The value of ultrasound enhancing agents in the echocardiographic acquisition of pulmonary artery systolic pressure: An invasive to non-invasive correlation study.

Abstract

Right heart catheterization (RHC) is the gold standard for the assessment of pulmonary artery systolic pressures (PASP). Despite high utilization of echocardiography for the non-invasive assessment of PASP, the data comparing real-time non-invasive echocardiographic PASP with invasive PASP is limited. Furthermore, evidence regarding the utility and diagnostic accuracy of ultrasound enhancing agents (UEA) for non-invasive PASP assessment is lacking. To evaluate the accuracy of non-invasive PASP assessment with real-time invasive measures and the incremental benefit of UEA in this setting. This was a prospective cohort study of 90 patients, undergoing clinically indicated RHC for hemodynamic assessment. All patients underwent a limited echocardiogram during RHC. Tricuspid regurgitant velocity (TRV) was measured on unenhanced echo, in the setting of centrally administrated agitated saline, then as either centrally administered or peripherally administered UEA. Of the 90 patients enrolled in our study, 41% had pulmonary hypertension. The overall mean PASP measured by RHC was 32.8 mmHg (+/- 11.3 mmHg). Unenhanced echocardiograms had a moderate correlation with invasive PASP (r = 0.57; p = < 0.001) which improved to a strong correlation with administration of agitated saline (r = 0.75; p = < 0.001) or centrally administered UEA (r = 0.77; p = < 0.001), with the best correlation noted with peripherally administered UEA (r = 0.83; p = < 0.001). Against invasive PASP, agitated saline enhanced PASP had the lowest bias (0.12mmHg; -15.6 to 15.8mmHg) when compared with all other non-invasive measures of PASP. Unenhanced echocardiographic estimation of TRV was found to have a poorer correlation with invasively measured PASP when compared to agitated saline and centrally administered UEA. Agitated saline enhanced PASP demonstrated the lowest bias with invasive PASP when compared to other non-invasive measures of PASP.