Therapy for management of acute myocardial infarction (AMI) varies according to patient, prescriber and geographical characteristics.
To describe the in-hospital use of reperfusion therapy for ST elevation MI (STEMI) and discharge use of acetylsalicylic acid, beta-blockers, angiotensin-converting enzyme inhibitors (ACEIs) and statins in patients presenting with either STEMI or non-STEMI in Canada from 1999 to 2002.
Four Canadian registries (FASTRAK II, Canadian Acute Coronary Syndromes, Enhanced Feedback for Effective Cardiac Treatment and Improving Cardiovascular Outcomes in Nova Scotia) were used to identify patients with AMI in Canada and to measure in-hospital reperfusion and medication use. Use rates were compared by age, sex, time period and geographical area, according to available data.
Use rates for reperfusion in STEMI patients ranged from 60% to 70%, primarily representing fibrinolytic therapy. A delay in presentation to hospital after symptom onset represented an impediment to timely therapy, which was particularly pronounced for women and elderly patients. Overall, less than 50% of patients met the door-to-needle target of less than 30 min. Medication use rates at discharge increased from 1999/2000 to 2000/2001 across the different data sources: acetylsalicylic acid, 83% to 88%; beta-blockers, 74% to 89%; ACEIs, 54% to 67%; statins, 41% to 53%; and calcium antagonists, 21% to 32%.
Canadian and provincial rates of use of evidence-based medications for the treatment of AMI have increased over time, although there remains room for improvement. A single, comprehensive data source would supply better insights into the management of AMI in Canada.
Atrial fibrillation (AF) substantially increases risk of stroke. Evidence suggests that anticoagulation to reduce risk is underused (a "care gap"). Our objectives were to clarify measures of this gap in care by including data from family physicians and to determine why eligible patients were not receiving anticoagulation therapy.
Telephone survey of family physicians regarding specific patients in their practices.
Ambulatory AF patients not taking warfarin who had risk factors that made anticoagulation appropriate.
Proportion of patients removed from the care gap; reasons given for not giving the remainder anticoagulants.
Half the patients thought to be in the care gap had previously unknown contraindications to anticoagulation, lacked a clear indication for anticoagulation, or were taking warfarin. Patients' refusal and anticipated problems with compliance and monitoring were among the reasons for not giving patients anticoagulants.
Adding data from primary care physicians significantly narrowed the care gap. Attention should focus on the remaining reasons for not giving eligible patients anticoagulants.
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Research into adverse events (AEs) has highlighted the need to improve patient safety. AEs are unintended injuries or complications resulting in death, disability or prolonged hospital stay that arise from health care management. We estimated the incidence of AEs among patients in Canadian acute care hospitals.
We randomly selected 1 teaching, 1 large community and 2 small community hospitals in each of 5 provinces (British Columbia, Alberta, Ontario, Quebec and Nova Scotia) and reviewed a random sample of charts for nonpsychiatric, nonobstetric adult patients in each hospital for the fiscal year 2000. Trained reviewers screened all eligible charts, and physicians reviewed the positively screened charts to identify AEs and determine their preventability.
At least 1 screening criterion was identified in 1527 (40.8%) of 3745 charts. The physician reviewers identified AEs in 255 of the charts. After adjustment for the sampling strategy, the AE rate was 7.5 per 100 hospital admissions (95% confidence interval [CI] 5.7- 9.3). Among the patients with AEs, events judged to be preventable occurred in 36.9% (95% CI 32.0%-41.8%) and death in 20.8% (95% CI 7.8%-33.8%). Physician reviewers estimated that 1521 additional hospital days were associated with AEs. Although men and women experienced equal rates of AEs, patients who had AEs were significantly older than those who did not (mean age [and standard deviation] 64.9 [16.7] v. 62.0 [18.4] years; p = 0.016).
The overall incidence rate of AEs of 7.5% in our study suggests that, of the almost 2.5 million annual hospital admissions in Canada similar to the type studied, about 185 000 are associated with an AE and close to 70 000 of these are potentially preventable.
