Incidence of recurrent venous thromboembolism and of chronic thromboembolic pulmonary hypertension in patients after a first episode of pulmonary embolism

After a first episode of pulmonary embolism (PE), two major problems need to be considered: risk of recurrence when anticoagulation is stopped, and risk of chronic thromboembolic pulmonary hypertension (CTPH). We followed prospectively consecutive patients who survived a first episode of PE, with or without deep vein thrombosis, to assess the incidence of venous thromboembolism (VTE) recurrences and of symptomatic and asymptomatic CTPH. After 3-6 months of oral anticoagulant therapy (OAT) patients underwent transthoracic echocardiography for measuring transtricuspid (rV-rA) gradient. When rV-rA gradient was >35 mmHg further evaluations were performed to rule in or out CTPH. During follow-up patients who developed persistent dyspnea were re-evaluated. In patients who underwent OAT withdrawal D-dimer (DD), prothrombin fragment 1 + 2 (F1 + 2), and thrombophilia were evaluated one month after warfarin discontinuation. Overall, 239 patients, 118 males, median age 59(16-89) years, were followed up for a median time of 36(9-192) months. Nine patients had rV-rA gradient >30 mmHg and ≤35 mmHg, and one of 37 mmHg. Among patients with normal rV-rA gradient, one developed persistent dyspnea 55 months after the first event and CPTH was confirmed. Among 206 patients who stopped OAT, 23(11.2%) had VTE recurrence, 11 PE(48%). Elevated DD and F1 + 2 levels after stopping OAT were significantly associated with recurrence. None of patients with recurrent VTE had elevated rV-rA gradient. In our series the incidence of CTPH after a first episode of PE was 0.4%. VTE recurrence and elevated DD and F1 + 2 levels seemed not to be related to the development of CTPH.