It is unknown whether there are any differences in risk factors for haemorrhagic and ischaemic stroke in HIV+ individuals, or whether elevated blood pressure (BP) is a major risk factor for haemorrhagic stroke as known from the general population.
D:A:D study participants were followed from the time of the first BP measurement at/after 1/1/1999 or individual study entry and until the first of a validated stroke, 6 months after last follow up or 1/2/2014. Elevated BP during follow-up was defined as current systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg. Poisson regression models were used to determine associations between haemorrhagic/ischaemic stroke and time-updated demographic, cardiovascular disease (CVD) -and HIV-related factors.
Of the 43,564 included persons, 74% were men; 69% were aged 30-50 years; 42% were smokers; 26% had elevated BP and 63% had received antiretroviral therapy (ART). Of 590 strokes; 83 (14%) were haemorrhagic (incidence rate (IR)/1000 person years 0.24, 95% confidence interval [0.19, 0.30]); 296 (50%) were ischaemic (0.87 [0.77, 0.97]) and the remaining 211 strokes were of unknown etiology. IRs for both stroke subtypes were higher in those with elevated BP than in those without; haemorrhagic stroke: (0.57 [0.41, 0.73]) vs. 0.13 [0.09, 0.18]); ischaemic stroke (1.74 [1.46, 2.02]) vs. 0.58 [0.49, 0.67]). In univariable models, factors most strongly associated with increased risk for both stroke subtypes were age, elevated BP and a low estimated glomerular filtration rate (eGFR) or CD4 count. The risk factor profile for the two stroke subtypes appeared to differ in multivariable models; Ischaemic strokes were more strongly associated with metabolic CVD risk factors (dyslipidaemia, previous CVD, diabetes) and smoking than haemorrhagic stroke. Conversely, elevated BP was associated with both stroke subtypes, but the association appeared stronger for haemorrhagic strokes. Low eGFR was markedly associated with haemorrhagic stroke only. Of the HIV-related variables, only low CD4 count but not type of ART was associated with risk of both stroke subtypes; previous AIDS and HIV acquisition via injection drug use were associated with ischaemic stroke only (Figure).
Elevated BP, age and low CD4 count were the strongest predictors for both stroke subtypes. Our findings suggest that similarly to the general population, elevated BP may be a stronger predictor for haemorrhagic than ischaemic stroke in HIV+ individuals.