Division of Cardiac Surgery, Departments of Surgery (D.Y.T., S.E.F.), University of Toronto, ON, Canada.
Schulich Heart Centre, Sunnybrook Health Sciences Centre, and Institute of Health Policy, Management and Evaluation (D.Y.T., H.C.W., D.N., S.E.F.), University of Toronto, ON, Canada.
Circulation. 2020 Jul 28;142(4):354-364. doi: 10.1161/CIRCULATIONAHA.119.044559. Epub 2020 Jun 4.
Recent clinical trial results showed that transcatheter aortic valve replacement (TAVR) is noninferior and may be superior to surgical aortic valve replacement (SAVR) for mortality, stroke, and rehospitalization. However, the impact of transcatheter valve durability remains uncertain.
Discrete event simulation was used to model hypothetical scenarios of TAVR versus SAVR durability in which TAVR failure times were varied to determine the impact of TAVR valve durability on life expectancy in a cohort of low-risk patients similar to those in recent trials. Discrete event simulation modeling was used to estimate the tradeoff between a less invasive procedure with unknown valve durability (TAVR) and that of a more invasive procedure with known durability (SAVR). Standardized differences were calculated, and a difference >0.10 was considered clinically significant. In the base-case analysis, patients with structural valve deterioration requiring reoperation were assumed to undergo a valve-in-valve TAVR procedure. A sensitivity analysis was conducted to determine the impact of TAVR valve durability on life expectancy in younger age groups (40, 50, and 60 years).
Our cohort consisted of patients with aortic stenosis at low surgical risk with a mean age of 73.4±5.9 years. In the base-case scenario, the standardized difference in life expectancy was <0.10 between TAVR and SAVR until transcatheter valve prosthesis failure time was 70% shorter than that of surgical prostheses. At a transcatheter valve failure time <30% compared with surgical valves, SAVR was the preferred option. In younger patients, life expectancy was reduced when TAVR durability was 30%, 40%, and 50% shorter than that of surgical valves in 40-, 50-, and 60-year-old patients, respectively.
According to our simulation models, the durability of TAVR valves must be 70% shorter than that of surgical valves to result in reduced life expectancy in patients with demographics similar to those of recent trials. However, in younger patients, this threshold for TAVR valve durability was substantially higher. These findings suggest that durability concerns should not influence the initial treatment decision concerning TAVR versus SAVR in older low-risk patients on the basis of current evidence supporting TAVR valve durability. However, in younger low-risk patients, valve durability must be weighed against other patient factors such as life expectancy.
最近的临床试验结果表明，经导管主动脉瓣置换术（TAVR）在死亡率、中风和再住院率方面不劣于或优于外科主动脉瓣置换术（SAVR）。然而，经导管瓣膜耐久性的影响仍不确定。
采用离散事件模拟方法对 TAVR 与 SAVR 耐久性进行假设情景建模，其中 TAVR 故障时间发生变化，以确定 TAVR 瓣膜耐久性对类似于最近试验的低危患者队列预期寿命的影响。采用离散事件模拟模型来估计具有未知瓣膜耐久性的微创程序（TAVR）与具有已知耐久性的更具侵袭性的程序（SAVR）之间的权衡取舍。计算了标准化差异，差值>0.10 被认为具有临床意义。在基本分析中，假定结构性瓣膜恶化需要再次手术的患者将接受经导管瓣中瓣 TAVR 手术。进行了敏感性分析，以确定 TAVR 瓣膜耐久性对 40 岁、50 岁和 60 岁年龄组预期寿命的影响。
我们的队列包括低手术风险的主动脉瓣狭窄患者，平均年龄为 73.4±5.9 岁。在基本情况下，TAVR 和 SAVR 之间的预期寿命标准化差异<0.10，直到经导管瓣膜假体失效时间比外科假体短 70%。当经导管瓣膜失效时间比外科瓣膜短 30%时，SAVR 是首选。在年轻患者中，当 TAVR 耐久性比外科瓣膜短 30%、40%和 50%时，40 岁、50 岁和 60 岁患者的预期寿命分别降低。
根据我们的模拟模型，TAVR 瓣膜的耐久性必须比外科瓣膜短 70%，才能导致与最近试验中患者相似的患者预期寿命缩短。然而，在年轻患者中，TAVR 瓣膜耐用性的这一门槛要高得多。这些发现表明，在基于当前支持 TAVR 瓣膜耐久性的证据支持下，在年龄较大的低危患者中，耐久性问题不应影响 TAVR 与 SAVR 的初始治疗决策。然而，在年轻的低危患者中，瓣膜耐久性必须与其他患者因素（如预期寿命）权衡。
