Myocardial blood volume reserve by intravenous contrast echocardiography predicts improvement in left ventricular function in patients with nonischemic dilated cardiomyopathy.

Background: Impaired myocardial perfusion has been shown in nonischemic dilated cardiomyopathy (DCM). Intravenous myocardial contrast echocardiography (MCE) has been introduced to examine myocardial blood volume (MBV) noninvasively. This study was designed to evaluate if MBV reserve assessed by intravenous MCE with adenosine triphosphate (ATP) can predict efficacy of optimal medical therapy in patients with DCM.

Methods And Results: Fifteen DCM patients and 8 control subjects underwent conventional echocardiography and intravenous MCE. We obtained the change in peak contrast integrated backscatter intensity (∆PI) by ATP on the left ventricular (LV) anteroseptal myocardium. After 3 months of optimal medical therapy in DCM patients, we reperformed conventional echocardiography. A good responder to therapy was defined as a decrease in LVDd >5 mm to final LVDd <55 mm and increase in LVEF >20 % to final LVEF >45 %. In DCM patients, ∆PI was lower compared to controls (p < 0.001). Good responders to therapy (n = 6) had higher ∆PI than poor responders (n = 9) (p < 0.05).

Conclusions: The present study demonstrates that the response to the medical therapy in DCM is predicted by the assessment of dilator reserve in MBV. Intravenous MCE with ATP may provide useful information to evaluate MBV reserve.