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Biomedical subjects

Louise Pilote

Publications and source records attributed to Louise Pilote.

At least 19 recordsLinked to original sources

Impact of age on hospital course and cost of coronary artery bypass grafting.

In-hospital outcomes and cost were examined among 2,272 elderly patients (> or =75 years) and 9,745 younger patients (<75 years) who underwent coronary artery bypass graft surgery at 5 United States and 4 Canadian hospitals. Hospital course and cost data were obtained from a resource and cost accounting system used by each of the 9 hospitals. Compared with younger patients, elderly patients had longer hospital stays, increased in-hospital mortality, and increased costs. After controlling for clinical differences, age > or =75 years was associated with an increase in cost of 11%. Given the aging North American population, these results have important implications for health care planning for the next several decades.

Age Factors↗

Evaluation of routine functional testing after percutaneous coronary intervention.

Following percutaneous coronary intervention, 348 patients were randomized to either routine or selective functional testing strategies. For the primary end point of maximal exercise endurance on a treadmill at 9 months, achievement was similar in the routine and selective groups. For the secondary end points measuring functional status and quality of life, scores were also similar. There was little difference in the rates of invasive cardiac procedures for the 2 groups at 9 months.

Angioplasty, Balloon, Coronary↗

Secondary prevention after acute myocardial infarction in four Canadian provinces, 1997-2000.

BACKGROUND: Publication of population-based analyses of medication use after acute myocardial infarction (AMI) could encourage the use of effective secondary prevention medications. OBJECTIVE: To describe outpatient use of beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, statins, calcium channel blockers and nitrates in elderly survivors of AMI over the fiscal years from 1997/98 to 1999/2000 in Nova Scotia, Quebec, Ontario and British Columbia. METHODS: Linked administrative databases were used to identify all AMI patients 65 years of age or older admitted in Quebec (n=14,880), Ontario (n=28,647) and British Columbia (n=7549) over the study period, and to measure 90-day postdischarge utilization rates of cardiac medications for these patients. A population-based clinical registry was used to measure rates of prescription at discharge for elderly patients in Nova Scotia admitted to an acute care hospital from 1997 to 2000 (n=1997). RESULTS: Utilization rates for beta-blockers, ACE inhibitors and statins increased over time, while rates for calcium channel blockers and nitrates decreased only slightly. The largest increases were for statins (Nova Scotia: 26% to 42%, Quebec: 27% to 43%; Ontario: 28% to 40%; British Columbia: 30% to 42%) and for ACE inhibitors in Ontario (55% to 65%) and Nova Scotia (46% to 68%). Of the three drugs recommended for secondary prevention, overall utilization rates for beta-blockers were highest in Nova Scotia, lowest in British Columbia, and similar in Quebec and Ontario. Rates for ACE inhibitors were highest in Ontario and similar in Quebec, Nova Scotia and British Columbia. Rates for statins were slightly higher in Quebec and British Columbia than in Ontario and Nova Scotia. The proportion of patients without a prescription for any of the recommended drugs was highest in British Columbia (20%), lowest in Nova Scotia (8%), and similar in Quebec and Ontario (Ontario: 12%; Quebec: 13%). There was marked regional variation in utilization rates within the four provinces. CONCLUSIONS: Although utilization rates for recommended cardiac medications are increasing over time, there remains room for improvement. Overall utilization rates and temporal trends are generally similar in all four provinces, but there are wide regional variations within provinces.

Adrenergic beta-Antagonists↗

Cardiac procedures after an acute myocardial infarction across nine Canadian provinces.

BACKGROUND: 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. OBJECTIVE: To describe variation in the use of invasive cardiac procedures and waiting times for these procedures across nine Canadian provinces. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Adult↗

Utility of routine functional testing after percutaneous transluminal coronary angioplasty: results from the ROSETTA registry.

