Determinants of ventricular arrhythmias in sickle cell anemia: toward better prevention of sudden cardiac death

Abstract

Sudden death is one of the leading causes of death in adults with sickle cell anemia (SCA) but its etiology remains most often unknown. Ventricular arrhythmia (VA) carries an increased risk of sudden death but its prevalence and determinants in SCA is poorly studied. The aim of this study is to identify the prevalence and predictors of VA in SCA patients. From January 2019 to March 2022, 100 SCA patients were referred to ambulatory cardiology department to specifically analyze cardiac function and were prospectively included in DREPACOEUR registry. They underwent a 24-hour ECG monitoring (24h-holter), a transthoracic echocardiography (TTE) and laboratory tests on the same day. The primary end-point was the occurrence of VA, defined as sustained or non-sustained ventricular tachycardia (VT), more than 500 premature ventricular contractions (PVCs) on 24h-holter, or recent history of VT ablation. Mean age was 46±13 years, 48% of patients were male. VA was observed in 22 (22%) patients (9 non-sustained VT [range 4-121 consecutive PVCs]), 15 with more than 500 PVCs and 1 history of VT ablation). Male sex (81 vs. 34%, p=0.02), impaired global longitudinal strain (GLS: -16±1.9% vs. -18.3±2.7%, p=0.02), and decreased platelet count (226±96G/L vs. 316±130G/L, p=0.02) were independently associated with VA occurrence. GLS correlated to PVC load/24h (r=0.39, p<0.001) and a cut-off of -17.5% could predict VA with a sensitivity of 82% and a specificity of 63%. Ventricular arrhythmias are common in SCA patients, especially in men. This pilot study uncovers GLS as a valuable parameter to improve rhythmic risk stratification.

Cardiac diastolic maladaptation is associated with the severity of exercise intolerance in sickle cell anemia patients

“…Therefore, an in-depth analysis of those patients during exercise is crucial to better understand the link between metabolic status and cardiovascular adaptation. Indeed, cardiovascular abnormalities at rest, such as pulmonary hypertension (PH) and diastolic dysfunction, have been identified as the leading cause of mortality and impaired quality of life in SCA patients 10 – 14 . These disorders rely on complex mechanisms associating chronic anemia, hemolysis-induced vasculopathy and repeated vaso-occlusive episodes, contributing to a maladaptive cardiovascular remodeling 15 – 17 .…”