Utility of B-natriuretic peptide in the evaluation of left ventricular diastolic function: comparison with tissue Doppler imaging recordings.

BACKGROUND

Although Doppler echocardiography provides assessment of abnormal left ventricular (LV) diastolic filling dynamics, its inherent limitations suggest the need for additional measures of diastolic dysfunction. The ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/E') derived from tissue Doppler imaging is associated with the mean LV end diastolic pressure (LVEDP). Because data suggest that B-natriuretic peptide (BNP) reflects ventricular pressure, we hypothesized that BNP levels correlate with indices of LV diastolic function by tissue Doppler imaging.

METHODS AND RESULTS

Doppler recordings of the mitral inflow and tissue Doppler imaging of the mitral annulus were obtained in 108 patients referred for echocardiography. BNP levels were measured by a rapid immunoassay and blinded to cardiologists making the assessment of LV function. BNP levels were higher when elevated E/E' ratios derived from tissue Doppler imaging were identified. Patients identified with elevated LVEDP, defined as E/E' >15 (n = 16), had the highest BNP levels (463 +/- 80 pg/mL). Those with normal LVEDP, as predicted by E/E' <8 (n = 36), had a mean BNP concentration of 97 +/- 27 pg/mL. Those with E/E' of 8 to 15 (n = 48) had a mean BNP level of 122 +/- 24 pg/mL. The area under the receiver-operating curve for BNP to detect E/E' >15 was 0.89 (95% CI, 0.82 to 0.96; P < .001). A BNP value of 173 pg/mL had a sensitivity of 88%, a specificity of 82%, and an accuracy of 83% for predicting E/E' >15.

CONCLUSIONS

BNP levels correlate with the E/E' ratios from tissue Doppler imaging (r = 0.48) and can reliably provide estimation of LV filling pressures. Although BNP levels do not correlate well with E/E' ratios across the full spectrum of values, the combination of BNP levels along with E/E' ratios from tissue Doppler imaging may be a better predictor of elevated LV filling pressures in patients with suspected diastolic dysfunction.