Prevalence and Characteristics of HIV-Associated Stroke in a Tertiary Hospital Setting in South Africa

Abstract

Background and objectives: Antiretroviral treatment (ART) era HIV-associated stroke data from sub-Saharan Africa are limited. We determined the prevalence of HIV in patients presenting with acute symptomatic stroke and compared risk factors, clinical characteristics, and brain imaging with age-matched stroke patients without HIV.

Methods: We conducted a retrospective study of adults presenting with any type of stroke to Tygerberg Hospital in a 12-month period. Patients living with HIV (PLWH) and HIV-uninfected (HIV-) patients were matched based on age group (1:2 ratio). Patients were identified by keyword search, while HIV status was ascertained from laboratory data. Clinical and imaging data were extracted from medical records.

Results: Among 884 patients presenting with acute strokes, the minimum prevalence of HIV infection was 9.3% (95% CI: 7.4%-11.2%), with 496 patients (56.1%) with negative HIV status and 306 patients with unknown HIV status (34.6%). The mean age at presentation in PLWH was 46 (±11) years compared with 55 (±14) years in HIV- patients (p < 0.001). Smoking was less prevalent in PLWH with an adjusted relative risk ratio of RR = 0.58 (95% CI: 0.39-0.86). Concurrent infection was more prevalent in PLWH (25.6% vs 4.9%, p ≤ 0.001) with an adjusted relative risk ratio of RR = 2.07 (95% CI: 1.49-2.84), largely in patients with a CD4 count <200 cells/μL. PLWH with higher CD4 counts (≥200 cells/μL, 51.3%) had more traditional risk factors and less concurrent infection. Among PLWH, 68.3% were on ART, and 39.3% of them had been started or restarted on ART within the past 6 months. Basal ganglia infarcts (35.6% vs 18.3%, p = 0.014) and multiple vascular territory involvement (25.4% vs 7.7%, p = 0.002) were more common in PLWH. Clinical presentation, ischemic stroke type, and in-hospital outcomes did not differ between the groups.

Discussion: Stroke patients with HIV were younger, had less traditional cardiovascular risk factors, and more concurrent infections than patients without HIV, especially those with a lower CD4 count. Recent ART initiation or reinitiation rates were high. Significant differences in CT brain imaging findings were seen. Understanding the multifactorial mechanisms underlying increased stroke risk, including associated infections and potential ART-associated immune reconstitution, is crucial and needs further study.

Figure 1. Diagram of the Selection of Patients for Study Inclusion and Age-Matching Process

Eligible patients (n = 884) were grouped as confirmed HIV-positive (HIV+, n = 82), confirmed HIV− (n = 496), and status unknown (n = 306). Status unknown consisted of patients who were either not tested or the HIV test was rejected by the laboratory for too little specimen or a separate sample not being provided. All patients in the abovementioned groups were involved to complete the primary objectives of prevalence and age and sex distribution. After this, we grouped the HIV+ and confirmed HIV- patients into 2 age groups: young (younger than 45 years) (HIV+, n = 39 [47.6%] and HIV-, n = 109 [22.0%]) and old (aged 45 year or older) (HIV+, n = 43 [52.4%] and HIV-, n = 387 [78.0%]). We then selected a random sample of double the HIV- patients from each age group. Therefore, we selected 78 patients from the 109 young HIV- group (39:78 = 1:2) and 86 patients from the 387 old HIV- group (43:86 = 1:2). The HIV+ group was further divided into immunologically severely compromised (CD4 count of <200 cells/μL) or not (CD4 count of ≥200 cells/μL). *ineligible patients delineated in supplemental tables (eTable 1 and eTable 2, links.lww.com/WNL/C108)