Background and Aims: Fulminant myocarditis (FM) is a complex clinical syndrome characterized by acute myocardial inflammation and cardiogenic shock. Evidence on long-term outcomes, mortality risk factors, and targeted treatment options remains limited. Methods: This retrospective analysis included consecutive adult patients admitted for FM between January 2012 and November 2022 at 26 European tertiary centres. According to endomyocardial biopsy (EMB) findings, patients were categorized as lymphocytic (LM), eosinophilic (EM), necrotizing eosinophilic (NEM), and giant-cell myocarditis (GCM) for the main analyses. Patients with inconclusive histopathology and those who did not undergo EMB were analysed separately. Primary outcomes were in-hospital and 1-year mortality. Multivariable logistic regression models were employed as generalized linear models to analyse the association of prespecified risk factors with mortality. Estimated associations are reported as odds ratios, generalized marginal effects, and adjusted prediction plots. Results: A total of 271 patients [median age 43 years (interquartile range: 33–55 years), 58% male] were included in the analysis, of whom 146 fulfilled histopathologic criteria of LM (n = 99), EM (n = 18), NEM (n = 3), or GCM (n = 26). In the remaining 125 cases, EMB was inconclusive (n = 48) or not performed (n = 77). While there were no significant differences in cardiac arrest rate, admission Simplified Acute Physiology Score (SAPS) II, ventricular function, initial pH, and liver and kidney function parameters between histopathologic subgroups, the use of immunosuppressive medications and need for organ replacement varied. In the overall population, in-hospital and 1-year mortality were 31% and 34%, respectively. The highest 1-year mortality rate was observed among patients with GCM (LM: 25%, EM: 28%, NEM: 33%, GCM: 54%, P = .04). Patients who survived to discharge had an excellent functional outcome and long-term recovery of ventricular function. In total, 17 patients (6%) received a heart transplant during follow-up. Older age, lower pH, and histopathologic diagnosis of GCM were independently associated with in-hospital and 1-year mortality. Conclusions: In-hospital mortality among patients with FM remains high. Age, pH, and histopathological findings may serve as prognostic markers to identify high-risk patients and to guide treatment strategies. Long-term outcomes are excellent among those who survive to discharge.

Background: MRI (magnetic resonance imaging) represents the diagnostic image modality of choice in several conditions. With an increasing number of patients requiring MRI for diagnostic purposes, the issue of safety in patients with cardiac implantable electronic devices (CIED) undergoing this imaging modality will play an ever more important role. The purpose of this study was to assess the safety and device function following MRI in an unrestricted real-world cohort of patients with a wide array of cardiac devices. Methods: We conducted a retrospective single-center study including 1010 MRI studies conducted in adult patients (≥18 years) with an implanted CIED treated in the University Hospital of Munich (LMU) between July 2012 and March 2024. Patients with non-MR conditionally labeled leads, abandoned or epicardial leads, as well as lead fragments, were included for analysis. Results: Across a total of 1010 MRIs (920 total MR-conditional device generators) performed in patients with an implanted CIED, there were no deaths, reports of discomfort, palpitations, heating, or ventricular arrythmias in the 24 h following MRI. Only 2/1010 MRIs were followed by a reported atrial arrhythmia within 24 h, both in patients with an MR-conditional pacemaker (PM) device without an abandoned lead. No significant changes in device function following MRI from baseline were observed across all included CIEDs. Lastly, no instances of severe malfunction, such as generator failure, loss of capture, electrical reset, or inappropriate inhibition of pacing, were found in post-MRI interrogation reports across all MRI studies. Conclusions: Based on the analysis of 1010 MRIs undergone by patients with CIEDs, following standardized device interrogation, manufacturer-advised device programming, monitoring of vital function, and manufacturer-advised reprogramming, MRI can be performed safely and without adverse events or changes in device function.

Sports-related physical activity is associated with an increased risk of ventricular dysfunction and arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). However, there are currently no standardized strategies for activity assessment. Thresholds for harmful levels of physical activity suggested by previous studies vary substantially and neither lifetime activity burden nor continuous modelling approaches were considered. For this single-centre retrospective study, ARVC patients were interviewed to assess sports-related and non-sports-related physical activity between the age of 10 years and the last follow-up. Activity data were aggregated to the median metabolic equivalent of task—hours (METh) per week for each year. The association between cumulative physical activity burden and clinical study endpoints was investigated using Cox regression models. A total of 124 patients (median age: 39.5 years, 48% male) were included in the analysis, of whom 93 had been diagnosed with definite ARVC. Study participants reported a median overall activity of 202.3 METh/week, with 38.7 METh/week attributed to sports-related activity. In the continuous model, cumulative overall activity burden was associated with the occurrence of symptomatic heart failure [hazard ratio (HR) per 100 METh/week: 1.017, 95% CI (1.003, 1.032), P = 0.015], sustained ventricular tachycardia [HR: 1.021, 95% CI (1.006, 1.037), P = 0.007], and implantable cardioverter defibrillator interventions [HR: 1.017, 95%CI (1.000, 1.034), P = 0.048]. This finding was consistent when considering sports-related activity separately as a predictor variable, whereas the resulting hazard ratios did not show a significant association for non-sports-related physical activity. This study demonstrates for the first time that cumulative physical activity as a continuous predictor variable is associated with symptomatic heart failure and arrhythmic risk in ARVC patients. Collaborative research is required in larger cohorts to investigate the influence of potential confounders on event occurrence and to develop threshold recommendations for clinical practice. ARVC, arrhythmogenic right ventricular cardiomyopathy; CI; confidence interval; HR, hazard ratio; ICD, implantable cardioverter defibrillator; METh, metabolic equivalent of task—hours; SCD, sudden cardiac death; VT, ventricular tachycardia.

Aim: Sports-related physical activity is associated with an increased risk of ventricular dysfunction and arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). However, there are currently no standardized strategies for activity assessment. Thresholds for harmful levels of physical activity suggested by previous studies vary substantially and neither lifetime activity burden nor continuous modelling approaches were considered. Methods and results: For this single-centre retrospective study, ARVC patients were interviewed to assess sports-related and non-sports-related physical activity between the age of 10 years and the last follow-up. Activity data were aggregated to the median metabolic equivalent of task—hours (METh) per week for each year. The association between cumulative physical activity burden and clinical study endpoints was investigated using Cox regression models. A total of 124 patients (median age: 39.5 years, 48% male) were included in the analysis, of whom 93 had been diagnosed with definite ARVC. Study participants reported a median overall activity of 202.3 METh/week, with 38.7 METh/week attributed to sports-related activity. In the continuous model, cumulative overall activity burden was associated with the occurrence of symptomatic heart failure [hazard ratio (HR) per 100 METh/week: 1.017, 95% CI (1.003, 1.032), P = 0.015], sustained ventricular tachycardia [HR: 1.021, 95% CI (1.006, 1.037), P = 0.007], and implantable cardioverter defibrillator interventions [HR: 1.017, 95%CI (1.000, 1.034), P = 0.048]. This finding was consistent when considering sports-related activity separately as a predictor variable, whereas the resulting hazard ratios did not show a significant association for non-sports-related physical activity. Conclusion: This study demonstrates for the first time that cumulative physical activity as a continuous predictor variable is associated with symptomatic heart failure and arrhythmic risk in ARVC patients. Collaborative research is required in larger cohorts to investigate the influence of potential confounders on event occurrence and to develop threshold recommendations for clinical practice.