Biomedical subjects

P Diane Galbraith

Publications and source records attributed to P Diane Galbraith.

At least 19 recordsLinked to original sources

PubMed2006

Revascularization in patients with heart failure.

BACKGROUND: Although practice guidelines recommend coronary revascularization for patients with heart failure, the evidence to support this recommendation is weak. The objective of our study was to determine the association of coronary revascularization with survival in patients who have had heart failure. METHODS: Data were obtained from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH), a clinical outcome-monitoring initiative that has captured data on all patients undergoing cardiac catheterization in the province of Alberta since 1995. Our study included data from patients with a history of heart failure and with documented coronary artery disease; patients with normal coronary arteries or prior coronary artery bypass grafting (CABG) were excluded. We constructed survival curves and adjusted them by the corrected group prognosis method (incorporating all clinical variables in APPROACH). Propensity scores were used to account for clinical characteristics that could influence the decision to revascularize. RESULTS: A total of 2538 patients (mean age 68 yr, standard deviation [SD] 11 yr, 31% female) underwent revascularization; 1690 patients (mean age 69 [SD 11] yr, 34% female) did not. Crude 1-year mortality was 11.8% among patients who underwent revascularization, compared with 21.6% among those who did not. Adjusted survival curves diverged early and continued up to 7 years of follow-up (hazard ratio 0.50, 95% confidence interval 0.44-0.57). Propensity scores showed improved survival with revascularization across all quintiles of likelihood of revascularization. INTERPRETATION: This new evidence lends support to practice guidelines, which recommend revascularization in patients with heart failure and coronary disease.

Aged↗

PubMed2006

Quality of life after coronary revascularization in the elderly.

AIMS: To describe health status outcomes at 4 years for a cohort of elderly patients with cardiac disease. METHODS AND RESULTS: Using the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease, an outcomes initiative capturing all patients undergoing cardiac catheterization in Alberta, Canada, health status was measured using the Seattle Angina Questionnaire (SAQ) and crude and risk-adjusted outcomes were determined and compared for patients treated with percutaneous coronary intervention or coronary artery bypass surgery (CABG) vs. medical therapy. Response rates among surviving, consenting patients were 64.8% for patients <70 years (n=7883), 77.3% for patients aged 70-79 years (n=2940), and 77.7% for patients >or=80 years of age (n=439). For patients aged <70 years, and those aged 70-79 years, for all dimensions of the SAQ, scores were significantly better for patients treated with revascularization procedures than with medical therapy. For patients over the age of 80 years, scores for patients treated with CABG in particular were significantly better, with the exception of exertional capacity. At 3 years, all scores remained stable or improved, and continued to favour revascularization. CONCLUSION: Elderly patients undergoing revascularization have better health status at 4 years than do those in the same age group who do not undergo revascularization. These findings suggest that age should not deter against revascularization given the combined survival and quality-of-life benefits.

Aged↗

PubMed2006

External validation of a percutaneous coronary intervention mortality prediction model in patients with acute coronary syndromes.

BACKGROUND: The recently published Michigan outcome prediction model (MM) for inhospital mortality was developed and validated on a series of consecutive patients undergoing percutaneous coronary intervention (PCI). Our purpose was to externally validate the performance of the MM in 2 separate cohorts of patients with acute coronary syndrome (ACS) undergoing PCI in Canada. METHODS: A validation of the MM and development of an extended MM were performed on data describing 10,050 patients from the APPROACH prospective cohort study between January 1995 and December 2000. Performance of both models was assessed on an external data set of 3259 PCI cases from the British Columbia Cardiac Registries. Only patients with a diagnosis of ACS were included in the study. RESULTS: The original MM predicted death rates ranging from 0.1% to 60.6%, but lacked accuracy to predict inhospital mortality as severity increased. The extended MM predicted death rates more widely from 0.0% to a high of 91.0% with better accuracy to predict inhospital death in patients with ACS undergoing PCI. The areas under the receiver operating characteristic curve for the MM and the extended MM on the external validation data set were 0.93 and 0.95, respectively. CONCLUSION: The MM predicts death after PCI in patients with ACS and identifies a clear gradient of risk. However, the enhanced MM developed specifically for the subset of patients with ACS demonstrated better prediction and cross-validated performance. These prediction rules can be useful for risk-adjustment analyses and for prognostication for individual patients.

