Dennis T Ko

Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

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Publications (137)1349.3 Total impact

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    ABSTRACT: The use of invasive coronary angiography in stable ischemic heart disease (IHD) varies widely. To validate the 2012 appropriate use criteria for diagnostic catheterization (AUC) by examining the relationship between the appropriateness of cardiac catheterization in patients with suspected stable IHD and the proportion of patients with obstructive coronary artery disease (CAD) and subsequent revascularization. Population-based, observational, multicenter cohort study. The Cardiac Care Network, a registry of all patients having elective angiography at 18 hospitals in Ontario, Canada, between 1 October 2008 and 30 September 2011. Persons without prior coronary revascularization or myocardial infarction who had angiography for suspected stable CAD. Appropriateness scores were ascertained by using data collected at the time of the index angiography and were categorized as appropriate, inappropriate, or uncertain. Among the final cohort of 48 336 patients, 58.2% of angiographic studies were classified as appropriate, 10.8% were classified as inappropriate, and 31.0% were classified as uncertain. Overall, 45.5% of patients had obstructive CAD. In patients with appropriate indications for angiography, 52.9% had obstructive CAD, with 40.0% undergoing revascularization. In those with inappropriate indications, 30.9% had obstructive CAD and 18.9% underwent revascularization; in those with uncertain indications, 36.7% had obstructive CAD and 25.9% had revascularization. Although more patients with appropriate indications had obstructive CAD and underwent revascularization (P < 0.001), a substantial proportion of those with inappropriate or uncertain indications had important coronary disease. Data were not available on whether symptoms were atypical. Despite the association between appropriateness category and obstructive CAD, this study raises concerns about the ability of the AUC to guide clinical decision making. Canadian Institutes of Health Research.
    Annals of internal medicine 03/2015; DOI:10.7326/M14-1889 · 16.10 Impact Factor
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    ABSTRACT: Many patients with chest pain do not receive follow-up from a physician after discharge from the emergency department despite significant survival benefit associated with follow-up care. Our objective was to evaluate factors associated with physician follow-up to understand this gap in practice. We conducted an observational study involving patients at high risk who were assessed for chest pain and discharged from an emergency department in Ontario between April 2004 and March 2010. We used multivariable logistic regression to determine the association of clinical and nonclinical characteristics with physician follow-up. We identified 56 767 patients, of whom 25.1% did not receive any follow-up by a physician, 69.0% were seen by their primary care physician, and 17.3% were seen by a cardiologist within 30 days. Patients who had medical comorbidities and cardiac conditions such as myocardial infarction or heart failure were less likely to have follow-up. In contrast, a previous visit to a primary care physician was associated with the highest odds of having physician follow-up (odds ratio [OR] 6.44, 95% confidence interval [CI] 5.91-7.01). Similarly, a previous visit to a cardiologist was strongly associated with follow-up by a cardiologist (OR 3.01, 95% CI 2.85-3.17). Patients evaluated in emergency departments with the highest tertile of chest pain volume were more likely to receive follow-up from any physician (OR 1.52, 95% CI 1.31-1.77) and from a cardiologist (OR 2.04, 95% CI 1.61-2.57). Nonclinical factors are strongly associated with physician follow-up for patients with chest pain after discharge from the emergency department. However, patients with comorbidities and at higher risk for future adverse events are less likely to receive follow-up care. © 8872147 Canada Inc.
