Heart failure in patients with complicated and uncomplicated myocarditis
B Zdzierak, M Wegiel, B Chyrchel, W Wojciechowska, A Dziewierz, S Bartus, A Surdacki, T RakowskiAbstract
Aim
Myocarditis presents a wide spectrum of clinical scenarios, ranging from mild symptoms to life-threatening complications. Impaired left ventricular ejection fraction (<50%), sustained ventricular arrhythmias, advanced atrioventricular block, acute heart failure, and cardiogenic shock are considered severe complications, defining complicated myocarditis. The aim of this study was to analyze the clinical, laboratory, and cardiac magnetic resonance (CMR) characteristics of patients with complicated and uncomplicated myocarditis.
Methods
A total of 64 consecutive patients with a working diagnosis of MINOCA were reviewed, among whom 41 with final diagnosis of myocarditis based on clinical and CMR criteria (revised Lake Louise Criteria) entered the registry. Patients were subsequently categorized into two groups: those with an uncomplicated (n = 31) and with a complicated myocarditis (n = 10; 8 with impaired LVEF, 1 with cardiac arrest due to sustained ventricular arrhythmia, 1 with acute heart failure).
Results
Patients with complicated presentation were significantly older. There were no significant differences between the groups in the prevalence of chest pain or heart failure symptoms. Similarly, the interval from symptom onset to hospital admission was comparable. Dynamic ST-segment changes on the admission electrocardiogram did not differ significantly. Hypertension was more frequent among patients with complicated myocarditis, and a trend toward higher rates of cardiovascular comorbidities—including prior myocardial infarction, hypercholesterolemia, and atrial fibrillation—was observed in this group. Patients with a complicated clinical course exhibited elevated creatinine and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. CMR analysis revealed reduced left ventricular ejection fraction, increased wall motion score index, higher end-systolic volume indexed to body surface area, greater left ventricular mass, and lower cardiac output in complicated patients. Furthermore, the complicated group showed a higher number of segments with T2 >50 ms and extracellular volume fraction (ECV) >25% (see Table 2 for details). NT-proBNP and C-reactive protein (CRP) demonstrated significant correlations with number of segments with T1 >1050 and with number of segments with T2 >50ms on CMR (NT-proBNP: R= 0.47, R=0.54; CRP: R= 0.53, R=0.35; respectively).
Conclusion
The main feature of complicated myocarditis in the study cohort was left ventricular systolic dysfunction. More pronounced CMR inflammation features were present in complicated presentation. Cardiovascular comorbidities may exacerbate cardiac dysfunction and increase the risk of heart failure in complicated myocarditis. Significantly higher NT-proBNP levels in the complicated group indicate more severe cardiac dysfunction, and, together with elevated CRP values, support a link between myocardial inflammation and functional impairment in patients with complicated myocarditis.Table 1.For image description, please refer to the figure legend and surrounding text.Table 2.For image description, please refer to the figure legend and surrounding text.