Aged↗

PubMed2006

Prophylactic amiodarone for prevention of atrial fibrillation after cardiac surgery: a meta-analysis.

Amiodarone has been proposed to decrease atrial fibrillation after cardiac surgery. The literature was systematically reviewed for randomized trials comparing amiodarone with control for prevention of atrial fibrillation. Data were extracted on study characteristics, quality, and incidence of atrial fibrillation, cardiovascular outcomes, and length of hospitalization. Nineteen trials were included. Amiodarone reduced the odds ratio of atrial fibrillation (0.50; 95% confidence interval [CI]: 0.43 to 0.59, p < 0.0001), ventricular tachyarrhythmias (0.39; 95% CI: 0.26 to 0.58, p < 0.0001), and strokes (0.53; 95% CI: 0.30 to 0.92, p = 0.02). Amiodarone reduced hospital stay (0.6 days; 95% CI: 0.4 to 0.8, p < 0.0001). Amiodarone decreased atrial fibrillation, reduced perioperative ventricular tachyarrhythmias and strokes, and reduced duration of hospitalization. The current evidence supports recommending the routine use of perioperative amiodarone for cardiac surgery.

Adrenergic beta-Antagonists↗

PubMed2006

Kaplan-Meier methods yielded misleading results in competing risk scenarios.

BACKGROUND AND OBJECTIVE: Time-to-event curves are routinely presented in the medical literature. The most widely used method is the Kaplan-Meier (K-M) method, but this analysis approach may not be appropriate when an analysis focuses on time-to-first event in scenarios where there are competing events. We compared K-M methods applying various censoring approaches with the lesser-known "cumulative incidence competing risks" (CICR) method in an analysis of competing events. METHODS: A registry containing data on 21,624 patients undergoing cardiac catheterization was analyzed. Time to coronary artery bypass grafting (CABG) was assessed in an analysis for which percutaneous coronary intervention and death were competing events. Time-to-CABG curves were calculated using the "K-M censor all method," "K-M censor death only method," "K-M ignore all method," and the CICR method. RESULTS: One-year CABG rates calculated for the K-M "censor all," "censor death only," and "ignore all" methods were 28.8%, 22.8%, and 22.4%, respectively compared to the "actual" rate of 20.8%. For the CICR method, the corresponding 1-year rate was identical to the "actual" rate. CONCLUSION: In situations with competing risks, and where an analysis focuses on first events, the CICR method is most appropriate, as K-M methods will tend to overestimate event rates.

Angioplasty, Balloon, Coronary↗

PubMed2006

Development and validation of a surname list to define Chinese ethnicity.

OBJECTIVE: Surnames have the potential to accurately identify ancestral origins as they are passed on from generation to generation. In this study, we developed and validated a Chinese surname list to define Chinese ethnicity. METHODS: We conducted a literature review, a panel review, and a telephone survey in a randomly selected sample from a Canadian city in 2003 to develop a Chinese surname list. The list was then validated to data from the Canadian Community Health Survey. Both surveys collected information on self-reported ethnicity and surname. RESULTS: Of the 112,452 people analyzed in the Canadian Community Health Survey, 1.6% were self-reported as Chinese. This was similar to the 1.5% identified by the surname list. Compared with self-reported Chinese ethnicity (reference standard), the surname list had 77.7% sensitivity, 80.5% positive predictive value, 99.7% specificity, and 99.6% negative predictive value. When stratifying by sex and marital status, the positive predictive value was 78.9% for married women and 83.6% for never married women. CONCLUSIONS: The Chinese surname list appears to be valid in identifying Chinese ethnicity. The validity may depend on the geographic origins and Chinese dialects in given populations.

Adolescent↗

PubMed2005

Population rates of cardiac catheterization and yield of high-risk coronary artery disease.

