Well's Scores Accurately Predict Presence of Massive Pulmonary Thromboembolism at Autopsy
Rachael A Girard, Vito Gulli, Marc Colaco, Billie Fyfe. UMDNJ Robert Wood Johnson University Hospital, New Brunswick, NJ
Background: Well's scores are utilized clinically to predict risk for pulmonary thromboembolism (PTE). Radiographic correlative studies have confirmed a high negative predictive value (NPV). This is the first autopsy study correlating Well's scores with PTE.
Design: A retrospective analysis of 85 adult autopsies from 2009 to 2011 was performed. Three cases were excluded due to inability to calculate Well's score due to death on arrival to hospital. Well's criteria were derived from chart review [clinical signs and symptoms of deep vein thrombosis (DVT), PTE first on differential diagnosis, heart rate > 100 bpm, immobilization ≥ 3 days or surgery in the previous four weeks, previous DVT or PTE, hemoptysis, and malignancy within 6 months]. Final autopsy reports were evaluated for presence or absence of PTE. Cases were classified by Well's score using the Clinical Decision Rule (CDR) [≤ 4, PTE unlikely; > 4, PTE likely]. Final autopsy reports were reviewed to classify cases as massive PTE (mPTE) with large saddle thromboemboli as cause of death, other PTE (oPTE) with small acute or chronic PTE that played a contributory role but were not sole cause of death, and negative PTE (nPTE) with no autopsy evidence of massive or other PTE.
Results: 85 autopsies with 11 PTE were studied, 3 were mPTE and 8 were oPTE. CDR accurately identified mPTE cases as likely for PTE. The oPTE all were classified as unlikely for PTE (false negative). For mPTE the CDR has a high NPV (100%) and a positive predictive value (PPV) of 23%. Detailed analysis of the ten falsely positive CDR revealed underlying malignancy (4), clinical signs of DVT (5), and positive DVT in the past (6) as the most prevalent criteria for the elevated score. The oPTE group (false negatives) contained 8 patients with CDR 1.5-4. Applying CDR to all PTE (oPTE plus mPTE) yielded a NPV of 89% and PPV of 23%.
Conclusions: Well's CDR is an effective tool used clinically for excluding acute PTE. This study confirms a high NPV for mPTE (100%) that decreases to 89% when including all PTE. Common causes for falsely elevated CDR include underlying malignancy, prior DVT, and clinical suspicion for DVT. This first autopsy study confirms the utility of Well's CDR to assess PTE risk. It is particularly useful for screening for massive PTE and less useful for smaller/chronic PTE. This study also shows that new clinical tools may help guide post-mortem investigations, potentially facilitating less invasive exams (virtopsy). This is a first post-mortem analysis of such a clinical tool, the Well's Criteria for pulmonary thromboembolism.
Wednesday, March 21, 2012 9:30 AM
Poster Session V # 9, Wednesday Morning