Agitated colloid is superior to saline and equivalent to Levovist in enhancing tricuspid regurgitation Doppler envelope and in the opacification of right heart chambers: A quantitative, qualitative, and cost-effectiveness study

Background: Doppler spectrum of tricuspid regurgitation (TR) is used to noninvasively assess right ventricular (RV) pressure. With mild TR, the native (Nat) TR envelope may not allow accurate pressure evaluation. Proprietary contrast agents, such as Levovist (Lev) can be used to augment TR Doppler and opacify right-sided heart chambers, but they are expensive, and their efficacy has not been objectively evaluated in patients with difficult baseline studies or compared with less expensive saline (Sal) or colloid solutions, such as Gelofusine (Gel). Methods. Twenty-five consecutive patients with poor quality Nat TR envelopes on transthoracic echocardiogram were reexamined after serial intravenous injection of 3 contrast agents (Sal, Gel, and Lev). Doppler signals for each agent recorded on video and digitally on optical disk were assessed for signal quality, estimated RV pressure, interobserver and intraobserver variation, and longevity of signal. Quality of right ventricular-right atrial (RV-RA) opacification was also determined for Sal and Gel. Of the 25 patients, 9 under-went percutaneous right-sided heart catheterization. We used the pressures obtained from the catheterization to independently evaluate the pressure estimates from echocardiography. Results: All 3 contrast agents significantly improved the mean quality grade (grades 0-5) of TR envelopes (Nat 1.12, Sal 1.97, Gel 2.56, Lev 2.41, P < .001), decreased the number of uninterpretable envelopes (grade 0) (Nat 49%, Sal 12%, Gel 4%, Lev 12%, P < .0001 for comparison of each agent relative to Nat), and improved the correlation between echocardiographic and catheter-derived RV-RA pressure measurements (Nat r = 0.65, Sal r = 0.75, Gel r = 0.90, Lev r = 0.88). The persistence of enhanced Doppler signals of interpretable quality (> grade 1) was greater for Lev (15.8 seconds) and Gel (15 seconds) than Sal (7.6 seconds) (P = .002). Opacification of RV and RA, measured as mean luminosity score during 2-dimensional harmonic imaging, was significantly higher for Gel than Sal (92.84 +/- 31.2 vs 56.06 +/- 25.6, respectively; P = .0003). Sal, Gel and Lev, respectively, cost $0.10, $2.50, and $75.00 per study. Conclusion: Agitated colloid is a novel, effective, and inexpensive alternative to proprietary agents and saline for the assessment of pulmonary systolic pressure and right-sided heart opacification.