BACKGROUND: The optimal population rate of cardiac catheterization is unknown. One potential way to determine it would be to examine whether there is a population rate beyond which the yield of high-risk coronary artery disease (CAD) does not rise. METHODS: Using a detailed clinical registry that captures all patients undergoing cardiac catheterization in Alberta, we determined annual population rates of cardiac catheterization and the corresponding yield of cases of high-risk CAD in each of Alberta's 17 health regions from 1995 to 2002. Least squares linear regression analysis and hierarchical modelling methods were then used to assess the linear relation between catheterization rates and rates of high-risk CAD. RESULTS: The age-adjusted average rate of cardiac catheterization among men ranged from 404.9 to 638.1 per 100,000 population aged over 20 years. Among women, the average rate ranged from 171.8 to 314.0 per 100,000. For both sexes, increased regional rates of catheterization were associated with a linearly increasing yield of high-risk CAD, with no evidence of a plateau in yield when more procedures were performed. One additional case of high-risk CAD was identified for every 2.5 additional cardiac catheterization procedures performed among men, and for every 3.7 additional procedures performed among women. INTERPRETATION: The increasing yield of patients with high-risk CAD associated with increased regional population rates of cardiac catheterization, together with the absence of a plateau in yield, suggests that Alberta's population rates of cardiac catheterization are suboptimal to detect people with high-risk CAD.

Adult↗

PubMed2005

Economic evaluation of sirolimus-eluting stents.

BACKGROUND: Sirolimus-eluting stents have recently been shown to reduce the risk of restenosis among patients who undergo percutaneous coronary intervention (PCI). Given that sirolimus-eluting stents cost about 4 times as much as conventional stents, and considering the volume of PCI procedures, the decision to use sirolimus-eluting stents has large economic implications. METHODS: We performed an economic evaluation comparing treatment with sirolimus-eluting and conventional stents in patients undergoing PCI and in subgroups based on age and diabetes mellitus status. The probabilities of transition between clinical states and estimates of resource use and health-related quality of life were derived from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) database. Information on effectiveness was based on a meta-analysis of randomized controlled clinical trials (RCTs) comparing sirolimus-eluting and conventional stents. RESULTS: Cost per quality-adjusted life year (QALY) gained in the baseline analysis was Can58,721 dollars. Sirolimus-eluting stents were more cost-effective in patients with diabetes and in those over 75 years of age, the costs per QALY gained being 44,135 dollars and 40,129 dollars, respectively. The results were sensitive to plausible variations in the cost of stents, the estimate of the effectiveness of sirolimus-eluting stents and the assumption that sirolimus-eluting stents would prevent the need for cardiac catheterizations in the subsequent year when no revascularization procedure was performed to treat restenosis. INTERPRETATION: The use of sirolimus-eluting stents is associated with a cost per QALY that is similar to or higher than that of other accepted medical forms of therapy and is associated with a significant incremental cost. Sirolimus-eluting stents are more economically attractive for patients who are at higher risk of restenosis or at a high risk of death if a second revascularization procedure were to be required.

Age Factors↗

PubMed2005

Characteristics and outcomes of patients with acute myocardial infarction and angiographically normal coronary arteries.

This study on patients undergoing coronary angiography for acute myocardial infarction demonstrated that 2.8% of patients had angiographically normal coronary arteries and that these patients have a better prognosis than patients with angiographically verified coronary artery disease. The trend toward a higher prevalence of malignancy in this unique patient group raises the possibility of malignancy-induced hypercoagulability or inflammation as an underlying etiologic factor.

Aged↗

PubMed2005

Association between completeness of percutaneous coronary revascularization and postprocedure outcomes.

BACKGROUND: Multivessel coronary artery revascularization may be accomplished by percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG). The importance of complete revascularization is emphasized in the surgical literature, but little is known about its impact on PCI outcomes. This study evaluated multivessel PCI patients to determine the predictors of complete revascularization and the association of complete revascularization with survival, subsequent CABG, and repeat PCI. METHODS: The Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) is a clinical data collection and outcome-monitoring initiative capturing all patients undergoing cardiac catheterization and revascularization in the province of Alberta, Canada. Characteristics and long-term outcomes of 1308 patients undergoing multivessel PCI with complete revascularization were compared with those of 648 patients with incomplete revascularization. RESULTS: The significant independent predictors of complete revascularization were pre-PCI Duke jeopardy score, the presence of a total occlusion, year of PCI, age > 65 years, renal failure, and left ventricular function. With a median follow-up time of 3.0 +/- 1.8 years, the adjusted hazard ratio (HR) (95% CI) for the association between complete revascularization and outcome was 0.75 (0.54-1.04) for death, 0.55 (0.37-0.84) for subsequent CABG, and 0.93 (0.65-1.34) for repeat PCI. CONCLUSIONS: Baseline angiographic characteristics and other clinical factors can predict complete revascularization in patients undergoing multivessel PCI. Complete multivessel PCI is associated with reduced need for future CABG, a trend toward better survival, and no difference in repeat PCI.

