Mind the Gap: Difference between Framingham heart age and real age increases with age in HIV-positive individuals - A clinical cohort study

Abstract

Objectives: To measure the excess risk of cardiovascular disease (CVD) in HIV-positive individuals by comparing 'heart age' with real age and to estimate associations of patients' characteristics with heart age deviation (heart age-real age). Design: Clinical Cohort Study. Setting: Bristol HIV clinic, Brecon Unit at Southmead Hospital, Bristol, UK. Participants: 749 HIV-positive adults who attended for care between 2008 and 2011. Median age was 42 years (IQR 35-49), 67% were male and 82% were treated with antiretroviral therapy. Main outcome measures: We calculated the Framingham 10-year risk of CVD and traced back to 'heart age', the age of an individual with the same score but ideal risk factor values. We estimated the relationship between heart age deviation and real age using fractional polynomial regression. We estimated crude and mutually adjusted associations of sex, age, CD4 count, viral load/treatment status and period of starting antiretroviral therapy with heart age deviation. Results: The average heart age for a male aged 45 years was 48 years for a non-smoker and 60 years for a smoker. Heart age deviation increased with real age and at younger ages was smaller for females than males, although this reversed after 48 years. Compared to patients with CD4 count <500 cells/mm3, heart age deviation was 2.4 (95% CI 0.7 to 4.0) and 4.3 (2.3 to 6.3) years higher for those with CD4 500-749 cells/mm3 and >750 cells/mm3, respectively. Conclusions: In HIV-positive individuals, the difference between heart age and real age increased with age and CD4 count and was very dependent on smoking status. Heart age could be a useful tool to communicate CVD risk to patients and the benefits of stopping smoking.