Kori J. Kingsbury

Assessing the Association of Appropriateness of Coronary Revascularization and Clinical Outcomes for Patients With Stable Coronary Artery Disease

OBJECTIVES The study assessed the appropriateness of coronary revascularization in Ontario, Canada, and examined its association with longer-term outcomes. BACKGROUND Although appropriate use criteria for coronary revascularization have been developed to improve the rational use of cardiac invasive procedures, it is unknown whether greater adherence to appropriateness guidelines is associated with improved clinical outcomes in stable coronary artery disease. METHODS A population-based cohort of stable patients undergoing cardiac catheterization was assembled from April 1, 2006, to March 31, 2007. The appropriateness for coronary revascularization at the time of coronary angiography was retrospectively adjudicated using the appropriate use criteria. Clinical outcomes between coronary revascularization and medical treatment without revascularization, stratified by appropriateness categories, were compared. RESULTS In 1,625 patients with stable coronary artery disease, percutaneous coronary intervention or coronary artery bypass grafting was only performed in 69% who had an appropriate indication for coronary revascularization. Coronary revascularization was associated with a lower adjusted hazard of death or acute coronary syndrome (hazard ratio [HR]: 0.61; 95% confidence interval [CI]: 0.42 to 0.88) at 3 years compared with medical therapy in appropriate patients. The rate of coronary revascularization was 54% in the uncertain category and 45% in the inappropriate category. No significant difference in death or acute coronary syndrome between coronary revascularization and no revascularization in the uncertain category (HR: 0.57; 95% CI: 0.28 to 1.16) and the inappropriate category (HR: 0.99; 95% CI: 0.48 to 2.02) was observed. CONCLUSIONS Using the appropriateness use criteria, we identified substantial underutilization and overutilization of coronary revascularization in contemporary clinical practice. Underutilization of coronary revascularization is associated with significantly increased risks of adverse outcomes in patients with appropriate indications.

Determinants of variations in coronary revascularization practices

Background: The ratio of percutaneous coronary interventions to coronary artery bypass graft surgeries (PCI:CABG ratio) varies considerably across hospitals. We conducted a comprehensive study to identify clinical and nonclinical factors associated with variations in the ratio across 17 cardiac centres in the province of Ontario. Methods: In this retrospective cohort study, we selected a population-based sample of 8972 patients who underwent an index cardiac catheterization between April 2006 and March 2007 at any of 17 hospitals that perform invasive cardiac procedures in the province. We classified the hospitals into four groups by PCI:CABG ratio (low [< 2.0], low–medium [2.0–2.7], medium–high [2.8–3.2] and high [> 3.2]). We explored the relative contribution of patient, physician and hospital factors to variations in the likelihood of patients receiving PCI or CABG surgery within 90 days after the index catheterization. Results: The mean PCI:CABG ratio was 2.7 overall. We observed a threefold variation in the ratios across the four hospital ratio groups, from a mean of 1.6 in the lowest ratio group to a mean of 4.6 in the highest ratio group. Patients with single-vessel disease usually received PCI (88.4%–99.0%) and those with left main artery disease usually underwent CABG (80.8%–94.2%), regardless of the hospital’s procedure ratio. Variation in the management of patients with non-emergent multivessel disease accounted for most of the variation in the ratios across hospitals. The mode of revascularization largely reflected the recommendation of the physician performing the diagnostic catheterization and was also influenced by the revascularization “culture” at the treating hospital. Interpretation: The physician performing the diagnostic catheterization and the treating hospital were strong independent predictors of the mode of revascularization. Opportunities exist to improve transparency and consistency around the decision-making process for coronary revascularization, most notably among patients with non-emergent multivessel disease.

Administrative hospitalization database validation of cardiac procedure codes.

Background:Although cardiac procedures are commonly used to treat cardiovascular disease, they are costly. Administrative data sources could be used to track cardiac procedures, but sources of such data have not been validated against clinical registries. Objectives:To examine accuracy of cardiac procedure coding in administrative databases versus a prospective clinical registry. Sample:We examined a total of 182,018 common cardiac procedures including percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG) surgery, valve surgery, and cardiac catheterization procedures during fiscal years 2005 and 2006 across 18 cardiac centers in Ontario, Canada. Research Design:Accuracy of codes in the Canadian Institute for Health Information (CIHI) administrative databases were compared with the clinical registry of the Cardiac Care Network. Results:Comparing 17,511 CIHI and 17,404 registry procedures for CABG surgery, the positive predictive value (PPV) of CIHI-coded CABG surgery was 97%. In 6229 CIHI-coded and 5885 registry-coded valve surgery procedures, the PPV of the administrative data source was 96%. Comparing 38,527 PCI procedures in CIHI to 38,601 in the registry, the PPV of CIHI was 94%. Among 119,751 CIHI-coded and 111,725 registry-coded cardiac catheterization procedures, the PPV of administrative data was 94%. When the procedure date window was expanded from the same day to ±1 days, the PPV was 96% (PCI) and exceeded 98% (CABG surgery), 97% (valve surgery), and 95% (cardiac catheterization). Conclusions:Using a clinical registry as the gold standard, the coding accuracy of common cardiac procedures in the CIHI administrative database was high.