Aged↗

PubMed2005

Absence of bias against smokers in access to coronary revascularization after cardiac catheterization.

OBJECTIVE: Many consider smoking to be a personal choice for which individuals should be held accountable. We assessed whether there is any evidence of bias against smokers in cardiac care decision-making by determining whether smokers were as likely as non-smokers to undergo revascularization procedures after cardiac catheterization. DESIGN: Prospective cohort study. Subjects and setting. All patients undergoing cardiac catheterization in Alberta, Canada. MAIN MEASURE: Patients were categorized as current smokers, former smokers, or never smokers, and then compared for their risk-adjusted likelihood of undergoing revascularization procedures (percutaneous coronary intervention or coronary artery bypass grafting) after cardiac catheterization. RESULTS: Among 20406 patients undergoing catheterization, 25.4% were current smokers at the time of catheterization, 36.6% were former smokers, and 38.0% had never smoked. When compared with never smokers (reference group), the hazard ratio for undergoing any revascularization procedure after catheterization was 0.98 (95% CI 0.93-1.03) for current smokers and 0.98 (0.94-1.03) for former smokers. The hazard ratio for undergoing coronary artery bypass grafting was 1.09 (1.00-1.19) for current smokers and 1.00 (0.93-1.08) for former smokers. For percutaneous coronary intervention, the hazard ratios were 0.93 (0.87-0.99) for current smokers and 1.00 (0.94-1.06) for former smokers. CONCLUSION: Despite potential for discrimination on the basis of smoking status, current and former smokers undergoing cardiac catheterization in Alberta, Canada were as likely to undergo revascularization procedures as catheterization patients who had never smoked.

Alberta↗

PubMed2005

Cross-provincial use of cardiac services: the importance of data-sharing for clinical registries and outcomes research.

BACKGROUND: The structure of the Canadian health care system lends itself to health services and health outcomes research. It is possible to track hospital admissions and discharges, physician billings and prescriptions using administrative databases. In addition, several provinces have developed registries that provide detailed clinical and procedural information. Using the unique personal health numbers assigned to all Canadian residents, linkage between administrative databases and population-based clinical registries provides important information regarding the use of health services and health outcomes. OBJECTIVE: To determine the extent of cross-border (British Columbia-Alberta border) use of cardiac services by British Columbia residents. METHODS: Population rates of cardiac procedures were calculated using two prospective clinical registries (British Columbia Cardiac Registries and Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease [APPROACH]), as well as administrative databases (the British Columbia Ministry of Health's hospitalization and Medical Services Plan databases). RESULTS: Analyses using only British Columbia data suggest low cardiac procedure rates for patients living in eastern British Columbia. By accessing APPROACH data, it was determined that more than 80% of British Columbia cardiac patients living along the British Columbia-Alberta border access procedural services in Alberta. CONCLUSIONS: While residents of eastern British Columbia appear to have reduced access to cardiac services when data from British Columbia are analyzed in isolation, they are actually accessing care in Alberta. Analyses based solely on single province data sources will underestimate cardiac procedures rates.

Adult↗

PubMed2004

Women with coronary artery disease report worse health-related quality of life outcomes compared to men.

