BackgroundRapid diagnosis and risk stratification are important to reduce the risk of
adverse clinical events and mortality in acute pulmonary embolism (PE).
Although clot burden has not been consistently shown to correlate with
disease outcomes, proximally located PE is generally perceived as more
severe.PurposeTo explore the ability of the Mean Bilateral Proximal Extension of the Clot
(MBPEC) score to predict mortality and adverse outcome.MethodsThis was a single center retrospective cohort study. 1743 patients with
computed tomography pulmonary arteriography (CTPA) verified PE diagnosed
between 2005 and 2020 were included. Patients with active malignancy were
excluded. The PE clot burden was assessed with MBPEC score: The most
proximal extension of PE was scored in each lung from 1 = sub-segmental to 4
= central. The MBPEC score is the score from each lung divided by two and
rounded up to nearest integer.ResultsWe found inconsistent associations between higher and lower MBPEC scores
versus mortality. The all-cause 30-day mortality of 3.9% (95% CI: 3.0–4.9).
The PE-related mortality was 2.4% (95% CI: 1.7–3.3). Patients with MBPEC
score 1 had higher all-cause mortality compared to patients with MBPEC score
4: Crude Hazard Ratio (cHR) was 2.02 (95% CI: 1.09–3.72). PE-related
mortality was lower in patients with MBPEC score 3 compared to score 4: cHR
0.22 (95% CI: 0.05–0.93). Patients with MBPEC score 4 did more often receive
systemic thrombolysis compared to patients with MBPEC score 1–3: 3.2% vs.
0.6% (p< .001). Patients with MBPEC score 4 where more
often admitted to the intensive care unit: 13% vs. 4.7% (p< .001).ConclusionWe found no consistent association between the MBPEC score and mortality. Our
results therefore indicate that peripheral PE does not necessarily entail a
lower morality risk than proximal PE.