Enoximone Echocardiography for Predicting Recovery of Left Ventricular Dysfunction After Revascularization

Abstract

Background —The possibility that enoximone, a nonglycoside, noncatechol, positive inotropic agent, in combination with 2-dimensional echocardiography may predict recovery of myocardial dysfunction after revascularization has not been yet evaluated. Methods and Results —Forty-five patients with chronic coronary artery disease and left ventricular dysfunction underwent dobutamine (DE, 5 to 10 μg · kg −1 · min −1 ) and enoximone (EE, 1.5 mg/kg, over 10 minutes) echocardiography. Myocardial wall motion was scored from 1 (normal) to 4 (dyskinesia): an asynergic segment was considered to have contractile enhancement when the score decreased by ≥1 grade. Of 478 asynergic segments, 216 (45%) exhibited functional recovery after revascularization. Dobutamine- and enoximone-induced contractile enhancement was observed in 41% and 46% of segments, respectively. Compared with DE, EE had higher sensitivity (88% versus 79%, P <0.01) and negative predictive value (90% versus 84%, P <0.05) in predicting functional recovery. The specificity (89% versus 90%) and positive predictive value (87% for both EE and DE) were similar. Concordant interpretation of EE and DE findings was found in 85% (406 of 478) of affected segments. Prerevascularization coronary angiography showed that stenosis severity of vessels supplying areas which only improved with enoximone was significantly greater (89.9%) than that of vessels (77.7%) supplying areas that responded to both agents ( P <0.02). Both dobutamine and enoximone increased heart rate (16% and 10%, respectively), whereas enoximone did not cause changes in systolic blood pressure that increased by 14% with dobutamine. Conclusions —Enoximone echocardiography provides a novel and reliable approach for the prediction of functional recovery after revascularization. Compared with dobutamine echocardiography, the test yields higher sensitivity and induces lesser hemodynamic alterations.

Enoximone echocardiography: a novel test to evaluate left ventricular contractile reserve in patients with heart failure on chronic beta-blocker therapy

“…These results are consistent with the theoretical background and the results of studies of post-infarction patients [3,4]. …”

“…Another study used enoximone echocardiography to predict functional recovery after myocardial revascularisation, and found that it was more sensitive and had a greater negative predictive value than dobutamine, and also induced fewer hemodynamic alterations [4]. Finally, enoximone has been combined with very low-dose dobutamine in order to detect myocardial viability in the infarcted myocardium of patients with severe heart failure and life-threatening arrhythmias [18].…”

“…Dobutamine echocardiography was performed using a low-dose protocol with incremental doses of 5 and 10 μg/kg/min at 10-minute intervals; the images were taken at baseline and at the end of each infusion step. Enoximone echocardiography was performed using a dose of 1.5 mg/kg, which was chosen on the basis of the results of a previous study showing that it had 87% sensitivity for predicting functional recovery after revascularisation [4]. The enoximone was diluted with saline to a concentration of 2.35 mg/mL in order to avoid a peripheral venous burning sensation, and infused over ten minutes.…”

“…Its effectiveness is therefore not impaired by beta-adrenoceptor down-regulation or the administration of beta-blocking agents [2]. A number of studies have previously demonstrated the feasibility and safety of enoximone stimulation in evaluating myocardial viability in patients with ischemic heart disease [3,4], and so the aim of this prospective study was to compare the feasibility of enoximone and conventional low-dose dobutamine echocardiography in assessing myocardial contractile reserve in chronic heart failure patients. We also evaluated regional myocardial function as recent studies have suggested that tissue Doppler is more accurate in identifying myocardial ischemia or viability than conventional stress echocardiography [5-7].…”

Stress echocardiography in heart failure

“…At least two drugs have these proprieties: the dobutamine, a synthetic β1 agonist with additional α1- and β2-stimulating properties and the enoximone that inhibits cyclic adenosine monophosphate-specific phosphosdiesterase [6,7]. Routinely, the dobutamine is the most common stressor used, whereas the enoximone is particularly useful in patients on beta-blocker therapy [7,8]. The mechanism by which dobutamine stimulation elicits a contractile response in hypoperfused dysfunctional segments without precipitating ischemia has been demonstrated by Sun et al [6].…”