Catheter ablation of atrial fibrillation (AF) offers a promising treatment for the maintenance of sinus rhythm in patients for whom a rhythm control strategy is desired. While the precise mechanisms of AF are incompletely understood, there is substantial evidence that in many cases (particularly for paroxysmal AF), ectopic activity most commonly located in and around the pulmonary veins of the left atrium plays a central role in triggering and/or maintaining arrhythmic episodes. Catheter ablation involves electrically disconnecting the pulmonary veins from the rest of the left atrium to prevent AF from being triggered. Further substrate modification may be required in patients with more persistent AF. Successful ablation of AF has never been shown to alter mortality or obviate the need for oral anticoagulation; thus, the primary indication for this procedure should be improvement of symptoms caused by AF. The success rate of catheter ablation for AF is superior to the efficacy of antiarrhythmic drugs, but success is still in the range of 75%-90% after 2 procedures. Ablation is also associated with a complication rate of 2%-3%. Thus, ablation should primarily be used as a second-line therapy after failure of antiarrhythmic drugs. In contrast to AF, catheter ablation of atrial flutter has a higher success rate with a smaller incidence of complications. Thus, catheter ablation for atrial flutter may be considered a first-line alternative to antiarrhythmic drugs.
The Canadian Network and Centre for Trials INternationally (CANNeCTIN) was jointly funded by the Canadian Institutes of Health Research and the Canadian Foundation for Innovation in April 2008 to provide infrastructure for clinical studies of cardiovascular diseases and diabetes mellitus. Its functional components include a national coordinating centre at the Population Health Research Institute (PHRI) in Hamilton (Ontario), a collaborative Canadian network and an affiliated international network of hospitals and clinics. The rationales for CANNeCTIN include the global health burden of cardiovascular diseases and diabetes, the strengths of randomized controlled trials - particularly large, multicentre and international - and the track record of success of the PHRI. CANNeCTIN will provide investigators from across Canada with opportunities to become the principal investigators of national and international trials coordinated by the PHRI. CANNeCTIN will support priority pilot studies, and successful investigators will be encouraged and assisted to apply for peer review and industrial funding for full studies to be conducted within the network and coordinated by the PHRI. An extensive education program offers hands-on experience in organizing and leading large national/international clinical trials led by accomplished researchers, distance learning courses in clinical research methodology, biostatistics and study coordination, and 'cutting-edge' workshops. A knowledge translation program seeks opportunities arising from clinical trials and encourages research into this paradigm for understanding how best to close the gaps between knowledge and effective practice. The five-year goals are to enhance the capacity of Canadian investigators to lead major clinical studies, facilitate knowledge translation and exchange, and augment Canada's capacity to train the next generation of leaders in cardiovascular and diabetes clinical research.
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Geographical variations in the use of invasive cardiac procedures have been documented. It remains unclear to what extent these variations exist across the Canadian provinces.
To describe variation in the use of invasive cardiac procedures and waiting times for these procedures across nine Canadian provinces.
Using longitudinal, de-identified patient data from the Canadian Institute for Health Information, records of patients who had suffered an acute myocardial infarction (AMI) in each of nine Canadian provinces between 1997/1998 and 1999/2000 were selected. Rates and median waiting times for percutaneous coronary intervention and coronary artery bypass graft surgery were calculated by age, sex and health region.
There was a large variation in the use of and waiting times for invasive cardiac procedures across the Canadian provinces studied. In general, cardiac procedure rates in Western provinces were higher than in Eastern provinces, most notably higher than in the Maritime provinces and Ontario. In addition to interprovincial variation, there was also significant regional variation in the rates of revascularization and waiting times. Rates of percutaneous coronary intervention increased over the study period, whereas rates of bypass surgery remained relatively stable.
Significant variation in the use of cardiac procedures after AMI exists across Canada and this April represent potential inequalities in the treatment of AMI across Canada.
Drug-reimbursement policies may have an adverse effect on patient outcomes if they interfere with timely access to efficacious medications for acute medical conditions. Clopidogrel in combination with aspirin is the recommended standard of care for patients receiving coronary stents to prevent thrombosis. We examined the population-level effect of a change by a Canadian provincial government in a pharmacy-benefits program from a prior-authorization policy to a less restrictive, limited-use policy on access to clopidogrel among patients undergoing percutaneous coronary intervention (PCI) with stenting after acute myocardial infarction.
We conducted a population-based, retrospective, time-series analysis from April 1, 2000, to March 31, 2005, of all patients 65 years of age or older with acute myocardial infarction who underwent PCI with stenting in Ontario, Canada. The primary outcome was the composite rate of death, recurrent acute myocardial infarction, PCI, and coronary-artery bypass grafting at 1 year, with adjustment for sex and age. The secondary outcome was major bleeding.
