The Heart Hospital, Clinical Research Department, Baylor Scott & White Research Institute, Plano, Texas; Department of Advance Biomedical Sciences, University Federico II, Naples, Italy.
New York Presbyterian Hospital, New York-Presbyterian/Columbia University Medical Center, New York, New York.
Am J Cardiol. 2020 Oct 1;132:106-113. doi: 10.1016/j.amjcard.2020.07.018. Epub 2020 Jul 13.
Leaflet thrombosis (LT) has been claimed as a potential cause of hemodynamic dysfunction or bioprosthetic valve degeneration of transcatheter heart valves. Sparse and contrasting evidence exists, however, regarding LT occurrence, prevention and treatment. MEDLINE, ISI Web of Science and SCOPUS databases were searched for studies published up to January 2020. Only studies reporting data on incidence and outcomes associated to the presence/absence of clinical or subclinical LT, detected or confirmed with a multidetector computed tomography exam were included. The study was designed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) requirements. Two reviewers independently screened articles for fulfillment of inclusion criteria. Data were pooled using a random-effect model. The primary end point was the incidence of LT. Secondary outcomes included: stroke and transient ischemic attacks and mean transvalvular gradients at different time-points in patients with and without LT. Of the initial 200 studies, 22 were finally included with a total of 11,567 patients. LT overall incidence was 8% (95% Confidence Interval [CI]: 5% to 13%, I = 96.4%). LT incidence in patients receiving only antiplatelets was 13% (95% CI: 7% to 23%, p <0.0001); patients discharged on oral anticoagulants had a reported incidence of 4% (95% CI: 2% to 8%, p <0.0001). Patients with LT, either clinical or subclinical, were not at increased risk of stroke (OR 1.06, 95% CI: 0.75 to 1.50, p = 0.730, I = 0.0%) or transient ischemic attacks (Odds Ratio 1.01, 95% CI: 0.40 to 2.57, p = 0.989, I = 0.0%). LT was associated with higher mean transvalvular gradients compared with patients without LT at 30 days post-transcatheter implantation, but not at discharge or at 1 year. LT is a relatively common event that, even when clinically manifest, is not associated with an increased risk of cerebrovascular events. Although patients on anticoagulants appear to be at lower risk of LT, the available evidence does not allow formulation of recommendations for prophylactical anticoagulation nor routine computed tomography after transcatheter aortic valve replacement.
瓣叶血栓形成（LT）被认为是经导管心脏瓣膜血流动力学功能障碍或生物假体瓣膜退化的潜在原因。然而，关于 LT 的发生、预防和治疗的证据仍然很少且相互矛盾。我们在 MEDLINE、ISI Web of Science 和 SCOPUS 数据库中检索了截至 2020 年 1 月发表的研究。仅纳入了报告与临床或亚临床 LT 存在/不存在相关的发生率和结局数据，并通过多排螺旋 CT 检查检测或确认的研究。该研究根据系统评价和荟萃分析的首选报告项目（PRISMA）要求进行设计。两名审查员独立筛选符合纳入标准的文章。使用随机效应模型汇总数据。主要终点是 LT 的发生率。次要结局包括：LT 患者和无 LT 患者不同时间点的卒中、短暂性脑缺血发作和平均跨瓣梯度。最初的 200 项研究中，最终有 22 项研究纳入了总共 11567 例患者。LT 的总发生率为 8%（95%置信区间：5%至 13%，I=96.4%）。仅接受抗血小板治疗的患者中 LT 的发生率为 13%（95%置信区间：7%至 23%，p<0.0001）；接受口服抗凝剂治疗的患者报告的发生率为 4%（95%置信区间：2%至 8%，p<0.0001）。无论是临床还是亚临床 LT 的患者，卒中风险均无增加（OR 1.06，95%置信区间：0.75 至 1.50，p=0.730，I=0.0%）或短暂性脑缺血发作（OR 1.01，95%置信区间：0.40 至 2.57，p=0.989，I=0.0%）。与无 LT 的患者相比，LT 患者在经导管主动脉瓣置换术后 30 天的平均跨瓣梯度更高，但在出院时或 1 年时没有差异。LT 是一种相对常见的事件，即使临床表现明显，也与脑血管事件风险增加无关。尽管接受抗凝治疗的患者 LT 风险似乎较低，但现有证据不允许制定预防性抗凝或经导管主动脉瓣置换后常规 CT 的建议。
