Functional Assessment by Myocardial Performance Index (Tei Index) Correlates With Plasma Brain Natriuretic Peptide Concentration in Patients With Hypertrophic Cardiomyopathy

BACKGROUND: Hypertrophic cardiomyopathy (HCM) might exhibit not only diastolic, but also latent systolic dysfunction. Therefore combined assessment of both systolic and diastolic function using myocardial performance index (Tei index) can be useful in HCM. Plasma brain natriuretic peptide (BNP) level is reported to be elevated in HCM, but the mechanism of BNP elevation in HCM remains to be established. METHODS AND RESULTS: The value of Tei index in 45 HCM patients was compared with that of 20 normal control subjects. The HCM patients showed a higher value of Tei index (0.55+/-0.12 vs 0.36+/-0.08, p < 0.0001) and longer isovolumic relaxation and contraction times than control subjects. The plasma BNP level correlated with Tei index in non-obstructive HCM (n = 35, r = 0.61, p < 0.0001), although the correlation was mild when overall HCM patients were included (r = 0.34, p = 0.02). The correlation was still significant after adjusting for age, or the extent and severity of left ventricular hypertrophy. Multiple stepwise regression analysis identified mitral E/A ratio (r = 0.49, F = 13.1) and Tei index (r = 0.37, F = 7.6) as independent predictors of higher plasma BNP level in non-obstructive HCM. CONCLUSIONS: Myocardial performance index was abnormal in HCM, reflecting both systolic and diastolic dysfunction in this disorder. Plasma BNP level correlated with functional assessment by Tei index in non-obstructive HCM.