Introduction Patients with three-vessel disease (3VD) have a worse prognosis than those with less extensive disease; but detecting a 3VD pattern of ischaemia can be very challenging due to balanced hypoperfusion. However, a large ischaemic burden can also correctly stratify patients with 3VD as high-risk and prompt the appropriate management. We hypothesised that high-resolution perfusion-CMR would detect more ischaemic burden than standard-resolution due to better detection of subendocardial ischaemia. This study compared ischaemic burden detected by standard-resolution and high-resolution cardiovascular magnetic resonance (CMR) perfusion imaging in patients with 3VD.

Methods CAD was defined as coronary stenosis >70% (QCA). 48 patients (24 with 3VD; 24 with no CAD) underwent stress/rest perfusion-CMR (1.5T Philips) with standard-resolution (2.5 mm in-plane) using twofold SENSE and on a separate visit high-resolution (1.6 mm in-plane) achieved by eightfold k-t broad linear speed up technique (BLAST) acceleration (Abstract 086 figure 1). Perfusion was visually graded in each segment on a 5-point scale and summed to produce a perfusion score for each patient.

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Abstract 086 Figure 1

Case example—standard-resolution shows perfusion defects (white arrows) in the basal inferior (A), mid inferior, mid inferoseptal (B), apical anterior and apical inferior segments (C), High-resolution demonstrates additional ischaemia in the basal lateral (D), mid anterior and mid anterolateral segments (E) with a circumferential defect in the apical slice (F), perfusion defects are also better delineated at high-resolution and the transmural extent of ischaemia more clearly seen.

Results In the 3VD group, high-resolution identified more abnormal segments per patient (7.3±3.7 vs 5.2±3.9; p=0.01), more abnormal territories per patient (2.0±0.9 vs 1.46±1.0; p=0.02) and a higher overall perfusion score (17.7±8.6 vs 13.9±10.2; p=0.03). The number of segments with subendocardial ischaemia was greater for high-resolution (134 vs 70 segments; 47% vs 24%; p<0.001) (Abstract 086 figure 2). The sensitivity, specificity and area under the curve (AUC) for identifying any perfusion defect were similar for both methods (high-resolution: 92%, 74% and 0.94 respectively vs standard-resolution: 79%, 84% and 0.87; p>0.05).

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Abstract 086 Figure 2

Distribution of transmural ischaemia index. High-resolution perfusion CMR detected significantly more subendocardial ischaemia and fewer normal segments than standard-resolution in angiographically underperfused segments.

Conclusion In patients with 3VD, high-resolution perfusion-CMR detected more ischaemic burden than standard-resolution by identifying more segments with subendocardial ischaemia. High-resolution perfusion-CMR therefore has incremental value in correctly stratifying this high-risk patient group.