Interobserver reliability of echocardiography for prognostication of normotensive patients with pulmonary embolism

OBJECTIVES To evaluate the interobserver reliability of echocardiographic findings of right ventricle (RV) dysfunction for prognosticating normotensive patients with pulmonary embolism (PE). METHODS A central panel of cardiologists evaluated echocardiographic studies of 75 patients included in the PROTECT study for the following signs: RV diameter, RV/left ventricular (LV) diameter ratio, hypokinesis of the RV free wall, and tricuspid plane systolic excursion (TAPSE). Investigators used intraclass correlation to assess agreement between the measurements of the central panel and each of the local cardiologists. Investigators used the single weighted kappa statistic to test for agreement between readers of interpretation of RV enlargement and RV hypokinesis. RESULTS The two observers had fair agreement (k = 0.45) for RV enlargement assessed by the RV diameter, and good agreement (k = 0.65) for RV enlargement assessed by the RV/LV diameter ratio. The interobserver reliability of the assessment whether hypokinesis of the RV free wall is present was good (к = 0.70), and whether RV dysfunction (assessed by TAPSE measurement) is present was very good (k = 0.86). The intraclass correlation for the RV/LV diameter ratio was fair (0.55; 95% confidence interval [CI], 0.37-0.69), for the RV diameter was good (0.70; 95% CI, 0.56-0.80), and for the TAPSE measurement was very good (0.85; 95% CI, 0.77-0.90). On Bland-Altman analysis, the mean differences for RV diameter, RV/LV diameter ratio and TAPSE measurement were 2.33 (±5.38), 0.06 (±0.23) and 0.08 (±2.20), respectively. CONCLUSION TAPSE measurement is the least user dependent and most reproducible echocardiographic finding of RV dysfunction in normotensive patients with PE.