六十四多切面電腦斷層冠狀動脈血管攝影與發生冠狀動脈疾病之相關性探討

Abstract

背景: 64多切面電腦斷層冠狀動脈血管攝影是近年來快速應用於診斷冠狀動脈疾病的非侵入性檢查，能同時提供冠狀動脈血管管腔和管壁之資訊。與心導管檢查及血管內超音波相比，証實該項檢查對於冠狀動脈之血管狹窄和管壁變化均具診斷價值。然而，64多切面電腦斷層冠狀動脈血管攝影用於評估冠狀動脈疾病的預後價值為何則尚待檢驗。 目的: 經由64多切面電腦斷層冠狀動脈血管攝影觀察到的冠狀動脈之動脈硬化嚴重度與發生冠狀動脈疾病之相關性探討，並和Framingham風險評估相比，以瞭解64多切面電腦斷層冠狀動脈血管攝影用於評估冠狀動脈疾病預後之價值。 材料與方法: 採回溯性世代研究設計，以2006年5月至2007年12月間於臺灣北部單一醫學中心接受64多切面電腦斷層冠狀動脈血管攝影檢查的受檢者共425人為研究樣本，在平圴22個月的追蹤期間內，對研究樣本的電腦斷層檢查冠狀動脈之動脈硬化嚴重度指標，與發生重大心臟事件(包括進一步接受冠狀動脈氣球擴張/支架置放、冠狀動脈繞道手術、不穩定心絞痛且需住院治療、心肌梗塞)或死亡之相關性以Cox proportional hazard regression analysis進行分析。以Receiver operating characteristic (ROC) curves分析和Area under ROC curves比較Framingham風險評估和電腦斷層動脈硬化嚴重度指標，藉以評估電腦斷層動脈硬化嚴重度指標的預測價值。 結果: 電腦斷層動脈硬化嚴重度較高者，發生重大心臟事件或死亡的風險比顯著高於嚴重度低者。控制干擾因子後，Modified Duke CAD Index [3-6分與0分相比]風險比為6.88 (95%信賴區間1.27-37.25)，Segment Stenosis Score [> 5分與0分相比]風險比為6.11(1.08-34.57)，Three-vessel Plaque Score [1分和0分相比]風險比為 5.81 (1.44-23.44)。和無動脈硬化者相比，兩條冠狀動脈疾病[血管狹窄≧50%]風險比為13.76 (2.14-88.51)、阻塞型冠狀動脈疾病[≧70%]風險比為6.08(1.06-34.81)，單一條冠狀動脈疾病[≧70%]風險比為8.01 (1.33-48.23)。有中段血管狹窄[≧50%或≧70%]者，其風險比為9.84 (2.33-41.66)和6.73 (1.87-24.20)。有近或中段血管狹窄[≧50%或≧70%]者，其風險比各為13.40 (2.60-69.06)和8.83 (2.36-33.04)。依性別、年齡、臨床症狀和糖尿病分層，男性族群在Modified Duke CAD Index 3-6分、Three-vessel Plaque Score 1分、兩條冠狀動脈疾病[≧50%]、阻塞型冠狀動脈疾病[≧70%]及單一條冠狀動脈疾病[≧70%]，有症狀族群在Modified Duke CAD Index 3-6分、Segment Stenosis Score > 5分、Three-vessel Plaque Score 1分、兩條冠狀動脈疾病[≧50%]、阻塞型冠狀動脈疾病[≧70%]及單一條冠狀動脈疾病[≧70%]，無糖尿病族群在兩條冠狀動脈疾病[≧50%]的風險比，均顯著高於嚴重度低者。 和Framingham風險評估相比，64多切面電腦斷層冠狀動脈血管攝影提供更為精確的預後評估，電腦斷層冠狀動脈之動脈硬化嚴重度指標的表現均優於Framingham風險，其中以未分組或分組後的Segment Stenosis Score , Presence of obstructive CAD [≧50%或≧70%]和分組後的Modified Duke CAD Index為最佳預測指標，五種指標的敏感度均接近100%，特異度則介於81-89%之間。 結論: 本研究証明64多切面電腦斷層冠狀動脈血管攝影和發生冠狀動脈疾病之間有顯著相關，並証明與Framingham風險評估相比，64多切面電腦斷層冠狀動脈血管攝影對短中期預後評估更為精確。

Background: The diagnostic accuracy of 64-multislice coronary computed tomography angiography (CCTA) regarding obstructive coronary artery disease has been demonstrated in previous studies compared with invasive coronary angiography and intravascular ultrasound. However, the prognostic performance remains to be further examined. Objectives: The study is aimed to assess the association between 64-multislice CCTA and occurrence of major cardiac events or death, and to evaluate the prognostic value of 64-multislice computed tomography coronary angiography compared with the Framingham risk score. Materials and Methods: The study retrospectively enrolled 425 patients who had undergone 64-multislice CCTA at single hospital in Northern Taiwan between May 2006 and December 2007. The severity of coronary atherosclerosis was determined by different CCTA indicators and the occurrence of severe cardiac events (revascularization after 90 days, unstable angina requiring hospitalization, myocardial infarct) or death were observed for mean follow up time of 22 months. The association between severity of coronary atherosclerosis on CCTA and the occurrence of severe cardiac events or death was analyzed using Cox proportional hazard regression model before and after adjustment. The prognostive value of 64-multislice CCTA was evaluated and compared with Framingham risk score using receiver operating characteristic (ROC) curves and area under ROC curves analysis. Results: Increased hazard ratios were observed in cases with more advanced coronary atherosclerosis detected by computed tomography. After adjustment, the hazard ratios were 6.88 (95% confidence interval 1.27-37.25) for modified Duke CAD index 3-6, 6.11 (1.08-34.57) for segment stenosis score > 5, and 5.81 (1.44-23.44) for three-vessel plaque score 1. The hazard ratios were 13.76 (214-88.51) for two-vessel obstructive CAD [≧50% stenosis], 6.08 (1.06-34.81) for obstructive CAD [≧70%], and 8.01 (1.33-48.23) for one-vessel obstructive CAD [≧70%]. Regarding stenosis in proximal and middle segment arteries, the hazard ratios for middle or either proximal or middle segment stenosis [≧50%,≧70%] were 9.84 (2.33-41.66), 13.40 (2.60-69.06), and 6.73 (1.87-24.20) and 8.83 (2.36-33.04), respectively. Further stratification by sex, age, presence of symptoms or diabetes showed significant increase in hazard ratios in the followings: modified Duke CAD index 3-6, three-vessel plaque score 1, two-vessel CAD [≧50%], obstructive CAD [≧70%] and single-vessel CAD [≧70%] in male subgroup; Modified Duke CAD index 3-6, segment stenosis score > 5, three-vessel plaque score 1, two-vessel CAD [≧50%], obstructive CAD [≧70%] and single-vessel CAD [≧70%] in symptomatic subgroup; two-vessel CAD [≧50%] in non-diabetic subgroup. Sixty-four multislice CCTA significantly outperformed the Framingham risk score in predicting severe cardiac events and death. Among the CCTA indicators for severity of coronary atherosclerosis, segment stenosis score [either 0-48 or classified into 0, 1-5 and > 5], presence of obstructive CAD [≧50% or ≧70%] and modified Duke CAD index [classified into 0, 1-2, 3-6] were among the best performing indicators with sensitivity approaching 100% and specificity between 81-89%. Conclusions: The study demonstrated the positive association between severity of coronary atherosclerosis detected by 64-multislice CCTA and occurrence of severe cardiac events or death, and the outperforming prognostic value of 64-multislice CCTA compared with Framingham risk score.