Search results
A total of 1199 articles were initially identified, with 180 undergoing full-text review. Ultimately, 11 studies from 2014 to 2022 were included in the meta-analysis. These comprised seven prospective and four retrospective designs, primarily conducted in Germany. (Table 1) (Table 2)
Table 1: Summary of study characteristics, demography of included studies.
SN
|
Author (First Author)
|
Year
|
Study design
|
Baseline characteristics of patients
|
Reference Standard
|
Age
|
Male (%)
|
N
|
Presentation
|
1
|
Huber
|
2018
|
Retrospective cohort with case-control element
|
|
|
60
|
Acute
|
CLINICAL
|
2
|
|
2014
|
Retrospective case control
|
44
|
76/24
|
125
|
Acute
|
CLINICAL
|
3
|
Isaaki
|
2021
|
Retrospective case control
|
17(14-20)
|
77/23
|
56
|
Acute
|
EMB
|
4
|
Palmisano
|
2020
|
Prospective case control
|
39(28-46)
|
51/49
|
43
|
Acute
|
CLINICAL
|
5
|
Luetkens
|
2015
|
Prospective case control
|
44.9(26.2-63.17)
|
50/50
|
84
|
Acute
|
CLINICAL
|
6
|
Li
|
2021
|
Retrospective cohort with case-control element
|
32 (18-50
|
71.2/28.8
|
73
|
Acute
|
EMB
|
7
|
Lurz
|
2016
|
Prospective cohort with case-control element
|
40
|
83/17
|
129
|
Acute
|
EMB
|
8
|
Knobelsdorff-Brenkenhoff
|
2017
|
Prospective cohort with case-control element
|
24.5
|
78/22
|
36
|
Acute
|
CLINICAL
|
9
|
Luetkens
|
2019
|
Prospective cohort with case-control element
|
41(23-64)
|
72.5/27.5
|
66
|
Acute
|
CLINICAL
|
10
|
Dabir
|
2019
|
Prospective cohort with case-control element
|
38(22-54)
|
77/23
|
80
|
Acute
|
CLINICAL
|
11
|
Brendel
|
2022
|
Prospective cohort with case-control element
|
48 (30–63)
|
44/56
|
48
|
Acute
|
EMB
|
Ms: millisecond
T1: Native T1
Acute myocarditis: patients presenting with symptoms within 28 days.
Table 2: CMR characteristics of included studies
Study ID
|
Native T1 Control
|
Native T1 Cases
|
T2 Control
|
T2 Cases
|
ECV Control
|
ECV Cases
|
Native T1 mapping technique
|
T2 mapping technique
|
Vendor
|
Magnet strength
|
Huber 2028
|
965 (940-990)
|
1044 (981-1107)
|
48 (46-50)
|
53 (49-57)
|
22 (19-25)
|
24 (17-31)
|
MOLLI
|
bSSFP
|
Siemens
|
1.5 T
|
Radunski 2014
|
1051 (1010-1063)
|
1098 (1057-1139)
|
55 (54-60)
|
61 (58-65)
|
25 (24-27)
|
31 (28-34)
|
MOLLI
|
N/A
|
Philips
|
1.5 T
|
Isaaki 2021
|
962 (945-979)
|
1031 (985-1077)
|
51 (49-53)
|
58 (53-63)
|
26.5 (23.7-29.3)
|
29.2 (23.3-35.1)
|
MOLLI
|
GraSE
|
Philips
|
1.5 T
|
Palmisano 2020
|
1008 (988-1033)
|
1093 (1050-1201)
|
47 (46-47.6)
|
55 (52-59)
|
25 (24-26)
|
30 (27-32)
|
MOLLI
|
N/A
|
Philips
|
1.5 T
|
Luetkens 2015
|
966.9 (939.1-994.7)
|
1048.6 (996.7-1100.5)
|
52.42 (49.86-54.98)
|
60.43 (52.96-67.9)
|
27.68 (21.86-33.5)
|
34.47 (25.95-43.99)
|
MOLLI/ShMOLLI
|
GraSE
|
Philips
|
1.5 T
|
Li 2021
|
1195 (1152-1238)
|
1252 (1210-1294)
|
54.5 (50.8-58.2)
|
63.2 (57.1-69.3)
|
29.3 (25.2-33.4)
|
32.7 (29.4-36)
|
MOLLI
|
GraSE
|
Philips
|
3 T
|
Lurz 2016
|
1044 (1002-1086)
|
1113 (1046-1180)
|
56.9 (49.7-64.1)
|
62.2 (57.7-66.7)
|
31.8 (26.9-36.7)
|
37.2 (30.7-43.7)
|
MOLLI
|
N/A
|
Philips
|
1.5 T
|
Knobelsdorff-Brenkenhoff 2017
|
975 (957-1004)
|
1004 (988-1048)
|
50.2 (49.2-52)
|
55.1 (53.3-57.2)
|
24 (24-25)
|
26 (25-28)
|
MOLLI
|
bSSFP
|
Philips
|
1.5 T
|
Luetkens 2019
|
965.8 (940.7-990.9)
|
