Table 2. Study Characteristics and Results.
| First Author (Reference) | Number of Patients | Follow-up Duration (Months)* | Mean LVEF (%) | Scar Patterns Included | Scar Prevalence (%) | Scar Quantification Method† | Scar Size (% LV Mass)* | Primary Endpoint |
|---|---|---|---|---|---|---|---|---|
| Assomull (19) | 101 | 22 | 35 | Midwall fibrosis | 35 | > 2SD | 4.6 (0.8-21) | All cause death, hospitalization for cardiovascular disease |
| Wu (27) | 65 | 17 | 24 | Midwall, endocardial, patchy foci often including RV insertion sites | 42 | > Peak remote | 10 (3-16) | Cardiovascular death, ICD shock, CHF hospitalization |
| Hombach (28) | 141 | 45 | 32 | Midwall, epicardial, diffuse | 26 | Manual planimetry | 5.6 (1.2-25.6) | Cardiac death |
| Cheong (42) | 215 | 53 | 52 | Midwall fibrosis and other patterns not specified | 18 | Visual scoring | [Scar index: 1.00] | All cause death, heart transplant |
| Cho (32) | 79 | 33 | 33 | Focal patchy, diffuse | 53 | Not quantified | - | All cause death, CHF hospitalization, transplant |
| Lehrke (29) | 184 | 22 | 38 | Midwall, epicardial, patchy/foci, diffuse; endocardial excluded | 39 | > 2SD | 2.9 | Cardiac death, ICD shock, CHF hospitalization |
| Iles (46) | 61 | 19 | 25 | Midwall, patchy | 51 | > 2SD | Not reported | Appropriate ICD shock |
| Klem (43) | 554 | 29 | 56 | Any | 26 | Visual scoring | [4 segments] | All cause death |
| Wu (44) | 98 | 43 | 25 | Any | 41 | FWHM | [0 (IQR 0-5.4) g] | Cardiac death, appropriate ICD shock |
| Gao (34) | 65 | 21 | 27 | Midwall, epicardial, endocardial | 71 | > 2, 3, and 5SD‡ | [34.5 g] | Appropriate ICD shock, SCD, survived cardiac arrest |
| Müller (41) | 185 | 21 | 43 | Midwall and non-midwall, excluding endocardial | 51 | Not quantified | - | All cause mortality, transplant, aborted SCD, sustained VT, CHF hospitalization |
| Neilan (30) | 162 | 29 | 28 | Midwall, epicardial, RV insertion, diffuse | 50 | > 2SD/FWHM§ | 9 (2SD)/6 (FWHM) | Cardiovascular death, ICD shock |
| Gulati (23) | 472 | 64 | 37 | Midwall fibrosis | 30 | FWHM | 2.5 (1.2-4.8) | All-cause death |
| Perazzolo Marra (31) | 137 | 36 | 32 | Epicardial, midwall, patchy/junctional; endocardial excluded | 56 | > 2SD | 9 (4-15) | SCD, ICD shock, VF, sustained VT |
| Masci (35) | 228 | 23 | 43 | Midwall, epicardial | 27 | Visual scoring∥ | [3 segments (1-10)] | Cardiac death, CHF onset, aborted SCD |
| Averaged | 183 | 32 | 35 | 41 | 6.2 |
*Mean or median, range as reported in study, if other measure of scar placed in parenthesis and not included in summary analysis, †Presence or absence of scar was determined by visual interpretation of experienced readers first in all studies, ‡Various thresholds were tested, optimal threshold were > 2SD in ischemic and > 5SD in non-ischemic subgroups, §Both methods used, showing similar and robust results with respect to prognostic association, ∥Visual scoring only of segments when hyperintense myocardium involved > 50% of its circumferential extent. CHF = congestive heart failure, FWHM = full width at half maximum, ICD = implantable cardioverter-defibrillator, IQR = interquartile range, LV = left ventricle, LVEF = left ventricular ejection fraction, RV = right ventricle, SCD = sudden cardiac death, SD = standard deviation, VF = ventricular fibrillation, VT = ventricular tachycardia