Prevalence and Extent of Obstructive Coronary Artery Disease Among Patients Undergoing Elective Coronary Catheterization in New York State and Ontario

Study Questions:

What is the extent of obstructive coronary artery disease (CAD) in patients undergoing cardiac catheterization in New York versus Ontario?


The authors compared the presence of obstructive CAD in patients without a history of cardiac disease who underwent elective cardiac catheterization between October 1, 2008, and September 30, 2011, in New York versus Ontario. Obstructive CAD was defined as diameter stenosis of 50% or more in the left main coronary artery, or stenosis of 70% or more in a major epicardial vessel.


The study population was comprised of 18,114 patients from New York and 54,933 from Ontario. This represented 29.3% and 34.2% of the total cohort of patients undergoing angiography in the two states, respectively. The observed rate of obstructive CAD was significantly lower in New York compared with Ontario (30.4% vs. 44.8%). In New York, a higher percentage of patients with low predicted probability of obstructive CAD underwent cardiac catheterization. The percentage of patients with left main or three-vessel CAD was also significantly lower in New York than in Ontario (7.0% vs. 13.0%, p < 0.001). At 30 days, crude mortality for patients undergoing cardiac catheterization was slightly higher in New York than in Ontario (0.65% vs. 0.38%, p < 0.001).


The authors concluded that patients undergoing elective cardiac catheterization in Ontario were significantly more likely to have obstructive CAD compared with those undergoing coronary angiography in New York.


This intriguing study assessing the presence of coronary angiography in New York compared with Ontario is an indirect reflection on resource utilization in the United States versus the Canadian health care system. In this study, a significant proportion of patients underwent angiography in the absence of angina (58% in New York vs. 29% in Ontario). This either reflects poor documentation or overuse of angiography in asymptomatic patients (or some combination of both). This study should result in a closer assessment of use of elective angiography, especially in the asymptomatic patients.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Atherosclerotic Disease (CAD/PAD), Interventions and Coronary Artery Disease, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Heart Diseases, Coronary Artery Disease, Surgical Procedures, Elective, Coronary Angiography, Cardiac Catheterization, Canada, Ontario, Coronary Vessels, New York, Angioplasty, Balloon, Coronary, United States

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