Cardiac diseases are becoming very difficult to manage. Diltiazem is recommended and frequently prescribed in patients with angina and non obstructive coronary artery disease (ANOCA), suspected of coronary vasomotor dysfunction (CVDys). However, studies substantiating its effect is this patient group are lacking.

One of the first performed Randomized Control Trial in patients with ANOCA has reported that six weeks therapy with diltiazem did not substantially improve coronary vasomotor dysfunction, symptoms or quality of life when compared with placebo , but did reduce prevalence of epicardial spasm.

The EDIT CMD trial has been published in JAAC Cardiovascular Imaging.
The randomized, placebo controlled EDIT CMD trial (RCT) , evaluated the effect of diltiazem on CVDys, as assessed by repeated coronary function testing (CFT), angina and quality of life. A total of 126 ANOCA patients were included and underwent CFT. CVDys, defined as the presence of vasospasm (after intracoronary acetylcholine provocation) and/or microvascular dysfunction (CFR <2.0, IMR ≥25), was confirmed in 99 patients, of whom 85 were randomized to receive either oral di ltiazem or placebo up to 360mg/day. After 6 weeks a second CFT was performed. The primary endpoint was the proportion of patients having a successful treatment, defined as normalization of one abnormal parameter of CVDys and no normal parameter becoming ab week follownormal. Secondary endpoints were changes from baseline to 6 up in vasospasm, IMR, CFR, symptoms (SAQ) or quality of life (RAND Results : 36).
The results of the trial were
• In total, 73 patients (38 diltiazem vs. 35 placebo) underwent the second CFT. Improvement of the CFT di d not differ between the groups (diltiazem vs. placebo: 21% vs. 29%, p=0.46).
• However, more patients on diltiazem treatment progressed from epicardial spasm to microvascular or no spasm (47% vs. 6%, p=0.006).
• No significant differences were observed betwee n the diltiazem and placebo group in microvascular dysfunction, SAQ or RAND36.
Researchers concluded that "In this first performed RCT in patients with ANOCA, we show that six weeks therapy with diltiazem did not substantially improve CVDys, symptoms or quality of life w hen compared with placebo , but did reduce prevalence of epicardial spasm."
Reference: https://doi.org/10.1016/j.jcmg.2022.03.012.