In summary, "traditional" cardiologists give as much lip-service to the importance of non-invasive testing as anyone, but deep down a lot of them just wish it would go away. These will always tend to find the negative aspects of non-invasive testing, and make sure you know about them.
The Non-traditional View of Non-invasive Testing
Non-traditional cardiologists (and increasingly, non-cardiologists) point out the following about CAD. First, it is a chronic, progressive disease that tends to be far more diffuse than implied by the presence of discrete "significant" blockages in the arteries. Plaques are often present in coronary arteries that appear "normal" on cardiac cath. Indeed, it has recently been recognized that some patients - especially women- can have extremely widespread CAD that produces a generalized narrowing without anydiscrete blockages. In these patients, the cardiac cath will be misinterpreted as being entirely "normal" (though a "small diameter" might be noted in the coronary arteries). Second, acute myocardial infarctions (heart attacks), which are produced when a plaque ruptures and causes a clot to form that acutely blocks the artery, can - and very often do - occur at the site of plaques that would have been called insignificant (or invisible) by cardiac cath. Third, evidence is building that with intensive medical therapy - largely based on statins, but also including risk factor modification and possibly new drugs that are being developed to increase HDL levels - CAD can be halted or even reversed. CAD, in other words, is properly treated not as an anatomically discrete phenomenon, but as a systemic problem, with aggressive systemic therapy. These cardiologists believe that with such therapy they can ultimately change the "natural history" of patients with CAD.
Therefore, for these doctors the critical question is not so much whether specific blockages exist that require stenting (though indeed that may be an additional consideration), but rather, whether the patient has active CAD. If so, that patient is at greatly increased risk for heart attack and death, and ought to have aggressive, intensive medical therapy for CAD.
For these non-traditionalists, the traditional work-up for CAD entirely misses the point, targeted, as it is, toward discovering discrete blockages. Instead, a method that is more sensitive to finding underlying CAD, whatever the degree of blockage that disease might be producing, would be more relevant. Therefore, these doctors are more likely to recommend widespread screening with CT scanning, either calcium scans (also called "ultrafast" EBCT scans) or multislice CT scans. Both of these methods can detect, with a high degree of accuracy, whether underlying CAD is present.
