Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
J Hypertens. 2011 Nov;29(11):2181-93. doi: 10.1097/HJH.0b013e32834b0eba.
Current ultrasound protocols to measure carotid intima-media thickness (CIMT) in trials differ considerably. The best CIMT protocol would be one that combines high reproducibility, a large and precise estimate of the rate of CIMT progression and a large and precise estimate of the treatment effect. We performed a post-hoc analysis to determine the best algorithm for determining CIMT using data from the METEOR study, a randomized double-blind, placebo-controlled study of the effect of rosuvastatin on CIMT progression in 984 low coronary heart disease risk individuals with increased CIMT.
CIMT information was collected from two walls (near and far wall), three segments (common carotid, bifurcation and internal carotid artery), five different angles (for the right carotid artery - 60, 90, 120, 150, and 180 degrees on the Meijer's carotid arc; for the left - 300, 270, 240, 210, and 180 degrees) of two sides (left and right carotid artery), resulting in possibly (2 × 3 × 5 × 2 =) 60 measurements. On the basis of combinations of these measurements, we built 66 different ultrasound protocols to estimate a CIMT for each individual (22 protocols for mean common CIMT, 44 protocols for mean maximum CIMT). For each protocol we assessed reproducibility [intraclass correlation (ICC), mean difference of duplicate scans], 2-year progression rate in the placebo group with its corresponding standard error and treatment effect (difference in CIMT progression between rosuvastatin and placebo) and its corresponding standard error.
Data of duplicate ultrasound examinations at baseline and end of study were available for 688 participants (70% of 984). The ICC based on duplicate baseline examinations ranged from 0.81 to 0.95. CIMT progression rates in the placebo group ranged from 0.0046 to 0.0177 mm/year, with SE ranging from 0.00134 to 0.00337. Treatment effects ranged from 0.0141 to 0.0388 mm/year. The protocols with highest reproducibility, highest CIMT progression/precision ratio and highest treatment effect/precision ratio were those measuring both near and far wall for at least two angles.
Ultrasound protocols that include CIMT measurements at multiple angles of both near and far wall give the best balance between reproducibility, rate of CIMT progression, treatment effect and their associated precision in this low-risk population with subclinical atherosclerosis.
目前临床试验中测量颈动脉内膜中层厚度（CIMT）的超声方案差异很大。最佳的 CIMT 方案应该具有高度的可重复性、对 CIMT 进展率的精确估计以及对治疗效果的精确估计。我们对 METEOR 研究的数据进行了事后分析，以确定确定 CIMT 的最佳算法，该研究是一项随机、双盲、安慰剂对照研究，旨在评估瑞舒伐他汀对 984 名低冠心病风险、CIMT 增加患者的 CIMT 进展的影响。
使用来自 METEOR 研究的数据，从 2 个壁（近壁和远壁）、3 个节段（颈总动脉、分叉和颈内动脉）、5 个不同角度（右侧颈总动脉-在 Meijer 的颈动脉弧上为 60、90、120、150 和 180 度；左侧-300、270、240、210 和 180 度）对双侧（左、右颈动脉）的 60 个可能的 CIMT 信息进行采集，共获得 60 个可能的测量值。基于这些测量值的组合，我们构建了 66 种不同的超声方案，为每位患者估算 CIMT（22 种方案估算平均颈总 CIMT，44 种方案估算平均最大 CIMT）。对于每种方案，我们评估了重复性[组内相关系数（ICC）、两次扫描的平均差值]、安慰剂组 2 年的进展率及其相应的标准误差、治疗效果（瑞舒伐他汀与安慰剂相比的 CIMT 进展差异）及其相应的标准误差。
在基线和研究结束时进行了两次超声检查的 688 名参与者（984 名患者中的 70%）的数据可用。基于两次基线检查的 ICC 值范围为 0.81 至 0.95。安慰剂组的 CIMT 进展率范围为 0.0046 至 0.0177mm/年，其标准误差范围为 0.00134 至 0.00337。治疗效果范围为 0.0141 至 0.0388mm/年。重复性最高、CIMT 进展/精度比最高、治疗效果/精度比最高的方案是那些至少测量两个角度的近壁和远壁的方案。
在具有亚临床动脉粥样硬化的低危人群中，包含近壁和远壁多个角度的 CIMT 测量的超声方案在可重复性、CIMT 进展率、治疗效果及其相关精度之间具有最佳的平衡。
