Bronchial Asthma and Rest Angina: Is It Safe to Perform Acetylcholine Spasm Provocation Tests in These Patients?

Objective Acetylcholine (ACh) use in patients with bronchial asthma (BA) is contraindicated. We examined the clinical usefulness and safety of ACh spasm provocation tests in rest angina patients with BA. Patients The study subjects were 495 rest angina patients (mean age: 64.4±10.9 years old, male: 81.0%). Organic stenosis was found in 69 patients (13.9%). Methods We investigated 495 rest angina patients who underwent ACh spasm provocation tests. ACh was injected in incremental doses of 20/50/100/200 μg into the left coronary artery and 20/50/80 μg into the right coronary artery. Provoked positive spasm was defined as transient ≥90% luminal narrowing and usual chest pain or ischemic electrocardiogram changes. Results Among 495 rest angina patients, 13 (2.6%) were complicated with BA. Eleven patients with BA were controlled under medications, and two patients had a history of medication for BA. The clinical characteristics were not markedly different between rest angina patients with and without BA. The rate of multi-vessel spasm was markedly higher in patients with BA than that in those without BA. No complications during ACh spasm provocation tests were recognized in rest angina patients with BA, whereas major complications in those without BA were observed in eight patients including two ventricular fibrillations, three non-sustained ventricular tachycardias, and three shocks. We were able to perform all 495 ACh spasm provocation tests without any irreversible complications, while electrical defibrillation was necessary for 2 patients without BA. Conclusion We were able to perform ACh spasm provocation tests in rest angina patients with BA irrespective of the off-label use of ACh.