Exploring the heart's shape: the sphericity index in myocarditis patients and its prognostic significance

Abstract Objectives Myocarditis, a leading cause of non-ischemic dilated cardiomyopathy, has increased in prevalence during the COVID-19 pandemic1. Although imaging is vital for diagnosing myocarditis, its prognostic value is not well understood2,3. The sphericity index, which assesses the roundness of the left ventricle, may help in both diagnosis and prognosis of various diseases4–6. This study examines the prognostic significance of the sphericity index in myocarditis patients. Methods We analyzed clinical and imaging data from 30 myocarditis patients diagnosed using the Revised Lake Louise criteria and a control group of 20 age- and gender-matched individuals. The primary outcomes were all-cause mortality, sudden cardiac death, heart failure hospitalization, and ventricular arrhythmia. We compared CMR and TTE parameters, including the CMR-derived sphericity index, between groups and used regression analysis to identify factors influencing outcomes. Results The mean age was 39.28 ± 15.2 years, with 72% of patients being male. LVEF values from TTE and CMR were significantly lower in the primary outcome group, while the sphericity index was significantly higher (0.51 ± 0.1 vs 0. 3 ± 0.1 and 0.39 ± 0.1, p-value 0.001). The sphericity index showed good intra- and interobserver reliability (ICC 0.95 and 0.88, respectively) and sphericity index >0.4 predicted primary outcomes with 88.89% sensitivity and 71.43% specificity (AUC 0.825, p<0.001). Regression analysis identified the sphericity index as a significant prognostic factor (OR 6.987, p=0.012). Conclusion The CMR-derived sphericity index is a straightforward imaging parameter that plays a crucial role in predicting the prognosis of myocarditis. Measurement of sphericity index Comparison of sphericity index