38 Local experience of ultrasound assisted catheter directed thrombolysis in london northwest university healthcare NHS trust for sub-massive pulmonary embolism

Abstract

Background and Objective Despite availability of sensitive diagnostic tests, the mortality and morbidity related to pulmonary embolism (PE) continues to cause tremendous economic burden. The objective of this service evaluation was to compare the length of stay and safety profile of newly adopted Ultrasound Assisted Catheter Directed Thrombolysis (UACDT) for patients with sub-massive PE and right heart strain to a historic control group of patients with a primary discharge diagnosis of PE. Methods and Results The historic control group was made of patients identified with a primary discharge diagnosis of PE in the calender year 2016 (131 patients). Of these 75 (57.3%) patients had sub-massive PE defined as radiologically large thrombus burden and evidence of right heart strain seen on CT pulmonary angiogram (CTPA). Only patients with a length of stay (LOS, defined as date of discharge – date of scan in days) > 2 days were included in the analysis. The final historical control group was made of 68 (51.1% of the total cohort) patients, mean age = 67.5 ± 17.9 years, 28 (36.8%) males, mean pulmonary artery pressure (PAP) on echo = 37.3 ± 17.7 mmHg (echo data available in 74.7% of the cohort). These patients were compared against the UACDT group. To be eligible for UACDT, patients needed to have sub-massive PE with radiologically large thrombus burden, right heart strain seen on CTPA and echocardiogram and elevated Troponin and or BNP on blood tests. The UACDT group comprised of 25 patients (mean age = 61.2 ± 14.1 years, 19 (76%) male, mean PAP 38.6 ± 22.3 mmHg on echo, all patients had echo data available prior to the procedure) that underwent the procedure at our district general hospital between June 2018 and Sep 2019. Time to procedure was a mean of 1.2 days (median of 1day with min of 0 and Max of 5 days). There was no death in the UACDT cohort whilst 3 deaths (3.9%) were observed in the historical control group (p = 0.6). Death or readmission occurred in 8 (10.5%) of the historical control group compared to 1 (4%) in the UACDT group (p = 0.4). One (4%) patient had haematemesis post UACDT with new diagnosis of gastric Cancer. There were 3 (12%) patients with new diagnosis of cancer among UACDT group and further 2 with known metastatic cancer. The LOS numerically lower in the UACDT group compared to the historical control group which was not significantly different (mean difference = 2.4 days, 95% CI = -0.5, 5.3 days, p = 0.1). Conclusion UACDT is a safe procedure and although there is no difference in LOS with the procedure there is a potential that this difference will become more important as confidence with the procedure increases. There is a 12% incidence of occult cancer in this group of patients. Conflict of Interest no