Angiotensin converting enzyme inhibitors (ACE-I) and HMGCoA reductase inhibitors (`statins’) have been shown to reduce CVD risk through their BP and cholesterol lowering properties, respectively [11,12]. However, both classes of medications appear to have additional anti-inflammatory pleotropic effects that may be uniquely beneficial for HIV positive patients [13,14,15]. Prior to expanding the use of ACE-I and/or statins for HIV-infected persons to patients for whom these treatments are not currently indicated, safety and tolerability data are needed to inform largescale trials that more clearly define the net risk-benefit balance. The goal of this study was to determine if a strategy using lisinopril (an ACE-I) at 10 mg daily and pravastatin (a `statin’) at 20 mg daily as adjunctive treatment was feasible, well tolerated, and led to risk factor reductions when given alone or in combination to virologically suppressed patients receiving ART. We also explored the potential treatment effect on biomarkers of systemic inflammation: high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-a).
Study Design
The study design was a randomized, double-blinded 262 factorial design of lisinopril (L) 10 mg daily versus matched Lplacebo daily in combination with pravastatin (P) 20 mg daily versus P-placebo (Figure 1). The goal of the study was to inform planning for larger studies by first assessing ability to recruit for the proposed interventions, and assessing tolerability and adherence. Planned sample size was 40 participants, which provided 80% power to detect a 12.6 mmHg difference between the lisinopril and L-placebo groups for systolic BP (assuming a standard deviation of 14 mmHG) and a 27 mg/dL difference in LDL cholesterol between the pravastatin and P-placebo groups (assuming a standard deviation of 30 mg/dL). The sample size and recruitment period was limited by budget and time restrictions associated with the American Heart Association funding mechanism supporting the study. In order to blind both participants and study investigators to the treatment assigned, active study drugs were over-encapsulated to match the respective placebo capsules. Treatment allocation was balanced in blocks of 4 or 8 providing four groups of approximately equal size. Treatment schedules were only known to the unblinded statistician and the pharmacist responsible for preparing study medication bottles; neither had contact with study participants. After the baseline assessment, participants were instructed to take 1 capsule from each study medication bottle by mouth daily and returned for repeat study visit procedures at 1 and 4 months.
Methods
The protocol for this trial and supporting CONSORT checklist are available as supporting information; see Checklist S1 and Protocol S1.
Outcomes
Adherence was assessed via participant self-reported estimates of number of missed doses per week during the study, and then objectively at month 4 by pill count. Tolerability and safety were ascertained through participant history at both 1 and 4 month visits. A fasting lipid profile (total cholesterol, LDL-C, HDL-C, and triglycerides) was obtained at the site clinical laboratory at baseline, 1 and 4 months. Research nurses measured BP in triplicate at each study visit, with mean values used for analyses. Plasma biomarkers of systemic inflammation were also assessed at baseline and the 1 and 4-month follow-up visits. Inflammatory markers were measured by the Laboratory for Clinical Biochemistry Research at the University of Vermont; hsCRP was measured with a NBTMII nephelometer, N Antiserum to Human CRP (Siemens Diagnostics, Norwood, MA); IL-6 with Chemiluminescent Sandwich ELISA (R&D Systems, Minneapolis, MN); and TNF-a with Millipore Panel B multiplex (Billerica, MA). The lower level of detection for hsCRP, IL-6, and TNF-a were 0.16 mg/mL, 0.16 pg/mL, and 0.32 pg/mL. All samples were analyzed blinded to treatment group. The assay coefficient of variance (CV) using these methods is 5% for hsCRP, 7% for IL-6, and 8% for TNF-a. In addition to these measures we also obtained a basic metabolic panel, aspartate aminotransferase, alinine aminotransferase, serum creatine kinase, and a complete blood count, and HIV clinical labs (HIV RNA level and CD4+ T-cell count) at each visit.
Participants
Participants with HIV infection receiving ART with HIV RNA levels ,200 copies/mL and a FRS $3% for 10-year coronary heart disease risk were enrolled after written informed consent at one of two HIV clinics (Hennepin County Medical Center [HCMC] and Clinic 42, Allina Hospitals and Clinics, Minneapolis, Minnesota) from January 2010 through February 2011. Exclusion criteria included known CVD, hypertension or BP $140/90 mmHg, low-density lipoprotein cholesterol (LDL-C) .160 mg/dL (or .130 mg/dL with a FRS .10%), triglycerides .500 mg/dL, diabetes, cirrhosis, serum creatinine $2.0 mg/dL, or a contra-indication to taking ACE-I or statin therapy. Our criteria specifying a FRS $3% both eliminates those at very low risk for CVD and efficiently selects for a target population at moderate CVD risk but for whom BP or cholesterol lowering therapy were not typically indicated. When applying data that HIV infection is associated with approximately a 2-fold increased CVD risk, our target population should have at least a 5% risk for coronary event in next 10 years [16]. FRS used for analyses was calculated from the published algorithm that considered age, gender, systolic BP, total cholesterol, high-density lipoprotein [HDL-C], and current smoking and diabetes status [17]. For screening purposes, FRS was estimated through application of a point-of-care online calculator (hp2010.nhlbihin.net/atpiii/calculator.asp). The study was approved by the institutional review board at each clinical site (HCMC Human Subjects Research Committee and Allina Hospitals and Clinics Institutional Review Board) and the protocol was registered at ClinicalTrials.gov (NCT00982189).