Higher Leukocyte Counts in HIV Increase Risk for Coronary Artery Disease Events

The risk for coronary artery disease events was increased among HIV-positive patients with higher leukocyte counts, to a degree similar to that of traditional HIV-related risk factors.

Individuals with HIV infection who have higher leukocyte counts may be at increased risk for coronary artery disease (CAD) events, according to results of a case-control study published in Clinical Infectious Diseases.

This study was nested within the Swiss HIV Cohort Study (SHCS). Patients with HIV infection who had experienced a CAD event (cases; n=536) were matched by sex, age, and date of SHCS registration against 1 to 3 HIV-positive participants with no reported CAD events (controls; n=1464). Researchers compared these cohorts to determine whether higher leukocyte counts are a risk factor for CAD event occurrence in the setting of HIV.

Among patients included in the analysis, the median age was 56 (IQR, 49-63) years, 86.7% were men, 93.8% were White, 94.7% were on antiretroviral therapy, 11.3% had a family history of CAD, and the median leukocyte count was 6020 (IQR, 5000-7460) cells/µL.

Specific CAD events among patients cases were myocardial infarction (n=274), coronary angioplasty or stenting (n=211), coronary artery bypass grafting (n=39), and fatal CAD events (n=12).

Stratified by quintiles of leukocyte counts, the proportion of patient cases increased with each quintile of leukocyte count, whereas the proportion of control patients decreased. Overall, the most recently recorded leukocyte counts were significantly higher among patients in the case vs control cohorts (P <.01), as were rates of leukocytosis (4.3% vs 2.1%; P =.01). The researchers found that leukocyte counts among participants in the case cohort, measured at 5 (P =.04), 3 (P <.01), 2 (P <.01), and 1 (P <.01) year(s) prior to CAD event occurrence, were significantly higher compared with those in the control cohort.

In the multivariate model, the risk for first CAD event occurrence was increased among patients with leukocyte counts in the highest quintile compared with those with counts in the lowest quintile (adjusted odds ratio [aOR], 1.59; 95% CI, 1.09-2.30).

Our findings expand on how inflammation (that may not yet be captured by current CAD risk assessment methods) may contribute to high leukocytes and CAD events in PWH.

In sensitivity analyses, higher leukocyte counts remained significantly associated with CAD event risk after adjusting for Framingham Risk Score (OR, 1.82; 95% CI, 1.30-2.56). This association also was observed after the analysis was restricted to only patients who had achieved HIV virologic suppression (OR, 1.63; 95% CI, 1.06-2.50).

The risk for CAD event occurrence associated with higher quintile-adjusted leukocyte counts was similar to that of risk for CAD event occurrence associated with diabetes (OR, 2.15; 95% CI, 1.5-3.07), recent abacavir exposure (OR, 1.81; 95% CI, 1.41-2.33), hypertension (OR, 1.54; 95% CI, 1.21-1.97), and dyslipidemia (OR, 1.44; 95% CI, 1.15-1.81).

These findings may not be generalizable to other HIV-positive individuals due to the predominance of White men in the study population.

“Our findings expand on how inflammation (that may not yet be captured by current CAD risk assessment methods) may contribute to high leukocytes and CAD events in PWH [people with HIV],” the researchers concluded.

Disclosure: Multiple authors declared affiliations with industry. Please see the original article for a full list of disclosures.

References:

Avery EF, Kleynhans JN, Ledergerber B, et al. Leukocyte count and coronary artery disease events in people with HIV: a longitudinal study. Clin Infect Dis. January 23, 2023. doi:10.1093/cid/ciad033