The Role of the Pan-Immune-Inflammatory-Value Index in Predicting Hospital Stay Duration in Patients with Myocarditis.

Background: Myocarditis is an inflammatory disease of the myocardium that can result from various etiologies, most commonly viral or bacterial infections and autoimmune processes. This study aimed to evaluate the predictive value of the Pan-Immune-Inflammatory Value (PIV) index for the duration of hospitalization. Methods: Laboratory parameters, comorbidities, and treatment data of patients diagnosed with myocarditis were retrospectively analyzed. Patients were divided into two groups: those discharged within 48 hours and those hospitalized for more than 48 hours. The relationship between the PIV index and the duration of hospital stay was evaluated. Results: Patients with a hospital stay longer than 2 days were significantly younger (p < 0.001). Red cell distribution width, C-reactive protein, and troponin levels were significantly higher in patients with prolonged hospitalization (p < 0.001, p < 0.001, p = 0.013, respectively). PIV values were significantly higher in patients with pericardial effusion and in those receiving intravenous steroid therapy (p < 0.001). Conclusions: Although PIV alone was not a statistically significant predictor of hospital stay duration, it was associated with markers of systemic inflammation and disease severity. PIV may serve as a supportive biomarker in the clinical assessment of myocarditis patients.