Does resting echocardiography predict a positive response to subsequent low-dose dobutamine stress echocardiography in patients with ischaemic cardiomyopathy?

Abstract

Objective We explored the accuracy of resting echocardiographic and tissue Doppler parameters to predict a positive response by low-dose dobutamine stress echocardiography (DSE) in patients with ischaemic cardiomyopathy.Methods and results We enrolled 100 consecutive patients with prior myocardial infarction, and a left ventricular ejection fraction (LVEF) <35%. They underwent resting echocardiographic assessment of LVEF, wall motion score index (WMSI), mitral E and A peak velocities, E/A ratio, E peak deceleration time, isovolumetric relaxation time (IVRT), early mitral annular diastolic velocity (e’), and E/e’ ratio. Subsequently, they underwent low-doseDSE for assessment of myocardial viability. The presence of viability was defi ned by improvement of the regional wall motion score by ≥ 1 grade in ≥ 5 myocardial segments, with ≥ 20% reduction in WMSI compared with baseline evaluation. Thirty-six patients had a negative response to DSE (group I); 64 had a positive response (group II). Resting LVEF was higher, and resting WMSI lower in group II versus group I; E peak deceleration time and IVRT shorter in group I (P < 0.05 for all). Multivariable regression analysis identifi ed LVEF, WMSI, and IVRT as the independent predictors of a positive response to DSE. A cutoff value of LVEF of > 25% predicted viability with a sensitivity of 85.9%, specifi city 80.6%; WMSI of ≤ 2.6 had a sensitivity of 85.7%, specifi city 61.1%; IVRT of > 60 msec had a sensitivity of 93.7%, specifi city 47.2%.Conclusions Resting LVEF > 25%, WMSI ≤ 2.6, and IVRT > 60 msec predicted viability with a high sensitivity; however, with the exception of LVEF, specifi city was quite low.