Background: Cardiac complications are the major cause of death in patients with beta-thalassemia major. The purpose of this study was to assess the impact of long-term treatment with the angiotensin-converting enzyme inhibitor enalapril on left ventricular (LV) performance, with an emphasis on diastolic LV function because diastolic dysfunction has been found to be an early event in an asymptomatic thalassemic population with only mild impairment of LV systolic function.
Methods: We used echocardiography to study the impact of treatment with oral enalapril on the evolution of standard M-mode and Doppler indices, along with a recently introduced Doppler index of combined systolic and diastolic LV performance.
Results: Patients were found to have significantly increased LV end-diastolic dimensions (LVEDD), LV end-systolic dimensions (LVESD), and left atrial dimensions and decreased LV fractional shortening (LVFS) compared with controls. After treatment with enalapril, LVESD decreased from 3.58 +/- 0.3 cm to 3.23 +/- 0.4 cm (P <.01) and LVFS increased from 32.6% +/- 4.0% to 38.0% +/- 3.1% (P <.001). Patients at baseline were found to have a significantly higher E-wave velocity, E/A ratio, and Doppler index compared with controls. The E-wave deceleration time was significantly shorter compared with that of controls. After treatment with enalapril, the E/A ratio decreased from 2.10 +/- 0.42 to 1.50 +/- 0.30 (P <.05), E-wave deceleration time increased from 0.12 +/- 0.02 seconds to 0.15 +/- 0.03 seconds (P <.01), and the Doppler index decreased from 0.46 +/- 0.10 to 0.37 +/- 0.14 (P <.05).
Conclusions: Enalapril was well tolerated in asymptomatic or minimally symptomatic patients with LV dysfunction resulting from beta-thalassemia major. Echocardiographically we demonstrated significant improvement in LV systolic and diastolic function. Whether this translates to improved long-term prognosis and survival remains to be further evaluated.