Carotid intima media thickness in patients with obstructive sleep apnea: comparison with a community-based cohort.

BACKGROUND: The impact of obstructive sleep apnea (OSA) on the development of atherosclerotic cardiovascular disease (CVD) in the absence of overt CVD or risk factors is unclear. Our purpose was to assess whether patients with OSA without overt CVD or risk factors have subclinical atherosclerosis as evaluated by carotid intima medial thickness (CIMT) compared to matched controls. METHODS: We measured CIMT in patients >40 years old, who underwent polysomnography for suspected OSA and did not have a history of CVD or risk factors (smoking, hypertension, diabetes, hyperlipidemia). OSA severity was classified according to apnea-hypopnea index. Serum levels of high-sensitivity C-reactive protein, fibrinogen, and lipids were assessed and relationships with OSA severity explored. CIMT measurements from patients with OSA were compared those of to age-, gender-, and BMI-matched controls from a community-based cohort without known CVD or OSA. RESULTS: Fifty-one patients were studied. Of these, patients with severe OSA had an increased CIMT compared to patients without OSA, but the relationship was not significant after controlling for age (p = 0.10). However, 37 patients had OSA and were matched to 105 controls. CIMT was significantly increased in OSA patients versus controls (0.77 vs. 0.68 mm, p = 0.03). The difference between patients and controls was greater for patients with severe OSA (0.83 vs. 0.71 mm) than for patients with mild-to-moderate OSA (0.71 vs. 0.67 mm). CONCLUSIONS: Patients with OSA but without a history of or risk factors for CVD have increased CIMT compared to a BMI-, age-, and gender-matched cohort. This provides evidence that OSA is an independent risk factor for the development of CVD.

Impact of coronary artery disease on outcomes after transcatheter aortic valve implantation.

BACKGROUND: Coronary artery disease (CAD) negatively impacts prognosis of patients undergoing surgical aortic valve replacement and revascularization is generally recommended at the time of surgery. Implications of CAD and preprocedural revascularization in the setting of transcatheter aortic valve implantation (TAVI) are not known. METHOD: Patients who underwent successful TAVI from January 2005 to December 2007 were retrospectively divided into five groups according to the extent of CAD assessed with the Duke Myocardial Jeopardy Score: no CAD, CAD with DMJS 0, 2, 4, and > or =6. Study endpoints included 30-day and 1-year survival, evolution of symptoms, left ventricular ejection fraction (LVEF), and mitral regurgitation (MR) and need of revascularization during follow-up. RESULTS: One hundred and thirty-six patients were included, among which 104 (76.5%) had coexisting CAD. Thirty-day mortality in the five study groups was respectively 6.3, 14.6, 7.1, 5.6, and 17.7% with no statistically significant difference between groups (P = 0.56). Overall survival rate at one year was 77.9% (95% CL: 70.9, 84.9) with no difference between groups (P = 0.63). Symptoms, LVEF, and MR all significantly improved in the first month after TAVI, but the extent of improvement did not differ between groups (P > 0.08). Revascularization after TAVI was uncommon. CONCLUSION: The presence of CAD or nonrevascularized myocardium was not associated with an increased risk of adverse events in this initial cohort. On the basis of these early results, complete revascularization may not constitute a prerequisite of TAVI. This conclusion will require re-assessment as experience accrues in patients with extensive CAD.

The design and rationale of SAVE BC: The Study to Avoid CardioVascular Events in British Columbia.

