Predictors of Ischemic and Hemorrhagic Strokes Among People Living With HIV: The D:A:D International Prospective Multicohort Study

Abstract

Background

Hypertension is a stronger predictor of hemorrhagic than ischemic strokes in the general population. We aimed to identify whether hypertension or other risk factors, including HIV-related factors, differ in their associations with stroke subtypes in people living with HIV (PLWHIV).

Methods

HIV-1-positive individuals from the Data collection on Adverse events of anti-HIV Drugs (D:A:D) study were followed from the time of first blood pressure (BP) measurement after 1/1/1999 or study entry until the first of a validated stroke, 6 months after last follow-up or 1/2/2014. Stroke events were centrally validated using standardized criteria. Hypertension was defined as one systolic BP ≥ 140 mm Hg and/or diastolic BP ≥ 90 mm Hg. Poisson and Cox proportional hazards regression models determined associations of established cerebro/cardiovascular disease and HIV-related risk factors with stroke and tested whether these differed by stroke subtype.

Findings

590 strokes (83 hemorrhagic, 296 ischemic, 211 unknown) occurred over 339,979 person-years (PYRS) (incidence rate/1000 PYRS 1.74 [95% confidence interval (CI) 1.60-1.88]). Common predictors of both hemorrhagic and ischemic strokes were hypertension (relative hazard 3.55 [95% CI 2.29-5.50] and 2.24 [1.77-2.84] respectively) and older age (1.28 [1.17-1.39] and 1.19 [1.12-1.25]). Male gender (1.62 [1.14-2.31] and 0.60 [0.35-0.91]), previous cardiovascular events (4.03 [2.91-5.57] and 1.44 [0.66-3.16]) and smoking (1.90 [1.41-2.56] and 1.08 [0.68-1.71]) were stronger predictors of ischemic then hemorrhagic strokes, whereas hypertension, hepatitis C (1.32 [0.72-2.40] and 0.46 [0.30-0.70]) and estimated glomerular filtration rate < 60 mL/min/1.72 m$^{3}$ (4.80 [2.47-9.36] and 1.04 [0.67-1.60]) were stronger predictors of hemorrhagic than ischemic strokes. A CD4 count < 200 cells/μL was associated with an increased risk of hemorrhagic stroke only.

Interpretation

Risk factors for stroke may differ by subtype in PLWHIV, emphasizing the importance of further research to increase the precision of stroke risk estimation.