Objective To analyse the clinical effect of anticoagulant treatment in acute pulmonary embolism stratified as intermediate-risk.

Method Patients with intermediate-risk acute pulmonary embolism (PE) were enrolled in Center for Pulmonary Vascular Diseases, Fu Wai Hospital between Aug 2008 and Apr 2010. The intermediate-risk acute PE was defined as stable haemodynamics and the presence of right ventricular dysfunction (echocardiography or CT showed right ventricle dilation, pressure overload, BNP or NT-proBNP elevation) and/or markers of myocardial injury (stratified as intermediate-risk acute pulmonary embolism were included in this study. There were 29 men (42.6%) and 39 women (57.4%) with a mean age of 61.7±13.4 years. Right ventricle (RV) dilatation or pressure overload was present on echocardiography or CT in 49 cases (%), NT-proBNP elevation in 58 cases (%) and cardiac troponin I positive in 8 cases (%). The mean onset time was 15.7±18.0 days. The main complaints included dyspnoea (60 patients, 88.2%), chest pain (16 patinets, 23.5%), cough (16 patients, 23.5%), haemoptysis (8 patients, 11.8%), syncope (7 patients, 10.3%), palpitation (5 patients, 7.4%), dizziness (4 patients, 5.9%) and cyanosis (1 patient, 1.5%). Referring to ECG, 34 cases (50%) presented S1QIIITIII and 27 cases (39.7%) with T wave inversion in V1–V4 leads. The symptoms, physical signs and results of laboratory tests were improved significantly after anticoagulation by hemarin or low molecular weight heparin with a target INR of : heart rate (82.5±14.8 vs 69.9±7.5 beats/min, p<0.001) and D-dimer (5.8±4.7 mg/l vs 1.1±1.2 mg/l, p<0.001CTnT or CTnI) positive.

Results Sixty-eight patients significantly decreased; PaO₂ (68.7±11.7 mm Hg vs 85.4±31.3 mm Hg, p<0.001), PCO₂ (37.2±5.3 mm Hg vs 40.3±4.6 mm Hg, p<0.001) and SaO₂ (93.5±3.4% vs 95.6±2.1%, p<0.001) significantly increased. During hospitalisation, ALT or AST was slightly increased in 12 cases (%) and became normal after regular treatment; Twelve patients had mild bleeding, including 4 cases with positive urine occult blood, 4 cases with slight conjunctival haemorrhage, 2 cases with slight haemoptysis and 1 case with positive fecal occult blood.

Conclusions Anticoagulant treatment to patients with acute pulmonary embolism stratified as intermediate-risk significantly improved the symptoms, physical signs and results of laboratory tests with slight and low occurrence rate of complications.