The rate of clopidogrel use within 30 days after hospital discharge following myocardial infarction increased from 35% in the prior-authorization period to 88% in the limited-use period. The median time to the first dispensing of a clopidogrel prescription decreased from 9 days in the first period to 0 days in the second period. The 1-year composite cardiovascular outcome significantly decreased from 15% in the prior-authorization group to 11% in the limited-use group (P=0.02). Rates of bleeding in the two groups did not change.
The removal of a prior-authorization program led to improvement in timely access to clopidogrel for coronary stenting and improved cardiovascular outcomes.
Although quality indicators for the care of acute myocardial infarction (AMI) patients have been described for other countries, there are none specifically designed for the Canadian health care system. The authors' goal was to develop a set of Canadian quality indicators for AMI care.
A literature review identified existing quality indicators for AMI care. A list of potential indicators was assessed by a nine-member panel of clinicians from a variety of disciplines using a modified-Delphi panel process. After an initial round of rating the potential indicators, a series of indicators was identified for a second round of discussion at a national meeting. Further refinement of indicators occurred following a teleconference and review by external reviewers.
To identify an AMI cohort, case definition criteria were developed, using a hospital discharge diagnosis for AMI of International Classification of Diseases-Ninth revision (ICD-9) code 410.x. Thirty-seven indicators for AMI care were established. Pharmacological process of care indicators included administration of acetylsalicylic acid, beta-blockers, angiotensin-converting enzyme inhibitors, thrombolytics and statins. Mortality and readmissions for AMI, unstable angina and congestive heart failure were recommended as outcome indicators. Nonpharmacological indicators included median length of stay in the emergency department, and median waiting times for cardiac catheterization, percutaneous coronary intervention and/or coronary artery bypass graft surgery.
A set of Canadian quality indicators for the care of AMI patients has been established. It is anticipated that these indicators will be useful to clinicians and researchers who want to measure and improve the quality of AMI patient care in Canada.
Several machine learning techniques (multilayer and single layer perceptron, logistic regression, least square linear separation and support vector machines) are applied to calculate the risk of death from two biomedical data sets, one from patient care records, and another from a population survey. Each dataset contained multiple sources of information: history of related symptoms and other illnesses, physical examination findings, laboratory tests, medications (patient records dataset), health attitudes, and disabilities in activities of daily living (survey dataset). Each technique showed very good mortality prediction in the acute patients data sample (AUC up to 0.89) and fair prediction accuracy for six year mortality (AUC from 0.70 to 0.76) in individuals from epidemiological database surveys. The results suggest that the nature of data is of primary importance rather than the learning technique. However, the consistently superior performance of the artificial neural network (multi-layer perceptron) indicates that nonlinear relationships (which cannot be discerned by linear separation techniques) can provide additional improvement in correctly predicting health outcomes.
Reimbursement for outpatient prescription drugs is not mandated by the Canada Health Act or any other federal legislation. Provincial governments independently establish reimbursement plans. We sought to describe variations in publicly funded provincial drug plans across Canada and to examine the impact of this variation on patients' annual expenditures.
We collected information, accurate to December 2006, about publicly funded prescription drug plans from all 10 Canadian provinces. Using clinical scenarios, we calculated the impact of provincial cost-sharing strategies on individual annual drug expenditures for 3 categories of patients with different levels of income and 2 levels of annual prescription burden ($260 and $1000).
We found that eligibility criteria and cost-sharing details of the publicly funded prescription drug plans differed markedly across Canada, as did the personal financial burden due to prescription drug costs. Seniors pay 35% or less of their prescription costs in 2 provinces, but elsewhere they may pay as much as 100%. With few exceptions, nonseniors pay more than 35% of their prescription costs in every province. Most social assistance recipients pay 35% or less of their prescription costs in 5 provinces and pay no costs in the other 5. In an example of a patient with congestive heart failure, his out-of-pocket costs for a prescription burden of $1283 varied between $74 and $1332 across the provinces.
Considerable interprovincial variation in publicly funded prescription drug plans results in substantial variation in annual expenditures by Canadians with identical prescription burdens. A revised pharmaceutical strategy might reduce these major inequities.
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