Assessing outcomes of acute myocarditis in Saudi Arabia: A retrospective tertiary center experience.

Objectives: To assess the clinical course and long-term outcomes of complicated and uncomplicated AM in Saudi Arabia. Acute myocarditis (AM) can have different presentations and outcomes based on different factors, one of which is left ventricular ejection fraction (LVEF).

Methods: Data from 382 patients with suspected AM, admitted between January 2016 and October 2023, were reviewed. Clinical course, in-hospital complications, and all-cause mortality were evaluated in both the acute and follow-up phases. Outcomes were compared between 2 groups: LVEF <50% (n=43); and normal LVEF (≥50% [n=41]) at presentation.

Results: Data from 84 patients (mean [±SD] age, 33.5±10.2 years; 26.2% female) who fulfilled the inclusion criteria were analyzed. The most common symptom was chest pain (83.3%) and 11 (13.1%) patients had fulminant presentation. ST-T changes were found on electrocardiography in 45.2% of patients. The mean LVEF was 46±12.4% at presentation. Patients in the LVEF <50% group were significantly more likely to experience a first-time cardiac-related adverse event (CRAE) (hazard ratio 2.6 [95% confidence interval 1.1-6.2]; =0.031) with a mean time of 38.8±3.8. The all-cause in-hospital and follow-up mortality rates in the LVEF <50% group were 4.7% (one-half cardiac-related) (=0.494) and 4.7% (all cardiac-related) (=0.494), respectively.

Conclusion: Of 84 patients diagnosed with AM, those with LVEF <50% were more likely to experience first-time CRAEs and exhibited low short- and long-term mortality rates.