BACKGROUND: Although there have been substantial medical advances that improve the outcomes following cardiac ischemic events, gender differences in the treatment and course of recovery for patients with coronary artery disease (CAD) continue to exist. There is a general paucity of data comparing the health related quality of life (HRQOL) in men and women undergoing treatment for CAD. The purpose of this study was to compare HRQOL outcomes of men and women in Alberta, at one-year following initial catheterization, after adjustment for known demographic, co-morbid, and disease severity predictors of outcome. METHOD: The HRQOL outcome data were collected by means of a self-reported questionnaire mailed to patients on or near the one-year anniversary of their initial cardiac catheterization. Using the Seattle Angina Questionnaire (SAQ), 5 dimensions of HRQOL were measured: exertional capacity, anginal stability, anginal frequency, quality of life and treatment satisfaction. Data from the APPROACH registry were used to risk-adjust the SAQ scale scores. Two analytical strategies were used including general least squares linear modeling, and proportional odds modeling sometimes referred to as the "ordinal logistic modeling". RESULTS: 3392 (78.1%) patients responded to the follow-up survey. The adjusted proportional odds ratios for men relative to women (PORs > 1 = better) indicated that men reported significantly better HRQOL on all 5 SAQ dimensions as compared to women. (PORs: Exertional Capacity 3.38 (2.75-4.15), Anginal Stability 1.23 (1.03-1.47), Anginal Frequency 1.70 (1.43-2.01), Treatment Satisfaction 1.27 (1.07-1.50), and QOL 1.74 (1.48-2.04). CONCLUSIONS: Women with CAD consistently reported worse HRQOL at one year follow-up compared to men. These findings underline the fact that conclusions based on research performed on men with CAD may not be valid for women and that more gender-related research is needed. Future studies are needed to further examine gender differences in psychosocial adjustment following treatment for CAD, as adjustment for traditional clinical variables fails to explain sex differences in health related quality of life outcomes.

Aged↗

PubMed2004

Accuracy of city postal code coordinates as a proxy for location of residence.

BACKGROUND: Health studies sometimes rely on postal code location as a proxy for the location of residence. This study compares the postal code location to that of the street address using a database from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACHCopyright ). Cardiac catheterization cases in an urban Canadian City were used for calendar year 1999. We determined location in meters for both the address (using the City of Calgary Street Network File in ArcView 3.2) and postal code location (using Statistic Canada's Postal Code Conversion File). RESULTS: The distance between the two estimates of location for each case were measured and it was found that 87.9% of the postal code locations were within 200 meters of the true address location (straight line distances) and 96.5% were within 500 meters of the address location (straight line distances). CONCLUSIONS: We conclude that postal code locations are a reasonably accurate proxy for address location. However, there may be research questions for which a more accurate description of location is required.

Journal Article↗

PubMed2004

Diagnostic cardiac catheterization and revascularization rates for coronary heart disease.

BACKGROUND: Despite evidence of regional variation across North America, there have been no comprehensive studies of cardiac procedure rates for coronary heart disease in Canada. OBJECTIVES: To use available administrative data and a survey of catheterization facilities to examine regional and demographic variations in cardiovascular procedure rates. METHODS: A survey of all cardiac catheterization facilities in Canada was conducted, and the procedure counts from these facilities were used to determine provincial catheterization rates from 1997/1998 to 2001/2002. Procedure counts for 1997/1998 to 1999/2000 for coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI) were provided by the Canadian Institute for Health Information and used to calculate revascularization procedure rates. Population projections provided by Statistics Canada were used as denominators for calculating the rates, and direct standardization was used to obtain age- and sex-adjusted rates. RESULTS AND CONCLUSIONS: The crude rate of cardiac catheterization in Canada increased from 359.9 to 471.5 per 100,000 population across the five years studied. There was considerable variation in revascularization procedure rates across health regions and provinces. Between 1997/1998 and 1999/2000, there was little increase in the rate of CABGs performed in Canada but a marked increase in the rate of PCIs. For both CABG and PCI, rates were higher for men than women, and highest in the 65- to 74-year-old age category. This study provides a valuable 'snapshot' of cardiac procedure use rates but indicates a clear need for more comprehensive collection of cardiac care data in Canada.

Adult↗

PubMed2004

Sex differences in outcomes after cardiac catheterization: effect modification by treatment strategy and time.

