Unit of Health Economics, University of Birmingham, Birmingham, UK.
Health Technol Assess. 2013 Aug;17(33):1-86. doi: 10.3310/hta17330.
Calcific aortic stenosis (AS) is a common valvular heart disease. Patients with severe symptomatic AS typically survive less than 3 years. In such patients, intervention with surgical aortic valve replacement (SAVR) may increase survival. However, in some patients SAVR is associated with a high operative risk and medical management is considered appropriate. Transcatheter aortic valve implantation (TAVI) is a relatively recent technique to avoid the invasiveness of open surgery. This procedure has been used for the treatment of patients with severe AS who are unsuitable for SAVR (because it is too high risk and/or for other reasons such as suffering from porcelain aorta) and is increasingly being considered for other patients.
To determine the cost-effectiveness of TAVI being made available for patients who are high risk or contraindicated for SAVR through a review of existing economic evaluations and development of a model.
Bibliographic databases [MEDLINE, EMBASE, The Cochrane Library, Health Technology Assessment (HTA), Database of Abstracts of Reviews of Effects (DARE) and NHS Economic Evaluation Database (EED), Centre for Reviews and Dissemination HTA, DARE and NHS EED], guideline resources, current trials registers, websites/grey literature and manufacturers' websites, and consultation with clinical experts were used to identify studies for the review and information for the model. Databases were searched from 2007 to November 2010. A model was built to assess the cost-effectiveness of TAVI separately in patients suitable and unsuitable for SAVR, together with overall results for the effect of making TAVI available. Substantial deterministic sensitivity analysis was carried out together with probabilistic sensitivity analysis.
No fully published cost-effectiveness studies were found. Modelling patients not suitable for SAVR, the base-case results show TAVI as more costly but more effective than medical management, with an incremental cost-effectiveness ratio (ICER) of £12,900 per quality-adjusted life-year (QALY). The ICER was below £20,000 per QALY for over 99% of model runs in the probabilistic sensitivity analysis. For patients suitable for SAVR, the comparator with TAVI is a mixture of SAVR and medical management. TAVI is both more costly and less effective than this comparator assuming that most patients would receive SAVR in the absence of TAVI. This is robust to a number of assumption changes about the effects of treatment, but sensitive to assumptions about the proportion of patients receiving SAVR in the comparator. If the use of TAVI is extended to include more patients suitable for SAVR, the overall results from the model become less favourable for TAVI.
The modelling involves extrapolation of short-term data and the comparison between TAVI and SAVR is not based on randomised data. More trial data on the latter have been published since the modelling was undertaken.
The results for TAVI compared with medical management in patients unsuitable for surgery are reasonably robust and suggest that TAVI is likely to be cost-effective. For patients suitable for SAVR, TAVI could be both more costly and less effective than SAVR. The overall results suggest that, if a very substantial majority of TAVI patients are those unsuitable for SAVR, the cost-effectiveness of a broad policy of introducing TAVI may fall below £20,000 per QALY. Future work required includes the incorporation of new data made available after completion of this work.
The National Institute for Health Research Health Technology Assessment programme.
心脏主动脉瓣钙化狭窄（AS）是一种常见的瓣膜性心脏病。有严重症状的主动脉瓣狭窄患者通常存活不到 3 年。在这些患者中，手术主动脉瓣置换（SAVR）干预可能会增加生存率。然而，在某些患者中，SAVR 与高手术风险相关，因此考虑进行药物治疗。经导管主动脉瓣植入（TAVI）是一种避免开胸手术的新技术。该技术已用于治疗不适合 SAVR 的严重主动脉瓣狭窄患者（因为手术风险太高，和/或由于其他原因，如患有瓷主动脉），并越来越多地用于其他患者。
通过对现有经济评估进行审查并建立模型，确定为不适合 SAVR 的高危或禁忌患者提供 TAVI 的成本效益。
使用书目数据库（MEDLINE、EMBASE、Cochrane 图书馆、卫生技术评估（HTA）、疗效评价文摘数据库（DARE）和英国国家卫生服务经济评价数据库（NHS EED）、系统评价和荟萃分析资源、当前临床试验登记处、网站/灰色文献和制造商网站，并咨询临床专家，以确定用于审查的研究和模型的信息。数据库搜索时间从 2007 年到 2010 年 11 月。建立了一个模型，以分别评估适合和不适合 SAVR 的患者进行 TAVI 的成本效益，以及提供 TAVI 的效果的总体结果。进行了大量确定性敏感性分析和概率敏感性分析。
未发现完全发表的成本效益研究。对不适合 SAVR 的患者进行模型分析，结果显示 TAVI 的成本更高，但比药物治疗更有效，增量成本效益比（ICER）为每质量调整生命年（QALY）12900 英镑。在概率敏感性分析中，超过 99%的模型运行中，ICER 低于 20000 英镑/QALY。对于适合 SAVR 的患者，与 TAVI 相比的比较对象是 SAVR 和药物治疗的混合体。假设大多数患者在没有 TAVI 的情况下会接受 SAVR，那么 TAVI 的成本更高，效果更差。这对治疗效果的许多假设变化是稳健的，但对比较对象中接受 SAVR 的患者比例的假设敏感。如果将 TAVI 的使用扩展到更多适合 SAVR 的患者，那么模型的总体结果对 TAVI 就变得不利。
建模涉及短期数据的推断，并且 TAVI 与 SAVR 的比较不是基于随机数据。自从建模以来，更多关于后者的临床试验数据已经公布。
与不适合手术的患者相比，TAVI 与药物治疗的结果相当稳健，表明 TAVI 可能具有成本效益。对于适合 SAVR 的患者，TAVI 的成本可能比 SAVR 更高，效果更差。总体结果表明，如果 TAVI 患者的绝大多数是不适合 SAVR 的患者，那么广泛推行 TAVI 的政策的成本效益可能低于每 QALY 20000 英镑。未来需要进行的工作包括纳入完成此项工作后提供的新数据。
英国国家卫生研究院卫生技术评估计划。
