PURPOSE: Patients with Acute Pulmonary Embolism (APE) have been traditionally classified based on their hemodynamic stability. Recent data suggests that patients with normal Blood Pressure (BP) and right ventricular dysfunction (RVD) have higher short term mortality than patients with normal BP without RVD. However, the echocardiogram is operator dependent and may not be readily available. We evaluated the usefulness of the 12-lead electrocardiogram (ECG) and Troponin to predict the presence of RVD by echocardiogram in the setting of APE.
METHODS: We retrospectively reviewed 66 consecutive patients (age 63.7 ± 16.8, 38.4% male) with documented APE between July/2005 and March/2006. All patients had an ECG (considered abnormal if the presence of either Sinus Tachycardia, T-wave inversion V1-V3, Right Bundle Branch Block, or S1Q3T3 pattern was noted), Troponin and echocardiogram within 48 hours of diagnosis. Exclusion criteria were Left Ventricular dysfunction with ejection fraction <35%, Chronic Obstructive Pulmonary Disease and known history of pulmonary hypertension. We analyzed the data with Chi-square test/SPSS 13.0 software.
RESULTS: Of the 66 study patients 34 had RVD (pretest probability 52%). In the abnormal ECG group 31 of 40 patients (77.5%) had RVD, compared to 3 of 26 (11.5%) in the negative ECG group (sensitivity 91%, specificity 72%, positive and negative likelihood ratios -LR- 3.25 and 0.13, posttest probability -PTP- 78% and 12% respectively, p<0.001). In the elevated Troponin group 27 of 34 patients (79.4%) had RVD, compared to 7 of 32 (21.9%) in the negative Troponin group (sensitivity 79%, specificity 78%, positive and negative LR 3.59 and 0.23, PTP 79% and 22% respectively, p<0.001). In the negative Troponin/negative ECG group 0 of 19 patients had RVD (negative LR 0, PTP 0%, p<0.001). In the elevated Troponin/abnormal ECG group 24 of 27 patients had RVD (positive LR 7.9, PTP 89%, p<0.001).
CONCLUSION: The combination negative ECG/negative Troponin excludes RVD. The combination elevated Troponin/abnormal ECG has a high predictive value of RVD.
CLINICAL IMPLICATIONS: An echocardiogram is not warranted in patients with a negative ECG and a negative Troponin.
DISCLOSURE: Natalia Moguillansky, None.