Dobutamine echocardiographic study in patients with nonischemic dilated cardiomyopathy and prognostically borderline values of peak exercise oxygen consumption: 18-month follow-up study

OBJECTIVES We sought to study the prognostic value of dobutamine echocardiography in patients with nonischemic dilated cardiomyopathy (DCM) and prognostically borderline values of peak oxygen consumption (Vimage2max) during exercise. BACKGROUND Changes in echocardiographic variables assessed by dobutamine echocardiography can be used to evaluate the functional status of patients with chronic heart failure (CHF) and DCM. METHODS In 27 consecutive patients (mean age 55 ± 15 years) with Vimage2max values between 10 and 14 ml/kg body weight per min, a low infusion rate (10 μg/kg per min) dobutamine echocardiographic test was performed. The induced changes in echocardiographic variables were measured, and an 18-month follow-up study was done. RESULTS At the end of the protocol, 9 patients (group I) had died from cardiac reasons, whereas the remaining 18 patients (group II) survived. After dobutamine infusion, the left ventricular end-systolic diameter (LVESD) was smaller in group II (6.22 ± 0.94 cm) than in group I (6.99 ± 0.76 cm; p < 0.05), whereas end-systolic wall stress (ESWS) was higher in group I (1030.66 ± 193.98 g/cm2) than in group II (691.57 ± 297.06 g/cm2; p < 0.05). The changes in LVESD and ESWS were greater in group I (0.75 ± 0.36 cm and 463.11 ± 159.87 g/cm2, respectively) than in group II (−0.04 ± 0.36 cm and 83.16 ± 291.74 g/cm2, respectively; p < 0.01 for both). CONCLUSIONS In the “gray” zone of Vo2max, dobutamine echocardiography seems to be a valuable prognostic indicator in patients with CHF and DCM.