CONTEXT: Studies comparing outcomes of cardiac care in women vs men yield various results, with some suggesting worse outcomes for women and others suggesting equivalent outcomes. OBJECTIVE: To determine whether extent of coronary disease, treatment strategy, and follow-up time influence the risk of death in women vs men among patients who have had cardiac catheterization. DESIGN, SETTING, AND PATIENTS: We studied a large inception cohort by using detailed clinical data from a registry of 37 401 patients undergoing cardiac catheterization in Alberta, Canada, from 1995-2000, with follow-up through December 31, 2001. MAIN OUTCOME MEASURES: The risk of death for women vs men was assessed for all patients combined and then in analyses stratified by degree of coronary anatomic risk and by treatment strategy (no revascularization, percutaneous coronary intervention [PCI], coronary artery bypass graft [CABG] surgery). The latter analysis included a graphic assessment of the changing relative risk over time for women vs men. RESULTS: Women had higher 1-year mortality than men did (5.6% vs 4.6%; P<.001). However, stratified analyses demonstrated that sex differences in risk occurred only early after catheterization and were most apparent among patients undergoing revascularization. The early risk-adjusted relative risks for women vs men were elevated at 3.49 (95% confidence interval [CI], 1.95-6.24) for CABG surgery and 2.38 (95% CI, 1.48-3.83) for PCI on day 1 after catheterization, with a subsequent decrease in relative risk over time to equivalence in risk between sexes before 1 year. CONCLUSIONS: Sex-based differences in death rates after cardiac catheterization are time- and treatment-specific. This finding may at least partially explain the discrepancies in results from earlier studies on sex differences in outcomes of cardiac care.

Aged↗

PubMed2004

Systematic review of statistical methods used to analyze Seattle Angina Questionnaire scores.

BACKGROUND: The Seattle Angina Questionnaire (SAQ) is being used with increasing frequency in clinical research to address the health-related quality of life (HRQOL) outcomes of patients with coronary artery disease. The reliability and validity of the SAQ as a disease-specific HRQOL questionnaire has been established. The purpose of this paper was to systematically identify all studies analyzing SAQ scores, and to review the suitability of the statistical methods used. METHODS: The literature search included all years from the development of the SAQ (1994) to December 2001. Electronic databases were searched using 'Seattle angina questionnaire' as a key word, text word or medical subject heading, as well as combinations of Seattle, angina and questionnaire. The Scientific Citation Index was searched to identify any manuscripts that cited the developmental articles of the SAQ. Relevant manuscripts were identified as studies that used the SAQ as a measurement tool for HRQOL outcome data. RESULTS: Of the 62 studies identified, 14 articles used the SAQ as an outcome measurement tool. The statistical validity of all but one of the 14 studies was doubtful because assumptions required for the use of parametric tests were not addressed and there was no mention of the distributions of the SAQ scores. Based on the designs of the studies, unsuitable analysis methods were used. CONCLUSIONS: Our results demonstrate that investigators may need to increase their attention to the distributional characteristics of their HRQOL data and the design of the study before applying statistical tests to appropriately analyze SAQ HRQOL data.

Angina Pectoris↗

PubMed2004

Geographical location of residence and uniformity of access to cardiac revascularization services after catheterization.

BACKGROUND: The centralization of health care services has numerous potential benefits but April compromise access for individuals living in remote areas. OBJECTIVES: To examine the association between a patient's place of residence and the likelihood of undergoing a coronary revascularization procedure within one year after cardiac catheterization. METHODS: All Alberta residents undergoing cardiac catheterization between 1995 and 1998 were examined. Geographical distance from patient place of residence to a centralized catheterization facility was calculated. The adjusted odds of undergoing cardiac revascularization within one year of catheterization was determined as a function of distance, controlling for differences in patient age, clinical factors and economic status. RESULTS: Of 21816 residents who underwent cardiac catheterization in the province, 10997 had a revascularization procedure. Graphical examination of distance revealed a change in revascularization rates in patients living more than 450 km from revascularization centres. Further analysis was conducted using this cutpoint. Patients living in these remote areas were more likely to undergo a coronary revascularization procedure within the next year (adjusted odds ratio 1.65, 95% CI 1.05 to 2.59). However, these same residents were also less likely to undergo catheterization in the first place when compared with other Albertans (270 versus 398 procedures per 100000 population). CONCLUSION: Only a small proportion of the population living in Alberta's most remote areas were more likely to undergo a revascularization procedure, indicating a remarkable uniformity of access to revascularization after coronary cardiac catheterization has occurred. This study examines the use of an existing database to gain further insights into the relationship between geography and access to cardiac care, and the distance-access relationship for coronary revascularization in Alberta.

Alberta↗