Improving bicycle stress echo accuracy with Albunex

Specificity of bicycle exercise echo (ExE) may be limited by poor visualization of LV segments. Albunex enhances feasibility of pharmacologic stress echo, but its efficacy with ExE is unclear We studied the effect of Albunex (0.3 mL/kg at 1 mL/sec) on the accuracy of ExE for detecting LV wall motion abnormalities in 62 pts with known or suspected CAD undergoing symptom-limited upright bicycle ExE. Digitized quad-screen echos were read separately with and without Albunex enhancement of peak stress apical 4- and 2- chamber views. Pts with >50% stenoses at angiography were identified as having significant CAD. Pts were designated without CAD if stenoses were <50% or (in those not undergoing angiography) pre-test CAD probability <15% (based on age, gender, and symptom status). Results: Of 62 pts undergoing ExE, 21 also underwent coronary angiography. Fourteen pts had significant CAD. No significant CAD was present in 7 pts, another 17 pts had low pre-test probability of CAD. Albunex did not alter the sensitivity of ExE (unenhanced = 71%, Albunex = 71%), However, Albunex improved the specificity of ExE by 25% (unenhanced = 58%, Albunex = 83%; p=0.057). Of 49 ExE performed at our institution, 73% had adequate LV opacification with Albunex in at least one apical view. Impaired LV systolic function was significantly more common in those with inadequate LV opacification (inadequate = 23%, adequate=3%; p=0.05). Conclusions: Albunex contrast enhancement in upright bicycle exercise echo improves specificity to 83% while maintaining sensitivity at 71% for the detection of CAD. However, pts with impaired LV systolic function may show inadequate LV opacification with Albunex.