Association of C-reactive protein and HIV infection with acute myocardial infarction

Abstract

Objective: To investigate whether elevated C-reactive protein (CRP) levels and HIV infection are independently associated with acute myocardial infarction (AMI) among patients receiving care in a large US health care system.

Methods: Analyses included patients receiving care in the Partners HealthCare System between January 1997 and December 2006, with a most recent CRP less than 3 years and more than 1 week before AMI. Over this period, 70,357 (487 HIV and 69,870 non-HIV) patients met these criteria, from the background population of 1,648,687 patients followed in the system. We included both CRP and high-sensitivity CRP and defined elevated CRP based on the normal range of the assay used. We used multivariate logistic regression analysis to test the association of elevated CRP and HIV with AMI after adjustment for demographic and other cardiovascular covariates, including hypertension, diabetes, and dyslipidemia.

Results: In univariate analyses, elevated CRP and HIV were each significantly associated with AMI [odds ratio (OR) 2.51; 95% confidence interval (CI) 2.27 to 2.78; P < 0.0001 for elevated CRP and OR 2.07; 95% CI 1.31 to 3.10; P = 0.001 for HIV]. In a combined model including CRP category and HIV status, elevated CRP (OR 2.50; 95% CI 2.26 to 2.77; P < 0.0001) and HIV (OR 1.74; 95% CI 1.10 to 2.61; P = 0.01) were both independently associated with AMI. In a fully adjusted model controlling for age, sex, race, hypertension, diabetes, and dyslipidemia, both elevated CRP (OR 2.13; 95% CI 1.92 to 2.37; P < 0.0001) and HIV (OR 1.93; 95% CI 1.21 to 2.93; P = 0.004) remained independently associated with AMI. Compared with patients with normal CRP and without HIV, the OR for AMI was increased more than 4-fold among patients with HIV and elevated CRP.

Conclusions: Elevated CRP and HIV are independently associated with increased AMI risk, and patients with HIV with increased CRP have a markedly increased relative risk of AMI. Measurement of CRP may be useful in the cardiovascular risk assessment of patients with HIV.

FIGURE 1

Study sample. The initial query generated 1,648,687 patients. Of these, 77,835 had CRP test data available during the study period from Brigham and Women's Hospital or Massachusetts General Hospital. After excluding patients whose most recent CRP value was after the first AMI, less than 1 week before the first AMI, or more than 3 years before the first AMI, there were 70,357 patients. Of these patients, 487 were HIV infected and 69,870 were not HIV infected. The distribution of normal vs. elevated CRP is shown in the Figure.