Publications (49) View all
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Article: Recent Temporal Trends and Geographic Distribution of Cardiac Procedures in Alberta.
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ABSTRACT: BACKGROUND: Prior Canadian studies of cardiac procedure rates showed changes over time and regional variability, but more recent Canadian cardiac procedure rates are unknown. METHODS: We performed a study using the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease registry to evaluate the temporal trends and geographic distribution of cardiac procedures in Alberta from April 1, 2003 through March 31, 2010. Rates were age- and sex-standardized by means of the 1996 Canadian census. RESULTS: While the raw number of cardiac catheterizations in Alberta was nearly uniform through the study period, age- and sex-standardized cardiac catheterizations declined from a rate of 480 per 100,000 in 2003 to a rate of 430 per 100,000 in 2010. The percutaneous coronary intervention (PCI) rates also declined, from a rate of 186 per 100,000 in 2003 to 170 per 100,000 in 2010. The rates for coronary artery bypass grafts declined from 84 per 100,000 in 2003 to 42 per 100,000 in 2010. There was geographic variability, with northern regions characterized by rates that were higher than the provincial average rates, and southern regions characterized by rates lower than the provincial average. CONCLUSION: During the study period, age- and sex-standardized rates of cardiac catheterization and PCI in Alberta declined, reversing previous trends of increasing PCI rates. The rates of coronary artery bypass grafts in Alberta declined significantly, suggesting a change in practice consistent with that seen elsewhere. There are geographic differences in rates of cardiac procedures. These data have implications for other regions of Canada, for which registry data may not be available.The Canadian journal of cardiology 08/2012; · 3.36 Impact Factor -
Article: Cardiac rehabilitation attendance and outcomes in coronary artery disease patients.
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ABSTRACT: Cardiac rehabilitation (CR) is an efficacious yet underused treatment for patients with coronary artery disease. The objective of this study was to determine the association between CR completion and mortality and resource use. We conducted a prospective cohort study of 5886 subjects (20.8% female; mean age, 60.6 years) who had undergone angiography and were referred for CR in Calgary, AB, Canada, between 1996 and 2009. Outcomes of interest included freedom from emergency room visits, hospitalization, and survival in CR completers versus noncompleters, adjusted for clinical covariates, treatment strategy, and coronary anatomy. Hazard ratios for events for CR completers versus noncompleters were also constructed. A propensity model was used to match completers to noncompleters on baseline characteristics, and each outcome was compared between propensity-matched groups. Of the subjects referred for CR, 2900 (49.3%) completed the program, and an additional 554 subjects started but did not complete CR. CR completion was associated with a lower risk of death, with an adjusted hazard ratio of 0.59 (95% confidence interval, 0.49-0.70). CR completion was also associated with a decreased risk of all-cause hospitalization (adjusted hazard ratio, 0.77; 95% confidence interval, 0.71-0.84) and cardiac hospitalization (adjusted hazard ratio, 0.68; 95% confidence interval, 0.55-0.83) but not with emergency room visits. Propensity-matched analysis demonstrated a persistent association between CR completion and reduced mortality. Among those coronary artery disease patients referred, CR completion is associated with improved survival and decreased hospitalization. There is a need to explore reasons for nonattendance and to test interventions to improve attendance after referral.Circulation 07/2012; 126(6):677-87. · 14.74 Impact Factor -
Article: Outcomes associated with bilateral internal thoracic artery grafting: the importance of age.
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ABSTRACT: Although bilateral internal thoracic artery (BITA) grafting in coronary artery bypass grafting (CABG) is associated with low morbidity and good long-term results, controversy exists about the age after which BITA grafting is no longer beneficial. We sought to determine if such an age cutoff point exists. The study cohort consisted of 5,601 consecutive patients from a cardiac surgery registry who underwent isolated CABG (1,038 [19%] BITA grafts, 4,029 [72%] single internal thoracic artery [SITA] grafts, 534 [10%] vein-only grafts) between 1995 and 2008. A Cox model was used to compare survival by use of bilateral, single, or no internal thoracic artery (ITA) grafts, adjusting for baseline clinical and demographic characteristics. Mean follow-up was 7.1 years. Patients undergoing BITA grafting had the lowest 1-year mortality (2.4% versus 4.3% SITA grafting and 8.2% vein-only grafting; p < 0.0001). Relative to SITA grafting, a crude survival benefit of 54% existed for BITA grafting (hazard ratio [HR] 0.46; 95% confidence interval [CI], 0.37 to 0.57; p < 0.0001) with worse survival for vein-only grafts (HR, 1.16; 95% CI, 0.99 to 1.37; p = 0.07). After adjustment, the benefit of BITA grafting was no longer statistically significant (HR, 0.87; 95% CI, 0.69 to 1.08; p = 0.2). However age may be an effect modifier: a spline analysis plotting HR (BITA grafting versus SITA grafting) against age suggested a potential survival advantage associated with BITA grafting in patients younger than 69.9 years. Bilateral internal thoracic artery grafting is a reasonable revascularization strategy in suitable patients up to age 70 years. As benefits of arterial grafting become more obvious over time, a longer period of follow-up will be needed to confirm the advantage of a BITA grafting strategy. In the meantime the BITA grafting advantage for patients older than 70 years is not clear.The Annals of thoracic surgery 10/2011; 92(4):1269-75; discussion 1275-6. · 3.74 Impact Factor -
Article: The clinical profile and outcomes associated with coronary collaterals in patients with coronary artery disease.
