Prevalence of Electrocardiographic Changes and Risk Factors for QTc Prolongation Among Steady State Sickle Cell Disease Patients: Cooperative Study of Sickle Cell Disease.

OBJECTIVES

Sickle cell disease (SCD) is associated with several cardiovascular adverse events. Corrected QT (QTc) interval prolongation is one of the potential life-threatening complications that predispose patients to sudden cardiac death. This study aims to assess the prevalence of electrocardiogram (ECG) changes and to investigate risk factors associated with increased propensity of QTc prolongation.

METHODS

This study utilized data from the Cooperative Study of Sickle Cell Disease Cardiac Ancillary Study. QT intervals were corrected using the Bazett formula, and prolongation was defined using sex-specific thresholds. The study population included African American patients with steady-state SCD across four clinical centers located in both urban and rural settings.

RESULTS

The study included 238 participants (92 (38.7%) males and 146 (61.3%) females), with a median age of 19.0 (IQR = 14.0 years). Of these, more than two-thirds of the sample (58.8%) had at least one abnormal ECG finding, which was more common in males (72.8%) compared to females (50.0%). In terms of ECG changes, almost half of the sample (41.1%, n = 97) had left ventricular hypertrophy, and 4.2% (n = 10) had left atrial hypertrophy. The prevalence of prolonged QTc was 20.6% (n = 49). Potential risk factors that showed higher odds of QTc prolongation included: male sex (odds ratio (OR) = 3.68, 95% CI: 1.67-8.11; p = 0.001), history of heart disease (OR =3.53, 95% CI: 1.38-9.01, p = 0.008), pericardial effusion (OR = 3.45, 95% CI: 1.10-10.86, p = 0.034), and lower hemoglobin levels (OR = 0.63, 95% CI: 0.43-0.93; p = 0.018).

CONCLUSIONS

Routine ECG screening is recommended among SCD patients, particularly for those at increased risk for prolonged QTc, in addition to avoidance of concomitant factors that prolong QTc intervals. Moreover, regular monitoring of hemoglobin levels is paramount, as it is a modifiable factor influencing QTc prolongation risk.