Did the widespread use of long-acting calcium antagonists decrease the occurrence of variant angina?

Abstract

BACKGROUND: We have not often encountered variant angina (VA) since the use of long-acting calcium antagonists (L-CAs) became widespread. OBJECTIVES: This study examined the frequency of VA retrospectively. METHODS: and results: We diagnosed angiographically confirmed coronary spastic angina (CSA) in 349 consecutive patients using selective spasm provocation tests from January 1991 to December 2002. During this period, 3,148 diagnostic cardiac catheterizations and 1,515 selective spasm provocation tests were performed. Seventy-four of these 349 patients (21.2%) had VA. Coronary spasms were defined as transient luminal narrowings of > 99%, and VA was defined as an ST elevation during spontaneous attacks or noninvasive stress tests. We classified the 12 years of the study into four periods of 3 years each. No tendency to decrease for the ratio of the number of patients with CSA and the number of selective spasm provocation tests was observed among the four time periods (18%, 24%, 32%, and 23%, respectively). However, the number of patients with VA (28, 33, 9, and 4) and the VA/CSA ratio (32%, 28%, 14%, and 5%, respectively) in the four group significantly decreased. The frequency of administration of calcium antagonists (CAs) before hospital admission (49% vs 33%, respectively; p < 0.05) was significantly higher in the last time period (from 2000 to 2002) than in the first period (from 1991 to 1993). L-CAs were administered in > 90% of CSA patients who had been medicated with CAs before hospital admission in the last period (from 2000 to 2002), while L-CAs were administered in only 20% in the former period (from 1991 to 1993). The administration of statins and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers before hospital admission gradually increased according to the period passed, but not significantly. CONCLUSION: The frequency of VA has decreased in Japan, possibly due to the widespread use of therapy with L-CAs.