Prognostic value of ⁶⁸Ga-DOTATATE PET/CT in assessing cardiac involvement in autoimmune diseases: a prospective study

This prospective study aimed to evaluate the prognostic value of ⁶⁸Ga-DOTATATE PET/CT imaging in assessing myocardial macrophage infiltration in patients with autoimmune diseases and its relationship with clinical outcomes, specifically all-cause mortality and cardiovascular rehospitalization.

A total of 36 patients with cardiac involvement due to autoimmune diseases were enrolled. All underwent ⁶⁸Ga-DOTATATE PET/CT imaging to assess left ventricular mononuclear macrophage infiltration. Clinical data, including myocardial biopsy results and left ventricular SUV values (LVmax and LVmean), were recorded. Prognostic thresholds were identified using ROC curve analysis, while Kaplan-Meier survival were used to analyze the relationship between myocardial macrophage activity and clinical outcomes.

Of the 36 patients, 9 died and 9 were rehospitalized for cardiovascular reasons. ROC analysis demonstrated that LVmax ≥ 2.405 predicted all-cause mortality with an AUC of 0.96 (95% CI: 0.92-1.00, P < 0.0001), while LVmean ≥ 1.36 predicted cardiovascular rehospitalization with an AUC of 0.87 (95% CI: 0.79-0.96, P < 0.0001). High ⁶⁸Ga-DOTATATE uptake thus significantly correlated with adverse clinical outcomes, surpassing traditional markers such as ejection fraction and inflammatory biomarkers. Moreover, ⁶⁸Ga-DOTATATE imaging results were more consistent with the patients' clinical conditions compared to myocardial biopsy, highlighting its superior diagnostic utility in assessing diffuse myocardial inflammation.

⁶⁸Ga-DOTATATE PET/CT imaging offers a valuable, non-invasive, and quantitative method for assessing myocardial inflammation in autoimmune diseases. This technique shows potential for improving personalized treatment and prognosis by identifying patients at higher risk for adverse outcomes in autoimmune diseases.