23 - EFFICACY OF ANGIOTENSIN II RECEPTOR BLOCKER/ANGIOTENSIN CONVERTING ENZYME FOR CORONARY ARTERY ANEURYSM REGRESSION IN JAPANESE PATIENT WITH KAWASAKI DISEASE

BACKGROUND/

Aim: Coronary artery aneurysm (CAA) is the most serious complication of KD and can lead to life-threatening cardiac events. However, no therapeutic agent has been shown to improve the prognosis of patients with CAA. A previous study reported that angiotensin II receptor blocker (ARB) significantly suppressed mouse coronary arteritis induced by injection of Lactobacillus casei cell wall extract. The objective of this study is to investigate whether ARB or angiotensin converting enzyme inhibitor (ACEi) can regress CAA in patients with KD.

Methods: This is a multicenter, prospective, observational study conducted 53 institutions throughout Japan. Patients who were diagnosed with KD after January 2015 and had medium-size or large CAA (maximal luminal diameter ≥ 4 mm or z-score ≥ +5) at 30 days and later after KD onset were enrolled. CAA regression was defined as achieving a coronary artery diameter below the standard set by the Japanese Ministry of Health, Labor, and Welfare, which is less than 3 mm for children under 4 years of age and less than 4 mm for those 5 years of age or older.

Results: The study included 209 patients, of whom 47 (22%) received ARB/ACEi treatment. The median age at KD onset was 1.2 years in the ARB/ACEi group and 2.5 years in the untreated group (p = 0.01). Compared to the group not treated with ARB/ACEi, the group treated with ARB/ACEi showed a higher frequency of bilateral CAA (70% vs. 59%, p = 0.01) and giant CAA (32% vs. 20%, p = 0.08). Although the overall regression rates did not differ between the two groups (67% vs. 65%), the regression rates from giant CAA in the ARB/ACEi group were approximately 1.7 times higher than those in the non-ARB/ACEi group (40% vs. 23%, p = 0.31). No progression of CAA was observed in the ARB/ACEi patient group. However, 12% of the non-ARB/ACEi group exhibited further expansion of CAA during the study period (p = 0.03). After adjusting for other clinical variables, multivariable COX regression analysis suggested that ARB/ACEi may be a factor in CAA regression (HR: 1.5, 95% C.I: 0.91-2.46, p = 0.11).

Conclusion: Although ARB/ACEi were used more frequently in patients with severe CAA, they showed similar CAA regression effects to patients without ARB/ACEi. In particular, these drugs tended to be more effective against giant CAA. ARB/ACEi may be a beneficial agent for KD aimed at inducing CAA regression.