Myocardial viability in dysfunctional LV segments is dependent upon maintenance/presence of an intact microcirculation [46]. It has been shown that, in such segments, peak contrast intensity reflects microvascular density and is inversely related to collagen content (i.e. fibrotic scar) [47]. MCE can predict functional recovery following acute MI [48] and is comparable to CMR imaging in this regard [49].
Myocardial response to dobutamine (i.e. contractile reserve) requires presence of both intact contractile proteins but also coronary flow reserve and thus it may be a less sensitive technique than MCE for detection of hibernating myocardium [16]. Initial studies have indicated that MCE may be more sensitive – and as specific – as low-dose DSE for detection of myocardial hibernation [50-51].
Study | Imaging technique | Patients (n) | MCE Sensitivity | MCE Specificity |
Sbano et al [52] | High MI | 50 | 95 | 52 |
Senior et al [53] | High MI | 96 | 62 | 83 |
Aggeli et al [54] | High MI | 34 | 88 | 61 |
Hillis et al [55] | Low MI | 33 | 86 | 44 |
Main et al [56] | Low MI | 46 | 69 | 85 |
Swinburn et al [57] | Low MI | 19 | 68 | 88 |
Hillis et al [58] | High MI | 35 | 80 | 67 |
Lepper et al [59] | High MI | 35 | 94 | 87 |
Janardhanan et al [49] | Low MI | 42 | 82 | 83 |
Hickman et al [60] | Low MI | 56 | 83 | 78 |
Greaves et al [61] | Low MI | 15 | 88 | 74 |
Janardhanan et al [48] | Low MI | 50 | 92 | 75 |
Shimoni et al [50] | High MI | 18 | 90 | 63 |
Hickman et al [51] | Low MI | 23 | 87 | 67 |
Agati et al [62] | High MI | 23 | 100 | 90 |
Huang et al [63] | Low MI | 34 | 83 | 82 |
Bolognese et al [64] | High MI | 30 | 96 | 18 |
Abe et al [65] | High MI | 31 | 98 | 32 |
Kousouglou et al [66] | Low MI | 32 | 81 | 88 |
MEAN | 85 | 70 |
Table 2: A summary of the published evidence for use of resting MCE for prediction of myocardial viability – from Senior et al [16].