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ABSTRACT: The clinical correlates of coronary collaterals and the effects of coronary collaterals on prognosis are incompletely understood. We performed a study of 55,751 patients undergoing coronary angiography to evaluate the correlates of angiographically apparent coronary collaterals, and to evaluate their association with survival. The characteristic most strongly associated with the presence of collaterals was a coronary occlusion (odds ratio [OR], 28.9; 95% confidence interval [CI], 27.1-30.6). Collaterals were associated with improved adjusted survival overall (hazard ratio [HR] 0.89; 95% CI, 0.85-0.95), and in both acute coronary syndrome (ACS) (HR 0.90; 95% CI, 0.84-0.96) and non-ACS (HR 0.84; 95% CI, 0.77-0.92) patients. Collaterals were associated with improved survival in those receiving angioplasty (HR 0.78; 95% CI, 0.71-0.85) and those with low risk anatomy treated medically (HR 0.84; 95% CI, 0.72-0.98), but not for those treated with coronary bypass graft surgery or those with high-risk anatomy treated without revascularization. The major correlate of coronary collaterals is the presence/extent of obstructive coronary artery disease. Collaterals are associated with better survival overall and in both ACS and non-ACS presentations, but not for those treated with coronary artery bypass graft (CABG) or those with high-risk anatomy who are not revascularized.The Canadian journal of cardiology 07/2011; 27(5):581-8. · 3.36 Impact Factor -
Article: Diagnostic accuracy and impact of computed tomographic coronary angiography on utilization of invasive coronary angiography.
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ABSTRACT: Computed tomographic coronary angiography (CTA), given its high negative predictive value, is a potential gatekeeper for invasive coronary angiography (ICA). Before CTA can be further accepted into clinical practice, its impact on healthcare resources needs to be better understood. We sought to determine the clinical impact of CTA on ICA referrals, CTA accuracy, and normalcy rate. To determine the impact of CTA, consecutive patients (n=7017) undergoing ICA before and after implementing a dedicated cardiac CT program were reviewed and compared with 3 other centers (n=11 508). To determine CTA accuracy, we evaluated consecutive CTA patients who underwent ICA. For normalcy rate, we identified patients with a low pretest probability for obstructive coronary artery disease. With the implementation of a cardiac CT program, the frequency of normal ICA decreased from 31.5% (1114 of 3538 patients) to 26.8% (932 of 3479 patients) (P<0.001). These findings were significantly different (P=0.003) from the 3 centers, in which normal ICAs were unchanged (30.0% [1870 of 6224 patients] to 31.0% [1642 of 5284 patients]). CTA had excellent per-patient sensitivity (99% [CI, 95% to 100%]), positive predictive value (92% [CI, 86% to 96%]) and negative predictive value (95% [CI, 72% to 100%]). Because of referral bias, specificity (64% [CI, 44% to 81%]) was low; however, the normalcy rate of CTA was 94% (CI, 90% to 97%). After adjusting for referral bias, the adjusted sensitivity was 90% (CI, 89% to 91%), and the adjusted specificity was 95% (CI, 94% to 96%), with positive and negative predictive values of 92% (CI, 91% to 93%) and 93% (CI, 92% to 94%), respectively. The clinical implementation of CTA appears to positively impact ICA by reducing the frequency of normal ICA. The operating characteristics of CTA support its potential role as a tool useful in ruling out obstructive coronary artery disease.Circulation Cardiovascular Imaging 01/2009; 2(1):16-23. · 5.94 Impact Factor
