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Detection of Early Diffuse Myocardial Fibrosis and Inflammation in Chagas Cardiomyopathy with T1 Mapping and
Rodrigo J L Melo1, Antonildes N Assunção1, Thamara C Morais1
1From the Cardiovascular Magnetic Resonance and Computed Tomography Sector (R.J.L.M., A.N.A., T.C.M., C.H.N., C.E.R.), Arrhythmia Unit (M.I.S.), Artificial Cardiac Stimulation Unit (M.M.F.), and Cardiomyopathy Unit (F.J.A.R., F.F., B.M.I., C.M.), Heart Institute (Instituto do Coração), University of São Paulo Medical School, Av Dr Enéas de Carvalho Aguiar 44, Andar AB, Cerqueira Cesar, São Paulo 05403-000 SP, Brazil.
Insights
Myocardial T1 mapping and extracellular volume (ECV) parameters correlate with Chagas cardiomyopathy severity. Elevated remote native T1 values predict major adverse cardiovascular events, aiding in early disease detection and risk stratification.
Area of Science:
- Cardiovascular Imaging
- Cardiac MRI
- Myocardial Tissue Characterization
Background:
- Chagas cardiomyopathy presents a spectrum of disease severity.
- Early detection of myocardial involvement is crucial for prognosis.
- Standard cardiac MRI metrics may not fully capture early disease changes.
Purpose of the Study:
- To evaluate myocardial T1 mapping and extracellular volume (ECV) parameters in different stages of Chagas cardiomyopathy.
- To determine if these parameters predict disease severity and prognosis.
Main Methods:
- Prospective enrollment of participants with Chagas disease and controls.
- Cardiac MRI including cine, late gadolinium enhancement (LGE), and T1 mapping.
- Measurement of native T1 and ECV values across disease severity subgroups (indeterminate, CCpEF, CCmrEF, CCrEF).
- Cox proportional hazards regression for outcome prediction.
Main Results:
- Significantly higher global native T1 and ECV values in CCmrEF and CCrEF groups compared to indeterminate, CCpEF, and control groups (P < .001).
- Elevated remote native T1 and ECV values observed in LGE-negative areas, increasing with disease severity.
- Abnormal remote ECV (>30%) found in 12% of the indeterminate group.
- A remote native T1 value >1100 msec independently predicted major adverse cardiovascular events (HR, 12; P < .001).
Conclusions:
- Myocardial native T1 and ECV values correlate with Chagas disease severity.
- These parameters may serve as early markers of myocardial involvement preceding LGE and LV dysfunction.
- T1 mapping and ECV quantification offer valuable insights into Chagas cardiomyopathy progression.
Purpose:
To evaluate myocardial T1 mapping and extracellular volume (ECV) parameters in different stages of Chagas cardiomyopathy and determine whether they are predictive of disease severity and prognosis.
Materials And Methods:
Prospectively enrolled participants (July 2013 to September 2016) underwent cine and late gadolinium enhancement (LGE) cardiac MRI and T1 mapping with a precontrast (native) or postcontrast modified Look-Locker sequence. The native T1 and ECV values were measured among subgroups that were based on disease severity (indeterminate, Chagas cardiomyopathy with preserved ejection fraction [CCpEF], Chagas cardiomyopathy with midrange ejection fraction [CCmrEF], and Chagas cardiomyopathy with reduced ejection fraction [CCrEF]). Cox proportional hazards regression and the Akaike information criterion were used to determine predictors of major cardiovascular events (cardioverter defibrillator implant, heart transplant, or death).
Results:
In 107 participants (90 participants with Chagas disease [mean age ± SD, 55 years ± 11; 49 men] and 17 age- and sex-matched control participants), the left ventricular (LV) ejection fraction and the extent of focal and diffuse or interstitial fibrosis were correlated with disease severity. Participants with CCmrEF and participants with CCrEF showed significantly higher global native T1 and ECV values than participants in the indeterminate, CCpEF, and control groups (T1: 1072 msec ± 34 and 1073 msec ± 63 vs 1010 msec ± 41, 1005 msec ± 69, and 999 msec ± 46; ECV: 35.5% ± 3.6 and 35.0% ± 5.4 vs 25.3% ± 3.5, 28.2% ± 4.9, and 25.2% ± 2.2; both P < .001). Remote (LGE-negative areas) native T1 and ECV values were also higher (T1: 1056 msec ± 32 and 1071 msec ± 55 vs 1008 msec ± 41, 989 msec ± 96, and 999 msec ± 46; ECV: 30.2% ± 4.7 and 30.8% ± 7.4 vs 25.1% ± 3.5, 25.1% ± 3.7, and 25.0% ± 2.2; both P < .001). Abnormal remote ECV values (>30%) occurred in 12% of participants in the indeterminate group, which increased with disease severity. Nineteen combined outcomes were observed (median follow-up time: 43 months), and a remote native T1 value greater than 1100 msec was independently predictive of combined outcomes (hazard ratio, 12 [95% CI: 4.1, 34.2]; P < .001).
Conclusion:
Myocardial native T1 and ECV values were correlated with Chagas disease severity and may serve as markers of myocardial involvement in Chagas cardiomyopathy that precede LGE and LV dysfunction.Keywords: MRI, Cardiac, Heart, Imaging Sequences, Chagas Cardiomyopathy Supplemental material is available for this article. © RSNA, 2023.