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    ABSTRACT: The CArdiovascular HEalth in Ambulatory care Research Team (CANHEART) is conducting a unique, population-based observational research initiative aimed at measuring and improving cardiovascular health and the quality of ambulatory cardiovascular care provided in Ontario, Canada. A particular focus will be on identifying opportunities to improve the primary and secondary prevention of cardiovascular events in Ontario's diverse multiethnic population. A population-based cohort comprising 9.8 million Ontario adults ≥20 years in 2008 was assembled by linking multiple electronic survey, health administrative, clinical, laboratory, drug, and electronic medical record databases using encoded personal identifiers. The cohort includes ≈9.4 million primary prevention patients and ≈400 000 secondary prevention patients. Follow-up on clinical events is achieved through record linkage to comprehensive hospitalization, emergency department, and vital statistics administrative databases. Profiles of cardiovascular health and preventive care will be developed at the health region level, and the cohort will be used to study the causes of regional variation in the incidence of major cardiovascular events and other important research questions. Linkage of multiple databases will enable the CANHEART study cohort to serve as a powerful big data resource for scientific research aimed at improving cardiovascular health and health services delivery. Study findings will be shared with clinicians, policy makers, and the public to facilitate population health interventions and quality improvement initiatives. © 2015 American Heart Association, Inc.
    Circulation Cardiovascular Quality and Outcomes 02/2015; DOI:10.1161/CIRCOUTCOMES.114.001416 · 5.66 Impact Factor
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    ABSTRACT: Public reporting of percutaneous coronary intervention (PCI) outcomes has been established in many jurisdictions to ensure optimal delivery of care. The majority of PCI report cards examine in-hospital mortality, but relatively little is known regarding the adherence to processes of care. A modified Delphi panel comprising cardiovascular experts was assembled to develop a set of PCI quality indicators. Indicators such as prescription of aspirin, dual antiplatelet therapy, statins and smoking cessation counselling were identified to represent high-quality PCI care. Chart abstraction was performed at 13 PCI hospitals in Ontario, Canada from 2009 to 2010 with at least 200 PCI patients randomly selected from each hospital. Our study sample included 3041 patients, of whom 18% had stable coronary artery disease (CAD) and 82% had an acute coronary syndrome (ACS). Their mean age was 63±12.4 years and 29% of patients were female. Prior to PCI, 89% were prescribed aspirin, and after PCI 98.7% were prescribed aspirin, 95.1% were prescribed dual antiplatelet therapy for 12 months after drug-eluting stents, and 94.9% were prescribed statins. The lowest performing quality indicator was smoking cessation counselling, observed in only 42% of current and past smokers (18% in patients with stable CAD and 47% in ACS). Our study demonstrates high levels of adherence to most quality indicators for patients undergoing PCI procedures in Ontario. In conclusion, smoking cessation counselling was not consistently performed across hospitals and represents an opportunity for future quality improvement efforts.
    01/2015; 2(1):e000200-e000200. DOI:10.1136/openhrt-2014-000200
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    ABSTRACT: BACKGROUND: There is a paucity of data on the comparative effectiveness of percutaneous coronary intervention using contemporary drug-eluting stent (DES) compared with coronary artery bypass graft (CABG) surgery in patients with chronic kidney disease. METHODS AND RESULTS: A population-based study was performed using the Cardiac Care Network, a provincial registry of all patients undergoing cardiac catheterization in Ontario, to evaluate patients treated with either percutaneous coronary intervention using DES or CABG between October 1, 2008, and September 30, 2011. Chronic kidney disease was defined as creatinine clearance <60 mL/min. A total of 1786 propensity-matched patients from 4006 patients with chronic kidney disease undergoing index revascularization for multivessel disease with either DES or isolated CABG (n=893 each group) were analyzed. Baseline and procedural characteristics between percutaneous coronary intervention and CABG groups were well-balanced, including urgent revascularization priority, diabetes mellitus, left ventricular function, and 3-vessel disease. The 1-, 2-, and 3-year Kaplan-Meier survival analyses in propensity-matched patients favored CABG (93.2% versus 89.3%; 86.6% versus 80.3%; 80.8% versus 71.5%, respectively; P<0.001). The CABG cohort had greater 1-, 2-, and 3-year freedom from major adverse cardiac and cerebrovascular events (89.4% versus 71.2%; 81.9% versus 60.5%; 75.2% versus 51.8%, respectively; P<0.001). Cox regression analysis identified DES use to be associated with greater hazard for late mortality (hazard ratio, 1.58; 95% confidence interval, 1.32-1.90) and major adverse cardiac and cerebrovascular events (2.62; 2.28-3.01; all P<0.001). CONCLUSIONS: In this large provincial registry, CABG was associated with improved early and late clinical outcomes when compared with percutaneous coronary intervention using DES in patients with chronic kidney disease undergoing index revascularization.
