Clinical characteristics and outcomes in patients evaluated for suspected cardiomyopathy: a comparative prospective cohort study of myocarditis, cardiac sarcoidosis, and non-confirmed disease
M Bjorkenstam, L Hansen Falk, E Bobbio, C Ljungman, E BollanoAbstract
Background
Inflammatory cardiomyopathies present with heterogeneous clinical features, and early risk stratification remains challenging. Whether patients with myocarditis or cardiac sarcoidosis differ prognostically from those undergoing similar evaluation but without a confirmed diagnosis is unclear.
Purpose
To assess differences in clinical characteristics and prognosis among patients with myocarditis, cardiac sarcoidosis, and non-confirmed disease evaluated for suspected inflammatory cardiomyopathy.
Methods and Results
This prospective cohort study included 218 patients. The primary outcome was a composite of death, heart transplantation and need of mechanical circulatory support. Patients with myocarditis were younger than those with cardiac sarcoidosis and non-confirmed disease, while all diagnostic groups showed a male predominance. The cumulative incidence of the primary outcome at 12 months was modest across groups (myocarditis 2.5%, sarcoidosis 10.7%, non-confirmed 7.5%). During a median follow-up of 3.8 years (IQR 2.7–5.3), the primary outcome occurred in 3.7% of patients with myocarditis, 15.5% with cardiac sarcoidosis, and 11.3% with non-confirmed disease. In total, 15 patients (6.9%) died, 2 (0.9%) required mechanical circulatory support, and 9 (4.1%) underwent heart transplantation. Event-free survival differed between diagnostic groups on unadjusted Kaplan–Meier analysis (log-rank p = 0.039). However, in age- and sex-adjusted Cox regression analyses, neither myocarditis (HR 0.99, 95% CI 0.22–4.43) nor cardiac sarcoidosis (HR 1.67, 95% CI 0.63–4.43) was associated with a statistically significant difference in risk compared with non-confirmed disease.
Conclusion
Adverse events were infrequent in patients evaluated for suspected inflammatory cardiomyopathy. Although unadjusted analyses suggested differences in event-free survival between diagnostic categories, no independent prognostic differences were observed after adjustment for age and sex. These findings highlight the importance of demographic characteristics when interpreting outcomes across diagnostic groups.For image description, please refer to the figure legend and surrounding text.