抽象的
急性肺栓塞后诊断出的慢性血栓栓塞疾病需要对其定义进行改进,并进一步评估最佳抗凝策略http://bit.ly/38SQXc0
To the Editor:
The recently updated European Society of Cardiology/European Respiratory Society guidelines for acute pulmonary embolism (PE) underline the importance of appropriate long-term management of PE sequelae in the era of extended anticoagulation [1]。Chronic thromboembolic disease (CTED) is one of several conditions contributing to breathlessness in this setting,i.e.persistent pulmonary vascular obstruction on imaging, with no evidence of pulmonary hypertension at rest. CTED is increasingly encountered in pulmonary vascular disease clinics following acute PE, and its diagnosis relies heavily on careful exclusion of other conditions that may contribute to symptoms. Given the need for careful follow-up after PE, in this paper we highlight two important points relating to the diagnosis and management of CTED: firstly, the location and extent of chronic pulmonary artery thrombus on imaging and secondly, the lack of evidence to support long-term anticoagulation in CTED, as opposed to chronic thromboembolic pulmonary hypertension (CTEPH).
The haemodynamic definition of CTED includes patients with evidence of pulmonary vascular obstruction and a mean pulmonary artery pressure <25 mmHg at rest assessed by right heart catheterisation [2]。In line with CTEPH, the diagnosis of CTED usually requires at least 3 months anticoagulation prior to the diagnostic work-up. The original description of CTED as a novel diagnosis, distinct from CTEPH, included highly selected symptomatic patients referred for pulmonary endarterectomy (PEA) on account of a large thrombotic burden on computed tomography (CT) pulmonary angiography (CTPA), mild right ventricle (RV) enlargement on echocardiography, but no pulmonary hypertension at rest [3]。The same research group later reported clinical improvement in terms of World Health Organization functional class and quality of life scores following surgery in a more extended CTED cohort [4]。Recently, the diagnostic definition of CTED has transformed to encompass breathless patients following acute PE who, despite anticoagulation, demonstrate persistent areas of perfusion/ventilation mismatch on nuclear scintigraphy, irrespective of the presence or location of thrombus on CT.
In broadening the clinical definition to include patients with distal vascular obstruction, more patients are being diagnosed with CTED. Pulmonary vascular resistance (PVR) is usually minimally affected by anatomical thrombus distribution. However, impedance to pulmonary forward flow is not well-captured by PVR and may be markedly different between patients with proximal相对distant lesions, with a greater effect on RV afterload arising from proximal pulmonary vascular obstruction [5,6]。Discrimination between proximal thrombus on CT and more distal obstruction on scintigraphy may, therefore, be important in defining the haemodynamic effect of CTED, and its impact on the RV and symptoms.
Secondly, anticoagulation in CTEPH is prescribed under a class 1 recommendation, and recourse to extended anticoagulation in CTED is extrapolated from this guideline [2]。However, when a diagnosis of CTED is made after an index PE associated with a major transient risk factor, such as immobilisation related to surgery, clinical uncertainty arises and the decision to pursue extended anticoagulation may not automatically apply. “Post-PE syndrome” has recently been introduced to describe permanent changes in pulmonary artery flow, gas exchange and/or cardiac function in the breathless patient following PE. While this entity links symptoms to abnormal gas exchange and RV dysfunction, definitive anticoagulation recommendations are lacking [7]。我们从Elope研究中学到了PE后呼吸困难与凝块负担和抗凝作用无关[8]; however, low levels of pulmonary vascular obstruction in this study leave unanswered questions around optimal anticoagulation strategies in patients with larger thrombotic burden after PE.
我们认为,当前的诊断景观似乎太广泛,无法出现有意义的临床指导。为了简化这种方法,我们建议保留CTPA的慢性近端血栓患者的CTED诊断标签,其中,在肺动脉高压的替代背景下,临床医生会考虑pea手术转诊。根据我们的经验,与在CTPA上没有近端血栓的人相比,这种患者更频繁地表现出对超声心动图的轻度RV扩张,并且不论PE危险因素如何。相比之下,PE后3-6个月在核闪烁显像中孤立的灌注缺陷的有症状患者,CTPA上没有近端血栓性负担,需要在抗凝研究中进行前瞻性评估,并在PE和/或风险时通过短暂的危险因素分组CTEPH的因素。因此,我们提出了一种根据我们的临床经验提出的算法(图1),其中诊断成为肺动脉高压专家中心的保存,可以提供运动血液动力学评估,豌豆转诊或气球肺血管成形术[9,10]。该算法目前在管理研究中未经测试,简化了在3-6个月的随访中CTED和PE后呼吸困难的差异,而无需进行心肺运动测试,这在解释方面带来了更大的可变性。由于很少有资格获得PEA的人,抗凝仍是大多数CTED患者可能提供的唯一药物治疗。鉴定可能从延长抗凝治疗中受益的患者的标准,相对those who may safely discontinue treatment with no detriment to their quality of life or risk of PE recurrence, will only emerge with a more robust definition of CTED in this diverse patient population.
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Footnotes
Conflict of interest: C. McCabe has nothing to disclose.
Conflict of interest: K. Dimopoulos has nothing to disclose.
利益冲突:A。投手无话可说。
Conflict of interest: E. Orchard has nothing to disclose.
利益冲突:L.C。价格没有什么可披露的。
Conflict of interest: A. Kempny has nothing to disclose.
利益冲突:S.J。麦芽汁没有什么可披露的。
- Received2019年10月1日。
- 一个cceptedJanuary 24, 2020.
- Copyright ©ERS 2020