    Circulation Cardiovascular Interventions 01/2015; 8(1):e001973. DOI:10.1161/CIRCINTERVENTIONS.114.001973. · 6.98 Impact Factor
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    ABSTRACT: -Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and poses a significant burden to the health care system, but few studies have evaluated whether OHCA incidence and survival have changed over time.
    Circulation 11/2014; 130(21). DOI:10.1161/CIRCULATIONAHA.114.010633 · 14.95 Impact Factor
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    ABSTRACT: The relationship between appropriateness score, treatment strategy and quality of life (QOL) among patients with stable ischemic heart disease (SIHD) is not known. In this prospective cohort study, we evaluated changes in generic and cardiac-specific quality of life in patients with documented SIHD, comparing patients with revascularization versus those with medical therapy alone, stratified by their appropriateness scores.
    BMC Cardiovascular Disorders 10/2014; 14(1):137. DOI:10.1186/1471-2261-14-137 · 1.50 Impact Factor
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    ABSTRACT: Background There is increasing demand for transcatheter aortic valve replacement (TAVR) as the primary treatment option for patients with severe aortic stenosis (AS) who are high risk surgical candidates or inoperable. We used mathematical simulation models to estimate the hypothetical effectiveness of TAVR with increasing wait-times. Methods We applied discrete event modelling, using data from the Placement of Aortic Transcatheter Valves (PARTNER) trials. We compared TAVR to medical therapy in the inoperable cohort, and compared TAVR to conventional aortic valve surgery in the high risk cohort. One-year mortality and wait-time deaths were calculated in different scenarios by varying TAVR wait-times from 10 days to 180 days, while maintaining a constant wait-time for surgery at a mean of 15.6 days Results In the inoperable cohort, the 1-year mortality for medical therapy was 50%. When the TAVR wait-time was 10 days, the TAVR wait-time mortality was 1.9% with a 1 year mortality of 31.5%. TAVR wait-time deaths increased to 28.9% with a 180-day wait, with a 1-year mortality of 41.4%. In the high risk cohort, the wait-time deaths and 1-year mortality for the surgical patients were 2.5% and 27% respectively. The TAVR wait-time deaths increased from 2.2% with a 10-day wait to 22.4% with a 180-day wait, and a corresponding increase in 1-year mortality from 24.5% to 32.6%. Mortality with TAVR exceeded surgery when TAVR wait-times exceeded 60 days. Conclusion Modest increases in TAVR wait-times have substantial impact on the effectiveness of TAVR in both inoperable patients and high risk surgical candidates.
    The Canadian journal of cardiology 10/2014; 30(10). DOI:10.1016/j.cjca.2014.03.009 · 3.94 Impact Factor
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    ABSTRACT: Background-Wide variation exists in the detection rate of obstructive coronary artery disease (CAD) with elective coronary angiography for suspected stable ischemic heart disease. We sought to understand the incremental impact of nonclinical factors on this variation. Methods and Results-We included all patients who underwent coronary angiography for possible suspected stable ischemic heart disease, from October 1, 2008, to September 30, 2011, in Ontario, Canada. Nonclinical factors of interest included physician self-referral for angiography, the physician type (invasive or interventional), and hospital type. Hospitals were categorized into diagnostic angiogram only centers, stand-alone percutaneous coronary intervention centers, or full service centers with coronary artery bypass surgery available. Multivariable hierarchical logistic models were developed to identify system and physician-level predictors of obstructive CAD, after adjustment for patient factors. Our cohort consisted of 60 986 patients, of whom 31 726 had obstructive CAD (52.0%), with significant range across hospitals from 37.3% to 69.2%. Fewer self-referral patients (49.8%) had obstructive CAD compared with nonself-referral patients (53.5%), with an odds ratio of 0.89 (95% confidence interval, 0.86-0.93; P<0.001). Angiograms performed by invasive physicians had a lower likelihood of obstructive CAD compared with those by interventional physicians (48.2% versus 56.9%; odds ratio, 0.85; 95% confidence interval, 0.81-0.90; P<0.001). Fewer angiograms at diagnostic only centers showed obstructive CAD (42.0%) compared with full service centers (55.1%; odds ratio, 0.62; 95% confidence interval, 0.39-0.98; P=0.04). Nonclinical factors accounted for 23.8% of the variation between hospitals. Conclusions-Physician and system factors are important predictors of obstructive CAD with coronary angiography.