1047.0 (993.2-1100.8)
|
52.8 (50.4-55.2)
|
61.8 (53.6-70)
|
26.1 (21.9-30.3)
|
28.6 (23.3-33.9)
|
MOLLI
|
GraSE
|
Philips
|
1.5 T
|
Dabir 2019
|
958.9 (936.4-981.4)
|
1027.2 (977.9-1076.5)
|
51.6 (49.7-53.5)
|
58 (52-64)
|
27.7 (24.5-30.9)
|
32 (25.6-38.4)
|
MOLLI
|
GraSE
|
Philips
|
1.5 T
|
Brendel 2022
|
1015 (1015-1015)
|
1069 (1024-1127)
|
50 (50-50)
|
53 (52-56)
|
30 (30-30)
|
33 (31-35)
|
MOLLI
|
bSSFP
|
Philips
|
|
Optimal Diagnostic Thresholds*
|
Native T1 Threshold=1021 ms
ROC AUC=0.82
Sensitivity=91%
Specificity=73%
|
T2 mapping threshold=54 ms
ROC AUC=0.93
Sensitivity=82%
Specificity=82%
|
ECV threshold=28%
ROC AUC=0.79
Sensitivity=82%
Specificity=73%
|
|
*Optimal diagnostic thresholds were determined using ROCs curve
Diagnostic accuracy results
Pooled mean T1 time was 1075.16±64.22 ms, and pooled mean T2 time was 58.25±3.58 ms for myocarditis cases. ECV cutoffs ranged from 22% to 34.47%, and post-contrast T1 timing ranged from 10 to 15 minutes. Out of the eleven studies, only two studies had Siemens as a vendor.17,8 Ten studies utilized MOLLI (Modified Look-Locker Inversion recovery) for native T1 mapping, with one using both ShMOLLI (Shortened Modified Look-Locker Inversion recovery) and MOLLI. We had five studies utilizing GraSE (Gradient and Spin Echo), three using bSSFP (balanced Steady-state free precession) as a T2 mapping technique and three studies did not report the T2 mapping technique utilized. Diagnostic accuracy for Native T1, T2 mapping, and ECV was reported in all studies (Table 3). Native T1 demonstrated the highest sensitivity (83%) and specificity (86%) among the evaluated parameters, with an inconsistency (I-square I2) of 69% for sensitivity and 75% for specificity. It also had a DOR of 39 and an AUC of 0.91. T2 mapping showed similar sensitivity (81%) and specificity (86%) with I2 of 72.2% and 69% respectively, and a DOR of 25 with an AUC of 0.89. ECV exhibited moderate sensitivity (71%) and specificity (81%) with I2 of 72% and 37%, along with a lower DOR of 13 and an AUC of 0.83. (Figure 2, 3, 4, 5)
Table 3: Diagnostic accuracies and heterogeneity indices of individual mapping parameters Native T1, T2 mapping and ECV
Parameter
|
Sensitivity
|
Inconsistency (I-square)
|
Specificity
|
Inconsistency (I-square)
|
Diagnostic Odds Ratio (DOR)
|
Area Under Curve (AUC)
|
Native T1
|
83%
|
69%
|
86%
|
75%
|
39
|
0.91
|
T2
|
81%
|
72%
|
86%
|
69%
|
25
|
0.89
|
ECV
|
71%
|
72%
|
81%
|
37%
|
13
|
0.83
|
The optimal cut-off for native T1 mapping was 1021 ms (ROC AUC=0.82, Sensitivity=91%, Specificity=73%). For ECV, the threshold was 28% (ROC AUC=0.79, Sensitivity=82%, Specificity=73%) and T2 mapping had an optimal threshold of 54 ms (ROC AUC=0.93, Sensitivity=82%, Specificity=82%). (Figure 6)
Subgroup analyses revealed no significant differences in diagnostic accuracy based on clinical criteria or EMB reference standards. Meta-regression showed no significant sensitivity differences for Native T1, T2, and ECV (P-value>0.05), though Native T1 mapping specificity varied significantly (P-value<0.05). (Table 4) Funnel plot examination and Egger’s test indicated no significant publication bias for T1, T2, and ECV parameters (p > 0.05 for all on Egger’s test).
