Acute mortality in hospitalized patients undergoing echocardiography with and without an ultrasound contrast agent (multicenter registry results in 4,300,966 consecutive patients).

We sought to define acute mortality in a large multicenter cohort of hospitalized patients undergoing clinically indicated echocardiography with and without use of an ultrasound contrast agent. Although the United States Food and Drug Administration recently relaxed the issued warnings for perflutren-containing ultrasound contrast agents on May 13, 2008, concerns still exist regarding the safety of these compounds, particularly in critically ill patients. A retrospective analysis was performed using the Premier Perspective Database. Patients undergoing echocardiography during hospitalization were separated into those performed without contrast enhancement and those performed with perflutren lipid microsphere (PLM) injectable suspension contrast agent (Definity, Lantheus Medical Imaging, North Billerica, Massachusetts). Vital status within 1 day of the echocardiogram was available for all patients using hospital billing data. Between January 1, 2002 and October 31, 2007, 4,300,966 patients underwent transthoracic echocardiography at rest during hospitalization (unenhanced studies n = 4,242,712 and contrast-enhanced studies n = 58,254). Multivariate logistic regression analysis was used to compare 24-hour mortality, controlling for case mix and clinical covariates; 1-day mortality rates were 1.08% (n = 45,789 deaths) for patients undergoing noncontrast studies and 1.06% (n = 616 deaths) for patients undergoing contrast-enhanced examinations (p = 0.613). Multivariate logistic regression analysis revealed that, in patients undergoing an echocardiogram, patients receiving PLM injectable suspension contrast agent were 24% less likely to die within 1-day than patients not receiving a contrast agent (adjusted odds ratio = 0.76, 95% confidence interval 0.70 to 0.82). In conclusion, acute crude mortality was not increased in patients receiving PLM injectable suspension contrast agent. Multivariate logistic regression analysis revealed that, compared with patients not receiving a contrast agent, administration of PLM injectable suspension contrast agent during echocardiography was associated with a 24% decreased risk of mortality.