Real-World Positivity, Procedural Events, and Management Changes After Intravenous Methylergometrine Provocation Testing for Coronary Vasospasm: A Single-Center Study of 139 Patients

Background: Intracoronary acetylcholine is the reference agent for coronary spasm provocation, but intravenous ergot derivatives remain in use in several European centres, with limited contemporary data on their positivity rate in current clinical practice.Aims: To assess the operator-defined positivity rate, procedural events, and associated changes in medical management following intravenous methylergometrine provocation.Methods: All coronary angiograms performed at a single centre between January 2025 and July 2026 were screened through a mandatory regional registry.Provocation consisted of a single 0.20-mg intravenous bolus of methylergometrine, with vasodilator therapy withdrawn 72 hours beforehand.The primary analysis was restricted to the first test performed in each patient.Medical treatment before and after provocation was compared using exact tests for paired data.Results: Among 2168 coronary angiograms screened, 152 provocation tests were performed in 139 patients.Among the 139 first tests, 28 were considered positive by the operator (20.1%; 95% confidence interval, 13.8-27.8%),while 14 fulfilled all three international diagnostic criteria.Current smoking was the only characteristic nominally associated with positivity (64.3% vs. 36.9%),although this association did not remain significant after correction for multiple comparisons.Transient events occurred during seven positive tests, including three self-terminating episodes of non-sustained ventricular tachycardia; none required cardioversion or vasopressor support.Vasodilator therapy was initiated or intensified after all 28 positive tests compared with 7 of 111 negative tests (6.3%).An alternative diagnosis was retained after 75 of 111 negative tests (67.6%).Conclusions: Intravenous methylergometrine provocation was associated with operator-defined positivity in approximately one fifth of patients undergoing a first test and was consistently followed by the initiation or intensification of vasodilator therapy.Transient events occurred during a quarter of positive tests, and all resolved without cardioversion or vasopressor support; because procedure reports were retrievable for only a subset of negative tests, no cohort-wide safety estimate can be derived.