Coronary microvascular spasm causes myocardial ischemia in patients with vasospastic angina.
OBJECTIVE
We aimed to test the hypothesis that coronary microvascular spasm (MVS) alone causes myocardial ischemia in patients with angina attributable to epicardial coronary spasm, and to determine whether there is a difference in clinical characteristics between those with and without microvascular spasm.


BACKGROUND
Patients with "vasospastic angina" have epicardial coronary artery spasm, but it is unknown whether coronary microvessel disease also contributes to the occurrence of angina in these patients.


METHODS
We studied 55 consecutive patients with angina in whom epicardial coronary spasm was provoked by intracoronary acetylcholine (ACH).


RESULTS
In 14 patients (25.5%, Group 1), submaximal dose of ACH induced myocardial ischemia (chest pain, ischemic electrocardiogram changes, lactate production) without large epicardial spasm, suggesting the occurrence of coronary microvascular spasm. By contrast, the remaining 41 patients (Group 2) had evidence of myocardial ischemia only when epicardial spasm was angiographically demonstrated. The Group 1 patients were predominantly women (p < 0.05) and had a history of prolonged (>30 min) chest pain (p < 0.05), whereas the Group 2 patients were more likely men and smokers (p < 0.01).


CONCLUSIONS
Myocardial ischemia most probably due to coronary MVS was demonstrated in a sizable portion of patients with epicardial vasospasm, preferentially in women having both typical and prolonged anginal pain. The result suggests that coronary microvascular disease may also contribute to angina in patients with "vasospastic angina."
Sun
Hongtao
H
Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
Mohri
Masahiro
M
Shimokawa
Hiroaki
H
Usui
Makoto
M
Urakami
Lemmy
L
Takeshita
Akira
A
D000109:Acetylcholine / Q000009:adverse effects; D000368:Aged; D000788:Angina Pectoris, Variant / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology; D003329:Coronary Vasospasm / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000000981:diagnostic imaging / Q000503:physiopathology; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology*; D010496:Pericardium / Q000000981:diagnostic imaging / Q000503:physiopathology; D014665:Vasodilator Agents / Q000009:adverse effects
D014665:Vasodilator Agents; D000109:Acetylcholine