Investigation of the change in myocardial blood flow by perfusion CMR after revascularisation of chronically occluded coronary arteries
© Zaman et al; licensee BioMed Central Ltd. 2011
Published: 2 February 2011
The perceived clinical benefits of undertaking revascularisation to coronary artery chronic total occlusions (CTO) relate to improvements in angina symptoms and prognosis1,2. Long term survival benefits from CTO revascularisation has been suggested in several large observational studies despite a significant failure rate1,3. Data about the physiological consequences of successful opening of a CTO are limited and heterogeneous4. CMR imaging can provide quantitative information on MBF (myocardial blood flow) in this context.
To determine changes in hyperaemic myocardial blood flow in patients undergoing revascularisation of CTO.
Twenty patients with CTO were recruited from clinical waiting lists and underwent perfusion-CMR before and after attempted CTO revascularisation on a Philips 1.5 T Intera system. Perfusion imaging was performed every heartbeat during the first pass using a T1-weighted fast (spoiled) GE sequence in 3 short-axis imaging planes. Stress perfusion imaging was performed using IV adenosine for 4 minutes (at 140mcg/kg/min) and 0.05 mmol/kg of gadolinium chelate via a power injector. The dynamic contrast enhanced image data were post-processed off-line using the software PMI 0.45. Following motion correction, a circular ROI was selected in the left ventricle to measure the arterial input function. MBF maps were created by model-free analysis. Two myocardial ROIs were drawn on these maps, one in the CTO territory and one in a remote normal region. MBF for these ROIs was calculated using the Fermi model6. Statistical calculations were performed using SPSS.
Stress perfusion CMR demonstrates significant improvements in hyperaemic MBF in patients with successful revascularisation of CTO.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.