In this cross-sectional study 217 patients admitted between 2018 till 2020 in two tertiary hospitals with acute PE were included. Our inclusion criteria included as hospitalized patients aged over 18 years, confirmed PE diagnosis with CT angiography and available serum LDH level at first 24-hours upon admission.
Our exclusion criteria were hepatic and renal diseases, pregnancy, hemolytic disorders, left ventricular infarction, recent stroke, positive history of active cancer, acute and chronic infections and reticuloendothelial- related diseases were excluded. Segmental and sub-segmental PE was treated with anticoagulant while massive PE defined as PE with systolic blood pressure less than 90 or/and existence of thrombus in left or right or main pulmonary artery took thrombolytic therapy. [17] Pulmonary computed tomography (CT) angiogram films were reported by two expert radiologists.
Diagnosis of PE was made by CTPA (Siemens 32-slice computed tomography scanners). Two expert radiologists were investigated CTPA images as blinded fashion.
This study was approved by ethics committee of our University. All patients had signed informed consent form and patient anonymity was preserved in our study.
Any death during hospital course due to PE was defined as in-hospital mortality. When death occurred due to non-PE causes (e.g. myocardial infarction, intracranial or gastrointestinal bleeding), patients were excluded from study. Overlay one patient had intracranial bleeding after fibrinolytic therapy and was excluded.
We measured simplified Pulmonary Embolism Severity Index (sPESI) value for all the patients. Factors including age over 80 years, positive history of cancer, heart rate below 110 beats/minute, chronic cardiopulmonary disease, systolic blood pressure less than 100 mm Hg, and oxyhemoglobin saturation less than 90% were assessed in this scoring system and each variable has one point. The patient will categorized as high risk even with presence of one point. [18]
Information about demographic characteristics of the patients, past medical history as well as presenting vital sings, laboratory variables and oxygen saturation, were collected from their medical records.
Hypertension was defined as SBP ≥ 140 mmHg or DBP ≥ 90 mmHg.[19] Diabetes mellitus was defined as fasting plasma glucose levels of ≥ 126 mg/dl and HbA1c ≥ 6.5%. [20]
Simplified pulmonary embolism severity index was calculated according to previous studies. [18]
Right ventricular dysfunction was defined as the presence of right ventricular dilatation and a TAPSE less than 16 mm in echocardiography findings. [21] Every ECG was reported by two expert cardiologists to find out right ventricular strain pattern (inverted T wave in V1-V3).
Statistical analysis
IBM SPSS V.22 software was used for statistical analysis (IBM Corp., Armonk, NY, USA). We used t-test for quantitative values and chi-squire test for qualitative variables. Multiple linear regression and ROC (receiver operating characteristics) curve were used to find cutoff value for LDH level and mortality. Univariate and multivariate analyses were employed to analyze risk factors for mortality