Cost-Effectiveness of Coronary Artery Calcium Testing for Coronary Heart and Cardiovascular Disease Risk Prediction to Guide Statin Allocation: The Multi-Ethnic Study of Atherosclerosis (MESA)

BackgroundThe Multi-Ethnic Study of Atherosclerosis (MESA) showed that the addition of coronary artery calcium (CAC) to traditional risk factors improves risk classification, particularly in intermediate risk asymptomatic patients with LDL cholesterol levels ObjectiveTo model the cost-effectiveness of CAC for cardiovascular risk stratification in asymptomatic, intermediate risk patients not taking a statin. Treatment based on CAC was compared to (1) treatment of all intermediate-risk patients, and (2) treatment on the basis of United States guidelines.MethodsWe developed a Markov model of first coronary heart disease (CHD) and cardiovascular disease (CVD) events. We modeled statin treatment in intermediate risk patients with CAC≥1 and CAC≥100, with different intensities of statins based on the CAC score. We compared these CAC-based treatment strategies to a “treat all” strategy and to treatment according to the Adult Treatment Panel III (ATP III) guidelines. Clinical and economic outcomes were modeled over both five- and ten-year time horizons. Outcomes consisted of CHD and CVD events and Quality-Adjusted Life Years (QALYs). Sensitivity analyses considered the effect of higher event rates, different CAC and statin costs, indirect costs, and re-scanning patients with incidentalomas.ResultsWe project that it is both cost-saving and more effective to scan intermediate-risk patients for CAC and to treat those with CAC≥1, compared to treatment based on established risk-assessment guidelines. Treating patients with CAC≥100 is also preferred to existing guidelines when we account for statin side effects and the disutility of statin use.ConclusionCompared to the alternatives we assessed, CAC testing is both effective and cost saving as a risk-stratification tool, particularly if there are adverse effects of long-term statin use. CAC may enable providers to better tailor preventive therapy to patients' risks of CVD.背景 多项族动脉粥样硬化研究（Multi-Ethnic Study of Atherosclerosis, MESA）表明，在传统危险因素基础上加入冠状动脉钙化（coronary artery calcium, CAC）指标可优化风险分层，尤其适用于低密度脂蛋白胆固醇水平处于中等范围的无症状中等风险患者。 研究目的 针对未服用他汀类药物的无症状中等风险患者，构建冠状动脉钙化用于心血管风险分层的成本效益模型。将基于CAC的治疗策略与以下两种方案对比：（1）所有中等风险患者均接受治疗的策略；（2）基于美国临床指南的治疗策略。 方法 本研究构建了首次冠心病（coronary heart disease, CHD）与心血管疾病（cardiovascular disease, CVD）事件的马尔可夫模型。针对CAC≥1及CAC≥100的中等风险患者，基于CAC评分采用不同强度的他汀类药物治疗方案。将该类基于CAC的治疗策略与“全员治疗”策略及依据美国成人治疗组第三次指南（Adult Treatment Panel III, ATP III）制定的治疗方案进行对比。在5年与10年两个时间跨度下模拟临床与经济学结局，结局指标包括冠心病、心血管疾病事件及质量调整生命年（Quality-Adjusted Life Years, QALYs）。敏感性分析考察了更高事件发生率、不同CAC检测与他汀类药物治疗成本、间接成本以及对携带偶发瘤患者进行复查的影响。 结果 相较于基于现有风险评估指南的治疗方案，对中等风险患者进行CAC检测并对CAC≥1的患者实施治疗，既节约成本又更具临床效益。当考虑他汀类药物使用的不良反应与负效用时，对CAC≥100的患者进行治疗同样优于现有指南方案。 结论 相较于本研究评估的其他替代方案，CAC检测作为风险分层工具既有效又节约成本，尤其在长期他汀类药物使用存在不良反应的场景下优势更为显著。CAC检测可帮助临床医师更精准地为患者制定个体化心血管疾病预防治疗方案。