The most common expression of this myth is the cardiac catheterization report which reads “Conclusion: no significant coronary disease. Plan: cardiac reassurance.” Such reassurance, however, may be false. It is increasingly recognized that patients with angiographically “minimal” coronary disease (usually interpreted as “No significant coronary disease”), or even “normal” coronary arteries, experience coronary events.
In the July 10 issue of Archives of Internal Medicine is a report of pooled data on patients experiencing non-ST segment elevation acute coronary syndromes, 9.1% of which had angiographically “insignificant” or no coronary disease. Long term follow up of such patients revealed a significant rate of recurrent events.
The mechanism of such seemingly discrepant findings is clarified by intravascular ultrasound (IVUS), which has shown that in the initial stages of atherosclerosis the growing plaque presses the adventitia outward rather than the intima inward. Since the lumen is uncompromised the coronary angiogram of such a patient (essentially only a “luminogram”) would appear normal. Nevertheless such a plaque could rupture, producing a coronary event.
A review of advanced coronary imaging, including a nice discussion and images of IVUS, is here.