Low dose dobutamine echo cardiography for predicting functional recovery after coronary revascularisation

Objective-To evaluate the effects of chronic coronary occlusion on the accu racy of low dose dobutamine echo cardiography in predicting recovery of dys functional myocardium after revascularisation. Design-Retrospective study. Setting-Tertiary referral centre. Patients-53 consecutive patients with greater than or equal to 70% stenosis of the left anterior descending coronary artery (LAD) and regional ventric ular dysfunction (group 1, non-occluded LAD; group 2, occluded LAD) who und erwent dobutamine echocardiography. Interventions-26 patients underwent coronary artery bypass grafting and 27 had percutaneous transluminal coronary angioplasty. Main outcome measures-Baseline studies before revascularisation included cr oss sectional echocardiography at rest and during dobutamine infusion (5-10 mug/kg min), and coronary angiography. The dobutamine study was performed mean (SD) 35 (28) days before revascularisation. Echo cardiography at rest was repeated 90 (48) days after revascularisation. Results-Of 296 dysfunctional segments, 63 in group 1 (43%; 63/146) and 69 i n group 2 (46%; 69/150) (NS) improved at follow up. Mean (SD) regional wall motion score index decreased from 1.97 (0.48) (95% confidence interval (CI ) 1.01 to 2.93) before revascularisation to 1.74 (0.52) (95% CI 0.70 to 2.7 8) at follow up in group 1 (p = 0.001), and from 2.12 (0.41) (95% CI 1.30 t o 2.98) to 1.88 (0.36) (95% CI 1.16 to 2.60) in group 2 (p = 0.0006). In gr oup 1, sensitivity (87% v 52%; p < 0.0001), negative predictive value (88% v 65%; p = 0.001), and accuracy (77% v 64%; p = 0.01) were all significantl y higher than in group 2, despite the angiographic evidence of collaterals in patients with occluded vessels. Conclusions-Dobutamine echocardiography shows reduced sensitivity in predic ting recovery of dysfunctional myocardium supplied by totally occluded vess els. Thus caution should be used in selecting such patients for revasculari sation on the basis of a viability assessment made in this way.