BACKGROUND: There is little consensus regarding the use of functional testing after percutaneous transluminal coronary angioplasty (PTCA). Some physicians employ a routine functional testing strategy, and others employ a symptom-driven strategy. OBJECTIVE: To examine the effects of routine post-PTCA functional testing on the use of follow-up cardiac procedures and clinical events. METHODS: The Routine versus Selective Exercise Treadmill Testing after Angioplasty (ROSETTA) Registry is a prospective multicenter observational study examining the use of functional testing after PTCA. A total of 788 patients (pts) were enrolled in the ROSETTA Registry at 13 clinical centers in 5 countries. The frequencies of functional testing, cardiac procedures and clinical events were examined during the first 6 months following a successful PTCA. RESULTS: Patients were predominantly elderly men (mean age, 61+/-11 years; 76% male) who underwent single-vessel PTCA (85%) with stent implantation (58%). During the 6-month follow-up, a total of 237 pts were observed to undergo a routine functional testing strategy (100% having functional testing for routine follow-up), while 551 pts underwent a selective (or clinically-driven) strategy (73% having no functional testing and 27% having functional testing for a clinical indication). Patients in the routine testing group underwent a total of 344 functional tests compared with 165 tests performed in the selective testing group (mean, 1.45 tests/patient versus 0.3 tests/patient; p<0.0001). There was little difference in the rates of follow-up cardiac procedures among the pts undergoing the routine and selective testing strategies [cardiac catheterization, 13.9% versus 17.5% (p=NS); percutaneous coronary intervention (PCI), 8.4% versus 8.7% (p=NS); coronary artery bypass graft surgery, 2.1% versus 3.3% (p=NS)]. However, clinical events were less common among pts who underwent routine functional testing, e.g., unstable angina (6.1% versus 14.4%; p=0.001), myocardial infarction (0.4% versus 1.6%; p=NS), death (0% versus 2.2%; p=0.02) and composite clinical events (6.3% versus 16.3%; p<0.0001). After controlling for baseline clinical and procedural differences, routine functional testing had a persistent independent association with a reduction in the composite clinical event rate (odds ratio, 0.45; 95% confidence interval, 0.24-0.81; p=0.008). CONCLUSION: Routine functional testing after PTCA is associated with a reduction in the frequency of follow-up clinical events. This association may be attributable to the early identification and treatment of pts at risk for follow-up events, or it may be due to clinical differences between pts who are referred for routine and selective functional testing.

Angioplasty, Balloon, Coronary↗

In-hospital cost of abdominal aortic aneurysm repair in Canada and the United States.

BACKGROUND: Global health care costs in Canada and the United States have been examined on a macroeconomic level. However, to our knowledge, comparative costs of specific procedures in the 2 countries have not been closely studied. METHODS: To perform a microeconomic comparison of costs of open abdominal aortic aneurysm (AAA) repair, we examined the costs of treating 1057 consecutive patients from 4 Canadian (n = 552) and 6 US (n = 505) hospitals. Participating hospitals used the same cost accounting system that provided demographic, clinical, and cost data (excluding physician's fees) for each patient. Canadian dollar costs were converted to US dollar costs using purchasing power parities. RESULTS: Compared with patients who underwent AAA repair in the United States, Canadian patients were significantly younger (mean +/- SD, 70.2 +/- 10.5 vs 73.3 +/- 8.5 years; P<.001) and were less likely to undergo elective repair (48.5% vs 73.3%; P<.001). The median length of hospital stay was longer in Canada (9.0 vs 7.0 days; P<.001), and mortality rates were similar (12.0% [Canada] vs 9.9% [United States]; P =.29). The mean +/- SEM cost of AAA repair was dollars 15 852 +/- dollars 790 in Canada compared with US dollars 23299 +/- US dollars 1410 in the United States. CONCLUSIONS: The cost of AAA repair is substantially higher in the United States compared with Canada, despite shorter lengths of stay and similar clinical outcomes. The difference in total treatment costs between Canadian and American hospitals was partially attributable to differences in direct costs, but was largely due to differences in overhead costs.

Aged↗

Effects of early and late administration of angiotensin-converting enzyme inhibitors on mortality after myocardial infarction.

