Hospital Variability in the Rate of Finding Obstructive Coronary Artery Disease at Elective, Diagnostic Coronary Angiography

Study Questions:

What is the hospital variability in the rate of finding obstructive coronary artery disease (CAD) at elective coronary angiography?

Methods:

The investigators performed a retrospective analysis of 565,504 patients without prior myocardial infarction or revascularization undergoing elective coronary angiography using CathPCI Registry® data from 2005-2008, to evaluate the rate of finding obstructive CAD (any major epicardial vessel stenosis >50%) at coronary angiography at 691 US hospitals. Annual trends were assessed using Spearman’s rank correlations of hospital median annual yield for consecutive years. Spearman’s rank correlations were also used to determine the association between diagnostic yields for different cut-points of CAD.

Results:

The rate of obstructive coronary disease found at elective coronary angiography varied from 23% to 100% among hospitals (median, 45%; interquartile range, 39-52%), and was consistent from year to year and when alternative definitions of coronary stenosis were applied. Sites with lower rates of finding obstructive CAD were more likely to perform procedures on younger patients, those with low Framingham risk (33% in lowest yield quartile vs. 21% in highest yield quartile, p < 0.0001); with no or atypical symptoms (73% vs. 58%, p < 0.0001); and with a negative, equivocal, or unperformed functional status assessment. Hospitals with lower rates of finding obstructive CAD also less frequently prescribed aspirin, beta-blockers, platelet inhibitors, and statins (all p < 0.0001). The CAD rate was lower at facilities with small volume catheterization labs, and was not associated with hospital ownership or teaching program status.

Conclusions:

The authors concluded that the rate of finding obstructive CAD at elective coronary angiography varied considerably among reporting centers, and was associated with patient selection and preprocedure assessment strategies.

Perspective:

This study found marked variation in the institutional rate of finding obstructive CAD among patients undergoing elective diagnostic cardiac catheterization. Centers with a low rate of finding obstructive CAD undertook procedures on patients who were younger, had a lower likelihood of disease, and who were less likely to have had a noninvasive evaluation demonstrating ischemia prior to coronary angiography. Furthermore, modeling suggests that up to one third of elective, diagnostic cardiac angiograms might not be required if low CAD rate centers were able to adopt similar patient selection, treatment, and testing patterns as currently practiced in those institutions with the highest rates of finding CAD. A balanced evidence/guideline-based approach is indicated prior to proceeding with elective invasive coronary angiography. Such a strategy will optimize coronary angiography utilization and avoid unnecessary procedures as well as radiation exposure.

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

Keywords: Coronary Artery Disease, Myocardial Infarction, Platelet Aggregation Inhibitors, Patient Selection, Coronary Angiography, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Cardiac Catheterization


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