Associations between immune depression and cardiovascular events in HIV infection

Objective: To consider associations between the latest/nadir CD4 + cell count, and time spent with CD4+ cell count less than 200 cells/ml (duration of immune depression), and myocardial infarction (MI), coronary heart disease (CHD), stroke, or cardiovascular disease (CVD) (CHD or stroke) in 33 301 HIV-positive individuals. Design: Longitudinal cohort study. Methods: Analyses were undertaken using Poisson regression. To investigate whether analyses of stroke were robust to the type of endpoint, we additionally included strokelike events and rejected strokes into the stroke endpoint. Results: Participants experienced 716 MI, 1056 CHD, 303 stroke, and 1284 CVD events. Whereas there was no evidence of a higher MI/CHD risk in those with lower latest/nadir CD4+ cell counts after adjustment [current CD4+<100 cells/ml: relative rate (95% confidence interval) 0.96 (0.62-1.50) for MI, 0.89 (0.30-2.36) for CHD; nadir CD4+<100 cells/ml: 1.36 (0.57-3.23) for MI, 0.98 (0.45-2.16) for CHD], stroke and CVD rates were higher in those with a latest CD4+ cell count less than 100 cells/ml [2.26 (1.29-3.94) and 1.14 (0.84-1.56), respectively]. All events occurred less frequently in those who had not experienced immune depression, although evidence for a linear association with duration of immune depression was weak. The association between stroke risk and the latest CD4+ cell count strengthened as stroke-like and rejected strokes were included; conversely, associations with established stroke risk factors weakened. Conclusion: We do not find strong evidence that HIV-positive individuals with a low CD4+ cell count are more likely to experience MI/CHD.Although strokes appear to occur more commonly at low CD4+ cell counts, this may be partly explained by misclassification or other biases. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.