Atherosclerotic cardiovascular disease (ASCVD) is highly heritable, particularly when it occurs at a young age. The screening of individuals with premature ASCVD, although often recommended, is not routinely performed. Strategies to address this gap in care are essential. We designed the Study to Avoid CardioVascular Events in British Columbia (SAVE BC) as a prospective, observational study of individuals with a new diagnosis of very premature ASCVD (defined as age ≤ 50 years in males and age ≤ 55 years in females) and their first-degree relatives (FDRs) and spouses. FDRs and spouses will undergo screening for cardiovascular (CV) risk factors and subclinical ASCVD using a structured screening algorithm. All subjects will be followed longitudinally for ≥10 years. The overall goal of SAVE BC is to evaluate the yield of a structured screening program for identifying individuals at risk of premature ASCVD. The primary objectives of SAVE BC are to identify and follow index cases with very premature ASCVD and their FDRs and to determine the diagnostic yield of a structured screening program for these individuals. We will collect data on CV risk factors, medication use, CV events, and healthcare costs in these individuals. SAVE BC will provide insight regarding approaches to identify individuals at risk for premature ASCVD with implications for prevention and treatment in this population.

Lecithin: cholesterol acyltransferase (LCAT) deficiency and risk of vascular disease: 25 year follow-up.

We have reassessed the clinical and biochemical status of a large Canadian kindred with LCAT deficiency 25 years after the initial investigations. There have been no vascular events or death in this family over the 25 years. Both the homozygous (N = 2) and heterozygous (N = 9) patients had highly abnormal lipid profiles with low HDL-C (extreme in the homozygotes); apo B levels were high in the heterozygotes. Lipoprotein and hepatic lipase activities were low in the homozygotes and several heterozygotes. In the two homozygotes the carotid intima media thickness (IMT) was above 75th percentile expected for age and gender. However, the IMT abnormalities were much more pronounced in the heterozygotes, four of whom also had detectable plaques. The homozygotes had only minimal increases in IMT, no plaques, no IMT changes over the last 4 years and normal endothelial function. We conclude that, in this kindred, no significant vascular changes were observed in the homozygotes. However, heterozygocity for LCAT deficiency is associated with both an atherogenic lipid profile and vascular abnormalities.

Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology/Canadian Society of Cardiac Surgery position statement on revascularization--multivessel coronary artery disease.

This position statement addresses issues in revascularization for multivessel coronary artery disease (CAD) from the perspective of both cardiologists and cardiac surgeons. Recommendations are made based on evidence from clinical trials and observational studies, with an emphasis on the increasing number of individuals with significant comorbid disease burden and functional debilitation who are being referred for definitive management of their multivessel CAD in the context of routine clinical practice. These types of individuals have traditionally not been included in the many clinical trials that have been the basis for guidelines and recommendations, and the objective of the proposed medical intervention or revascularization (or both) would not necessarily be to improve prognosis but to improve quality of life. One purpose of this document is to propose practical multidisciplinary approaches to the management of these patients. Recommendations are made for revascularization in acute coronary syndromes and stable CAD, with specific considerations for individuals with left ventricular dysfunction and heart failure, chronic renal failure, and chronic obstructive pulmonary disease. We also consider the use of various risk scores, including the Society of Thoracic Surgeons score, the EuroSCORE, and the SYNTAX II score. The importance of a heart team approach is also emphasized. The complementary role of coronary bypass surgery and percutaneous coronary intervention is highlighted, along with the importance of optimal medical therapy.

Early atherosclerosis detection in asymptomatic patients: a comparison of carotid ultrasound, coronary artery calcium score, and coronary computed tomography angiography.

BACKGROUND: Detailed multimodality assessment of subclinical atherosclerosis in asymptomatic subjects referred for risk stratification has not been performed. We analyzed the detection of early atherosclerosis using 3 imaging modalities: coronary artery calcium (CAC) scoring, carotid ultrasound (US), and coronary computed tomography angiography (CCTA). METHODS: Asymptomatic subjects free of known vascular disease scheduled to undergo a carotid US for risk stratification were invited to undergo CCTA/CAC. Subjects taking lipid-lowering medication were excluded. All images were assessed by experienced core laboratory personnel. Carotid intima media thickness ≥ 75th percentile for age and sex, CAC > 0, and detection of either carotid or coronary artery plaque were indicators of atherosclerosis. RESULTS: Fifty patients were included with a median age of 53 years. Atherosclerosis was observed in 28%, 78%, and 90% of subjects using CAC, CCTA, and carotid US, respectively. All subjects showed atherosclerosis on at least 1 modality. In 36 patients with a CAC score = 0, 69% and 86% had atherosclerosis on CCTA and carotid US, respectively. CONCLUSIONS: In this detailed analysis, all subjects identified to warrant further risk stratification had subclinical atherosclerosis on at least 1 imaging modality. Concordance between modalities was highly variable, dependent on the specific definition of atherosclerosis used. Carotid US and CCTA detection of plaque were significantly more sensitive than CAC > 0 in this middle-aged population. Considering the prevalence of subclinical disease on carotid US and CCTA, the threshold at which to treat warrants further research.