    Circulation Cardiovascular Quality and Outcomes 09/2014; 7(5). DOI:10.1161/CIRCOUTCOMES.114.001098 · 5.66 Impact Factor
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    ABSTRACT: Background Chest pain is one of the most common reasons for presentation to the emergency department (ED), however there is a paucity of data evaluating the impact of physician follow-up and subsequent management. To evaluate the impact of physician follow-up for low risk chest pain patients after ED assessment. Methods We performed a retrospective observational study of low risk chest pain patients who were assessed and discharged home from an Ontario ED. Low risk was defined as ≥50 years of age, and no diabetes or pre-existing cardiovascular disease. Follow-up within 30 days was stratified as: a) no-physician, b) primary care physician (PCP) alone, c) PCP with cardiologist, and d) cardiologist alone. The primary outcome was death or myocardial infarction (MI) at one-year. Results Among 216,527 patients, 29% had no-physician, 60% had PCP alone, 8% had PCP with cardiologist, and 4% had cardiologist alone follow-up after ED discharge. The mean age of the study cohort was 64.2 years and 42% of the patients were male. After adjusting for important differences in baseline characteristics between physician follow-up groups, the adjusted hazard ratios for death or MI were 1.07 (95% CI, 1.00 to 1.14) for the PCP group, 0.81 (95% CI, 0.72 to 0.91) for the PCP with cardiologist group, and 0.87 (95% CI, 0.74 to 1.02) for the cardiologist alone group, as compared to patients who had no follow-up. Conclusion In this cohort of low risk patients who presented to an ED with chest pain, follow up with a PCP and cardiologist was associated with significantly reduced risk of death or MI at one-year.
    The Canadian journal of cardiology 09/2014; 168(3). DOI:10.1016/j.ahj.2014.05.016 · 3.94 Impact Factor
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    ABSTRACT: Background Extensive research has demonstrated the importance of traditional cardiovascular risk factors in predicting acute coronary events. Our main objective was to evaluate the relationship between traditional risk factors and the presence of obstructive coronary artery disease (CAD), and to explore potential differences in men versus women. Methods An observational study was conducted in a population-based cohort of stable patients who underwent cardiac catheterization in Ontario, Canada. We examined the relationship of diabetes, hypertension, hyperlipidemia and smoking with the presence of obstructive CAD in men and women using multivariable logistic regression models. Results Of the 46,490 patients who were included in our study, 61.2% were men and 38.8% were women. We found that 97% of patients with obstructive CAD had at least one conventional cardiovascular risk factor. The adjusted odds ratios (OR) for obstructive CAD in women with diabetes (OR 1.51), hypertension (OR 1.38), and smoking (OR 1.39) were statistically significantly higher than in men (OR 1.20 for diabetes, OR 1.08 for hypertension, OR 1.14 for smoking, P < 0.001). The sex difference was even greater for patients with multiple risk factors. For example, the association with obstructive CAD in women with four cardiac risk factors (OR 4.30;95%CI 3.49-5.28) was almost doubled when compared to men (OR 2.26;95%CI 1.99-2.57, P < 0.001). Conclusions Almost all patients with stable CAD undergoing cardiac catheterization had at least one traditional cardiac risk factor. Importantly, the association between multiple cardiac risk factors and the presence of obstructive CAD is substantially stronger in women than men.
