1-045 Structured and standardised follow-up in acute myocarditis is key to better outcomes: insights from an 11-year single-centre cohort analysis

Background Myocarditis requires vigilant post-discharge monitoring to mitigate complications, such as heart failure, arrhythmias and sudden cardiac death. Current guidelines recommend close follow-up and exercise restriction with gradual return to physical activity after 3–6 months. We investigated the impact of follow-up intensity on patient outcomes, identified predictors of follow-up intensity and evaluated any care disparities in patients with acute myocarditis. Methods This retrospective single-centre cohort study (Jan 2013-Feb 2024) initially identified 157 patients diagnosed with acute myocarditis. After cardiac MRI (CMR) reclassification of 27 patients with alternative diagnoses (including myocardial infarction and cardiac amyloidosis), 130 patients were included. Follow-up intensity was categorized as none (0 components), minimal (1), moderate (2) and intensive (all 3) based on repeat troponin levels, cardiac imaging (echocardiography/cardiac MRI) and clinic consultation. Adverse outcome was defined as a composite of all-cause mortality and cardiac-related readmissions within 12 months post-discharge. Logistic regression analyses assessed the impact of follow-up intensity and guideline-directed medical therapy (GDMT) on outcomes. Ordinal regression and decision tree analyses identified predictors of follow-up intensity. Results The cohort was predominantly male (75.4%) with mean age 49.7±19.7 years. Presenting symptoms included chest pain (73%), dyspnoea (11%), palpitation (6%) and syncope (5%). Median left ventricular ejection fraction (LVEF) was 58% (IQR 50–65) and CRP 59 mg/L (IQR 11.5–172.3). The average troponin rise was 31.2±48.1 above assay-specific thresholds (table 1). Median length of hospital stay (LOHS) was 4 days (IQR 2–7). Exercise restriction was advised in only 44.6% of patients (age range 19–86). Higher follow-up intensity was associated with 49.5% reduced odds of adverse outcomes (OR 0.506, 95% CI 0.274–0.935, p=0.03), persisting after adjusting for GDMT (p=0.044). After controlling for presenting symptoms, troponin rise, LVEF and LOHS, patients who underwent CMR were nearly eight times more likely to receive intensive follow-up (OR 7.94, p=0.001), while those >53 years (based on a decision tree analysis) were 61% less likely to receive follow-up (OR 0.39, 95% CI 0.17–0.88, p=0.023) (figure 1) Conclusion Structured follow-up is associated with significantly improved outcomes in patients with myocarditis, independent of GDMT. However, older patients and those not undergoing CMR received less intensive follow-up, highlighting care disparities. The low rate of exercise restriction counselling indicates suboptimal guideline adherence. This study underscores the importance of comprehensive and standardised follow-up protocols, integrating CMR surveillance and exercise restriction to optimise outcomes. Larger, multicentre studies are required to increase generalisability of these findings.