Myocardial tissue function and characterization in patients with idiopathic cardiac magnetic resonance myopericarditis: evolutionary analysis
Authors: Soeiro A , Bossa A S , Cesar M C , Leal T C A T , Garcia G , Fonseca R A , Nakamura D , Guimaraes P O , Soares P R , Mueller C , Mebazaa A , Fernandes F , Nomura C H , Rochitte C E , Oliveira Jr M T 
Published: October 2021

Abstract

Introduction
The identification of prognostic markers related to the occurrence of events and recovery of ventricular function may be important in patients with acute myopericarditis (AMP). There is still a lack of data related to tissue characterization by cardiac magnetic resonance (CMR) of AMP, evolution and definition of possible long-term prognostic markers.

Purpose
To evaluate the myocardial tissue characterization of CMR related to the occurrence of combined events (death from all causes, heart failure and AMP recurrence) and the increase in left ventricular ejection fraction (LVEF) in patients with AMP.

Methods
Inclusion criteria were chest pain and/or electrocardiographic changes associated with elevated troponin (above the 99th percentile) in the absence of coronary stenosis and diagnosis of AMP by CMR &lt;48 hours of admission confirmed by the presence of edema and/or late enhancement. After a follow-up of up to 24 months, 100 patients remained and in the assessment of the increase in LVEF (increase &gt;5%), 36 cases remained, recalled for a new CMR between 6 and 18 months from the initial event.

Results
Significant differences in CMR were found between patients who had combined events (n=26) versus no combined events (n=74) in the following characteristics evaluated: initial LVEF (OR=0.938; CI: 0.895–0.984, p=0.008), left ventricular (LV) systolic volume index (OR=1.034; CI: 1.005–1.062, p=0.019), LV diastolic volume index (OR=1.029; CI: 1.002–1.056, p=0.038), presence of hypersignal in T2 (OR=11.325; CI: 2.247–57.075, p=0.003), presence of late anteroseptal enhancement (OR=0.160; CI: 0.037–0.685, p=0.014), basal anteroseptal (OR=0.255; CI: 0.071–0.914, p=0.036) and lateral apical (OR=5.902; CI: 1.236–28.187, p=0.026). In relation to the increase in LVEF, significant differences were found in CMR in the following characteristics evaluated: LVEF (OR=0.870; CI: 0.758–0.988, p=0.047), end systolic volume of the right ventricle (OR=1.047; CI: 1.001–1.096, p=0.047), LV systolic diameter (OR=1.283; CI: 1.034–1.593, p=0.023), LV diastolic diameter (OR=1.225; CI: 1.012–1.482, p=0.038), LV systolic volume index (OR=1.340; CI: 1.066–1.685, p=0.012), LV diastolic volume index (OR=1.111; CI: 1.017–1.213, p=0.019) and right ventricular systolic volume index (OR=1.116; CI: 1.006–1.236, p=0.037).

Conclusion
We observed a significant association between combined events in the long-term follow-up with initial LVEF, LV systolic and diastolic volume indexes, T2 hypersignal and the presence of mid and basal anteroseptal and lateral apical late enhancement. Already related to the increase in LVEF in evolutionary CMR, we observed a significant association with initial LVEF, end systolic volume of the right ventricle, LV systolic and diastolic diameters, LV systolic and diastolic volume indexes and right ventricle systolic volume index.

Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): FAPESP