Does Stroke Mechanism in HIV Vary According to Preceding CD4 Counts?
Strokes in people living with HIV are most frequently caused by large artery atherosclerosis.
Strokes in HIV+ individuals are most frequently caused by large artery atherosclerosis, according to a study recently published in AIDS Care. This stroke mechanism was most common among those whose minimum CD4 counts were less than 200, but increased before the stroke occurred.
This retrospective chart review included 115 cases of either transient ischemic attack or stroke in individuals who were HIV+. Large artery atherosclerosis was responsible for 22% of stroke, while 21% were cryptogenic, 17% were caused by small artery disease, 16% by infection, 8% cardioembolic, and 16% by other causes. Infectious stroke occurred most frequently in individuals with immunosuppression.
The median minimum CD4-count was 153 (interquartile range [IQR], 22 to 274). When stroke occurred, CD4-counts were 312 (IQR, 88 to 518); 53% of individuals were using antiretroviral medications. Large artery atherosclerosis was associated with minimum CD4-counts of less than 200 and with a longer duration of HIV infection, with odds ratios of 6.7 (1.4 to 31.9) and 1.1 per year (1.0 to 1.2), respectively.
Higher CD4 counts one year before stroke correlated with stroke caused by large artery atherosclerosis (B=0.009; P =.06), though small vessel disease was unrelated. This relationship was not dependent on minimum CD4-counts (B=1.88; P =.035).
The median age of individuals in this study was 52 years, and 36% were female. All individuals received care at a tertiary care center between 2002 and 2016 for ischemic events defined by ICD-9. To determine stroke mechanisms, clinical and radiographic presentations were examined; each was confirmed by both a third party vascular neurologist and by the original clinical team.
Generalized linear models and logistic regressions were constructed using minimum CD4 counts, current CD4 counts, antiretroviral drug use status, and vascular risk factors. These models were used to calculate 95% confidence intervals and odds ratios.
The study researchers conclude that “in this sample, [large artery atherosclerosis] was the most frequent stroke mechanism among HIV+ individuals with nadir CD4 < 200 but higher CD4 counts near the time of stroke. Determining the association between pre-stroke immune status and stroke mechanisms may allow a targeted approach to stroke prevention.”
This study was supported by the Campbell Foundation and the National Institute of Allergy and Infectious Diseases. Please refer to reference for the full list of authors' disclosures.
Gutierrez J, Hatleberg CI, Evans H, Yin MT. Role of pre-stroke immunity in ischemic stroke mechanism among patients with HIV [published online August 20, 2018]. AIDS Care. doi: 10.1080/09540121.2018.1510096