Table 4: Results of meta-regression and subgroup analyses based on reference standard of studies.
Mapping technique
|
Approach
|
Study number
|
sensitivity
|
p-value
|
specificity
|
p-value
|
Native T1
|
Clinical
|
7
|
79% (70-87)
|
0.77
|
92% (87-96)
|
0.001
|
EMB
|
4
|
88% (82-93)
|
70% (50-84)
|
T2
|
Clinical
|
7
|
78% (67-87)
|
0.205
|
90% (84-93)
|
0.076
|
EMB
|
4
|
85% (79-90)
|
77% (56-90)
|
ECV
|
Clinical
|
7
|
67% (55-78)
|
0.174
|
84% (78-89)
|
0.102
|
EMB
|
4
|
81% (64-91)
|
74% (62-84)
|
Study quality assessment and integrated diagnostic performance of different CMR approaches
Overall study quality was moderate and acceptable per QUADAS-2, with one study showing high risk of bias due to non-uniform EMB performance, case control selection. (Figure 7) (Table 5). Five studies investigated combined CMR approaches, with various combinations showing high sensitivity, specificity, and AUC (Table 6).
Table 5: Quality Assessment (QADAS-2)
Study Number
|
Study ID
|
Domain 1
|
Domain 2
|
Domain 3
|
Domain 4
|
Overall Risk of Bias
|
1
|
Huber 2018
|
Low
|
Low
|
Low
|
Low
|
Low
|
2
|
Radunski 2014
|
Low
|
Low
|
Low
|
Low
|
Low
|
3
|
Isaak 2021
|
Low
|
Low
|
Low
|
Low
|
Low
|
4
|
Palmisano 2020
|
Low
|
Low
|
Low
|
Unclear
|
Low
|
5
|
Luetkens 2015
|
Low
|
Low
|
Low
|
Unclear
|
Low
|
6
|
Li 2021
|
Low
|
Low
|
Low
|
Low
|
Low
|
7
|
Lurz 2016
|
Low
|
Low
|
Low
|
Low
|
Low
|
8
|
Knobelsdorff-Brenkenhoff 2017
|
Low
|
Low
|
Low
|
Low
|
Low
|
9
|
Luetkens 2019
|
Low
|
Low
|
Low
|
Unclear
|
Low
|
10
|
Dabir 2019
|
Low
|
Low
|
Low
|
Low
|
Low
|
11
|
Brendel 2022
|
Low
|
Unclear
|
High
|
Low
|
High
|
Domain 1: Was the patient population representative of the population under investigation, with clear criteria for patient inclusion and exclusion, enrollment through consecutive or random sampling, and balanced reporting of patient demographics (age, gender) across study groups? , Domain 2: Were the CMR parameters (T1, T2, ECV) described in sufficient detail, with consistency in the application and interpretation of CMR techniques across studies, blinded assessment of CMR parameters to the reference standard results, and a pre-specified threshold for abnormal CMR findings?, Domain 3: Was endomyocardial biopsy deemed an appropriate reference standard for myocarditis diagnosis, with blinded interpretation of biopsy findings to CMR parameter results, consistency in the application of clinical criteria across studies, and uniform timing of clinical criteria utilization in relation to symptom presentation?, Domain 4: Was there inclusion of all eligible patients in the analysis, with consistent intervals between symptom presentation and CMR testing, CMR testing and the reference standard (EMB/clinical criteria), and analysis of patients in the groups to which they were initially assigned?
Table 6: Results of diagnostic values of combined parametric mapping techniques
S.N.
|
Author
|
Combination
|
Sensitivity
|
Specificity
|
1.
|
Radunski et al
|
LGE+ECV
|
94% (88-98)
|
71% (48-89)
|
2.
|
Isaak et al
|
T1+T2 mapping
|
85% (64–96)
|
100% (79–100)
|
3.
|
Li et al
|
- T1+T2 mapping
- LGE + T2 mapping
|
a. 82.2%
b. 79.5%
|
|
4.
|
Brenkenhoff et al
|
a. T1+T2
b. T2+ECV
c. T1+LGE
d. T2+LGE
e. T1+T2+LGE
|
a.77.8% (52.4-93.6)
b.82.4% (56.6-96.2)
c.72.2% (46.5-90.3)
d.66.7% (41-86.7)
e. 66.7% (41-86.7)
|
a. 94.4% (72.7-99.9)
b.94.4% (72.7-99.9)
c.100% (81.5-100)
d. 100% (81.5-100)
e. 100% (81.5-100)
|
5.
|
Brendel et al
|
|
a. 96%
b. 83%
|
a. 83%
b. 92%
|
All the combinations are based on Native T1 mapping.