Bicuspid Valve Aortopathy: Feasibility of a Comparative Effectiveness Study

描述（由申请人提供）：多达300万的美国人已经或将要在二尖瓣主动脉瓣设置中扩大胸主动脉，即使在瓣膜功能正常的情况下。进行性扩张和主动脉夹层可能导致灾难性的后果。有时采用药物治疗来减轻进行性增大，但从未在临床试验中进行过测试。最佳的药理学候选药物是β受体阻滞剂或血管紧张素受体阻滞剂，主要基于其他影响主动脉的血管状况的新经验。需要研究来确定这两种策略是否优于不治疗。理想的研究是一项随机临床试验，测试各种治疗方案的实际有效性，尽管这样的试验需要充分的试点数据来进行适当的计划。我们假设可以证明其中一种方法的优越性。为了获得未来试验所需的试点数据和经验，我们提出了这个可行性方案，具体目标是：1)量化在参与医疗中心和周边诊所就诊的所有双尖瓣患者中符合未来试验条件的患者的患病率；2)确定处方习惯和患者对当前采用的各种治疗策略的依从性；3)量化目标人群主动脉面积随时间变化的方差。这项有限的为期三年的可行性研究将收集所有二尖瓣主动脉瓣患者的信息，从中对符合条件的患者进行前瞻性随访，包括60名患者在22-24个月内接受连续MRI检查以测量主动脉面积的变化。

DESCRIPTION (provided by applicant): As many as 3 million Americans have or will have an enlarged thoracic aorta in the setting of a bicuspid aortic valve, even when valve function is normal. Progressive dilatation and aortic dissection may result with catastrophic consequences. Medical therapy is sometimes adopted to attenuate the progressive enlargement, but has never been tested in clinical trials. The best pharmacologic candidates are beta blockers or angiotensin receptor blockers, mainly based on emerging experience in other vascular conditions affecting the aorta. Research is needed to determine whether either strategy is superior to no treatment. The ideal study would be a randomized clinical trial testing the pragmatic effectiveness of the various treatment options, although such a trial requires adequate pilot data for proper planning. We hypothesize that superiority of one approach can be demonstrated. In order to obtain the necessary pilot data and experience for a future trial, we propose this feasibility protocol with the specific aim to: 1) quantify the prevalence of eligible patients for a future trial from all bicuspid valve patients seen at participating medical centers and surrounding clinics, 2) determine prescribing habits and patient compliance with various treatment strategies currently employed, and 3) quantify variance of change in aortic area over time for the target population. This limited three year feasibility study will gather information o all patients with a bicuspid aortic valve, from which eligible patients will be followed prospectively, including 60 patients undergoing serial MRI over 22-24 months to measure change in aortic area.