Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bengaluru, India.
Institute of Nephro Urology, Bengaluru, India.
Eur Heart J Acute Cardiovasc Care. 2020 Oct;9(3_suppl):S58-S62. doi: 10.1177/2048872619846329. Epub 2019 Apr 26.
A significant number of patients with prosthetic valve thrombosis have a prothrombin time international normalised ratio in the therapeutic range at presentation. Surgery may not be possible in many patients and traditionally a high international normalised ratio is considered a relative contraindication for fibrinolysis.
We conducted an observational study in patients with left-sided obstructive prosthetic valve thrombosis with international normalised ratio at or above the therapeutic range at presentation who received fibrinolysis. The fibrinolytic regimens, timing of initiation, success of fibrinolysis, risk of major and minor bleeding and ischaemic stroke were evaluated in the study.
Of 30 patients included in the study 70% received immediate fibrinolysis and in 30% it was delayed. The majority of patients (90%) presented with New York Heart Association class III/IV symptoms. The mean international normalised ratio at fibrinolysis was 3.04 ± 0.70 in the immediate group and 2.42 ± 0.89 in the delayed group. Haemodynamically stable patients who had delayed initiation of fibrinolysis had a trend towards less bleeding without an increase in mortality. The rates of intracranial haemorrhage (0% vs. 7.7%), minor bleeding (12.5% vs. 25.1%) and ischaemic stroke (0% vs. 30.7%) were lower in patients who received low dose infusion compared to a conventional dose.
Fibrinolysis can be considered in patients with prosthetic valve thrombosis with high international normalised ratio at presentation. For haemodynamically stable patients, delayed initiation of fibrinolysis is associated with a marginally lower bleeding risk without an increase in mortality. Low dose infusion may be considered over a conventional dose as it is associated with a lower incidence of ischaemic stroke and a good rate of valve function restoration with a trend towards less bleeding.
相当数量的人工瓣膜血栓形成患者在就诊时的凝血酶原时间国际标准化比值在治疗范围内。许多患者可能无法进行手术，传统上高国际标准化比值被认为是纤维蛋白溶解治疗的相对禁忌证。
我们对就诊时国际标准化比值在治疗范围内或以上的左侧阻塞性人工瓣膜血栓形成患者进行了一项观察性研究，这些患者接受了纤维蛋白溶解治疗。该研究评估了纤维蛋白溶解方案、起始时机、纤维蛋白溶解的成功率、大出血和小出血及缺血性卒中的风险。
在纳入的 30 例患者中，70%立即接受了纤维蛋白溶解治疗，30%延迟了治疗。大多数患者（90%）出现纽约心脏协会心功能分级 III/IV 级症状。立即组和延迟组的纤维蛋白溶解时平均国际标准化比值分别为 3.04 ± 0.70 和 2.42 ± 0.89。延迟开始纤维蛋白溶解的血流动力学稳定患者出血减少，但死亡率无增加，趋势明显。与接受常规剂量相比，接受低剂量输注的患者颅内出血发生率（0% vs. 7.7%）、小出血发生率（12.5% vs. 25.1%）和缺血性卒中发生率（0% vs. 30.7%）较低。
对于就诊时国际标准化比值较高的人工瓣膜血栓形成患者，可以考虑纤维蛋白溶解治疗。对于血流动力学稳定的患者，延迟开始纤维蛋白溶解治疗可降低出血风险，且不增加死亡率。与常规剂量相比，低剂量输注可能是更好的选择，因为它与较低的缺血性卒中发生率和较高的瓣膜功能恢复率相关，同时出血倾向较低。
