Prevalence of subclinical Cardiovascular Disease in healthy HIV infected patients at the University Teaching Hospital in Lusaka, Zambia

Abstract

Background: Cardiovascular diseases are among the leading cause of morbidity and mortality worldwide. The association between HIV and CVD has been established in many studies. However, information is still lacking on subclinical disease as well as its associated risk factors in this population. This study aimed at establishing the prevalence of subclinical CVD among clinically healthy HIV people attending their regular out- patient visits. It also looked at risk factors (traditional and non traditional) as well as the association of CVD to the CD4 count.

Methods: we enrolled a total of 243 asymptomatic HIVinfected patients from the HIV outpatient clinic at the University Teaching Hospital. Data collected included demographic characteristics, duration of HIV infection, drug history including HAART regimen and cardiovascular risk factors (hypertension, diabetes and smoking). Clinical data included blood pressure, weight and height. Laboratory data included CD4 counts, serum creatinine, total cholesterol and triglycerides. We  tested for subclinical CVD using 3 tools: Ankle Brachial Index (ABI) to measure for the presence of peripheral artery disease, 12 lead Electrocardiogram (ECG) for  electrical abnormalities and transthoracic Echocardiography (ECHO), to measure abnormalities in cardiac structure and function. At analysis, patients where  dichotomised into those with CD4≤350 and those with CD4>350.

Results: participants characteristics were as follows: the mean age, 42 years (SD±10); 143 (58.5%) females; CD4≤350cells/ml was found in 140 (57.6%); 112(86.2%) were receiving HAART with 86.2% being on 1st line regimen. Systolic hypertension was present in 84(34.6%), diastolic hypertension in 89(36.6%) and 39.5% had creatinine clearance<90. Diabetes and current smoking were not very common (3.3% and 2.9% respectively). High total cholesterol was found in  19(7.82%) of the participants while 37(15.23%) had high triglycerides. On ECG, ECHO and ABI, abnormalities were found in 53.9%, 44.4% and 20.2%   respectively). The commonest cardiac lesion on both ECG and ECHO was left ventricular hypertrophy (27.4% and 23.3%  respectively). Participants with CD4≤350 had higher prevalence of abnormalities on ECG (P=0.022) and ABI (P=0.043). Clinical factors associated with increased risk of subclinical CVD on multivariate logistical regression included CD4≤350, systolic BP>140mmHg and diastolic BP >90mmHg.

Conclusions: Prevalence of subclinical CVD in healthy HIV infected patients is high and those with CD4≤350 have a higher risk. Hypertension is the most important traditional CVD risk factor in this population. There is need to screen HIV patients attending their routine clinic visits for hypertension and subclinical CVD. ABI and ECG are readily available in most institutions and can be used with minimal  expertise.