,” Tijn P.J. Jansen, MD, PhD candidate in the department of cardiology at Radboud University Medical Center, Nijmegen, the Netherlands, said during a presentation at the American College of Cardiology Scientific Session.
“Guidelines recommend the use of calcium channel blockers in coronary vasomotor dysfunction, and diltiazem is one of the most frequently prescribed medications in these patients. However, these recommendations are based on dated nonrandomized trials. The effect of diltiazem had never been studied in ANOCA patients in a blinded, randomized, placebo-controlled trial.”
All patients had chronic angina occurring at least twice per week and coronary vasomotor dysfunction confirmed by the presence of vasospasm and/or microvascular dysfunction, defined as coronary flow reserve
The primary endpoint was a successful treatment at 6 weeks, defined as normalization of one of the abnormal parameters of coronary vasomotor dysfunction and no normal parameter becoming abnormal.
Among the 73 patients who underwent coronary function testing for a second time, there was no difference between the groups in improvement in coronary function test score, Jansen said, noting there were also no differences in the cohort with coronary artery spasm or in the cohort with coronary microvascular dysfunction.
However, he said, more patients in the diltiazem group than in the placebo group progressed from epicardial spasm to microvascular spasm or no spasm.
The Seattle Angina Questionnaire Summary Score did not differ between the groups, nor did the RAND-36 quality of life score, nor did any metric of microvascular dysfunction, according to the researchers.
“Six weeks’ treatment with diltiazem was not effective in improving coronary vasomotor dysfunction, symptoms or quality of life as compared to placebo,” Jansen said.
“Diltiazem seems to reduce epicardial spasm. However, large trials on the effect of medical therapy on individual endotypes are needed. We believe that this first study using repeated coronary function testing provides a platform for future research.”
The data were published in JACC: Cardiovascular Imaging.
Editorial Board Member C. Noel Bairey Merz, MD, FACC, FAHA, professor of cardiology and director of the Barbra Streisand Women’s Heart Center at the Smidt Heart Institute at Cedars-Sinai, said the study “is a nice example of a pragmatic trial, but we know as treating physicians, not everything works for everyone.
This study is an example of how for every complex problem, there is a simple answer that’s wrong. I think probably the reason that this trial was negative was that it was too heterogenous.”
In contrast, she said, the CorMicA trial showed calcium channel blockers could be effective in this population, but only when physicians could titrate the medication and offer it in conjunction with other therapies if necessary.
Source: Medindia
