Volume 18 Supplement 1
Role of adenosine Stress CMR before Chronic Total Occlusion reopening
© Monti et al. 2016
Published: 27 January 2016
Conflicting data exists on the usefulness of a perfusion stress test prior to reopening a chronically occluded coronary artery (CTO). We sought to test whether a stress MR may improve patient selection for Chronic Total Occlusion (CTO) reopening over a conventional LGE study.
70 CTO patients without any other relevant coronary artery stenosis (or already treated if present at baseline angiography), underwent an adenosine stress CMR before a reopening attempt. ECG and echocardiographic (echo) data were available for all. Patients were considered suitable for the reopening procedure in case of myocardial ischemia and / or viable myocardium subtended to the CTO.
Presence of a previous myocardial infarction (MI) was defined at ECG: Q waves > 40 msec; at echo: akinetic areas with reduced wall thickness; at stress MR: presence of ischemic Late gadolinium Enhancement.
Presence of myocardial ischemia was defined as a subendocardial perfusion defect lasting for at least 4 heart beats during adenosine infusion in a segment without LGE.
ISCHEMIA: adenosine stress MR showed a perfusion abnormality in 100% of CTO territory. Inducible ischemia was observed in 71% of cases, with a perfect concordance with CTO occlusion.
PREVIOUS MI: using CMR as the gold standard for the diagnosis, the prevalence was globally high: 69% in our series. Both ECG and echo significantly underestimate this data (36% and 53% respectively). Presence of LGE in different sites from the CTO territory was often observed: in fact, only 58% of patients with LGE had it exactly in the CTO territory. At echo, 82% of pts with wall motion abnormality (WMA) had it described in CTO segments: this can be explained with a portion of patients with viable, non-ischemic myocardium. The true prevalence of LGE in CTO segments was 40% for the whole population, but only 13% (n = 9) of patients showed a mean LGE transmurality >50%, contraindicating a reopening attempt. These patients were not identified by echo that identified 30 patients with akinetic areas subtended to a CTO.
Perfusion stress MR did not show any additional diagnostic value in our population of patients with CTO and known coronary anatomy, since a perfusion abnormality was observed in all patients.
Previous MI in CTO patients
ECG (Q waves)
ECHO (akinesia + wall < 6 mm)
Ischemic LGE pattern
Global prevalence of diagnostic criterion
36% (n = 25)
53% (n = 37)
69% (n = 48)
Correct site of a positive criterion
80% (n = 20)
81% (n = 30)
58% (n = 28)
Previous MI in the CTO territory
29% (n = 20)
43%(n = 30)
40% (n = 28)
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