Patients with pulmonary embolism (PE) and right ventricular dysfunction (RVD) are at greater risk for adverse outcomes compared to patients without RVD. Those with non-massive PE (those without evidence of shock) are comprised of a low risk group (small PE) and a higher risk group (sub-massive PE, those with RVD). It is difficult to distinguish the small PE group from the sub-massive group clinically. The CT pulmonary embolism (CT-PE) protocol may detect RVD, thus predict adverse outcomes. We sought to determine if one can predict poor outcomes in PE, specifically normotensive PE patients (those with non-massive PE), using the CT-PE protocol.
In a preliminary analysis 44 patients with PE detected by CT-PE protocol were retrospectively examined for an aggregate adverse outcome (intubations, pressors, death, cardiac arrest, ICU admission). Studies were reviewed in the four chambered view for RV/left ventricular (LV) cross sectional area ratio, Aortic (Ao)/ Pulmonary artery (PA) diameter ratio, and presence of septal flattening . Data was analyzed to see if a relationship between adverse outcome and the measurements existed in the entire cohort and non-massive group. A multivariate logistic regression was performed to determine if other variables affected the relationship between the CT-PE protocol measures and the adverse outcome.
RV / LV area ratio and PA / Ao diameter ratio did not differ between the adverse outcome and non-adverse outcome group. The RR for septal flattening and adverse outcomes in PE was 2.00 (95% CI 1.15 –3.48), and significance was maintained after multivariate analysis. In the non-massive PE group the RR was 2.57 (95% CI 1.23 - 5.39).
Septal flattening detected by CT-PE protocol identifies PE patients at greater risk for adverse outcomes. It can also identify a higher risk group among those with non-massive PE.
The CT-PE protocol may provide a rapid means of identifying higher risk PE patients among those with non-massive PE. It may influence further testing, triage and the choice of therapy (i.e. IVC filter, thrombolytics).Table 2—
CT-PE Measurements for Entire Cohort–comparing Adverse Outcome and Non-adverse Outcome (N = 44)CT MeasuresCohort DataAdverse OutcomeNon-adverse Outcomep-valueRV area* (mm2)2284 (466)2304 (492)2263 (451)0.79RV/LV ratio*0.54 (0.14)0.55 (0.15)0.53 (0.13)0.58PA / Ao ratio*0.92 (0.12)0.94 (0.12)0.91 (0.11)0.47LV area (mm2)4362 (950)4443 (1087)4284 (818)0.60Septal Flattening>27.3 (12)27.3 (9)6.8 (3)0.03*
Means with t-test as test for significant differences; Measurements and standard deviations areTable 4—
CT Measurements for Adverse and Non-adverse Outcomes in Non-Massive PE (N = 32)CT MeasuresNon-Massive PE**p-values+++Adverse Outcome (n = 13)Non-adverse Outcome (n = 19)RV area*2313 (461)2163 (525)0.42RV / LV ratio*0.56 (0.15)0.50 (0.13)0.30PA / Ao ratio*0.91 (0.10)0.94 (0.13)0.40LV*4356 (156)4275 (834)0.82Septal Flattening+18.75 (6)6.25 (2)0.04*
Means with standard deviations
Peter Marshall, None.