Characteristics and prognostic assessment of acute myocarditis in patients under martial law in Ukraine: long-term follow-up results

The aim of the study – to investigate the course of myocarditis in patients, including combatants, with different risk profiles and to determine prognostic factors for an unfavorable outcome over 24 months of observation under martial law conditions. Material and methods. A total of 204 patients with AM (134 men and 70 women; mean age 38.2±8.6 years), including 90 combatants, were examined. Patients were stratified into three risk categories: the 1st group consisted of 80 high risk patients with de novo reduced LVEF (≤ 40 %), clinical signs of heart failure, and extensive LGE on cardiac MRI; the 2nd group comprised 64 intermediate risk patients with moderately reduced LVEF (41–49 %) and ≥ 2 affected LV segments on MRI; the 3rd group included 60 low risk patients with preserved LVEF (≥ 50 %) and < 2 affected LV segments. All patients underwent speckle-tracking echocardiography, 24-hour ECG monitoring with arrhythmia and HRV assessment, cardiac MRI with LGE. Comprehensive diagnostic assessments were performed within the AM onset and repeated at 12 and 24 months.Results and discussion. Predictors of persistent myocarditis over the 24-month follow-up were identified: baseline LV EDVi ≥ 105 mL/m², LVEF ≤ 40 %, GLS ≤ 9.0 %, GCS ≤ 8.0 %, presence of NSVT paroxysms, a total of ≥ 5 affected LV segments and ≥ 3 LV segments with inflammatory involvement. Predictors of transition to dilated cardiomyopathy included an LV EDVi ≥ 105 mL/m², LVEF < 30 %, GLS ≤ 8.0 %, GCS ≤ 7.0 %, a total of ≥ 9 affected LV segments, and ≥ 5 LGE-positive segments during baseline investigation. Predictors of recovery at 24 months were an LV EDVi ≤ 85 mL/m², LVEF ≥ 50 %, GLS ≥ 11.0 %, GCS ≥ 12.0 %, involvement of ≤ 3 LV segments, and absence of NSVT during the baseline assessment within the first month after symptom onset. Among combatants with myocarditis predictors of persistent frequent supraventricular ectopy and atrial fibrillation at 24 months included a HADS anxiety score ≥ 11, HAM-A score ≥ 25, LF/HF ratio ≤ 1.20, ≥ 5 affected LV segments, and ≥ 2 LV segments with LGE on baseline MRI. Additional predictors of persistent atrial fibrillation included an LV EDVi ≥ 105 mL/m² and LVEF ≤ 40 %.Conclusions. Results of the study refined contemporary approaches to prognosticating the clinical course of myocarditis and identified predictors of recovery, long-term disease persistence and transition to dilated cardiomyopathy. Among combatants with myocarditis predictors of persistent frequent supraventricular ectopy and atrial fibrillation paroxysms at 24 months were established, along with an association between these arrhythmias, the presence of anxiety and impaired heart rate variability.