Dobutamine echocardiography in patients with aortic stenosis and left ventricular dysfunction - Predicting outcome as a function of management strategy

Study objective: To prospectively address the question whether the assessme nt of valvular hemodynamics and myocardial function during low-dose dobutam ine infusion can guide decision making in patients with aortic stenosis and left ventricular (LV) dysfunction. Patients and measurements: Twenty-four patients with aortic stenosis and LV dysfunction (mean ejection fraction, 28%; New York Heart Association class , II to IV) were studied by dobutamine echocardiography assessing mean pres sure gradient, aortic valve area, and aortic valve resistance. Patients wer e prospectively divided into severe and nonsevere aortic stenosis groups ac cording to the response of the valve area to the augmentation of systolic f low. The clinical decision was considered to be concordant with the results of dobutamine echocardiography, when patients with severe aortic stenosis and preserved contractile function were referred by a specialist for aortic valve replacement and when patients with nonsevere aortic stenosis were no t. Patients were observed for up to 3 years. Results: Ail eight patients with severe aortic stenosis who were referred f or surgery survived and had good I cardiovascular outcomes, and six of eigh t patients who were not initially referred for surgery had poor outcomes, i ncluding heart failure and sudden cardiac death. The eight patients with no nsevere aortic stenosis did comparatively well without valve replacement Ca rdiac death or pulmonary edema occurred in 4 of 16 patients (25%) when the clinical decision was concordant with the results of the dobutamine echocar diogram and occurred in 6 of 8 patients (75%) when the clinical decision wa s discordant (p = 0.019 [chi (2) test]). Conclusion: Patients with aortic stenosis, LV dysfunction, and relatively l ow gradients have better outcomes when management decisions are based on th e results of dobutamine echocardiograms. Those patients identified as havin g severe aortic stenosis and preserved contractile reserve by dobutamine ec hocardiography should undergo surgery, while patients identified as having nonsevere aortic stenosis can be managed conservatively.