Prevalence of cardiac abnormalities in sickle cell disease identified using cardiac magnetic resonance imaging
Authors: Bawor M , Kesse-Adu R , Gardner K , Marino P , Howard J , Webb J 
Published: November 2020

Abstract

Background
Sickle cell disease (SCD) affects thousands of individuals in the United Kingdom causing significant morbidity and mortality. Modern therapies have been successful in increasing life expectancy, however these patients have an increased risk of cardiovascular complications and the extent to which sickle cell disease affects cardiac function is not well understood. Cardiac magnetic resonance imaging (MRI) is the gold standard imaging modality for evaluating myocardial function. It is known that sickle cell patients can present with pulmonary hypertension, left ventricular diastolic dysfunction, and atrial enlargement however the prevalence of other cardiac abnormalities has not been sufficiently investigated with cardiac MRI. In addition, the European Society of Cardiology (ESC) updated their definition of Heart Failure in 2016 and therefore will need to be re-assessed in this population.

Purpose
To evaluate the prevalence of cardiac abnormalities in the sickle cell population using cardiac MRI and based on the recently updated diagnostic criteria.

Methods
We conducted a retrospective review including all patients with sickle cell disease at a large tertiary hospital in London, United Kingdom who had been referred for cardiac MRI between 2011 and 2019. Data was collected data on various measures of cardiac function including: left ventricular ejection fraction (LVEF), left ventricular hypertrophy, left and right atrial enlargement, regional wall motion abnormalities, valvular disease, myocardial scarring, and cardiac iron load.

Results
82 patients and 123 cardiac MRI scans were reviewed in this study. 68% of patients were female and the average age at time of scan was 37 years. The average left ventricular ejection fraction was 57% (n=82). Cardiac abnormalities were identified in 60% of patients. The most common cardiac abnormalities reported were: valvular regurgitation (46%; n=28), left atrial enlargement (28%; n=19), right atrial enlargement (16%; n=11), left ventricular hypertrophy (11%; n=8), regional wall motion abnormalities (10%; n=7), and myocardial scar with late gadolinium enhancement (9%; n=7). 28% of the patients were diagnosed with Heart Failure; 11% of the patients satisfied the diagnostic criteria for HFpEF (Heart failure with preserved ejection fraction, n=9), 10% with HFrEF (Heart Failure with reduced ejection fraction, n=8), and 7% with HFmrEF (Heart Failure with mid-range ejection fraction, n=6).

Conclusion
Sickle cell disease affects cardiac function in the majority of patients resulting in numerous cardiac abnormalities. We have described the overall extent of these effects using data from cardiac MRI scans, which has not been commonly used thus far. This has implications for both the diagnosis and subsequent management of cardiac abnormalities in this population, and it can be used to further investigate and guide the development of targeted treatments for these patients.

Funding Acknowledgement
Type of funding source: None