Identification and management of patients at elevated cardiometabolic risk in canadian primary care: how well are we doing?

BACKGROUND: We evaluated the risk assessment and management patterns employed by primary care physicians in patients at elevated cardiometabolic risk. METHODS: Between April 2011 and March 2012, multiple physicians from 9 Primary Care Teams (PCTs) and 88 physicians from traditional nonteam (Solo) practices completed a practice assessment on the management of 2461 patients > 40 years old with no clinical evidence of cardiovascular disease and diagnosed with at least 1 of the following: dyslipidemia, type 2 diabetes mellitus (T2DM), or hypertension. RESULTS: Individuals with dyslipidemia, T2DM, or hypertension tended to have a body mass index ≥ 25 kg/m(2). Waist circumference measurements, obtained for only 392/829 (47.0%) Solo patients, revealed that 88.9% of these individuals were abdominally obese and that at least 52.2% of Solo patients had metabolic syndrome. Cardiovascular risk, determined by the physicians for 83.5% of all patients without T2DM and typically performed using traditional risk engines, was often miscalculated (43.2% PCTs, 58.8% Solo; P = 0.0007). Healthy behavioural modifications were infrequently recommended (< 50%). Pharmacotherapy was widely used (> 70%) but treatment targets were infrequently met. The composite outcome of guideline-recommended low-density lipoprotein cholesterol, glycemic, and blood pressure targets was met by 9.0% and 8.1% of patients managed by PCT and Solo physicians respectively. CONCLUSIONS: Obesity and cardiovascular risk were underassessed and the latter often underestimated. Patients were infrequently counselled on the benefits of healthy behavioural changes. A paradigm change in assessing and managing obesity and cardiovascular risk via aggressive lifestyle interventions is warranted in individuals at elevated cardiometabolic risk.

Plasma protein biosignatures for detection of cardiac allograft vasculopathy.

BACKGROUND: Coronary angiography remains the most widely used tool for routine screening and diagnosis of cardiac allograft vasculopathy (CAV), a major pathologic process that develops in 50% of cardiac transplant recipients beyond the first year after transplant. Given the invasiveness, expense, discomfort, and risk of complications associated with angiography, a minimally invasive alternative that is sensitive and specific would be highly desirable for monitoring CAV in patients. METHODS: Plasma proteomic analysis using isobaric tags for relative and absolute quantitation-matrix-assisted laser desorption ionization double time-of-flight mass spectrometry was carried out on samples from 40 cardiac transplant patients (10 CAV, 9 non-significant CAV, 21 possible CAV). Presence of CAV was defined as left anterior descending artery diameter stenosis ≥ 40% by digital angiography and quantitatively measured by blinded expert appraisal. Moderated t-test robust-linear models for microarray data were used to identify biomarkers that are significantly differentially expressed between patient samples with CAV and with non-significant CAV. A proteomic panel for diagnosis of CAV was generated using the Elastic Net classification method. RESULTS: We identified an 18-plasma protein biomarker classifier panel that was able to classify and differentiate patients with angiographically significant CAV from those without significant CAV, with an 80% sensitivity and 89% specificity, while providing insight into the possible underlying immune and non-alloimmune contributory mechanisms of CAV. CONCLUSION: Our results support of the potential utility of proteomic biomarker panels as a minimally invasive means to identify patients with significant, angiographically detectable coronary artery stenosis in the cardiac allograft, in the context of post-cardiac transplantation monitoring and screening for CAV. The potential biologic significance of the biomarkers identified may also help improve our understanding of CAV pathophysiology.

