Background: Microbubble safety concerns led to changes in product recommendations for patients with pulmonary hypertension. Noninvasive estimation of right ventricular systolic pressure (RVSP) is equivalent to pulmonary artery systolic pressure in the absence of pulmonary outflow obstruction. We analyzed the short- and long-term outcomes of patients who received microbubble contrast and those who did not during stress echocardiography (SE) according to resting RVSP.
Methods and results: From November 2003 to December 2007, 26,774 patients underwent SE. RVSP (mean, 32.6+/-9.6 mm Hg) was measured in 16 434 patients. Of these, 6164 (37.5%) received contrast for left ventricular opacification and 10 270 (62.5%) did not. Short-term (< or =72 hours and < or =30 days) and long-term (4.3 years) end points were death and myocardial infarction. Analysis was done for rest RVSP cut-points > or =35, > or =50, and > or =60 mm Hg and tricuspid regurgitant velocities > or =2.7 ms(-1) and > or =3.5 ms(-1). Adjusted Cox regression models were used. The contrast cohort comprised older patients (age, 67+/-12 versus 64+/-14 years; P<0.001), who were more likely to have positive SE results (35% versus 30%, P<0.001) compared with the noncontrast cohort. Using RVSP > or =50 mm Hg, there was no significant difference in short-term events between the contrast and noncontrast cohorts. For long-term events, there was no significant difference between both cohorts (adjusted hazard ratios [95% confidence intervals] for death, 1.10 [0.80 to 1.50], P=0.56; and myocardial infarction, 0.34 [0.11 to 1.03], P=0.06). Similar results were obtained at different RVSP and tricuspid regurgitant cut-points. Contrast agent-related adverse effects occurred in <1% of patients.
Conclusions: RVSP had no impact on predisposition to adverse outcomes in patients undergoing contrast SE in the population studied.