Dobutamine Stress Echocardiography for Predicting the Postoperative Recovery of Left Ventricular Function in Patients with Chronic Severe Aortic Regurgitation: A Comparative Prospective Study

Abstract
Background: Patients with chronic severe aortic regurgi-tation often present to our practice at a late stage. Patients with poor left ventricular function may or may not improve functionally or by left ventricular dimensions after surgery.
Aim of Study: We aim to answer this question; can dob-utamine stress echocardiography predict the postoperative recovery of left ventricular function in patients with chronic severe aortic regurgitation?
Patients and Methods: This is a comparative prospective study from December 2014 to December 2015 in which we studied 49 patients undergoing aortic valve replacement for chronic severe aortic regurgitation. Patients were divided into 2 groups according to their resting ejection fraction, Group I with ejection fraction <50% and Group II with ejection fraction >50%. Group I was further divided into Ia and Ib. Group IA included 16 patients who respond to dobutamine infusion by increase in ejection fraction >30%. Group IB included 16 patients who respond to dobutamine by increase in ejection fraction <30%. All the relevant clinical data was collected from all patients pre-operatively and 3 month follow-up visit. All patients in were stressed by infusion of dobutamine 20ugm/kg/min and the change in their End Systolic Volume (ESV) and End Diastolic Volume (EDV) and Ejection Fraction (EF) were evaluated.
Results: There was no hospital or 3 months mortality for the whole group. For Group II, the comparison between the response to aortic valve replacement and peak dobutamine reveals: The mean 3 months post-operative EF 56.87±6.03%. The peak dobutamine EF was 68.3±7.5%. There was statisti-cally significant difference between the 2 values (p-value <0.001) i.e there relation was not obvious in this group.
For Group IA; the mean 3 months post-operative EF was 44.27±8.78%. The peak dobutamine EF was 47.2±10.69%. There was no statistically significant difference between the 2 values (p-value=0.177). For Group IB; the mean 3 months post-operative EF was 37.75±13.7%. The peak dobutamine EF was 41.33±7.44 %. There was no statistically significant difference between the 2 values (p-value=0.175).
Conclusion: Dobutamine stress echocardiography was found to be predictor for post-operative left ventricular function in patients with chronic severe aortic regurgitation and impaired function.