BACKGROUND: Clinical trials demonstrating that angiotensin-converting enzyme (ACE) inhibitors reduce mortality when prescribed following myocardial infarction have focused on either early or late administration. It is unclear what the overall mortality benefits are and how long they last. METHODS: We identified trials of ACE inhibitor therapy after myocardial infarction that were published between 1987 and 2002. Studies were included if they were randomized placebo-controlled trials with follow-up of at least 1 month. Separate analyses were performed for trials of therapy initiated within 48 hours of infarction (early administration) or initiated more than 48 hours after infarction (late administration). The Yusuf-Peto modification of the Mantel-Haenszel method was used to obtain summary odds ratios for mortality. RESULTS: Twenty-two trials (14 early administration, 8 late administration) met the inclusion criteria. Early administration of ACE inhibitors was associated with a slight reduction in 1-month mortality (odds ratio [OR] = 0.93; 95% confidence interval [CI]: 0.88 to 0.97) and a much larger reduction in 1-year mortality (OR = 0.68; 95% CI: 0.54 to 0.87). Late therapy was associated with significant reductions in 1-year mortality (OR = 0.84; 95% CI: 0.73 to 0.97), 2-year mortality (OR = 0.75; 95% CI: 0.67 to 0.85), and 3-year mortality (OR = 0.74; 95% CI: 0.65 to 0.84). CONCLUSION: Both early and late administration of ACE inhibitor therapy are associated with lower mortality following myocardial infarction, with the largest benefits observed with long-term mortality.

Angiotensin-Converting Enzyme Inhibitors↗

An NS3 serine protease inhibitor abrogates replication of subgenomic hepatitis C virus RNA.

The hepatitis C virus (HCV) NS3 protease is essential for polyprotein maturation and viral propagation, and it has been proposed as a suitable target for antiviral drug discovery. An N-terminal hexapeptide cleavage product of a dodecapeptide substrate identified as a weak competitive inhibitor of the NS3 protease activity was optimized to a potent and highly specific inhibitor of the enzyme. The effect of this potent NS3 protease inhibitor was evaluated on replication of subgenomic HCV RNA and compared with interferon-alpha (IFN-alpha), which is currently used in the treatment of HCV-infected patients. Treatment of replicon-containing cells with the NS3 protease inhibitor or IFN-alpha showed a dose-dependent decrease in subgenomic HCV RNA that reached undetectable levels following a 14-day treatment. Kinetic studies in the presence of either NS3 protease inhibitor or IFN-alpha also revealed similar profiles in HCV RNA decay with half-lives of 11 and 14 h, respectively. The finding that an antiviral specifically targeting the NS3 protease activity inhibits HCV RNA replication further validates the NS3 enzyme as a prime target for drug discovery and supports the development of NS3 protease inhibitors as a novel therapeutic approach for HCV infection.

Antiviral Agents↗

Introduction to the Canadian Cardiovascular Outcomes Research Team's (CCORT) Canadian Cardiovascular Atlas project.

The Canadian Cardiovascular Outcomes Research Team's (CCORT) Canadian Cardiovascular Atlas project was developed to provide Canadians with a national report on the state of cardiovascular health and health services in Canada. Written by a group of Canada's leading experts in cardiovascular outcomes research, the CCORT cardiac Atlas will cover a wide variety of topics ranging from cardiac risk factors and cardiac mortality rates to the treatment of patients with acute myocardial infarction and congestive heart failure and the outcomes of invasive cardiac procedures across Canada. Data in the Atlas will be presented at a national, provincial and health region level. The Atlas will be published as a series of 20 articles and chapters in future issues of The Canadian Journal of Cardiology and on CCORT's web site (www.ccort.ca). The journal version of the Atlas chapters will be written for a clinical audience and will include editorials written by invited experts, whereas the web-based version of each chapter will be written for a more general audience and will include additional supplemental information (for example, interactive colour maps and tables) that cannot be included in the journal version. Material from the Journal and the web will eventually be compiled into a book that will be distributed across Canada. This article serves as an introduction to the Atlas project and describes the rationale for and objectives of the CCORT national cardiac Atlas project.

Atlases as Topic↗

Depression and prognosis following hospital admission because of acute myocardial infarction.