The impact of CPAP on cardiovascular biomarkers in minimally symptomatic patients with obstructive sleep apnea: a pilot feasibility randomized crossover trial.

BACKGROUND: Previous, largely uncontrolled studies demonstrated the substantial effects of continuous positive airway pressure ventilation (CPAP) on a variety of physiologic and biochemical markers known to be risk factors for cardiovascular disease in patients with obstructive sleep apnea (OSA). In this pilot crossover study, we assessed (1) the feasibility of using CPAP in a group of minimally symptomatic patients with OSA, assessed through patient compliance and (2) CPAP therapy's effect on biomarkers in these patients. METHODS: We studied patients with minimal daytime sleepiness who were referred to the University of British Columbia's Hospital Sleep Clinic with suspected OSA and an apnea-hypopnea index (AHI) > 15 events/h. Patients were randomized to either CPAP or no therapy for 4 weeks followed by a washout of 4 weeks, and then a crossover to the other intervention. Fasting morning blood and urine, 24-h blood pressure (BP) measurements, and endothelial function (peak flow-mediated dilation to nitroglycerin-mediated dilation ratio) were assessed before and after each study intervention. RESULTS: Nine adult male and four female patients were studied. Mean (SD) age was 55 (7) years, mean AHI = 27.9/h, mean Epworth Sleepiness Score = 6.8 (11/13 had a score < 10), and mean BMI = 31.1 kg/m(2). Mean compliance with CPAP therapy was 5.53 h/night. Compared to no therapy, potential improvements were observed with CPAP for urinary microalbumin, norepinephrine, and epinephrine to creatinine ratios (decreased by 3.51 mg/mmol, 1.70 nmol/mmol, and 0.95 nmol/mmol, respectively); 24-h BP (systolic decreased by 3.60 mmHg, diastolic by 0.70 mmHg); homeostasis model for insulin resistance score (decreased by 1.11); and endothelial function (increased by 7.4%). However, none of the above differences was significant (p > 0.10). CONCLUSION: In this pilot study there were potential improvements in a variety of cardiovascular biomarkers with CPAP. CPAP compliance was reasonably good even though patients were not particularly sleepy. Accordingly, larger randomized controlled trials in this area appear feasible and warranted.

Angiographic core laboratory reproducibility analyses: implications for planning clinical trials using coronary angiography and left ventriculography end-points.

OBJECTIVES: To assess reproducibility of core laboratory performance and impact on sample size calculations. BACKGROUND: Little information exists about overall reproducibility of core laboratories in contradistinction to performance of individual technicians. Also, qualitative parameters are being adjudicated increasingly as either primary or secondary end-points. The comparative impact of using diverse indexes on sample sizes has not been previously reported. METHODS: We compared initial and repeat assessments of five quantitative parameters [e.g., minimum lumen diameter (MLD), ejection fraction (EF), etc.] and six qualitative parameters [e.g., TIMI myocardial perfusion grade (TMPG) or thrombus grade (TTG), etc.], as performed by differing technicians and separated by a year or more. Sample sizes were calculated from these results. TMPG and TTG were also adjudicated by a second core laboratory. RESULTS: MLD and EF were the most reproducible, yielding the smallest sample size calculations, whereas percent diameter stenosis and centerline wall motion require substantially larger trials. Of the qualitative parameters, all except TIMI flow grade gave reproducibility characteristics yielding sample sizes of many 100's of patients. Reproducibility of TMPG and TTG was only moderately good both within and between core laboratories, underscoring an intrinsic difficulty in assessing these. CONCLUSIONS: Core laboratories can be shown to provide reproducibility performance that is comparable to performance commonly ascribed to individual technicians. The differences in reproducibility yield huge differences in sample size when comparing quantitative and qualitative parameters. TMPG and TTG are intrinsically difficult to assess and conclusions based on these parameters should arise only from very large trials.