Structural Interventional Cardiology, Department of Clinical and Experimental Medicine, University Hospital Careggi, Florence, Italy.
Intern Emerg Med. 2019 Oct;14(7):1033-1040. doi: 10.1007/s11739-019-02140-1. Epub 2019 Jul 11.
Degenerative mitral regurgitation in elderly patients and functional mitral regurgitation secondary to severe left ventricular dysfunction are not easy options for conventional surgery. Recently, a new percutaneous approach has been proposed with the MitraClip, based on the Alfieri edge-to-edge repair technique. The aim of the study is to report, compare and discuss the results of two multicenter randomized trials: MITRA.FR and COAPT in light of the current practice. In both trials patients with functional mitral regurgitation grade 3/4+ or 4/4+ were randomly assigned, in 1:1 ratio, to undergo percutaneous repair and optimal medical therapy or optimal medical therapy alone. Other baseline characteristics reflecting severity of mitral regurgitation and of left ventricular impairment were statistically different, such as the effective regurgitant orifice area (0.31 cm in MITRA.FR vs 0.41 cm in COAPT) and the indexed LVEDV (135 ± 37 ml/m in MITRA.FR vs 101 ± 34 ml/m in COAPT). A 24 months follow-up and a 12 months follow-up have been completed, respectively, in COAPT and MITRA.FR. Out of the 307 patients enrolled in the MITRA.FR, 152 were randomized to percutaneous treatment but only in 138 (95.8%) the MitraClip was actually implanted. At the end of the follow-up a residual mitral regurgitation of at least grade 3+ has been observed in 17% of the patients. A composite of death from any cause or unplanned hospitalizations for heart failure at 12 months respectively occurred in 83 patients (54.6%) treated percutaneously and 78 patients (51.3%) treated with medical therapy only. A total of 614 patients have been enrolled in the COAPT and 293 underwent transcatheter treatment. A successful implantation of the MitraClip was achieved in 287 patients (98.0%). Hospitalization for heart failure at 24 months occurred in 160 patients in the device group and in 283 in the control group, with an annualized ratio of 35.8% and 67.9%, respectively (p > 0.001). The conflicting results of the two trials may have many explanations, but probably the main cause is the most stringent inclusion criteria in COAPT. The effective reduction of mitral regurgitation and improvement in exercise capacity already observed in registries including more than 70,000 patients was confirmed in a randomized trial with improvement observed in hard end-points. This has already led to an extension of FDA approval to functional regurgitation and a more liberal use across the world.
老年退行性二尖瓣关闭不全和严重左心室功能障碍引起的功能性二尖瓣关闭不全对传统手术来说并非理想选择。最近，一种新的经皮方法已经提出，即使用 MitraClip，基于 Alfieri 边缘对边缘修复技术。本研究旨在根据目前的实践，报告、比较和讨论两项多中心随机试验：MITRA.FR 和 COAPT 的结果。在这两项试验中，功能性二尖瓣关闭不全 3/4+或 4/4+的患者按 1:1 比例随机分配，分别接受经皮修复和最佳药物治疗或单独最佳药物治疗。其他反映二尖瓣关闭不全和左心室损害严重程度的基线特征在统计学上有所不同，例如有效反流口面积（MITRA.FR 为 0.31cm，COAPT 为 0.41cm）和左心室舒张末期容积指数（MITRA.FR 为 135±37ml/m，COAPT 为 101±34ml/m）。COAPT 和 MITRA.FR 分别完成了 24 个月和 12 个月的随访。在 MITRA.FR 中，307 名患者中有 152 名被随机分配进行经皮治疗，但实际上只有 138 名（95.8%）患者植入了 MitraClip。在随访结束时，17%的患者观察到至少有 3+级的残余二尖瓣反流。12 个月时，分别因任何原因死亡或因心力衰竭计划外住院的复合终点在接受经皮治疗的 83 名患者（54.6%）和接受单纯药物治疗的 78 名患者（51.3%）中发生。COAPT 共纳入 614 名患者，其中 293 名接受了经导管治疗。287 名患者（98.0%）成功植入 MitraClip。在设备组中，24 个月时因心力衰竭住院的患者为 160 例，在对照组中为 283 例，年发生率分别为 35.8%和 67.9%（p>0.001）。两项试验的结果相互矛盾，可能有很多解释，但可能的主要原因是 COAPT 的纳入标准最为严格。在包括超过 70000 名患者的登记研究中已经观察到的二尖瓣反流的有效减少和运动能力的改善在随机试验中得到了证实，并且观察到了硬终点的改善。这已经导致 FDA 批准扩展到功能性反流，并在全球范围内更自由地使用。
