Basal interventricular septum thinning and long-term left ventricular function in patients with sarcoidosis

Background Basal interventricular septum (IVS) thinning on transthoracic echocardiography (TTE) is highly specific to cardiac sarcoidosis. Although basal IVS thinning is listed as one of the five major diagnostic criteria for cardiac sarcoidosis, its association with long-term cardiac function has not been investigated. This study aimed to evaluate the epidemiology and clinical relevance of basal IVS thinning in a clinic-based cohort of patients with sarcoidosis. Methods This retrospective observational study was conducted at a general sarcoidosis clinic. The incidence of basal IVS thinning and associations with variables at baseline and a delayed onset of left ventricular (LV) dysfunction (LV ejection fraction [LVEF] < 50%) were analyzed. Results Of the 1009 patients, 23 (2.3%) had basal IVS thinning. Basal IVS thinning was associated with cardiac pacemaker (PM) implantation at baseline (adjusted odds ratio = 20.5; 95% confidence interval [CI] = 7.9–53.2; P < 0.01). Of the 768 patients with an LVEF of ≥50% at baseline who underwent one or more longitudinal TTEs after baseline, 36 (4.7%) developed LV dysfunction over a median observation period of 88.9 months. Basal IVS thinning and PM implantation at baseline were the independent predictors of a delayed onset of LV dysfunction (basal IVS thinning, adjusted hazard ratio [HR] = 3.7; 95% CI = 1.5–9.6; PM implantation, adjusted HR = 15.7; 95% CI = 7.4–33.3). Conclusions Basal IVS thinning in patients with sarcoidosis can predict a delayed onset of LV dysfunction even when the LV function is preserved at the time of detection.