Predictive value of cardiac magnetic resonance atrial and ventricular strain for adverse prognosis in patients with myocarditis: a systematic review and meta-analysis

Background: Myocarditis refers to an inflammatory response of myocardial tissue caused by various causes. Patients with myocarditis are at high risk of adverse prognosis, defined as major adverse cardiac events (MACEs). Atrial and ventricles strain analysis using cardiovascular magnetic resonance (CMR) plays a crucial role in the prognostic evaluation of myocarditis. This meta-analysis provides the first comprehensive evaluation of the predictive value of atrial and ventricular strain derived from CMR for MACE in patients with myocarditis.

Methods: We searched PubMed, Embase, web of science, Cochrane Library, OVID Medline, Scopu, Sinomed, CNKI, Wanfang, VIP Database, and the search time range spans from the establishment of the database to June 2026. The level of evidence was assessed based on meta-analyses of the hazard ratios (HR) and 95% confidence intervals (CIs) of atrial and ventricular strain parameters for predicting MACE. Fixed-effect or random-effect models were used to synthesize data, with I2 and sensitivity analyses for heterogeneity.

Results: A total of 18 studies involving 3,454 participants were included, comprising 15 studies on left ventricular (LV) strain, 8 on right ventricular (RV) strain, and 8 on left atrial (LA) strain. Regarding LV myocardial strain, global longitudinal strain (GLS) (HR 1.22, 95% CI: 1.13–1.31), global circumferential strain (GCS) (HR 1.18, 95% CI: 1.10–1.28), and global radial strain (GRS) (HR 0.91, 95% CI: 0.86–0.95) all showed prognostic value for MACE in acute myocarditis. The timing of magnetic resonance (MR) examination is critical, and imaging appears to be most informative when performed within 2 weeks, or even within 1 week, after symptom onset. Regarding LA myocardial strain, Ԑs (HR 0.89, 95% CI: 0.83–0.96) and Ԑe (HR 0.92, 95% CI: 0.88–0.96) showed prognostic value for MACE in both acute and chronic myocarditis. In contrast, RV strain parameters showed limited prognostic value for MACE.

Conclusions: LA and LV strain derived from CMR are associated with MACE events in patients with myocarditis. Incorporating myocardial strain into the management of myocarditis may improve risk stratification.