    The Canadian journal of cardiology 07/2014; 30(7). DOI:10.1016/j.cjca.2014.04.032 · 3.94 Impact Factor
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    ABSTRACT: Background-Clinical guidelines emphasize medical therapy as the initial approach to the management of patients with stable coronary artery disease (CAD). However, the extent to which medical therapy is applied before and after percutaneous coronary intervention (PCI) in contemporary clinical practice is uncertain. We evaluated medication use for patients with stable CAD undergoing PCI, and assessed whether the COURAGE study altered medication use in the Canadian healthcare system. Methods and Results-A population-based cohort of 23 680 older patients >65 years old) with stable CAD undergoing PCI in Ontario between 2003 and 2010 was assembled. Optimal medical therapy (OMT) was defined as prescription for a beta-blocker, statin, and either angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker in the 90 days before PCI, and the same medications plus thienopyridine 90 days following PCI. Prior to PCI, 8023 (33.9%) patients were receiving OMT, 11 891 (50.2%) were on suboptimal therapy, and 3766 (15.9%) were not prescribed any medications of interest. There was significant improvement in medical therapy following PCI (OMT: 11 149 [47.1%], suboptimal therapy: 11 591 [48.9%], and none: 940 [4.0%], P<0.001). Utilization rate of OMT reduced significantly after the publication of COURAGE (34.9% before versus 32.8% after, P<0.001). Similarly, the rate of OMT following PCI was lower in the period after publication of COURAGE (47.3% before versus 46.9% after, P<0.001). Conclusions-OMT was prescribed in about 1 in 3 patients prior to PCI and less than half after PCI. In contrast to the anticipated impact of COURAGE, we found lower rates of medication use in PCI patients after its publication.
    The Canadian journal of cardiology 06/2014; 3(4). DOI:10.1161/JAHA.114.000882 · 3.94 Impact Factor
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    ABSTRACT: Background-Ezetimibe use has steadily increased in Canada during the past decade even in the absence of evidence demonstrating a beneficial effect on clinical outcomes. Among the 4 most populated provinces in Canada, there is a gradient in the restrictiveness of ezetimibe in public-funded formularies (most to least strict: British Columbia, Alberta, Quebec, and Ontario). The effect of formulary policy on the use of ezetimibe over time is unknown. Methods and Results-We conducted a population-level cohort study using Intercontinental Marketing Services Health Canada's data from June 2003 to December 2012 to examine ezetimibe use in these 4 provinces to better understand the association between use and formulary restrictiveness. We found regional variations in the patterns of ezetimibe use. From June 2003 to December 2012, British Columbia (most restrictive) had the lowest monthly increasing rate from $261 to $21 926 ($190/100 000 population/mo), whereas Ontario (least restrictive) had the most rapid monthly increase from $223 to $74 030 ($647/100 000 population/mo), and Quebec from $130 to $59 690 ($522/100 000 population/mo) and Alberta from $356 to $37 604 ($327/100 000 population/mo) were intermediate (P<0.001). Conclusions-Ezetimibe use remains common, increasing during the past decade. Use steadily increased in provinces with the most lenient formularies. In contrast, use was lower, plateauing since 2008 in British Columbia and Alberta, which have more restrictive formularies. The gradient in ezetimibe use was related to variability in restrictiveness of the provincial formularies, illustrating the potential of a policy response gradient that may be used to more effectively manage medication use.
