Association Between HIV Infection, Antiretroviral Therapy, and Risk of Acute Myocardial Infarction: A Cohort and Nested Case-Control Study Using Quebec's Public Health Insurance Database

Background: Morbidity associated with cardiovascular disease is increasing in the HIV-infected population. We aimed to study the impact of HIV and of antiretrovirals on acute myocardial infarction (AMI). Methods: We performed a cohort and a nested case-control study using the dataset of the Regie de l'Assurance Maladie du Quebec. HIV-positive patients were identified using ICD-9 diagnostic codes and matched to HIV-negative patients. Within the HIV-positive cohort, cases of AMI were identified and matched to HIV-positive patients without AMI. The coprimary outcomes were the risk of AMI associated with HIV exposure in the cohort study and that associated with exposure to antiretrovirals in the case-control study. Data were analysed using Poisson and conditional logistic regression. Results: About 7053 HIV-positive patients were matched to 27,681 HIV-negative patients. Incidence rates of AMI in the HIV+ cohort was 3.88 95% confidence interval (CI) (3.26 to 4.58) per 1000 patient-years, compared to 2.21 95% CI (1.93 to 2.52) per 1000 patient-years in the HIV cohort. The adjusted incidence ratio of AMI for HIV-infected patients was 2.11 95% CI (1.69 to 2.63). Among HIV+ patients, 125 AMI cases were matched with 1084 HIV+ patients. We found increased odds ratio (95% CI) of AMI associated with any exposure to abacavir 1.79 (1.16 to 2.76), P = 0.02, efavirenz 1.83 (1.21 to 2.76) P = 0.004, lopinavir 1.98 (1.24 to 3.16) P = 0.004, and ritonavir 2.29 (1.48 to 3.54) P < 0.001. Conclusions: HIV+ individuals were at higher risk of AMI than the general population, and several antiretrovirals were associated with an increased risk of AMI. Results should be interpreted with caution in absence of data on smoking and HIV clinical status.