BACKGROUND: Whether there is an association between depression at the time of acute myocardial infarction and subsequent risk of cardiac complications and death remains controversial. Most studies of this risk factor have been limited to patients of single institutions, and this might account for the varying results. We prospectively evaluated patients admitted to 5 tertiary care and 5 community hospitals and followed them for 1 year to measure the prevalence and prognostic impact of depressive symptoms after acute myocardial infarction. METHODS: Patients were recruited for the study by trained nurse interviewers who had documented acute myocardial infarction within 2-3 days of admission. The nurses collected information from the medical records and asked study subjects to complete the Beck Depression Inventory questionnaire during their stay in hospital and using a mailed questionnaire 30 days, 6 months and 1 year later. We obtained information on vital status for patients lost to follow-up from a central death registry. RESULTS: Of the 587 study subjects, 550 (94%) completed the Beck Depression Inventory at baseline and 191 (35%) had a score of 10 or more, indicating at least mild depression. Rates of depression did not vary over the follow-up period and were similar among patients admitted to tertiary care or community hospitals. Depressed patients were more likely to undergo catheterization (57% v. 47%, 95% confidence interval [CI] around the difference 0.1%-19.6%) and were more likely to undergo percutaneous coronary intervention (32% v. 24%, 95% CI around the difference 0.1%-16.2%) within 30 days of first admission to hospital. Patients with depression on admission had higher rates of a composite of cardiac complications, including recurrent ischemia, infarction or congestive heart failure during their first stay in hospital or readmission for angina, recurrent acute myocardial infarction, congestive heart failure or arrhythmia (adjusted hazard ratio 1.4, 95% CI 1.05-1.86), compared with patients who were not depressed on admission. After 1 year, death rates were higher among patients who were depressed at admission (30 patients, 16%) compared with nondepressed patients (28 patients, 8%), although the difference was not statistically significant (hazard ratio 1.3, 95% CI 0.59-3.05). INTERPRETATION: Depressive symptoms are common after acute myocardial infarction and are associated with a slight increase in risk of in-hospital catheterization and angiography and readmission because of cardiac complications. Death was infrequent, with no statistically significant difference between the 2 groups.

Angioplasty, Balloon, Coronary↗

The importance of indirect costs in primary cardiovascular disease prevention: can we save lives and money with statins?

BACKGROUND: The losses in productivity due to cardiovascular disease (CVD) are substantial but rarely considered in health economic analyses. We compared the cost-effectiveness of lipid level modification in the primary prevention of CVD with and without these indirect costs. METHODS: We used the Cardiovascular Life Expectancy Model to estimate the long-term benefits and cost-effectiveness of lipid level modification with atorvastatin calcium, including 28% and 38% reductions in total cholesterol and low-density lipoprotein cholesterol levels, respectively, and a 5.5% increase in high-density lipoprotein cholesterol level. The direct costs included all medical care costs associated with CVD. The indirect costs represented the loss of employment income and the decreased value of housekeeping services after different manifestations of CVD. All costs were expressed in 2000 Canadian dollars. RESULTS: When only direct medical care costs were considered, the incremental cost-effectiveness ratios for lifelong therapy with atorvastatin calcium, 10 mg/d, were generally positive, ranging from a few thousand to nearly $20 000 per year of life saved. When the societal point of view was adopted and indirect costs were included, the total costs were generally negative, representing substantial cost savings (up to $50 000) and increased life expectancy for most groups of individuals. CONCLUSIONS: Lipid therapy with statins can reduce CVD morbidity and mortality as demonstrated in a number of clinical trials. Adding the indirect CVD costs associated with productivity losses at work and home can result in forecasted cost savings to society as a whole such that lipid therapy could potentially save lives and money.

Adult↗

Amiodarone and the risk of bradyarrhythmia requiring permanent pacemaker in elderly patients with atrial fibrillation and prior myocardial infarction.

