Implication of Spasm Provocation Tests under Medication

To the Editor I congratulate Sueda et al. on their strategy of performing spasm provocation tests under medication in patients with aborted sudden cardiac death due to coronary spasm in order to decide whether to continue medication or perform implantable cardioverter-defibrillator therapy (1). Despite the small size of the case series, their findings will help expand our knowledge concerning how to manage refractory coronary spasm. I would like to highlight several points that I feel will improve the implications of their findings.

Given that patients with aborted sudden cardiac death had a worse prognosis than those without among approximately 2,000 patients with coronary spasm, Ahn et al. recommend implantable cardioverter-defibrillator in these high-risk patients as a secondary prevention (2). The authors' comments on this proposal, which conflicts with their findings, would help bolster their arguments.

Medications were eventually up-titrated in almost all patients following the spasm provocation tests under medication (1). Which medication as an initial regimen do the authors recommend for those with aborted cardiac sudden death due to coronary spasm? Using the optimal initial medication might negate the need for repeated spasm provocation tests.

Finally, I am interested in discovering the implication of sequential spasm provocation tests using both acetylcholine and ergonovine. Were there any patients who experienced repeated coronary spasms despite negative results using acetylcholine alone?

The author states that he has no Conflict of Interest (COI).