Low Diagnostic Yield of Elective Coronary Angiography

BACKGROUND: Guidelines for triaging patients for cardiac catheterization recommend a risk assessment and noninvasive testing. We determined patterns of noninvasive testing and the diagnostic yield of catheterization among patients with suspected coronary artery disease in a contemporary national sample.

METHODS: From January 2004 through April 2008, at 663 hospitals in the American College of Cardiology National Cardiovascular Data Registry, we identified patients without known coronary artery disease who were undergoing elective catheterization. The patients' demographic characteristics, risk factors, and symptoms and the results of noninvasive testing were correlated with the presence of obstructive coronary artery disease, which was defined as stenosis of 50% or more of the diameter of the left main coronary artery or stenosis of 70% or more of the diameter of a major epicardial vessel.

RESULTS: A total of 398,978 patients were included in the study. The median age was 61 years; 52.7% of the patients were men, 26.0% had diabetes, and 69.6% had hypertension. Noninvasive testing was performed in 83.9% of the patients. At catheterization, 149,739 patients (37.6%) had obstructive coronary artery disease. No coronary artery disease (defined as <20% stenosis in all vessels) was reported in 39.2% of the patients. Independent predictors of obstructive coronary artery disease included male sex (odds ratio, 2.70; 95% confidence interval [CI], 2.64 to 2.76), older age (odds ratio per 5-year increment, 1.29; 95% CI, 1.28 to 1.30), presence of insulin-dependent diabetes (odds ratio, 2.14; 95% CI, 2.07 to 2.21), and presence of dyslipidemia (odds ratio, 1.62; 95% CI, 1.57 to 1.67). Patients with a positive result on a noninvasive test were moderately more likely to have obstructive coronary artery disease than those who did not undergo any testing (41.0% vs. 35.0%; P<0.001; adjusted odds ratio, 1.28; 95% CI, 1.19 to 1.37).

CONCLUSIONS: In this study, slightly more than one third of patients without known disease who underwent elective cardiac catheterization had obstructive coronary artery disease. Better strategies for risk stratification are needed to inform decisions and to increase the diagnostic yield of cardiac catheterization in routine clinical practice. Chris Wormley Womens Jersey

PMID:

Posted in * Journal Club Selections, Computed Tomography, Invasive Imaging and tagged , .

7 Comments

  1. What does a 37.6% obstructive CAD rate among patients referred for elective coronary angiogram tell us? Probably that we have a lot of “false positive” results during risk assessment (clinical + non-invasive). It does not say much about our “false negative” studies, but represent a low yield of our current risk assessment tools.

    We need better and more personalized risk assessment tools, and perhaps coronary CT angiography will have a more important role in risk assessment. Especially in symptomatic patients. Thus reducing our “normal coronary arteries” (or near normal) rate by invasive angiograms.

  2. I agree 100% with Dr. Rubinshtein! To cardiologist cardiac catheterization is the Gold Standard in diagnostics for coronaries (and to some degree they’re right). However, with the advent and continual advancement of the noninvasive CTA; there is a new tool in the cardiologists’ diagnostic kit that can be used for risk stratification.

    Just because a patient has a high Framingham risk score with a family history of CAD, or an equivocal stress test doesn’t mean they NEED a cath. And if they do after the fact, the CTA can be used as a guide map, and decrease the chance of an adverse event.

  3. Catheter angiography IS the gold-standard for coronary assessment. I agree with the comments above, however, I believe that risk-stratification may not be the issue here, rather how the established guidelines are followed.

    With over 80% of low-risk patients going directly to cath, and over 80% of high-risk patients being initially worked up with a non-invasive test, a disconnect with the guidelines is obvious.

  4. a lot of patients whitout CAD. The question is, how do they use the tools for stratification and what mean positive test. Another issue its clinical data and primary diagnosis in this group. So I think the indication for cat lab its so light…

  5. 45 years ago I published the first prospective correlative study to explore the relationship between clinical presentation of suspected ischemic heart disease and evidence of arterial obstruction on coronary arteriography. A positive relation was present but was by no means absolute. In this well controlled material of 192 patients, performed before the days of CABG and angioplasty some of the most interesting findings were that 8% with typical effort angina had completely normal vessels. On the other end of the spectrum 50% of those who had at least one complete arterial occlusion no evidence of previous infarction or acute myocardial ischemia could be demonstrated. The here quoted study by Patel “Low Diagnostic Yield of Elective Coronary Angiography” has come to similar results using an almost 400,000 patient material and should not surprise anybody. Although I sympathize greatly with the study’s main purpose to reduce excessive use of invasive angiography (please do not call it cardiac catheterization which is something completely different) I must bring forward critique. The use of an arbitrarily chosen border between negative and positive result merely based % calibre reduction, appears absurd, particularly in light of the known shortcomings of measurement on angiographic images. Furthermore in this huge material the subjectively made assessment was made by an undisclosed large number of anonymous observers of most likely varying degree of expertise. The term “elective” as used here for the paper’s title must also be questioned. When the authors point out that not less than 30% of the patients had no evidence of chest pain, including typical angina or other non invasive findings that suggested ischemic heart disease, one may surmise other motives than merely medical. Then why don’t we call” a spade a spade” and speak of medical malpractice in these cases?

  6. Just published:

    The impact of cardiac CT on the appropriate utilization of catheter coronary angiography.
    Wagdi P, Alkadhi H.
    Int J Cardiovasc Imaging. 2010 Mar;26(3):333-44.
    PMID:

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