Researchers investigate challenges of treating acute myocardial infarction caused by variant angina

In a new publication from Cardiovascular Innovations and Applications, Wen-Yuan Ding, Jia-Min Li, Fei Zheng, Li-Li Wang, Xin-Yi Wei and Guo-Hua Li from Shandong Provincial Qianfoshan Hospital, Ji'nan, China, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Ji'nan, China and Shandong First Medical University, Tai'an, China consider the challenges of treating acute myocardial infarction due to variant angina.

Coronary spasm plays an important part not only in the pathogenesis of variant angina (VA) but also in ischemic disease generally, including resting and effort angina, acute myocardial infarction (AMI), and sudden death. In approximately one in ten patients with AMI, angiography does not reveal any obstructive coronary artery disease.

VA is characterized by chest pain that is not related to exercise and is frequently accompanied by transient ST segment elevation on ECG.

The patient is symptom-free with normal ECG findings during the symptom-free periods. Although the underlying mechanism is not well understood, it appears to involve a combination of endothelial damage and vasoactive mediators.

In this case study, a 58-year-old man with myocardial infarction secondary to coronary artery vasospasm experienced recurrent chest pain and had a noncritical lesion as revealed by a normal coronary angiogram.

The patient was treated with diltiazem. Diltiazem is a non-dihydropyridine CCB. CCBs seem to be the first-line therapy for VA. Nitrates were also found to be efficient therapy. Clinical trials have revealed that patients who received diltiazem have better outcomes than patients treated with other medical therapy. Diltiazem inhibits mainly L-type calcium channels.

Diltiazem can reduce arterial wall injury caused by calcium overload, inhibit smooth muscle proliferation and arterial matrix protein synthesis, increase vascular compliance, inhibit lipid peroxidation, and protect endothelial cells.

This case provides information about the treatment with diltiazem of patients with AMI secondary to VA. VA can be life-threatening. Since the patient positively responded to the therapy, he was followed up without further intervention and did not have an additional episode of VA during a 3-month period of follow-up.