PURPOSE: CTPA has significantly increased the detection of subsegmental pulmonary emboli(SSPE). Whether SSPE, in the absence of deep venous thrombosis(DVT), should be treated is controversial. We investigated the problems associated with therapeutic anticoagulation for officially reported SSPE in the community hospital setting.
METHODS: We reviewed the reports of 7794 consecutive CTPA performed between January 1, 2006 and December 31, 2008 at 3 northeastern US community hospitals. All CTPA reported positive for PE were reviewed by an experienced chest radiologist for location of largest PE and likelihood of false positive(FP) study. For reported SSPE, clinicians reviewed all available medical records and contacted the patient's physician as necessary for follow-up information. Experienced clinicians retrospectively calculated modified Well's score for reported SSPE.
RESULTS: 759/7794(9%)CTPA were officially reported positive for PE. On review, 71/759(9%) were FP studies. 49/71(69%)FP-PE were at the subsegmental level. Of all SSPE without DVT, 49/157(31%)were FP studies. Retrospective modified Well's score was PE unlikely in 45/49(92%) FP-SSPE and 64/107(59%) TP-SSPE. D-dimer was high in 17/33(52%)TP-SSPE and 5/22(23%)FP-SSPE. D-dimer was intermediate in 15/33(45%)TP-SSPE and 14/22(64%) of FP-SSPE. D-dimer was low in 1/33(3%) TP-SSPE and 3/22(14%) of FP-SSPE. Of FP-SSPE, 35/49(71%) were treated with anticoagulation or inferior vena caval filter(IVCF). 3/34(9%)FP-SSPE treated with anticoagulation had bleeding requiring transfusion. There was no PE in the subsequent 1 year for FP-SSPE. Of TP-SSPE, 103/107(96%) were treated with anticoagulation and/or IVCF. 11/99(11%) TP-SSPE treated with anticoagulation had bleeding requiring transfusion. 4/99(4%)TP-SSPE treated with anticoagulation required surgery for bleeding and 2/99(2%)TP-SSPE treated with anticoagulation died of bleeding complications. One other patient potentially died of bleeding complications.
CONCLUSION: Most FP-PE were at the subsegmental level. A significant proportion of reported SSPE were FP. Neither retrospective modified Well's score nor d-dimer results were predictive for FP-SSPE. The majority of reported SSPE were treated with anticoagulation and/or IVCF. There was significant morbidity/mortality associated with anticoagulation.
CLINICAL IMPLICATIONS: Further study is necessary to determine if the risk of anticoagulation outweighs the benefit for reported SSPE.
DISCLOSURE: Wallace Miller, Jr., No Financial Disclosure Information; No Product/Research Disclosure Information