Treatment with diltiazem for six weeks is not associated with reduced coronary vasomotor dysfunction (CVDys) or improved angina symptoms or quality of life (QOL) among patients with angina and nonobstructive coronary artery disease (ANOCA), according to results of the EDIT-CMD trial presented April 2 at ACC.22 and simultaneously published in JACC: Cardiovascular Imaging.

In a randomized trial, Tijn P.J. Jansen, MD, et al., tested the effects of diltiazem vs. placebo on coronary vasomotor function, angina symptoms and QOL among patients referred for coronary function tests (CFT) at three sites in the Netherlands. All patients met the following inclusion criteria: presence of chronic angina, no signs of obstructive coronary artery disease (CAD) based on coronary angiography, and presence of an abnormal CFT. After undergoing a screening CFT, patients who met criteria were then randomized to receive either 120 mg of diltiazem per day or a placebo. If well-tolerated, diltiazem was titrated every two weeks up to 360 mg per day. The dose was decreased for patients experiencing asymptomatic hypotension (systolic blood pressure <90 mmHG) or symptomatic hypotension. Patients then received a second CFT at six weeks.

The researchers randomly assigned 85 patients to receive diltiazem (41 patients) or the placebo (44 patients). During the study, 11 patients withdrew (2 in the diltiazem group and 9 in the placebo group). A total of 74 patients received the second CFT at six weeks. The primary endpoint – the proportion of patients with successful treatment, defined as normalization of at least one abnormal CVDys parameter, with none of the normal parameters becoming abnormal – was achieved in eight patients in the diltiazem group (21%) vs. 10 patients in the placebo group (29%). Among the diltiazem group, the most positive and negative scenarios did not demonstrate a meaningful higher success rate, compared with the placebo group.

Regarding secondary endpoints – change in individual CFT parameters and QOL symptoms – 47% of patients receiving diltiazem treatment progressed from epicardial spasm to microvascular or no spasm vs. 6% in the placebo group. There were no significant differences between the two groups regarding microvascular dysfunction, Seattle Angina Questionnaire scores or QOL symptoms.

According to the researchers, the study is the first randomized, placebo-controlled trial looking at the effects of diltiazem vs. placebo on CVDys in ANOCA patients via an initial and second CFT. They conclude that diltiazem did not reduce coronary vasospasm and did not improve microvascular dysfunction or QOL. "Larger clinical trials are warranted to further explore the effect of [diltiazem] on the specific endotypes of CVDys, symptoms, QOL, and prognosis," they add.

Clinical Topics: Atherosclerotic Disease (CAD/PAD)

Keywords: ACC Annual Scientific Session, ACC22, Diltiazem, Coronary Circulation, Angina Pectoris, Coronary Artery Disease

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