Peer-review started: August 28, 2022
First decision: November 21, 2022
Revised: December 4, 2022
Accepted: December 21, 2022
Article in press: December 21, 2022
Published online: January 26, 2023
Several reports show that two types of coronary vasospasm (diffuse and focal spasm) are associated with the severity or prognosis of coronary spasm in patients with vasospastic angina (VSA). It is unclear whether intracoronary pressure differs between the two spasm types.
To investigate such relationships using a pressure wire during the spasm provocation test (SPT) in patients with VSA.
Eighty-seven patients with VSA (average age: 67 years; 50 men, 37 women) underwent SPT. During the SPT, a pressure wire was advanced into the distal portion of the right coronary artery and left anterior descending coronary artery, and the ratio of the intracoronary pressure to the aortic pressure (Pd/Pa) was continuously monitored. An SPT was performed using acetylcholine (ACh), and the presence of coronary spasm was defined as the presence of > 90% arterial narrowing in response to an ACh infusion, with the usual chest symptoms and/or ischemic ECG changes. Focal spasm was defined as total or subtotal spasm within one segment of the AHA classification, while diffuse spasm was defined as > 90% spasm with two or more segments.
Among 87 patients, the frequencies of metabolic syndrome and having coronary atherosclerosis were higher in the focal group (n = 33) than in the diffuse spasm group (n = 54, P < 0.05). In the vessel analyses, in these 134 spastic segments, diffuse and focal spasms were detected in 100 and 34 vessels, respectively. The Pd/Pa at baseline was similar in both groups (diffuse: 0.96 ± 0.05, focal: 0.95 ± 0.05, P = 0.35); however, the Pd/Pa during coronary spasm was lower in focal spastic vessels (0.66 ± 0.20) than in diffuse spastic vessels (0.76 ± 0.11, P < 0.01), and the reduction in Pd/Pa during an SPT was also lower in focal spastic vessels (-0.29 ± 0.20) than in diffuse spastic vessels (-0.18 ± 0.11, P < 0.01). The presence of focal spasm was a significant factor responsible for reduction in Pd/Pa during SPT.
These findings suggest that focal spasm may be more severe than diffuse spasm, judging from the intracoronary pressure during coronary spasm.
Core Tip: Coronary spasm is classified into diffuse spasm and focal spasm based on its morphology; it is noted that focal spasm may have a worse prognosis. We compared the clinical backgrounds of patients with focal spasms. We also evaluated the intracoronary pressure in diffuse and focal spasms using a pressure wire. Patients in the focal spasm group were more likely to have metabolic syndrome and coronary atherosclerosis. The reduction in intracoronary pressure during coronary spasms was greater in focal spasms than in diffuse spasms. These findings suggest that the degree of ischemia may be greater in patients with focal spasms.