Management of Single Subsegmental Pulmonary Embolism – a Prospective Observational Study at North Shore and Waitakere Hospitals, Auckland

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Intern Med J. 2021 Sep 15. doi: 10.1111/imj.15531. Online ahead of print.


BACKGROUND: Single subsegment pulmonary embolism is increasingly diagnosed but the benefit to anticoagulate in the absence of concurrent deep vein thrombosis is not consistently established.

AIMS: To investigate the safety of an observational approach in patients with isolated subsegmental pulmonary embolism and the utility of the second lower limb ultrasound after seven days.

METHODS: Prospective observational study of patients diagnosed with isolated subsegmental pulmonary embolism between July 2016 and July 2020 at North Shore and Waitakere Hospitals, Auckland. The primary outcome was the venous thromboembolism recurrence rate within three months of SSPE diagnosis. Secondary outcomes included all-cause mortality, bleeding complications and the percentage of deep vein thrombosis diagnosed at serial compressive ultrasounds of lower limbs.

RESULTS: Amongst the forty-eight patients studied (two excluded due to revised diagnosis), no statistically significant differences were found in the baseline characteristics between the anticoagulated (n=17) and observed (n=31) groups. After patients with deep vein thrombosis were excluded, comparisons did not reveal significant differences in the primary outcome (0 vs. 1 recurrent VTE in the anticoagulated vs. observational groups, respectively), and the secondary outcomes. In the observational cohort, 77.4% (n=24) patients had repeat bilateral lower limb CUS after seven days, and none had deep vein thrombosis diagnosed on the second CUS.

CONCLUSIONS: Withholding anticoagulation was a feasible management option for this cohort of patients with single subsegmental pulmonary embolisms with an absence of deep vein thrombosis. The utility of a second lower limb ultrasound is questionable and would warrant further assessment in a prospective study. This article is protected by copyright. All rights reserved.

PMID:34523216 | DOI:10.1111/imj.15531