Predictors of normal coronary arteries at coronary angiography

BACKGROUND Coronary angiograms are important in the diagnostic workup of patients with suspected coronary artery disease. However, little is known about the clinical predictors of normal angiograms and whether this rate varies across different cardiac centers in Ontario. METHODS We conducted a study using the Cardiac Care Network Variations in Revascularization Practice in Ontario database of 2,718 patients undergoing an index cardiac catheterization for an indication of stable angina between April 2006 and March 2007 at one of 17 cardiac hospitals in Ontario. We determined predictors of normal coronary angiograms (0% coronary stenosis) and compared rates of patients with normal catheterizations across centers. RESULTS Overall, 41.9% of patients with stable angina had a normal catheterization. A multivariate model demonstrated female gender to be the strongest predictor of a normal angiogram (odds ratio 3.55, 95% CI 2.93-4.28). In addition, atypical ischemic symptoms or no symptoms, the absence of diabetes, hyperlipidemia, smoking history, peripheral vascular disease, and angiography performed at a nonteaching site were associated with higher rates of normal catheterization. The rate of normal angiograms studied varied from 18.4% to 76.9% across hospitals and was more common in community compared with academic settings (47.1% vs 35.4%, P < .001). CONCLUSIONS The absence of traditional cardiac risk factors, female gender, and lack of typical angina symptoms are all associated with a higher frequency of normal cardiac catheterizations. The wide variation in Ontario in the frequency of normal angiograms in patients with stable angina suggests that there are opportunities to improve patient case selection.

Specialized multi-disciplinary heart failure clinics in Ontario, Canada: an environmental scan

BackgroundMulti-disciplinary heart failure (HF) clinics have been shown to improve outcomes for HF patients in randomized clinical trials. However, it is unclear how widely available specialized HF clinics are in Ontario. Also, the service models of current clinics have not been described. It is therefore uncertain whether the efficacy of HF clinics in trials is generalizable to the HF clinics currently operating in the province.MethodsAs part of a comprehensive evaluation of HF clinics in Ontario, we performed an environmental scan to identify all HF clinics operating in 2010. A semi-structured interview was conducted to understand the scope of practice. The intensity and complexity of care offered were quantified through the use of a validated instrument, and clinics were categorized as high, medium or low intensity clinics.ResultsWe identified 34 clinics with 143 HF physicians. We found substantial regional disparity in access to care across the province. The majority of HF physicians were cardiologists (81%), with 81% of the clinics physically based in hospitals, of which 26% were academic centers. There was a substantial range in the complexity of services offered, most notably in the intensity of education and medication management services offered. All the clinics focused on ambulatory care, with only one having an in-patient focus. None of the HF clinics had a home-based component to care.ConclusionsMultiple HF clinics are currently operating in Ontario with a wide spectrum of care models. Further work is necessary to understand which components lead to improved patient outcomes.

Drivers of healthcare costs associated with the episode of care for surgical aortic valve replacement versus transcatheter aortic valve implantation

Objective Transcatheter aortic valve implantation (TAVI) is generally more expensive than surgical aortic valve replacement (SAVR) due to the high cost of the device. Our objective was to understand the patient and procedural drivers of cumulative healthcare costs during the index hospitalisation for these procedures. Design All patients undergoing TAVI, isolated SAVR or combined SAVR+coronary artery bypass grafting (CABG) at 7 hospitals in Ontario, Canada were identified during the fiscal year 2012–2013. Data were obtained from a prospective registry. Cumulative healthcare costs during the episode of care were determined using microcosting. To identify drivers of healthcare costs, multivariable hierarchical generalised linear models with a logarithmic link and γ distribution were developed for TAVI, SAVR and SAVR+CABG separately. Results Our cohort consisted of 1310 patients with aortic stenosis, of whom 585 underwent isolated SAVR, 518 had SAVR+CABG and 207 underwent TAVI. The median costs for the index hospitalisation for isolated SAVR were

Comparison of Outcomes of Balloon-Expandable Versus Self-Expandable Transcatheter Heart Valves for Severe Aortic Stenosis

21 811 (IQR

Clinical outcomes after trans‐catheter aortic valve replacement in men and women in Ontario, Canada

18 148–

Determinants of variations in initial treatment strategies for stable ischemic heart disease

30 498), while those for SAVR+CABG were

Impact of System and Physician Factors on the Detection of Obstructive Coronary Disease With Diagnostic Angiography in Stable Ischemic Heart Disease

27 256 (IQR