changes in natriuretic peptide levels could be affected with heart rhythm.

METHODS: Forty five patients with severe rheumatic MS undergoing PTMC were enrolled. We evaluated the serum NT-Pro BNP levels before and 24 hours after PTMC. BNP levels were also measured from the blood samples obtained from LA before and 20 minutes after the procedure. Changes in biomarkers were assessed based on heart rhythm and success of the procedure.

RESULTS: While serum NT-Pro BNP levels showed significant decrease 24 hours after the procedure (P= 0.04), BNP levels taken 20 minutes after PTMC from LA were similar to their baseline concentrations (P= 0.26). NT-Pro BNP levels decreased 51.7±182.86 pg/ml for sinus rhythm (SR) and 123.4±520 pg/ml for atrial fibrillation (AF) (P= 0.68).

CONCLUSION: Immediate changes in BNP levels did not predict the success of procedure probably due to the additional balloon inflation attempts in LA in several patients and half-life of BNP. BNP levels obtained later may be of more value considering the half-life of this marker. Heart rhythm was not found to influence the changes in biomarker levels. BNP and NT-pro BNP changes were not found to predict success of the procedure.