Introduction
Predictive value of delayed enhancement CMR is moderate especially in segments with an intermediate transmural extent of infarction (TEI).
Purpose
We sought to improve the predictive value of cardiac magnetic resonance imaging (CMR) using combined viability assessment in patients before percutaneous coronary intervention (PCI) of a chronic total coronary occlusion (CTO).
Methods
We studied patients with a successful (43/71) and without a successful (29/71) PCI of a CTO. Segmental wall thickening (SWT) was quantified before and after PCI. Before PCI, using CMR, 5 viability indexes were evaluated: TEI, contractile reserve during dobutamine, end diastolic wall thickness (EDWT), unenhanced rim thickness and SWT of the unenhanced rim (SWTur). We determined predictive value for improvement in SWT>10% after PCI for each viability index and for combined viability assessment.
Results
Mean SWT improved significantly in patients with successful PCI (16 ± 19% to 39 ± 35 %; p < 0.0001), mean SWT did not improve in patients without successful PCI (19 ± 21% to 21 ± 25%; p = 0.54). Predictive value for each viability index is presented in Table 1. Combined viability assessment using contractile reserve during dobutamine, SWTur and TEI, improved the predictive value with a sensitivity of 92%(95% CI 82–97) and specificity of 83%(95% CI 70–91).
Table 1.
Diagnostic performance of each viability index for the prediction of improvement in SWT.
| Sensitivity (%) |
Specificity (%) |
PPV (%) |
NPV (%) |
Accuracy (%) |
|
|---|---|---|---|---|---|
| LDD (>7%) | 94 (88–98) | 77 (63–87) | 89 (82–94) | 87 (73–95) | 89(83–94) |
| TEI (<50%) | 89 (81–94) | 50(36–64) | 79 (70–85) | 68 (51–82) | 76(69–83) |
| EDWT (>6 mm) | 92 (84–96) | 27 (16–41) | 72 (64–79) | 61 (39–80) | 71(63–78) |
| Unenhanced rim thickness (>3 mm) | 94(88–98) | 48 (34–62) | 79 (71–85) | 81 (62–92) | 79(73–86) |
| SWTUR (<45%) | 88 (80–93) | 33 (21–47) | 73 (64–80) | 57(38–74) | 69(62–76) |
LDD, contractile reserve during low dose dobutamine; TEI, transmural extent of infarction; EDWT, end diastolic wall thickness; SWTur, Segmental wall thickening of the unenhanced rim; PPV, positive predictive value; NPV, negative predictive value; 95% confidence interval is presented between brackets.
Conclusion
Combined viability assessment was superior to viability assessment using a single parameter. This may be useful for the selection of patients for PCI of a CTO.