Elevated B-type natriuretic peptide despite normal left ventricular function on rest and exercise stress echocardiography in mitral regurgitation

AIMS: To determine whether elevated B-type natriuretic peptide (BNP) predicts left ventricular (LV) contractile dysfunction on exercise stress echocardiography in patients with severe mitral regurgitation (MR). METHODS AND RESULTS: Thirty three patients with moderate-to-severe or severe MR, a LV ejection fraction > or =60% and New York Heart Association Class I or II symptoms, and 12 controls underwent resting and exercise stress echocardiography. In 20 MR patients, BNP was within the normal range (mean +/- SD, 7.7 +/- 2.7 pmol/L), and in 13 MR patients, BNP was >12 pmol/L (19.6 +/- 7.6 pmol/L). LV end-systolic volume index after exercise was lower in controls than patients with MR (P 0.05). However, pulmonary artery systolic pressure (PAP) after exercise was higher in MR with high BNP (70 +/- 20 vs. 48 +/- 11 mmHg, 0.05 for all). CONCLUSION: The plasma level of BNP may be within the normal range in patients with moderate-to-severe or severe MR despite significant increases in LV end-systolic volume. Increase in BNP is associated with pulmonary artery hypertension on exercise and left atrial enlargement even when LV systolic function on exercise stress echocardiography is normal.