Spasm Provocation Tests under Medication May Help Decide on Medical or Mechanical Therapy in Patients with Aborted Sudden Cardiac Death due to Coronary Spasm

OBJECTIVE: The decision to perform medical or mechanical therapy in patients with aborted sudden cardiac death (ASCD) due to coronary spasm is controversial. The Japanese Circulation Society guidelines for the diagnosis and treatment of patients with coronary spastic angina mentioned that implantable cardioverter-defibrillator (ICD) is one option in patients with ASCD due to coronary spasm. We investigated the usefulness of spasm provocation tests under medications in five patients with ASCD due to coronary spasm. METHODS: We performed the spasm provocation tests under medications in five ASCD patients due to coronary spasm. Pharmacological spasm provocation tests, including five acetylcholine (ACh) tests, two ergonovine (ER) tests, and two ACh added after ER tests, were performed to estimate the effect of medications to suppressing the next fatal spasms. RESULTS: ACh tests under medications did not provoke spasm in one patient but did provoke in two patients. In the remaining two patients, neither the ACh test nor the ER test provoked spasm, but the ACh added after ER test induced a focal spasm in one coronary artery. We increased the medication dosage in four patients. An ICD was implanted in two patients, including one with refractory spasm and one with left main trunk spasm. One patient died due to pulseless electrical activity without ventricular fibrillation, while the remaining four patients survived. CONCLUSION: Spasm provocation tests under medication in patients with ASCD due to coronary spasm may be an option when deciding on medical or mechanical therapy.