    Circulation Cardiovascular Quality and Outcomes 06/2014; 7(4). DOI:10.1161/CIRCOUTCOMES.114.001023 · 5.66 Impact Factor
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    ABSTRACT: Background-Higher-risk patients may not receive evidence-based therapy because of limited life expectancy, which is a composite measure that encompasses many patient factors, including age, frailty, and comorbidities. In this study, we evaluated the extent to which treatment care gaps can be explained by a difference in projected life expectancy. Methods and Results-An observational cohort study was conducted on acute myocardial infarction patients hospitalized in Ontario, Canada. Projected life expectancy was estimated using actual survival data with extrapolation using proportional hazard models adjusting for important covariates. The relationship between projected life expectancy with statins and reperfusion therapy was examined using generalized linear models. Among the 7001 acute myocardial infarction patients, 84.3% were prescribed statins and 72.9% were treated with reperfusion therapy. When projected life expectancy was <10 years, the likelihood of receiving either treatment declined progressively with reduction in life expectancy (P<0.001). At the 25th percentile of projected life expectancies, the likelihood of receiving a statin decreased by 1.4% (95% confidence interval, 1.0-1.8%), and acute reperfusion therapy decreased by 2.6% (95% confidence interval, 1.8-3.3%) for each year decline in projected life expectancy. Conclusions-Life expectancy of a patient strongly influences evidence-based treatment in acute myocardial infarction. It was seen not only among patients with limited life expectancies but also among those with many years to live. Treatment care gaps may reflect clinicians' synthesis about frailty and life-expectancy gains.
    Circulation Cardiovascular Quality and Outcomes 06/2014; 7(4). DOI:10.1161/CIRCOUTCOMES.113.000795 · 5.66 Impact Factor
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    ABSTRACT: We previously found that the use of ezetimibe increased rapidly with different patterns between the United States (US) and Canada prior to the landmark Ezetimibe and Simvastatin in Hypercholesterolemia Enhance Atherosclerosis Regression (ENHANCE) trial, which was reported in January 2008, and failed to show that the drug slowed the progression of atherosclerosis. What is not known is how practice in the 2 countries changed after the ENHANCE trial. We examined ezetimibe use trends in the US and Canada before and after the reporting of the ENHANCE trial. We conducted a population-based, retrospective, time-series analysis using the data collected by IMS Health in the US and CompuScript in Canada from January 1, 2002, to December 31, 2009. The main outcome measure was monthly number of prescriptions for ezetimibe-containing products. The monthly number of ezetimibe prescriptions/100,000 population rose from 6 to 1,082 in the US from November 2002 to January 2008, then significantly declined to 572/100,000 population by December 2009 after the release of the ENHANCE trial, a decrease of 47.1% (P < .001). In contrast, in Canada, use continuously rose from 2 to 495/100,000 population from June 2003 to December 2009 (P = .2). United States expenditures totaled $2.24 billion in 2009. Ezetimibe remains commonly used in both the US and Canada. Ezetimibe use has decreased in the US post-ENHANCE, whereas use has gradually but steadily increased in Canada. The diverging patterns of ezetimibe use in the US and Canada require further investigation, as they reveal that a common evidence base is eliciting very different utilization patterns in neighboring countries.
