Last year a report in the New England Journal of Medicine from the National Cardiovascular Data Registry (NCDR) raised concerns about the low diagnostic yield for diagnostic coronary angiography. Now a new analysis of the NCDR registry appearing in the Journal of the American College of Cardiology finds a great deal of variability between hospitals in the diagnostic yield.
Pamela Douglas and colleagues analyzed data from 565,504 patients without known coronary disease who underwent elective angiography at 691 hospitals in the US from 2005 to 2008. The rate of obstructive disease identified upon angiography ranged from 23% to 100% (median 45%; interquartile range: 39% to 52%). Hospitals with a low diagnostic yield performed angiography on patients who were younger, had lower risk, had no or atypical symptoms, or did not have a noninvasive assessment of ischemia. Hospitals with a better diagnostic yield were more likely to prescribe optimal medical therapy, including aspirin, beta-blockers, antiplatelets, and statins. Hospitals that performed fewer procedures had a lower diagnostic yield.
The authors note that the rate of catheterization in western countries ranges from 12 per 10,000 in the Netherlands to 83 per 10,000 in the US. In the UK, with a rate of 26 catheterizations per 10,000, the diagnostic yield is 62%.
The authors acknowledge that their “data cannot indicate what the ideal or ‘optimal’ CAD rate is for elective coronary angiography” but they write that their findings “suggest that improved patient selection could increase the rate of finding CAD” in some hospitals. They conclude that “local clinical practice patterns may be the most influential factor in guiding use of diagnostic coronary angiography and could be a target for quality-improvement efforts, including appropriate use criteria development. “