Chronic thromboembolic pulmonary hypertension in acute pulmonary embolism: a risk factor evaluation study

Aims: Pulmonary thromboembolism (PTE) is a highly mortal disease, defined by presence of thrombus partially or completely obstructing pulmonary arteries and/or veins, commonly originated from deep venous system. Chronic thrombroembolic pulmonary hypertension (CTEPH) is a rare complication of PTE with high mortality if not treated properly. In recent studies, incidence of CTEPH was found between %0,4-9,1. Due to clinically silent PTE in roughly %50 of patients, it is difficult to pinpoint the exact incidence of CTEPH. In this study, we aim to investigate PTE patients during their long-term follow up to observe CTEPH presence and evaluate CTEPH risk factors. Methods: Patients who had been evaluated in emergency service and/or admitted to pulmonary medicine ward between January 2014 and January 2017 with PTE diagnosis confirmed by computed tomography pulmonary angiogram (CTPA) were accepted retrospectively into the study. Their echocardiography, CTPA and lower extremity venous Doppler ultrasonography at 3., 6. and 12. months follow up were also included. In the patient group with pulmonary arterial pressure (PAP ) above 50 mmHg and residual thrombosis at CTPA, ventilation-perfusion scintigraphy had been performed and was added to the study. Among those suitable for CTEPH, right cardiac catheterization had been done to confirm the diagnosis and accepted as CTEPH. In addition to this group, patients who were not found suitable for right cardiac catheterization but wereclinically suitable for CTEPH are also included in the CTEPH group. Results: Average age of patients included into the study was 62(±16, 5), with 71 (%39) being male and 111 (%61) female. As for risk factors, 130 (%71,4) had acquired, 16 (%8,8) had genetic and the rest 36 (%19,8) did not have any prominent risk factors. At time of diagnosis, 10 patients were accepted as massive, 26 as sub massive and the rest 139 were considered non-massive PTE. Due to hemodynamic instability, 7 (%3,8) patients were given thrombolytic therapy. During 1 year follow-up, 5 (%2,7) patients were diagnosed with CTPH. When further investigation was performed on these 5 patients, atrial fibrillation (AF), persistent thrombosis at 12. month follow up CTPA and PAP above 55 mmHg upon time of diagnosis were found significant risk factors (p being 0,001/0,023/0,009 respectively). In multivariate analysis, no independent predictive factors were found in regards to CTEPH diagnosis. Conclusion: CTEPH is a preventable complication of PTE with severe mortality and morbidity if not properly treated. It might prove useful to utilize echocardiography and CTPA together, especially in those in high risk groups, for diagnosis of patients in early stage of CTEPH with no evident signs or symptoms.