    American heart journal 05/2014; 167(5):683-9. DOI:10.1016/j.ahj.2014.01.014 · 4.56 Impact Factor
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    ABSTRACT: Randomized studies have shown optimal medical therapy to be as efficacious as revascularization in stable ischemic heart disease (IHD). It is not known if these efficacy results are reflected by real-world effectiveness. To evaluate the comparative effectiveness of routine medical therapy versus revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in stable IHD. Observational cohort study. Stable IHD patients from 1 October 2008 to 30 September 2011, identified using a Registry of all angiography patients in Ontario, Canada. Revascularization, defined as PCI/CABG within 90 days after index angiography. Death, myocardial infarction (MI) or repeat PCI/CABG. Revascularization was compared to medical therapy using a) multivariable Cox-proportional hazard models with therapy strategy treated as a time-varying covariate; and b) a propensity score matched analysis. Post-angiography medication use was determined. We identified 39,131 stable IHD patients, of whom 15,139 were treated medically, and 23,992 were revascularized (PCI = 15,604; CABG = 8,388). Mean follow-up was 2.5 years. Revascularization was associated with fewer deaths (HR 0.76; 95 % CI 0.68-0.84; p < 0.001) ,MIs (HR 0.78; 95 % CI 0.72-0.85; p < 0.001) and repeat PCI/CABG (HR 0.59; 95 % CI 0.50-0.70; p < 0.001) than medical therapy. In the propensity-matched analysis of 12,362 well-matched pairs of revascularized and medical therapy patients, fewer deaths (8.6 % vs 12.7 %; HR 0.75; 95 % CI 0.69-0.81; p < 0.001) , MIs (11.7 % vs 14.4 %; HR 0.84; 95 % CI 0.77-0.93 p < 0.001) and repeat PCI/CABG ( 17.4 % vs 24.1 %;HR 0.67; 95 % 0.63-0.71; p < 0.001) occurred in revascularized patients, over the 4.1 years of follow-up. The revascularization patients had higher uptake of clopidogrel (70.3 % vs 27.2 %; p < 0.001), β-blockers (78.2 % vs 76.7 %; p = 0.010), and statins (94.7 % vs 91.5 %, p < 0.001) in the 1-year post-angiogram. Stable IHD patients treated with revascularization had improved risk-adjusted outcomes in clinical practice, potentially due to under-treatment of medical therapy patients.
    Journal of General Internal Medicine 03/2014; 29(7). DOI:10.1007/s11606-014-2813-1 · 3.42 Impact Factor
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    ABSTRACT: Although multidisciplinary heart failure (HF) clinics are efficacious, it is not known how patient factors or HF clinic structural indicators and process measures have an impact on the cumulative health care costs. In this retrospective cohort study using administrative databases in Ontario, Canada, we identified 1216 HF patients discharged alive after an acute care hospitalization in 2006 and treated at a HF clinic. The primary outcome was the cumulative 1-year health care costs. A hierarchical generalized linear model with a logarithmic link and gamma distribution was developed to determine patient-level and clinic-level predictors of cost. The mean 1-year cost was $27,809 (range, $69 to $343,743). There was a 7-fold variation in the mean costs by clinic, from $14,670 to $96,524. Delays in being seen at a HF clinic were a significant patient-level predictor of costs (rate ratio 1.0015 per day; P<0.001). Being treated at a clinic with >3 physicians was associated with lower costs (rate ratio 0.78; P=0.035). Unmeasured patient-level differences accounted for 97.4% of the between-patient variations in cost. The between-clinic variation in costs decreased by 16.3% when patient-level factors were accounted for; it decreased by a further 49.8% when clinic-level factors were added. From a policy perspective, the wide spectrum of HF clinic structure translates to inefficient care. Greater guidance as to the type of patient seen at a HF clinic, the timeliness of the initial visit, and the most appropriate structure of the HF clinics may potentially result in more cost-effective care.
    Medical care 03/2014; 52(3):272-9. DOI:10.1097/MLR.0000000000000071 · 2.94 Impact Factor
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    ABSTRACT: Aims: Our objective was to evaluate the relationship between coronary chronic total occlusion (CTO) treatment strategy and quality of life improvements. Methods and results: This multicentre prospective cohort study enrolled consecutive CTO patients undergoing a non-urgent coronary angiogram who completed the Seattle Angina Questionnaire (SAQ) and EQ-5D at baseline and at one year. Strategies were: i) medical therapy, ii) PCI to non-CTO, iii) PCI to CTO, and iv) CABG. Multivariable regression models compared quality of life changes over time among strategies, accounting for repeat measures per patient. In our cohort of 387 patients, 154 underwent medical therapy, 83 had PCI to the non-CTO artery, 104 underwent CABG, and 46 underwent PCI to the CTO. Medically treated patients had no improvement on any SAQ domains. Patients with revascularisation of the CTO territory with either PCI or CABG had significant improvements in the physical limitation (PCI to CTO 60.5-76.4; CABG 61.6-80.1; p<0.001), angina frequency (PCI to CTO 79.0-92.7; CABG 82.1-97.9; p<0.001), and disease perception (PCI to CTO 50.5-75.0; CABG 50.2-80.0; p<0.001) domains. In non-CTO PCI patients, improvement was restricted to the angina frequency (82.8-93.3; p<0.001), and disease perception (53.8-71.4; p<0.001) domains. Conclusions: CTO territory revascularisation was associated with quality of life improvements.
    EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology 02/2014; 9(10):1165-72. DOI:10.4244/EIJV9I10A197 · 3.76 Impact Factor
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    ABSTRACT: To describe rates and risk factors for prolonged postoperative use of opioids in patients who had not previously used opioids and undergoing major elective surgery. Population based retrospective cohort study. Acute care hospitals in Ontario, Canada, between 1 April 2003 and 31 March 2010. 39 140 opioid naïve patients aged 66 years or older who had major elective surgery, including cardiac, intrathoracic, intra-abdominal, and pelvic procedures. Prolonged opioid use after discharge, as defined by ongoing outpatient prescriptions for opioids for more than 90 days after surgery. Of the 39 140 patients in the entire cohort, 49.2% (n=19 256) were discharged from hospital with an opioid prescription, and 3.1% (n=1229) continued to receive opioids for more than 90 days after surgery. Following risk adjustment with multivariable logistic regression modelling, patient related factors associated with significantly higher risks of prolonged opioid use included younger age, lower household income, specific comorbidities (diabetes, heart failure, pulmonary disease), and use of specific drugs preoperatively (benzodiazepines, selective serotonin reuptake inhibitors, angiotensin converting enzyme inhibitors). The type of surgical procedure was also highly associated with prolonged opioid use. Compared with open radical prostatectomies, both open and minimally invasive thoracic procedures were associated with significantly higher risks (odds ratio 2.58, 95% confidence interval 2.03 to 3.28 and 1.95 1.36 to 2.78, respectively). Conversely, open and minimally invasive major gynaecological procedures were associated with significantly lower risks (0.73, 0.55 to 0.98 and 0.45, 0.33 to 0.62, respectively). Approximately 3% of previously opioid naïve patients continued to use opioids for more than 90 days after major elective surgery. Specific patient and surgical characteristics were associated with the development of prolonged postoperative use of opioids. Our findings can help better inform understanding about the long term risks of opioid treatment for acute postoperative pain and define patient subgroups that warrant interventions to prevent progression to prolonged postoperative opioid use.
    BMJ (online) 02/2014; 348:g1251. DOI:10.1136/bmj.g1251 · 16.38 Impact Factor
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    Mony Shuvy, Dennis T Ko
    02/2014; 1(1):e000036. DOI:10.1136/openhrt-2014-000036

Publication Stats

3k Citations
1,349.30 Total Impact Points

Institutions

  • 2005–2015
    • Sunnybrook Health Sciences Centre
      • • Department of Medicine
      • • Division of Cardiology
      Toronto, Ontario, Canada
  • 2007–2014
    • Institute for Clinical Evaluative Sciences
      Toronto, Ontario, Canada
    • Yale University
      New Haven, Connecticut, United States
  • 2004–2014
    • University of Toronto
      • • Institute of Health Policy, Management and Evaluation
      • • Division of Cardiology
      • • Institute for Clinical Evaluative Sciences
      Toronto, Ontario, Canada
  • 2006–2010
    • McMaster University
      • Department of Pathology and Molecular Medicine
      Hamilton, Ontario, Canada
    • University of Western Australia
      • School of Population Health
      Perth City, Western Australia, Australia
  • 2008
    • University Health Network
      Toronto, Ontario, Canada
  • 2004–2005
    • The Toronto Centre for Phenogenomics
      Toronto, Ontario, Canada
  • 2003
    • Yale-New Haven Hospital
      • Department of Laboratory Medicine
      New Haven, Connecticut, United States