Background: Right ventricular (RV) function is predictive of outcome in patients with acute pulmonary embolism (PE). We assessed the possible incremental value of ventricular function with ECG-synchronized cardiac CT scanning over pulmonary CT scan angiography (CTA) for predicting short-term outcome in patients with suspected acute PE.
Methods: The local ethics committee approved the study, and informed consent was obtained. In addition to standard CTA, 430 consecutive patients (193 men, 237 women; age, 55 ± 17 years) with suspected acute PE underwent ECG-synchronized CT scanning to assess ventricular function. RV/left ventricular (LV) function ratio and pulmonary obstruction index were obtained from non-ECG-synchronized CTA. Ventricular function was used to predict adverse events (< 6 weeks). Receiver operating characteristic analysis was performed to determine differences between ECG-synchronized CT scan and CTA in predicting outcome.
Results: In 113 patients with PE, RV and LV ejection fraction (EF) and RV/LV diameter and volume ratios were associated with adverse outcome (P < .05), whereas vascular obstruction index was not. RVEF had the largest area under the receiver operating characteristic curve (0.75; 95% CI, 0.62-0.88) for predicting adverse outcome but had no significant incremental value over the RV/LV function ratio (0.72; 95% CI, 0.57-0.86; P = .25). All parameters revealed high negative predictive values (94%-98%) but low positive predictive values (13%-18%). For disease-specific outcome, areas under the curve were 0.80 (95% CI, 0.69-0.91) for RVEF vs 0.68 (95% CI, 0.48-0.88) for axial RV/LV ratio; the difference was not significant (P = .07). RVEF and RV/LV ratio proved better predictors for outcome than pulmonary obstruction index (both P < .001).
Conclusions: RVEF was the best predictor for clinical outcome in patients with acute PE. However, incremental value of RVEF over axial RV/LV ratio was not found.