Myocardial ischemia and right ventricular dysfunction in adult patients with sickle cell disease.

BACKGROUND AND OBJECTIVES: Patients with sickle cell disease (SCD) have multi-organ manifestations of microvascular disease, though cardiac manifestations have been poorly characterized in vivo. This study sought to characterize myocardial characteristics in adult patients with SCD. DESIGN AND METHODS: Twenty-two consecutive outpatients and 11 age-matched controls underwent magnetic resonance imaging to assess myocardial perfusion reserve as well as left and right ventricular size and function and myocardial iron. Computed tomography of the coronary arteries was performed to assess epicardial coronary stenosis.
RESULTS: Three of 22 outpatients with clinically stable SCD and no controls had abnormal myocardial perfusion reserve limited to the subendocardium, consistent with microvascular disease. Coronary arteries were free of disease as detectable by computed tomography angiography. Myocardial T2* was normal in all subjects (29 +/- 5 ms, median 29 ms), consistent with absence of cardiac iron deposition despite a high prevalence of hepatic iron overload (liver T2* 14 +/- 9 ms, median 12.0 ms). SCD patients had right ventricular enlargement and dysfunction (right ventricular ejection fraction 45 +/- 15 in SCD patients vs. 58 +/- 5% in controls, p=0.001) even in the absence of overt pulmonary hypertension. INTERPRETATION AND
CONCLUSIONS: A subset of adult SCD patients may have myocardial ischemia in the absence of infarcted myocardium, myocardial iron overload, or coronary artery disease. Right ventricular dysfunction is present in stable SCD patients, despite normal resting pulmonary artery pressures. These findings could represent under-recognized mechanisms for chest pain and mortality in this population, and warrant further investigation in SCD crises.