Variable predictors of acute pulmonary embolism recurrence with duration of follow-up.

Background: Acute pulmonary embolism (PE) is a critical disease and often leads to a high mortality and morbidity. Several studies have identified predictors of PE recurrence, but whether these predictors have prognostic value and how they vary during varied follow-up periods remain unclear.

Methods: We retrospectively assessed the occurrence of recurrent PE and the survival time of patients with a diagnosis of acute PE at Shanghai Pulmonary Hospital from May 2007 to May 2018. Potential predictors of recurrent PE were evaluated at different points (1, 3, 6, 12, 24, 60 and 120-month) during a long-term follow-up for each patient. Patients were stratified into two groups by gender to analyze the impact of sex in period-guided prognostic prediction. Receiver operating characteristic curve analysis, survival analysis and multivariate Cox proportional hazards analysis were implemented as statistical analysis methods.

Results: In total, 597 acute PE patients were included, of whom 62 reported a PE recurrence. Male patients tend to have a lower risk of PE recurrence than female patients during 3- to 60-month follow-up period but have a higher risk of PE recurrence than female patients during 120-month follow-up period. The independent predictors of recurrence-free survival varied among different follow-up periods: In all patients, diabetes was an independent predictor only within 30 days follow-up period and female was considered as an independent predictor during 3- to 120-month follow-up period. Among male patients, hyperlipidemia and Log D-dimer (cut-off value =3.436) was observed as a predictor of recurrent PE within 6-month and over 12-month follow-up respectively. However, there is no unified independent prognostic indicator for female patients identified.

Conclusions: In the early stage of follow-up, male PE patients have better prognosis, but with the extension of follow-up, female PE patients have better prognosis. The independent predictors of recurrence-free survival vary in different follow-up periods in PE patients when stratified based on gender and associated medical conditions.