Utility of tissue Doppler imaging to predict exercise capacity in hypertrophic cardiomyopathy: comparison with B-type natriuretic peptide.

Abstract

Recent reports suggest that left ventricular diastolic function assessed by tissue Doppler imaging (TDI) and plasma B-type natriuretic peptide (BNP) levels can relate to functional status in patients with hypertrophic cardiomyopathy (HCM). However, it is unclear which is more useful to predict the exercise capacity in HCM patients without systolic impairment and/or atrial fibrillation, TDI or BNP levels.
The present study directly compared the clinical relevance of assessing diastolic function using TDI and measuring the plasma BNP level in patients with HCM.
We evaluated diastolic function using TDI as well as plasma BNP levels in 31 patients (52.2+/-16.9 years of age; 20 males) with HCM and examined the relationship of these values to exercise capacity (peak O(2) consumption (VO(2))) measured by cardiopulmonary exercise tests.
Average peak VO(2) was 18.5+/-4.7 ml/(kg min). Although the E/A ratio by transmitral flow was not correlated with peak VO(2), the lateral E/E(a) ratio assessed by TDI was significantly correlated with peak VO(2) (r=-0.52, p=0.003). On the other hand, plasma BNP level was not significantly related to peak VO(2) but NYHA class.
Assessment of diastolic function using TDI, not plasma BNP levels, is more useful for predicting objective exercise capacity in HCM patients without systolic impairment and/or atrial fibrillation.