Excellent discussion! I would add that a negative cath in a patient that often complains of chest pain tends to save unnecessary hospital admissions.  A negative cath tends to convince a patient not to run to the ER with every chest pain episode.  Even if they do end up in an ER with CP, the ER docs tend not to admit a patient if there is a negative recent cath. The same is not as true with negative stress testing, and this is coming from a non-invasive cardiologist. Thanks again for a great discussion.

According publication of Patel MR,

1.I think that one of its big drawback is that we do not know wich are "non-invasive tests", that have been used to predict CAD. We can not depend on ECG, sonogram, X-ray as tests with good sensitivity and specifity to detect CAD. 

2.Usefull non-invasive tests for CAD are stress exercise ECG,  SPECT thallium scan, stress Echo, Dobutamine Echo, PET. They have different sensitivity and specifity but quite close positive and negative predictive value when are interpreted wisely(dobutamine Echo is the best in view of usefullness-price), because:

3. It is very important how the result(negative or positive) of one test is interpreted. Bayes'theorem tell as how much the probability(odds) of disease change after a test result: post-test odds = pre-test odds X likelihood ratio. This relation tells us that you must know pretest probability of disease in order to interpret a test result. One of best clinical predictors for CAD are chest pain history and gender. For example atypical chest pain  has 0,14 probability of CAD in men and 0,05 in women, for Atypical angina 0,66 vs 0,36 and for typical angina 0,93 vs 0,72. 

3. I am sure if we having all this in mind the predictive value of "true" non-invaSIVE TESTS for CAD will be quite better.

Angiogram is grossly overused allover. Violation of guidelines are very common in advising this test. As such Angiogram gives information about only initial few centimeters of Coronary vessels. It can NOT give information about Myocardial Perfusion or residual ischemia after Myocardial infarction. It can NOT diagnose or exclude Micro-vascular disease, which is very common in women and diabetics.

In majority of patients there is No Need to know about the anatomical localization, number and so called percentages of the Blockages. A clinician requires mainly if there is any reduction in the myocardial perfusion or not. This can be diagnosed by various Non-invasive tests like Stress ECG, MPI(by SPECT), Thallium Scan etc. No medical or non-invasive treatment (like EECP) is done on the basis of angiogram report.

Moreover, patients are exposed to so many side effects and complications which are well known to all. In my opinion , idealy , Angiogram should be done to the patients, with confirmation of CAD by non-invasive invesigations and for those who give written consent to go for CABG/PTCA, if required. Those who are NOT willing for these procedures, irrespective of the severity, their Angiogram should NOT be performed at all.

Dr.ANUPAM SHRIVASTAVA,MD CARDIOLOGIST, INDIA. 

You are very right doctor, CT Angio is a Non-invasive test mainly to rule out CAD. But it can NOT predict the severity, extent and risk of existing disease in a patient.CT Angio gives information about the anatomical localization of the blockage which has limited value unless you know about the myocardial perfusion is reduced or not. One has to peroform Thallium scan or MPI test to know the actual severity, even after CT Angio. Negative finding in CT Angio usually means exclusion of CAD but Positive finding does NOT necessarily indicate an active Ischaemic state. Moreover, lifetime long term risk of cancer due to exposure to heavy radiation during CT Angiogram. Anyway, the discussion is on Sir.... - Dr.ANUPAM SHRIVASTAVA,MD CARDIOLOGIST, INDIA     

    I think CT Coronary Angiography should be done where there is very likely hood

of normal epicrdial coronary arteries.It may be  particulrly helpful in ladies.

As they touched on in the interview, the interpretation of this study should not be that there are too many caths, but that the non-invasive studies are inadequate. But that doesn't play as well in the media (either that mainstream or professional).

Plus, Dr. Tierstein's mother's opinion is important. Remember we are treating patients not disease processes. Most patients who I cath who are normal, have either had prior noninvasive studies and are not satisfied for one reason or another, or have clinical syndromes that are most efficiently and safely investigated via angiography.

It is very often the case that the angiogram is the most efficient way to achieve a resolution of the clinical problem at hand--as long as three noninvasive tests are not also performed. 

One traditional test for determining the presence and severity of CAD is myocardial perfusion imaging (MPI), that indirectly assesses arterial blockage. This test is done with a nuclear camera over a period of up to several hours. Another traditional test is the invasive coronary catheterization angiogram. A conventional angiogram is an expensive procedure with a small but definite risk of complications, and that requires either a brief hospitalization or a period of observation for several hours after the procedure. According to Dr. Armin Zadeh, Director of Cardiac CT at Johns Hopkins School of Medicine, "The complication statistically at least of dying with a diagnostic cardiac catheterization is 1 in 1,000. There's still 1 in 500 of having strokes. The vascular complication rate is really quite drastic...."

What is your opinion of MR coronary angiography, especially in those patients in whom ct coronary angio may be too risky ie in those with renal insufficency