Differentiation of Acute Total Occlusion of Coronary Artery from Chronic Total Occlusion in Coronary Computed Tomography Angiography

관상동맥 CT 혈관촬영술을 이용한 관상동맥의 급성완전폐쇄와 만성완전폐쇄의 감별

Purpose: To compare the features of coronary computed tomography angiography (CCTA) imaging of the patients with acute total occlusion (ATO) of coronary artery with those of chronic total occlusion (CTO). Materials and Methods: CCTA of 26 patients with complete interruption of the coronary artery in CCTA and occlusion in conventional coronary angiography, were retrospectively analyzed. Discrimination between the ATO group (n = 11, patients with non ST-elevation myocardial infarction or unstable angina) and the CTO group (n = 15, patients with stable angina or nonspecific symptom) was arbitrarily determined by clinical diagnosis. Lesion length, remodeling index (RI), plaque density measured by Hounsfield units (HU), plaque composition, percentage attenuation drop across the lesion, and presence of myocardial thinning were evaluated. Results: Comparisons between the ATO and CTO groups revealed significantly shorter lesion length in the ATO group (0.40 cm vs. 1.87 cm, respectively; p = 0.001), and significantly higher RI (1.56 vs. 1.10, respectively; p = 0.004). Plaque density of the ATO group was lower (37.0 HU vs. 104.7 HU, respectively; p < 0.001) and non-calcified plaque was frequently seen in the ATO group (72.7% vs. 26.7%, respectively; p = 0.02). Percentage attenuation drop across the lesion was lower for the ATO group (10.92% vs. 25.44%, respectively; p = 0.005). Myocardial thinning was exclusively observed in the CTO group (seven of 15 patients, p = 0.01). Conclusion: CCTA shows various statistically significant differences between the ATO and CTO groups.

목적: 관상동맥 급성완전폐쇄와 만성완전폐쇄의 관상동맥 CT 혈관촬영술 영상소견을 비교하고자 하였다. 대상과 방법: 관상동맥 CT 혈관촬영술에서 관상동맥 조영증강이 완전히 중단되고 고식적 관상동맥혈관촬영술에서 관상동맥 완전폐쇄가 있던 26명의 환자를 후향적으로 분석하였다. 급성완전폐쇄군(11명, 비ST절상승 심근경색 또는 불안정협심증 환자)과 만성완전폐쇄군(15명, 안정협심증 또는 비특이적 증상을 보이는 환자)의 구분은 임상진단을 통해 임의로 결정하였다. 병변의 길이, 혈관재형성 지수, 죽상판 음영, 죽상판 유형, 병변 전후 감쇄 정도와 심근 얇아짐 유무에 대하여 분석하였다. 결과: 급성완전폐쇄군에서 병변의 길이가 짧았고(0.40 cm vs. 1.87 cm, p = 0.001) 혈관재형성 지수가 높았다(1.56 vs. 1.10, p = 0.004). 급성완전폐쇄군의 죽상판 음영이 낮았고[37.0 Hounsfield unit (이하 HU) vs. 104.7 HU, p < 0.001] 비석회화 죽상판의 빈도가 높았다(72.7% vs. 26.7%, p = 0.02). 병변 전후 감쇄 정도는 급성완전폐쇄군에서 낮았다(10.92% vs. 25.44%, p = 0.005). 심근 얇아짐은 만성완전폐쇄군에서만 보였다(15명 중 7명, p = 0.01). 결론: 관상동맥의 급성완전폐쇄군과 만성완전폐쇄군 사이에서 통계적으로 유의한 차이를 보이는 다양한 관상동맥 CT 혈관촬영술 영상소견을 보인다.