OBJECTIVES: The aim of this study was to determine whether the use of amiodarone in patients with atrial fibrillation (AF) increases the risk of bradyarrhythmia requiring a permanent pacemaker. BACKGROUND: Reports of severe bradyarrhythmia during amiodarone therapy are infrequent and limited to studies assessing the therapy's use in the management of patients with ventricular arrhythmias. METHODS: A study cohort of 8,770 patients age > or =65 years with a new diagnosis of AF was identified from a provincewide database of Quebec residents with a myocardial infarction (MI) between 1991 and 1999. Using a nested case-control design, 477 cases of bradyarrhythmia requiring a permanent pacemaker were matched (1:4) to 1,908 controls. Multivariable logistic regression was used to estimate the odds ratio (OR) of pacemaker insertion associated with amiodarone use, controlling for baseline risk factors and exposure to sotalol, Class I antiarrhythmic agents, beta-blockers, calcium channel blockers, and digoxin. RESULTS: amiodarone use was associated with an increased risk of pacemaker insertion (OR: 2.14, 95% confidence interval [CI]: 1.30 to 3.54). This effect was modified by gender, with a greater risk in women versus men (OR: 3.86, 95% CI: 1.70 to 8.75 vs. OR: 1.52, 95% CI: 0.80 to 2.89). Digoxin was the only other medication associated with an increased risk of pacemaker insertion (OR: 1.78, 95% CI: 1.37 to 2.31). CONCLUSIONS: This study suggests that the use of amiodarone in elderly patients with AF and a previous MI increases the risk of bradyarrhythmia requiring a permanent pacemaker. The finding of an augmented risk of pacemaker insertion in elderly women receiving amiodarone requires further investigation.

Aged↗

Universal health insurance coverage does not eliminate inequities in access to cardiac procedures after acute myocardial infarction.

BACKGROUND: It remains unclear whether socioeconomic status (SES) influences access to invasive cardiac procedures after acute myocardial infarction (AMI) in a universal health care system. The objective of this study was to evaluate the effect of SES on access to cardiac procedure after AMI in a universal health care system. METHODS: This was an observational cohort study of all patients with a first AMI in the province of Quebec, Canada, between 1985 to 1995. Information on treatment was obtained from the discharge and physicians' claims databases. SES was obtained from census data by linking postal codes. SES-independent predictors of use were identified, then incorporated in hierarchical models to predict use in low, medium, and high SES areas. The main outcome measures were rates of cardiac catheterization, percutaneous coronary intervention (PCI), and coronary artery bypass graft surgery (CABG) as a function of SES. RESULTS: SES data were available for 62,364 individuals with a first AMI. Of these, 65% were men and the mean age was 64 +/- 13 years. Rates of cardiac procedures rose with an increase in several SES measures. After adjustment for individual-level predictors of use of cardiac catheterization, average rent, (odds ratio per $100 difference: 1.57, 95% credible interval: 1.36 to 1.80) and proportion of renters, (odds ratio, 2.2; 95% CI: 1.21 to 3.73) in the area were independent SES predictors. Patients in low SES areas (median family income: $ 30,809 CDN) were less likely to undergo cardiac catheterization than patients in high SES areas ($92,169 CDN) (men: 33%; compared with 47%; women: 18%; compared with 47%). However, among patients with cardiac catheterization, SES was not associated with the use of revascularization procedures. For example, PCI rates for men within 90 days after AMI were 26%, compared with 25% in low and high SES areas, respectively. CABG rates were 15%, compared with 19%. CONCLUSIONS: We found that in the universal health care system of Canada, access to cardiac catheterization after AMI varied according to SES. Among those with cardiac catheterization, SES did not appear to influence further use of revascularization procedures.

Aged↗

The nested case-control study in cardiology.

