Assessment of Ankle-Brachial Pressure Index in Sickle Cell Patients: An Approach through Spectral Waveform Analysis

Background: Sickle cell patients suffer from a plethora of vascular complications. Assessment of Ankle-Brachial Pressure Index (ABPI) using ultrasonographic Spectral Wave Analysis (SWA) serves as an effective method for screening vascular complications. However, this has been the least studied in the sickle cell population to date. This study was conducted to assess ABPI in sickle cell disease (SCD) and sickle cell trait (SCT) using SWA. In addition, the correlation between ABPI and duration of hydroxyurea (HU) therapy was also evaluated in SCD. Materials and Methods: This cross-sectional study included 124 subjects (62 SCD and 62 SCT) aged between 16 and 30 years. ABPI was assessed by USG color Doppler SWA. Subjects were categorized into four groups: normal, acceptable, some arterial disease, and moderate arterial disease, based on ABPI cutoff values, and into three subgroups according to waveforms: triphasic, biphasic, and monophasic. Statistical analysis was performed using appropriate methods. Results: The mean ABPI was lower in SCD than SCT (0.98 ± 0.11 vs. 1.03 ± 0.03, P < 0.001). Among SCD, 6.4% of patients had monophasic waves with ABPI ranging from 0.5–0.9, and 53.2% of patients had biphasic waves with ABPI ranging from 0.8–1.0. Among SCTs, 11.2% of patients had biphasic waves with an ABPI of 0.9–1. We found a negative correlation between the duration of HU and ABPI in SCD ( r = −0.194). Conclusions: SWA was able to detect subclinical peripheral arterial disease in both SCD and SCT, despite the ABPI being within an acceptable range. The potential vascular risk of long-term HU should not be overlooked.