Prevalence of cardiovascular disease in Sickle cell disease (SCD)- An echocardiographic and pharmacological analysis
Authors: Natarajan N , Al-Mohammad A A , Robinson G R , Pillai R P , Tsitsikas D T , Ang R A 
Published: January 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Sickle cell disease (SCD) is an inherited disorder of globin chains that cause haemolysis and chronic organ damage. It is an autosomal recessive condition. SCD is a condition more prevalent in sub-saharan Africa. It is estimated that there are between 12,500 and 15,000 people with SCD in the United Kingdom (UK) in 2014. The prevalence of the disease is increasing due to immigration into the UK and new births. As a result, there is a need to understand cardiovascular complications within this population, as despite a significant increase in longevity for SCD patients over the last few decades, there are significant cardiac complications.

Method
We present retrospective data from a single center tertiary centre for SCD. A total of 318 patients were followed up from diagnosis to current day with a mean age of 43.4 and median of 42. 136 (43%) were male and 182 (57%) Female.

Results
A total of 157 (49%) patients underwent a transthoracic echocardiogram (TTE). 56 (17.5%) had a dilated Left Atrium, 36 (11.3%) had Valvular heart disease, 18 (5.7%) Pulmonary Hypertension (PHT) or Right Heart Dysfunction and 17 (5.34%) had a dilated Left Ventricular cavity.
14 patients had Tricuspid regurgitation (13 mild and 1 severe), 15 had Mitral regurgitation (14 mild and 1 moderate), 7 had mild Aortic regurgitation, 6 had Mild Pulmonary regurgitation, 3 had mild Pulmonary Stenosis and 3 were noted to have sclerotic aortic valve.
From a Left ventricular systolic function perspective, 151 patients had a normal ejection fraction, 4 had mild Left ventricular systolic dysfunction (LVSD), 1 moderate LVSD and 1 severe LVSD. A normal ejection fraction was defined as &gt;55%, mild 45-55%, moderate 35-45% and severe &lt;35%.
40 (12.60%) Patients were taking Calcium channel blockers (Dihydropyridine), 25 (7.86%) were taking Angiotensin converting enzyme inhibitor/ Angiotensin receptor blocker, 20 (6.29%) taking an anticoagulant (DOAC), 16 (5.03%) were taking a statin, 15(4.72%) taking B blockers, 11(3.46%) taking an antiplatelet, 5(1.57%) patients were taking a loop diuretic, 4 (1.26%) thiazide diuretic, 4 (1.26%) on an alpha blocker and 1(0.3%) patient on digoxin.
The prevalence of Atrial Fibrillation was 1.57% (5 patients).

Conclusions
The Echocardiographic data suggests the commonest findings are of a dilated left atrium, dilated ventricle, valvular heart disease and PHT. The dilated left atrium is secondary to the hyperdynamic states found in sickle cell disease. Despite this being very common the rates of arrhythmia are low.
The prevalence of LVSD remains low. The findings of PHT are of particular interest as it guides SCD management with exchange transfusion. The pharmacological data suggests high burden of cardiovascular risk factors i.e. hypertension and hypercholesterolemia despite the young demographic. It is vital to follow up these patients with aggressive primary prevention medications to reduce risk of future cardiovascular events.