BACKGROUND: The nested case-control study is an efficient epidemiological design whereby a case-control approach is employed within an established cohort. The large number of recent prospective studies and randomized trials conducted in cardiology provide cohorts within which the nested case-control approach is increasingly used. METHODS: This paper describes the design of the nested case-control study, and evaluates its role in cardiology by reviewing all such studies indexed in Medline from 1966 to 2000. The example of homocysteine is used to illustrate how discrepancies between results of nested case-control and case-control studies played an important role in the decisions and recommendations of national and international organizations. RESULTS: Seventy-seven nested case-control studies in cardiology were reviewed. The number of studies per year has been increasing since the first publication in 1987. The majority (96%) of studies evaluated potential risk factors for cardiovascular disease while the remainder evaluated drugs with cardiac adverse effects. In studies of homocysteine and coronary artery disease, nested case-control studies did not confirm the strong association suggested by early case-control studies that may have been influenced by bias (eg, selection, publication, or reverse causality). This led national and international organizations to advise against routine screening. CONCLUSIONS: The nested case-control study is increasingly used to study causal relationships in cardiology. The large cohorts of cardiac patients created by prospective studies, clinical trials, and administrative databases should be exploited using this methodology to assess potential cardiac risk factors and other causal relationships that cannot be studied in randomized trials.

Biomarkers↗

Drug prescriptions after acute myocardial infarction: dosage, compliance, and persistence.

BACKGROUND: Although it has been well documented that aspirin, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and lipid-lowering drugs are under-prescribed for patients with acute myocardial infarction (Am Heart J 2003;145:438-44.), few studies have examined dosage and long-term compliance and persistence patterns for the use of these drugs after AMI. METHODS: Using Quebec administrative data on all elderly (aged > or =65 years) survivors of hospital admissions for AMI between 1996 and 1998 (n = 14,057), we studied the discharge prescriptions, dosages, patient compliance, and persistence during this period for aspirin, beta-blockers, ACE inhibitors, and lipid-lowering drugs. RESULTS: Rates of discharge medications were suboptimal (aspirin 65%, beta-blockers 54%, ACE inhibitors 45%, lipid-lowering drugs 21%). Most patients with prescriptions for aspirin and ACE inhibitors were prescribed dosages equivalent to those administered in clinical trials (99% and 88%, respectively). In contrast, only 20% of patients with beta-blocker prescriptions and 48% of patients with lipid-lowering drug prescriptions were prescribed clinical trial doses. For patients with discharge prescriptions, 1-year compliance rates were high (aspirin 74%, beta-blockers 74%, ACE inhibitors 70%, lipid-lowering drugs 84%), as were the 1-year persistence rates (aspirin 71%, beta-blockers 72%, ACE inhibitors 69%, lipid-lowering drugs 80%). CONCLUSION: Although cardiac drugs are under-prescribed to patients with AMI, once prescribed, patients are likely to adhere to these prescriptions, with high rates of compliance and persistence.

Acute Disease↗

Cardiac procedure use and outcomes in elderly patients with acute myocardial infarction in the United States and Quebec, Canada, 1988 to 1994.

BACKGROUND: Studies from the early 1990s have documented greater intensity of treatment for patients with acute myocardial infarction (AMI) in the United States compared with Canada, with little difference in health outcomes. Little is known about whether treatments and outcomes are changing differently over time in the two countries, and whether the differences vary with patient age. METHODS: We conducted a retrospective cohort study of trends in cardiac procedure use, mortality, and recurrent AMI for patients 65 years or older hospitalized with AMI in the United States and Quebec. We examined Medicare claims and enrollment data from the United States (1.5 million) and provincial claims data from Quebec (35,000) between 1988 and 1994. RESULTS: Use of cardiac procedures grew more rapidly between 1988 and 1994 in the United States, particularly for patients 75 years or older; unlike in Quebec, these cardiac procedures were performed soon after AMI. Both countries experienced significant declines in 1-year mortality: the decline averaged 1.27% points per year in the United States and 1.05% points in Quebec (P = ns). For AMI patients 75 years or older, 30-day and 1-year mortality declined approximately twice as rapidly in the United States as in Quebec (P < 0.01). The decline in mortality in the United States relative to Canada was significantly greater among patients 75 years or older but not among those age 65 to 74 years. Readmission rates with recurrent AMI were almost unchanged. CONCLUSIONS: Over time, the use of cardiac procedures in elderly patients with AMI has risen more rapidly in the United States than in Quebec. These differences in procedure trends were associated with reductions in overall long-term AMI mortality in both countries.

Aged↗