[Predictors of myocardial contractile reserve in patients with nonischemic dilated cardiomyopathy. An echo-stress dobutamine study].
OBJECTIVE
Myocardial contractile reserve studies with low-dose dobutamine echocardiography have been shown to be useful to assess functional myocardial status. However, the variables associated with contractile reserve after inotropic stimulation are not well known.


METHODS
We studied 50 patients (35 men, mean age 56.4 +/- 9.5 years) with nonischemic dilated cardiomyopathy (NIDC), LVEF 28.7% +/- 8.5% and wall motion score index (WMSI) 2.42 +/- 0.34 with low-dose dobutamine echocardiography. Left ventricular contractile reserve was assessed by a differential parameter defined as the difference between rest and stress WMSI (DeltaWMSI).


RESULTS
After dobutamine infusion the WMSI was 1.95 +/- 0.58; from this value we calculated a DeltaWMSI of 0.45 +/- 0.39. None of the clinical variables showed a relationship with the presence of contractile reserve. In contrast, the following echocardiographic parameters correlated with DeltaWMSI: end-diastolic (p=0.05) and end-systolic (p=0.02) diameters, end-systolic volume index (p=0.01) and LVEF (p=0.002). In the multivariate analysis, only end-diastolic diameter was an independent predictor of contractile reserve (hazard ratio=0.852; 95% CI, 0.735-0.987; p=0.03).


CONCLUSIONS
Ventricular diameters, end-systolic volume index and LVEF are related with improvements in myocardial contractility after dobutamine infusion, although only end-diastolic diameter was an independent predictor of contractile reserve. Thus, this parameter should receive particular attention in evaluations of the functional status of the myocardium in patients with NIDC.
Pérez-Paredes
Matías
M
Unidad de Cardiología, Laboratorio de Ecocardiografía, Hospital Universitario Morales Meseguer, Murcia, España. matiasperez@medynet.com
Carnero
Andrés
A
Giménez
Diego M
DM
Ruiz Ros
José A
JA
Gonzálvez
Manuel
M
Carrillo
Andrés
A
Cascales
María J
MJ
Martínez-Corbalán
Francisco
F
Villalba
María J G
MJ
Cubero
Tomás
T
D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011237:Predictive Value of Tests