Thrombosis Program, Division of Hematology, Department of Medicine, University of Ottawa, Ottawa Clinical Epidemiology Program, The Ottawa Hospital Research Institute, Ottawa, Canada.
J Thromb Haemost. 2012 Aug;10(8):1486-90. doi: 10.1111/j.1538-7836.2012.04804.x.
The introduction of computed tomography pulmonary angiography (CTPA) has led to an increase in the incidence of pulmonary embolism (PE) diagnosis. However, the case fatality rate is lower and the mortality rates of PE have remained unchanged, suggesting a lower severity of illness. Specifically, the multiple-detector CTPA increased the rate of subsegmental filling defect reported in patients with suspected PE. Whether these filling defects reported on CTPA would correlate with true subsegmental PE (SSPE) on pulmonary angiography or are actually artifacts is unknown. The inter-observer agreement for SSPE diagnosis among radiologists with varied levels of experience is low (κ of 0.38; 95% CI, 0.0-0.89). Furthermore, the clinical importance of a symptomatic SSPE diagnosed by CTPA is unclear. SSPE are frequent on pulmonary angiography in patients with a low probability ventilation-perfusion (V/Q) scan for suspected PE. Several prospective management cohort studies have demonstrated that patients with low or intermediate V/Q scan results can be safely managed without anticoagulation by combining the scan results with the pretest probability (PTP) of PE and compression ultrasonography. Although clinical equipoise exists, the majority of patients diagnosed with SSPE on CTPA are currently treated with anticoagulant therapy. Only a small number of patients with SSPE diagnosed by CTPA and without DVT who did not receive anticoagulation treatment have been reported in the literature. None of these patients suffered recurrent symptomatic VTE (PE or DVT) during the 3-month follow-up period (0%; 95% CI, 0-7.4%), suggesting that SSPE might be clinically unimportant. These conclusions are only hypothesis generating and need to be confirmed in prospective clinical management studies before changing clinical practice.
计算机断层肺动脉造影（CTPA）的引入导致肺栓塞（PE）诊断的发生率增加。然而，病死率较低，PE 的死亡率保持不变，表明疾病严重程度较低。具体而言，多探测器 CTPA 增加了疑似 PE 患者亚段充盈缺损的报告率。在 CTPA 上报告的这些充盈缺损是否与真正的亚段 PE（SSPE）相关，或者实际上是伪影尚不清楚。不同经验水平的放射科医生对 SSPE 诊断的观察者间一致性较低（κ 值为 0.38；95%置信区间，0.0-0.89）。此外，CTPA 诊断的有症状 SSPE 的临床重要性尚不清楚。在疑似 PE 的低概率通气灌注（V/Q）扫描患者的肺动脉造影中，SSPE 很常见。几项前瞻性管理队列研究表明，对于低或中等 V/Q 扫描结果的患者，可以通过将扫描结果与 PE 的术前概率（PTP）和压缩超声结合起来，无需抗凝治疗即可安全管理。尽管存在临床均衡，但目前大多数在 CTPA 上诊断为 SSPE 的患者都接受抗凝治疗。文献中仅报道了少数在 CTPA 上诊断为 SSPE 且无 DVT 且未接受抗凝治疗的患者。在 3 个月的随访期间（0%；95%置信区间，0-7.4%），这些患者均未发生复发性有症状 VTE（PE 或 DVT），这表明 SSPE 可能在临床上不重要。这些结论只是假设产生的，需要在前瞻性临床管理研究中得到证实，然后才能改变临床实践。
