Effect of decrease in heart rate variability on the diagnostic accuracy of 64-MDCT coronary angiography

OBJECTIVE: The purpose of this study was to evaluate the effect of average heart rate and heart rate variability on the diagnostic accuracy of 64-MDCT in the assessment of coronary artery stenosis. SUBJECTS AND METHODS: CT and invasive coronary angiography were performed on 114 patients (mean age, 62 years) referred for known coronary artery disease (n = 26), atypical chest pain (n = 58), and presurgical exclusion of coronary artery disease before abdominal aortic (n = 14) or cardiac valve (n = 16) surgery. The population was divided into two groups depending on median average heart rate (60.0 beats/min) and median heart rate variability (2.7 beats/min) during scanning. Heart rate variability was calculated as SD from the mean heart rate. Two blinded observers using a 4-point scale independently assessed the quality of images of each coronary artery segment and classified each segment as being stenosed (luminal diameter narrowing > 50%) or not. Invasive coronary angiography was used as the reference standard. RESULTS: In 71 (62.3%) of the patients, 241 significant coronary artery stenoses were identified with invasive coronary angiography. In 11 (9.7%) of the patients, 1.6% (26/1,672) of the segments were not evaluable with CT. Overall sensitivity, specificity, and positive and negative predictive values in a patient-based analysis were 97%, 81%, 90%, and 95%, respectively. Image quality was better (p < 0.05) in the low average heart rate group than in the high average heart rate group, but diagnostic accuracy was comparable for the two groups. In contrast, image quality and diagnostic accuracy were significantly better (p < 0.01) among patients in the low heart rate variability group than in the high heart rate variability group. CONCLUSION: Lower heart rate variability is associated with higher diagnostic accuracy of 64-MDCT coronary angiography

Effect of atazanavir versus other protease inhibitor-containing antiretroviral therapy on endothelial function in HIV-infected persons: randomized controlled trial

OBJECTIVE: Impaired endothelial function was demonstrated in HIV-infected persons on protease-inhibitor (PI)-containing antiretroviral therapy, probably due to altered lipid metabolism. Atazanavir is a PI causing less atherogenic lipoprotein changes. We studied whether endothelial function improves after switching from other PI to atazanavir. DESIGN: Randomized, observer-blind, treatment-controlled trial. SETTING: Three university-based outpatient clinics. PATIENTS: 39 HIV-infected persons with suppressed viral replication on PI-containing regimens and fasting LDL-cholesterol >3mmol/L. INTERVENTION: Patients were randomized either to continue the current PI or change to unboosted atazanavir. MAIN OUTCOME MEASURES: Endpoints at week 24 were endothelial function assessed by flow-mediated vasodilation (FMD) of the brachial artery, lipid profiles, high sensitive C-reactive protein, malondyaldehyde, total antioxidative capacity and oxidized LDL. RESULTS: Baseline characteristics and mean FMD values of the two treatment groups were comparable (3.9+/-1.8% on atazanavir vs. 4.0+/-1.5% in controls). After 24 weeks' treatment, FMD decreased to 3.3+/-1.4% and 3.4+/-1.7%, respectively (all p=n.s.). Total cholesterol improved in both groups (p=<0.0001 and p=0.01, respectively) but changes were more pronounced on atazanavir (p=0.05, changes between groups). HDL and triglyceride levels improved on atazanavir (p=0.03 and p=0.003, respectively) but not in the control group. Serum inflammatory and oxidative stress parameters did not change; oxidized LDL improved significantly in the atazanavir group. CONCLUSIONS: The switch from another PI to atazanavir among treatment experienced patients did not result in improvement of endothelial function despite significantly improved serum lipids. Not only atherogenic lipid profiles but also direct effects of reverse transcriptase inhibitor plus PI-containing combination on the endothelium may affect vascular function. ClinicalTrials.gov Identifier: NCT00447070

Apolipoprotein B, Residual Cardiovascular Risk After Acute Coronary Syndrome, and Effects of Alirocumab.

Background: Apolipoprotein B (apoB) provides an integrated measure of atherogenic risk. Whether apoB levels and apoB lowering hold incremental predictive information on residual risk after acute coronary syndrome beyond that provided by low-density lipoprotein cholesterol is uncertain. Methods: The ODYSSEY OUTCOMES trial (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) compared the proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome and elevated atherogenic lipoproteins despite optimized statin therapy. Primary outcome was major adverse cardiovascular events (MACE; coronary heart disease death, nonfatal myocardial infarction, fatal/nonfatal ischemic stroke, hospitalization for unstable angina). Associations between baseline apoB or apoB at 4 months and MACE were assessed in adjusted Cox proportional hazards and propensity score–matched models. Results: Median follow-up was 2.8 years. In proportional hazards analysis in the placebo group, MACE incidence increased across increasing baseline apoB strata (3.2 [95% CI, 2.9–3.6], 4.0 [95% CI, 3.6–4.5], and 5.5 [95% CI, 5.0–6.1] events per 100 patient-years in strata 35–<50, and ≤35 mg/dL, respectively). Compared with propensity score–matched patients from the placebo group, treatment hazard ratios for alirocumab also decreased monotonically across achieved apoB strata. Achieved apoB was predictive of MACE after adjustment for achieved low-density lipoprotein cholesterol or non–high-density lipoprotein cholesterol but not vice versa. Conclusions: In patients with recent acute coronary syndrome and elevated atherogenic lipoproteins, MACE increased across baseline apoB strata. Alirocumab reduced MACE across all strata of baseline apoB, with larger absolute reductions in patients with higher baseline levels. Lower achieved apoB was associated with lower risk of MACE, even after accounting for achieved low-density lipoprotein cholesterol or non–high-density lipoprotein cholesterol, indicating that apoB provides incremental information. Achievement of apoB levels as low as ≤35 mg/dL may reduce lipoprotein-attributable residual risk after acute coronary syndrome. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01663402.gov; Unique identifier: NCT01663402.URL: https://www