Association Between Basal Thinning of Interventricular Septum and Adverse Long-Term Clinical Outcomes in Patients With Cardiac Sarcoidosis

BACKGROUND: Basal thinning of the interventricular septum (IVS) is an important diagnostic feature of cardiac sarcoidosis (CS), but its long-term prognostic significance remains unclear. METHODS AND RESULTS: We examined 74 consecutive patients who were diagnosed with CS. Basal IVS thickness at a point located 10 mm from the aortic annulus was measured. IVS thickness at the left ventricular minor axis level (IVS) was also measured according to the recommended procedure of the American Society of Echocardiography. Patients were divided into 2 groups based on the presence or absence of basal IVS thinning, which was defined as basal IVS ≤4 mm and/or basal IVS/IVS ratio ≤0.6. Basal IVS thinning was observed in 21 patients and was associated with greater long-term adverse events during follow-up (5.1±2.5 years), although the baseline characteristics were comparable between groups (overall, P<0.01; all-cause death, P=0.53; symptomatic arrhythmias, P<0.01; heart failure admission, P=0.027). Multivariate analysis showed basal IVS thinning was an independent determinant of long-term adverse events (hazard ratio 2.86, 95% confidence interval 1.31-6.14) even after adjustment for existing prognostic variables. CONCLUSIONS: The presence of basal IVS thinning at the time of CS diagnosis was associated with poor long-term clinical outcomes, suggesting its prognostic significance in patients with CS.