Association of Aortic Vascular Stiffness with Epicardial and Pericardial Adipose Tissues on 64-Multidetector Computed Tomography : In Relation with Coronary Atherosclerosis

Abstract

OBJECTIVES: Increased measured vascular stiffness is an early marker of atherosclerosis and is associated with cardiovascular risk factors. Coronary artery calcium (CAC) and adipose tissues are accurate markers of overall burden of coronary atherosclerosis and metabolic status, respectively. We evaluated the relation of vascular stiffness with epicardial (EAT) and pericardial (PAT) adipose tissues, as well as the presence and severity of CAC. METHODS: One hundred and eleven consecutive subjects, mean age 59±11 years, 78% male, underwent 64-multidetector row cardiac computed tomography (MDCT) and their carotid-radial pulse wave velocity (PWV) was measured using SphygmoCor tonometry. EAT and total thoracic adipose tissue (TAT) volumes were measured using MDCT. PAT was calculated as TAT – EAT. The highest tertile of EAT (≥ 111 ml) and PAT (≥ 103 ml) were defined as significant adipose tissue depots. RESULTS: PWV was moderately associated with EAT (r=0.46, p<.001), and PAT (r=0.41, p<.001). PWV increased proportionally with the severity of CAC from 0-400+. The relative risk of highest vs. lowest tertile of PWV was 3.03 (95% CI 1.22-7.51, p=0.01) for significant EAT, 2.34 (95% CI 1.10-4.90, p=0.02) for significant PAT and 2.46 (95% CI 1.13-3.14, p=0.01) for significant CAC (CAC 100+) after adjustment for conventional cardiovascular risk factors. This relative risk was increased after combination of CAC 100+ with each significant adipose tissue. CONCLUSION: Increased vascular stiffness is associated with increase in EAT, PAT and coronary atherosclerosis. EAT was associated with higher relative risk of PWV, compared with CAC, suggesting a role of adipose tissue in vascular stiffness.

목적: 증가된 대동맥 혈관 경직도는 죽상경화증의 조기 표지자로 심혈관 사건의 위험인자로 알려져 있으며, 관동맥 석회화 (coronary artery calcium, CAC) 및 지방 조직은 각각 관동맥 죽상경화 및 체내 대사성 상태를 반영할 수 있는것으로 알려져 있다. 본 논문에서는 대동맥 혈관 경직도와 심외막 (epicardial adipose tissue, EAT) 및 심장막주변 지방 (pericardial adipose tissue, PAT)과의 연관성을 CAC 정도와 관련하여 알아보고자 하였다. 방법: 흉통을 주소로 내원하여 64채널 다중 검출기 심장 전산화 촬영(multi-detector cardiac computed tomography, MDCT) 및 경동맥-요골동맥 맥파 속도 (pulse wave velocity, PWV)을 측정한 111명 (남성 87명, 평균 연령 59±11세)의 환자를 대상으로 MDCT에서 EAT 및 흉곽내 지방 (thoracic adipose tissue, TAT)을 측정하였고 TAT에서 EAT을 감한 값을 PAT로 정의하였다. 결과: PWV은 EAT (r=0.46, p<.001) 및 PAT (r=0.41, p<.001)와 중등도 연관성을 보였고, CAC이 증가할수록 PWV도 증가하는 양상을 보였다. 일반적 심혈관 위험인자를 보정했을 때, 최고 삼분위의 EAT (≥ 111 ml) 및 PAT (≥ 103 ml), CAC 100+에서 최고 삼분위의 PWV을 보일 상대 위험도는 각각 3.03 (95% 신뢰구간 [CI] 1.22-7.51, p=0.01), 2.34 (95%CI 1.10-4.90, p=0.02), 2.46 (95% CI 1.13-3.14, p=0.01)이었으며, 최고 삼분위의 EAT, PAT에 CAC 100+을 조합하였을 때 그 상대 위험도는 더욱 증가하였다. 결론: 대동맥 혈관 경직도의 증가는 EAT, PAT 및 관동맥 죽상경화와 관련이 있으며, 특히 EAT는 CAC에 비하여 대동맥 혈관 경직도에 대한 높은 상대 위험도를 보였다. 이는 심장 주위로 분포된 지방이 대동맥 혈관 경직도 관련하여 중요한 역할을 담당할 수 있음을 제시한다.