Myocardial Contrast Echocardiography for the Detection of Coronary Artery Disease in Patients with Global Hypokinesis Admitted for First-Onset Acute Heart Failure: Pilot Study

BACKGROUND The non-invasive differentiation of ischemic and nonischemic acute heart failure (AHF) not resulting from acute myocardial infarction is difficult and has therapeutic and prognostic implications. The aim of this study was to assess whether resting myocardial contrast echocardiography (MCE) can detect coronary artery disease (CAD) in patients with decreased left ventricular (LV) systolic function and global hypokinesis presenting with AHF. METHODS Twenty-one consecutive patients underwent low-power real-time MCE based on color-coded pulse inversion Doppler. Standard apical LV views were acquired during contrast IV infusion of Definity®. Following transient microbubbles destruction, the contrast replenishment rate (β), reflecting myocardial blood flow velocity, was derived by plotting signal intensity vs. time and fitting data to the exponential function: y (t) = A (1 - e(-β(t-t0))) + C. RESULTS Of the 21 (mean age 56.6 ± 13.6 years) patients, 5 (23.8%) demonstrated flow-limiting CAD (> 70% of luminal diameter narrowing). The mean ± standard deviation of LV ejection fraction was 29.6 ± 8.6%. Quantitative MCE analysis was feasible in 258 of 378 segments (68.3%). There were no significant difference in "β" and "Aβ" in patients without and with CAD (0.48 ± 0.27 vs. 0.45 ± 0.25, p = 0.453 for β and 2.99 ± 2.23 vs. 3.68 ± 3.13, p = 0.059 for Aβ, respectively). No contrast-related side effects were reported. CONCLUSION Resting quantitative MCE analysis in patients with AHF was feasible, however, the parameters did not aid in detecting of CAD.