Abstract

Objective To determine whether plasma levels of B-type natriuretic peptide (BNP) predict left ventricular (LV) dysfunction on exercise echocardiography in patients with moderate to severe aortic regurgitation (AR).

Design Case-control study.

Setting Outpatient cardiology departments.

Patients 39 asymptomatic or mildly symptomatic patients with chronic moderate to severe AR and a normal LV ejection fraction (>50%), and 10 normal controls.

Main outcome measures Plasma level of BNP and echocardiographic measures of LV function at rest and immediately after treadmill exercise.

Results LV end systolic volume index (LVESVI) was significantly increased in AR patients with normal BNP (iU12 pmol/L) compared to controls (mean (SD) 32 (13) vs 17 (7) mL/m2, p=0.002) but was similar for AR patients with normal and elevated BNP (38 (16), p=0.14). In AR patients there was no association between plasma BNP and measures of LV function on echocardiography at rest (r<0.30, p>0.05 for all). However there were modest but statistically significant associations between the plasma level of BNP and severity of AR indicated by a greater AR:LV outflow tract width ratio (r=0.37, p=0.02) and lower diastolic blood pressure (r=-0.44, p=0.004). Increase BNP was also associated with a greater LVESVI (r=0.33, p=0.04) and lower LV longitudinal strain rate (r=-.037, 0.02) on echocardiography after exercise.

Conclusions In moderate to severe AR compensatory LV remodelling can occur with no increase in plasma BNP. Increased BNP is associated with more severe regurgitation and changes consistent with early LV dysfunction on exercise echocardiography.