Association Between the Severity of Coronary Artery Stenosis and the Minimum Responsive Dose of Intracoronary Provocation Test

초록

Background Coronary artery spasm (CAS) is typically diagnosed by intracoronary provocation test. Intracoronary provocation test is performed by either acetylcholine (ACH) or ergonovine (ERG). Investigations regarding association between the severity of coronary artery stenosis and the minimum responsive dose of ACH or ERG required for provocation is limited. Methods A total of 4,271 patients underwent ACH or ERG provocation test. Patients were divided into 3 groups based on the minimum responsive dose: Dose 1 group (ACH 20 μg or ERG 20 μg, n = 240), Dose 2 group (ACH 50 μg or ERG 40 μg, n = 1,419) and Dose 3 group (ACH 100 μg or ERG 80 μg, n = 2,612). Results In patients with positive intracoronary provocation test, 5.6% responded at the lowest dose, 33.2% responded at the medium doses, and 61.2% responded only at the highest dose of ACH or ERG. The baseline characteristics of the patients were similar, demonstrating no significant difference in the prevalence of HTN, DM, and dyslipidemia. However, patients who responded at the lower dose showed a higher proportion of smoking history (Dose 1 35.8% vs Dose 2 35.6% vs Dose 3 30.4%; P = 0.002). The Dose 1 group demonstrated the highest proportion of severe stenosis (64.6%), followed by Dose 2 group (61.2%) and Dose 3 group (49.8%) (Figure 1). In addition, incidence of multivessel CAS were higher among those who responded to lower doses (36.7% vs 39.7% vs 32.5%). Conclusion In patients with chest pain with positive intracoronary provocation test, severe stenotic lesions were found to be more frequent and susceptible in patients who responded at lower doses of ACH or ERG.