Determinants of In-hospital Clinical Outcome in Patients with Sub-massive Pulmonary Embolism

Introduction: There is limited data regarding in hospital determinants of clinical deterioration and outcome in sub massive pulmonary embolism (PE). We aimed to evaluate these determinants by comparing biomarkers, CT pulmonary angiogram echocardiography, electrocardiography variables.

Methods: 57 patients of sub massive PE diagnosed on CT pulmonary angiogram were included. All patients received UFH on admission and were divided into two groups based on their clinical course. Group 1 comprised of patients who remained stable, group 2 of patients who showed signs of clinical deterioration.

Results: There were 34(59.6%) patients in group 1 and 23(40.4%) patients in group 2. No significant difference in age, gender, BMI. 59.37% had sub massive PE, 5.26% had mortality and 40.4% had clinical deterioration. Intravenous UFH infusion given to 59.6%, systemic thrombolysis 22.8%, catheter directed mechanical breakdown 14%, surgical embolectomy in 3.5% patients. S1Q3T3, new onset RBBB, T wave inversion > 1.63 mm, Basal RV size > 40 mm, RV: LV ratio > 1.2, Global RV longitudinal strain <-10.75% and RVSP > 39 mmHg profiled high risk group. Serum BNP and CT pulmonary angiogram derived scores didn't differ significantly although CT findings helped to exclude low risk patients (specificity 88%, sensitivity 95%).

Conclusions: Physicians should be aware that patients who have ECG and Echocardiography changes suggestive of right ventricular strain and dysfunction above the cut off values and have documented thrombus in Proximal branches (RPA/LPA) or in distal portion of main pulmonary artery may require aggressive management with systemic/catheter based thrombolysis besides routine anticoagulation with heparin to prevent clinical deterioration.