Abnormal myocardial flow reserve in sickle cell disease:: A myocardial contrast echocardiography study

Background: Sickle cell disease (SCD) is characterized by obstruction of microvessels leading to ischemia and necrosis. We have aimed to demonstrate whether myocardial contrast echocardiography (MCE) is able to detect myocardial perfusion abnormalities in SCD patients and to assess their relationship with left ventricle (LV) perfusion and systolic function. Methods: A group of 25 patients with SCD and a control group of 19 normal individuals were studied. Using MCE, myocardial perfusion reserve indices (A, beta, and A x beta) were obtained, before and after hyperemia with dypiridamole. LV function was also analyzed: ejection fraction (EF), index of myocardial performance (IMP), the ratio of transmitral early-diastolic flow velocity E and the pulsed tissue Doppler mitral annular early diastolic velocity Ea (E/Ea) (E/Ea), tissue Doppler mitral annular peak systolic velocity (Sa), and peak systolic strain (S) were obtained. Results: Myocardial velocity (beta) and myocardial blood flow (A x beta) reserves were lower in the patients than in controls (1.7 +/- 0.4 vs. 3.3 +/- 0.2, P = 0.000 and 2.1 +/- 0.6 vs. 4.1 +/- 0.2, P = 0.000, respectively). In SCD patients, a correlation was found between beta reserve and EF, IMP, Sa, E/Ea, and S% and between A x beta reserve and Sa. Conclusions: MCE detected abnormal perfusion reserve in patients with SCD, which correlated with systolic function indices. This suggests that perfusion plays a role in SCD ventricular dysfunction.