Too old too soon? Heart age compared with actual age in HIV-positive individuals

Absolute risk of cardiovascular disease (CVD) may be calculated using the Framingham equation. Since risk increases with age, a useful measure of excess risk adjusted for age is ‘heart age’, the age of a reference person with the same estimated risk, but based on ideal values of risk factors defined as non‐smoker, non‐diabetic, untreated SBP of 125 mmHg, total cholesterol of 180 mg/dL and HDL cholesterol of 45 mg/dL [1]. Patients attended the Bristol HIV Cohort between 2008–11. HDL and total cholesterol, SBP, CD4 count and viral load measured within a period of 6 months were available for 749/1013 (74%) patients. The median age was 42 years, 33% were female and 82% were on ART. We calculated heart‐age deviation (heart age‐actual age) by sex and age group. Smoking status was not available and therefore we did all calculations twice assuming all a) non‐smokers b) smokers. We used fractional polynomials to model change in heart‐age deviation with actual age. We used mutually adjusted multivariable linear regression to determine whether sex, age, CD4, viral load, treatment status and year of starting ART were associated with heart‐age deviation. The mean heart‐age deviation in males was 3.4 years (females 1.7) for non‐smokers, and 14.8 years (females 12.5) for smokers. The figure shows that deviation increased with age; eg for male smokers it was 9.7, 15.0, 20.4 and 23.3 years at ages 16–39, 40–49, 50–59 and ≥60 years respectively. On average a 45‐year‐old male smoker had a heart age of 60 years. Compared with males, deviation was lower in younger females, but became higher after age 48 years. Compared with treated patients (assuming non‐smoker) with viral suppression, untreated patients had similar heart age (0.33 [95% CI 1.67, 2.33]) and treated patients with unsuppressed viral replication had higher heart age (3.01 [0.61, 5.42]). Higher CD4 count was associated with higher heart age: those with CD4 between 500–750 and >750 (v.<500) had an increase of 2.25 (0.61, 3.89) and 4.39 (2.41, 6.36) years respectively. HIV+ve individuals have a considerably increased risk of CVD compared with the ideal reference values, although we do not know if estimated risk translates to CVD events. Heart‐age deviation increases with age and is greater for smokers. Deviation increases more sharply in women, possibly due to lower CVD risk at younger ages or to increased risk postmenopause. Heart age could be a useful communication tool in attempts to reduce CVD risk in HIV+ve individuals. Heart age deviation by actual age by sex and smoking status (95% CI shown shaded) image