Coronary artery ectasia (CAE) has been defined as localized or diffuse dilatation of
epicardial coronary arteries more than 1.5 fold of adjacent normal segments. Isolated CAE
constitutes minor portion of the total CAE cases, with an incidence of 0.1% to 0.79% in which
coronary artery stenosis or severe valvular heart diseases are not present. CAE represents
not only an anatomical variant but also a clinical constellation of coronary artery disease
(CAD) like association with myocardial ischemia and acute coronary syndromes. Patients with
CAE without significant coronary narrowing may still present with angina pectoris, positive
stress tests, or acute coronary syndromes. Impaired epicardial and microvascular perfusion
were demonstrated in ectatic coronary arteries.
Myocardial blush grading (MBG) technique has been utilized in various conditions such as
acute myocardial infarction, coronary artery ectasia, syndrome X and idiopathic dilated
cardiomyopathy to evaluate myocardial perfusion.
There is still no consensus for management of CAE. Previously improvement of coronary flow
has been demonstrated by mibefradil in patients with slow coronary flow. A new trial is
needed to explore the effect of calcium channel blockers (CCB) in isolated CAE. Diltiazem
improves myocardial perfusion by blocking calcium channels in coronary arteries. This agent
has been widely used in coronary catheter labs to prevent and treat no-reflow.
The current study with prospective design was therefore set up to assess whether epicardial
flow and tissue level perfusion would be improved by diltiazem in myocardial regions
subtended by the ectatic coronary arteries among patients with isolated CAE.