Bhandari Sanjay S, Nicolson William B
Department of Cardiology, Glenfield Hospital, University Hospitals of Leicester, Groby Rd, Leicester, UK.
Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Groby Rd, Leicester, UK.
Eur Heart J Case Rep. 2018 Jul 27;2(3):yty089. doi: 10.1093/ehjcr/yty089. eCollection 2018 Sep.
Despite overcoming the morbidity from severe native valve disease, prosthetic metallic valve replacement is not without its inherent morbidity, in particular from prosthetic valve thrombosis (PVT). The contemporary pure carbon bileaflet metallic valve confers reduced thrombogenicity.
We describe the case of a 45-year-old woman with a pure carbon bileaflet metallic mitral valve replacement (27/29 mm On-X) 6 months previously for severe rheumatic mitral stenosis, who presented with a rapid onset of dyspnoea, paroxysmal nocturnal dyspnoea, and haemoptysis. This was preceded by an interruption in therapeutic anticoagulation. On admission the patient was in cardiogenic shock. Transthoracic and transoesophageal (TOE) echocardiograms revealed increased transmitral gradients with disc hypomobility, suggestive of PVT, unexpected given the favourable safety profile of the On-X valve. Fluoroscopy confirmed the findings. The patient was thrombolysed successfully with alteplase, with restoration of normal transmitral gradients. A target international normalized ratio of 3.5-4.5 was chosen, in addition to aspirin 75 mg, to minimize thrombotic sequalae. Repeat TOE 6 weeks later revealed disc hypomobilty with a large adherent clot. Due to the high risks from thrombolysis, emergency redo-mitral bioprosthetic valve surgery was performed, to negate the need for long-term anticoagulation.
Subtherapeutic anticoagulation and the rapid development of dyspnoea, should prompt the clinician to suspect PVT. Thorough clinical examination and immediate bedside echocardiography are critical for assessing prosthetic valve patients in cardiogenic shock. The treatment of PVT is complex, with considerable risks to the patient, irrespective of the strategy (thrombolysis/emergency valve replacement), necessitating the expertise of cardiologists and cardiac surgeons.
尽管人工金属瓣膜置换术克服了严重的自身瓣膜疾病的发病率问题，但它并非没有其固有的发病率，特别是人工瓣膜血栓形成（PVT）。当代的纯碳双叶金属瓣膜具有降低的血栓形成倾向。
我们描述了一名45岁女性的病例，她6个月前因严重风湿性二尖瓣狭窄接受了纯碳双叶金属二尖瓣置换术（27/29毫米On-X瓣膜），出现了呼吸困难、阵发性夜间呼吸困难和咯血的快速发作。在此之前，治疗性抗凝出现了中断。入院时患者处于心源性休克状态。经胸和经食管（TOE）超声心动图显示二尖瓣跨瓣压差增加，瓣叶活动减弱，提示PVT，鉴于On-X瓣膜良好的安全性，这一情况出乎意料。荧光透视证实了这些发现。患者用阿替普酶成功溶栓，二尖瓣跨瓣压差恢复正常。除了75毫克阿司匹林外，选择目标国际标准化比值为3.5 - 4.5，以尽量减少血栓形成后遗症。6周后复查TOE显示瓣叶活动减弱，有一个大的附着血栓。由于溶栓风险高，进行了急诊二尖瓣生物瓣膜再次置换手术，以消除长期抗凝的必要性。
抗凝不足以及呼吸困难的快速发展，应促使临床医生怀疑PVT。全面的临床检查和即时床边超声心动图对于评估心源性休克的人工瓣膜患者至关重要。PVT的治疗很复杂，无论采用何种策略（溶栓/急诊瓣膜置换），对患者都有相当大的风险，这需要心脏病专家和心脏外科医生的专业知识。
