CAD detection by angiography ‘varies considerably’ across hospitals
MedWire News: The detection rate of obstructive coronary artery disease (CAD) at elective coronary angiography varies widely among hospitals, report US researchers.
Variation was associated with patient selection and pre-procedure assessment strategies, write Pamela Douglas (Duke University, Durham, North Carolina) and co-authors in the Journal of the American College of Cardiology.
"This institutional variation suggests that an important opportunity may exist for quality improvement," they say.
The analysis of 691 US hospitals included 565,504 patients without prior myocardial infarction or revascularization who underwent elective coronary angiography between 2005 and 2008.
The findings revealed that the rate of obstructive CAD, defined as any major epicardial vessel stenosis of 50% or more, ranged from 23% to 100% among hospitals. The rates were consistent from year to year, and remained unchanged when alternative definitions of coronary stenosis were applied.
The median detection rate was 45%, suggesting that the majority of patients selected for elective catheterization did not have obstructive CAD, report the authors.
When hospitals were grouped into quartiles by CAD detection rate, those with lower rates were more likely than hospitals with higher rates to perform angiography on patients aged younger than 60 years, those with low Framingham risk scores, patients with no or atypical clinical symptoms, and those with a negative, equivocal, or unperformed functional status assessment.
Patients who were treated at hospitals with low detection rates were also less likely to have been prescribed cardiac medications before angiography, including aspirin, beta blockers, platelet inhibitors, and statins (all p<0.0001).
Conversely, hospitals that had high rates of finding obstructive CAD were more likely to perform procedures on patients who had risk factors such as hypertension, diabetes, and dyslipidemia.
According to the authors, local clinical practice patterns are the most influential factor in guiding the use of diagnostic coronary angiography.
"A balanced consideration of all the relevant steps inherent in a decision to proceed to elective invasive coronary angiography, as well as the findings of CAD at catheterization, is needed to optimize coronary angiography utilization," they conclude.
By Piriya Mahendra