The mean bilateral proximal extension of the clot is associated with pulmonary embolism severity parameters and management-associated outcomes

Abstract

Background The value of the proximal extension of the clot in risk stratification of pulmonary embolism (PE) has not been established. The mean bilateral proximal extension of the clot (MBPEC) is a computed tomography (CT) radiological score, where initial evaluation showed promising results considering its ability in predicting the severity of PE. Purpose To explore the possible associations between MBPEC and PE-severity parameters, short- and long-term outcomes of PE, and inter-observer agreement. Material and Methods Patients diagnosed with PE at Østfold Hospital, Norway during 2003–2011 were identified. MBPEC was calculated by calculating the mean of a score in the range of 1–4 assigned for the most proximal extension of the clot in each lung: sub-segmental; segmental; lobar; and main pulmonary arteries. Medical records were reviewed to capture clinical, biochemical, and management-associated data (thrombolysis, admission to ICU). Results The mean age of 245 included patients was 55 ± 16 years; 42% were women. Patients with higher MBPEC scores had a significantly higher pulse rate and lower oxygen saturation. MBPEC score <4 predicted a negative troponin value with a negative predictive value of 90% (95% confidence interval [CI] 81–95). Patients with MBPEC 4 were 5.3 times more likely to have elevated troponin (odds ratio [OR] 5.3, 95% CI 2.0–14.3). MBPEC score of 4 was independently associated with admission to ICU (OR 3.8, 95% CI 1.8–7.9). The inter-observer agreement was excellent; weighted kappa 0.82. Conclusion MBPEC is associated with PE-severity parameters and can predict short-term adverse outcomes.

Does the clot burden as assessed by the Mean Bilateral Proximal Extension of the Clot score reflect mortality and adverse outcome after pulmonary embolism?

“…Although our results indicate that the extent of PE should not be given decisive clinical importance in the risk stratification following PE, we have previously shown an association between Troponin elevation in acute PE and MPBEC score. 24,25 This indicates that MBPEC might be relevant in contexts other than mortality. Furthermore, there may be clot parameters other than total clot volume/burden that may be important to assess, such as semi-quantitative clot burden measurement, clot volume quantification and lung perfusion quantification using iodine maps, signs of chronicity, as those accurately predict chronic thromboembolic pulmonary hypertension (CTEPH) and other post-PE sequelae.…”

“…However, a previous study has demonstrated excellent MBPEC score inter-rater agreement. 25 Qanadli or Mastora scores were not assessed, hindering a comparison between MBPEC and a reference standard score. However, excellent correlation between the Qanadli score and MBPEC score has previously been demonstrated.…”

“…24 In a more recent study, the MBPEC score was shown to correlate with PESI score, RV/ LV ratio and cardiac biomarkers beside several other PE related clinical markers. 25 However, the ability of the MBPEC score to predict mortality and other adverse outcomes has not been studied previously.…”

Prognostic Role of Ct Pulmonary Angiography in Acute Pulmonary Embolism

“…Central clot location can be of value as a prognostic marker for rapid risk stratification of PE. In contrast to obstruction scores, the classification of PE according to its most proximal level is frequently included in radiology reports and easier to understand by the physician (24,25) . In agreement with multiple studies and meta-analyses (19&25) , our study demonstrated that clinical prognosis in patients with PE is significantly influenced by PE location, and large proximal pulmonary emboli are expected to have more serious consequences (table 2).…”

“…Comparison of RVD qualitative findings between study outcome groups showed significant differences in leftward bowing of the interventricular septum (57.1% vs. 25 The mean diameters of the pulmonary artery, and SVC, were significantly higher in adverse than in non-adverse outcome groups (P = 0.001 and 0.016) with an odds ratio of 1.33 (table 2 & 4). ROC curve revealed AUC for PA diameter = 0.747 (95% CI 0.620-0.873, p 0.001) with optimum cut off =29.5 mm (sensitivity 75%, specificity 71%) (table 3…”