Patients
The SAMMC Institutional Review Board approved a retrospective analysis of all ART-naïve USAF members with newly diagnosed HIV evaluated between September 1, 2015 and September 30, 2016. All active duty USAF members are required to have annual HIV screening and those diagnosed with HIV infection have an initial medical evaluation at the San Antonio Military Medical Center (SAMMC). The initial visit consists of a multidisciplinary evaluation to determine fitness for military duty by an infectious disease physician which includes a comprehensive cardiovascular risk assessment and structural evaluation by transthoracic echocardiogram (TTE).
All the patients evaluated during the period met inclusion criteria for the study.
HIV disease characteristic evaluation
Electronic medical record data were used to classify patients by HIV disease severity and estimated duration of HIV infection. The estimated date of seroconversion was defined as the midpoint between the last negative HIV test and the first positive HIV test. The estimated duration of HIV infection at initial evaluation was defined as the time from the estimated date of seroconversion to the initial evaluation. In addition to HIV-related data, records were also examined for family history, active or prior tobacco use, obesity, hypertension, diabetes, dyslipidemia, and other CVD risk factors.
Echocardiographic Evaluation
Echocardiographic measurements of systolic ejection fraction (EF) and global longitudinal strain (GLS) were used to determine normal cardiovascular function defined as >51% and -15.9% to -22.1%, respectively using the Phillips iE33 ultrasound device using biplane method of disc as well as onboard strain and 3D analysis software. Diastolic function was assessed by measurement of medial and lateral mitral annular motion, mitral valve and pulmonary venous pulse wave Doppler in accordance with current American Society of Echocardiography guidelines [8]. Left ventricular geometry was determined from 2D-guided linear measurement of the parasternal long axis view. The interventricular septum, left ventricular and posterior wall diameters were measured at end diastole. Remodeling was defined as relative wall thickness of >0.42 and hypertrophy was defined as an indexed mass of >95g/m2 for females and >115g/m2 for males [9]. Right ventricular size and function was obtained by measuring end-diastolic and end-systolic areas from a right ventricular focus apical view with [9]. A right ventricular fractional area change of <35% was considered systolic dysfunction and an indexed diastolic area of >12.6cm2/m2 for male and >11.5cm2/m2 for females was considered dilated. Other incidental TTE abnormalities including right ventricular (RV) dilatation, left ventricular remodeling and diastolic dysfunction were also described.
Statistical analysis
Variables including CD4 cell count, serum HIV viral load (VL), high–sensitivity C-reactive protein (hs-CRP) and, N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, estimated duration of HIV infection and traditional cardiovascular disease risk factors were analyzed for potential association with TTE abnormalities using chi-squared and Fisher’s exact tests.