Prognostic value of ankle-brachial index and cardio-ankle vascular index for mortality and cardiovascular events in older people with HIV on long-term ART.

OBJECTIVES

To assess the association of the Cardio-Ankle Vascular Index (CAVI) and ankle-brachial index (ABI) with all-cause mortality and major adverse cardiovascular events (MACE) in older people with HIV receiving long-term antiretroviral therapy (ART) in Thailand.

METHODS

We conducted a prospective cohort study of 307 virologically suppressed participants aged ≥50 years who underwent baseline CAVI and ABI measurements. ABI was analysed both as a continuous variable and as a categorical variable using a cut-off <0.9. Outcomes were all-cause mortality and MACE (non-fatal myocardial infarction, ischaemic stroke or percutaneous coronary intervention). Associations between high CAVI (≥9) or continuous CAVI and outcomes were examined using Cox proportional hazards models adjusted for age, smoking, hypertension and interleukin-6 (IL-6).

RESULTS

At baseline, 18.2% of participants had high CAVI (≥9). Over a median follow-up of 8 years, 50 participants (16.3%) experienced the composite outcome, including 37 deaths (12.1%). After adjustment, categorical CAVI ≥ 9 was significantly associated with all-cause mortality (aHR 2.67, 95% CI: 1.37-5.21, p = 0.004) but did not reach statistical significance for the composite outcome (aHR 1.64, 95% CI: 0.89-3.01, p = 0.112). However, when modelled as a continuous variable, each unit increase in CAVI was associated with an increased risk of composite outcome (aHR 1.29, 95% CI: 1.08-1.54, p = 0.004). Ever smoking, hypertension and elevated IL-6 were significantly associated with increased risk of mortality and MACE. ABI < 0.9 was strongly associated with mortality (aHR 4.20, 95% CI: 1.43-12.27).

CONCLUSIONS

In older people with HIV on long-term ART, traditional cardiovascular risk, systemic inflammation (IL-6) and low ABI (<0.9) were stronger predictors of mortality and MACE. CAVI demonstrated prognostic value for mortality and the composite outcome, suggesting a potential complementary role in cardiovascular risk assessment.

CLINICAL TRIAL REGISTRATION: HIVNAT 006 (NCT00411983).