Sudden Cardiac Death in the Late-Phase Kawasaki Disease: Fatal Coronary Stenosis Without Aneurysms at Autopsy.

BACKGROUND: Long-term coronary complications of Kawasaki disease (KD) remain a critical concern, even after the apparent regression of coronary artery aneurysms (CAAs). CASE SUMMARY: A 40-year-old male with a history of childhood KD suffered sudden cardiac arrest. Emergency coronary angiography revealed a "lotus root" appearance in the right coronary artery (RCA) and left main trunk (LMT) occlusion. Despite resuscitation efforts, the patient died. Autopsy showed no macroscopic CAAs. Histologically, the RCA demonstrated mature microvessels with distinct elastic laminae, whereas the LMT showed severe intimal thickening and acute thrombus. DISCUSSION: While CAA regression is often considered favorable, persistent, irreversible transmural remodeling can silently progress and lead to fatal ischemic events. TAKE-HOME MESSAGES: Morphological regression of CAAs does not equate to histological healing. Long-term surveillance should evaluate vascular remodeling and myocardial ischemia beyond simple lumen diameter.