Different cardiac phenotypes of sickle cell disease revealed using cardiac magnetic resonance imaging

Sickle cell disease (SCD) is an inherited haematologic disorder with cardiac-related complications. Cardiac magnetic resonance (CMR) imaging allows us to assess the cardiac morphology and function of this population. Our aim was to better characterise phenotypic variations among SCD patients utilising CMR data. This retrospective study included 72 patients with SCD who underwent CMR between May 2013 and July 2023. We recorded baseline characteristics, medical history, and indication and setting of CMR. CMR parameters relating to morphology and function were collected. Patients were placed into the following groups based on cardiac parameters on CMR: high output, pulmonary hypertension (PH; defined by mean pulmonary artery pressure >20 mmHg on right heart catheterisation or elevated tricuspid regurgitation velocity >3.4 m/s on echocardiogram), left ventricular (LV) dysfunction, or normal size and function. Between- and within-group comparisons were performed. Demographic data were similar among groups. The PH group was more likely to have a history of smoking, chronic hypoxia, lower baseline haemoglobin, and need for blood transfusion (p<0.05 for all). There were significant between-group differences in CMR structural and function parameters. In conclusion, sickle cell patients present with different cardiac phenotypes. Patients with PH are associated with significantly higher morbidities.