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Figure 1 Changes in MBF in Segments Subtended by a Stenosis and Remote Segments in the 3 Patient Groups

Each myocardial segment is represented by a circle at each time point, with larger circles denoting greater transmural extent of infarction (TEI). Mean ± standard error of the mean are displayed for each time point. Hyperemic myocardial blood flow, measured in ml/min/g, in territories subtended by a chronic total occlusion (CTO) (stenosed segments) decreased significantly with increasing TEI. At baseline, stenosed segments had significantly worse hyperemic myocardial blood flow (MBF) in all patient groups. In both intervention groups, hyperemic MBF was greater in treated segments, relative to baseline, at both 24 h (24h) and 6 months (6m) after percutaneous coronary intervention (PCI), such that the differences in hyperemic MBF between treated segments and remote segments were no longer significant. There was no change in hyperemic MBF in untreated CTO segments or remote segments. Untreated CTO segments had lower hyperemic MBF than treated CTO segments at 6-month follow-up. *p < 0.01 for comparison with baseline; p < 0.01 for comparison between stenosed and remote segments at the same time point; p < 0.01 for comparison with CTO PCI group at the same time point. MRI = magnetic resonance imaging.