A Prediction Rule for Occurrence of Chronic Thromboembolic Disease After Acute Pulmonary Embolism

Abstract

Occurrence of chronic thromboembolic disease (CTED) after 3 or 6 months of standard and effective anticoagulation is not uncommon in patients with acute pulmonary embolism (PE). To date, there has been no scoring model for the prediction of CTED occurrence. A Prediction Rule for CTED (PRC) was established in the establishment cohort (n=1,124) and then validated in the validation cohort (n=211). Both original and simplified versions of the PRC score were provided by using different scoring and cut-offs. The PRC score included 10 items: active cancer (3.641; 2.338-4.944; p<0.001), autoimmune diseases (2.218; 1.545-2.891; p=0.001), body mass index >30 kg/m2 (2.186; 1.573-2.799; p=0.001), chronic immobility (2.135; 1.741-2.529; p=0.001), D-dimer >2,000 ng/mL (1.618; 1.274-1.962; p=0.005), PE with deep vein thrombosis (3.199; 2.356-4.042; p<0.001), previous venous thromboembolism (VTE) history (5.268; 3.472-7.064; p<0.001), thromboembolism besides VTE (4.954; 3.150-6.758; p<0.001), thrombophilia (3.438; 2.573-4.303; p<0.001), and unprovoked VTE (2.227; 1.471-2.983; p=0.001). In the establishment cohort, the sensitivity, specificity, Youden index (YI), and C-index were 85.5%, 79.7%, 0.652, and 0.821 (0.732-0.909) when using the original PRC score, whereas they were 87.9%, 74.6%, 0.625, and 0.807 (0.718-0.897) when using the simplified one, respectively (Kappa coefficient 0.819, p-value of McNemar's test 0.786). In the validation cohort, the sensitivity, specificity, YI, and C-index were 86.3%, 76.3%, 0.626, and 0.815 (0.707-0.923) when using the original PRC score, whereas they were 85.0%, 78.6%, 0.636, and 0.818 (0.725-0.911) when using the simplified one, respectively (Kappa coefficient 0.912, p-value of McNemar's test 0.937); both were better than that of the DASH score (72.5%, 69.5%, 0.420, and 0.621 [0.532-0.710]). A prediction score for CTED occurrence, termed PRC, predicted the likelihood of CTED occurrence after 3 or 6 months of standard anticoagulation in hospitalised patients with a diagnosis of acute PE.