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.
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.
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).
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.