Identification of a novel presumed cardiac sarcoidosis category for patients at high risk of disease.

Histologic evidence is required for a definitive diagnosis of cardiac sarcoidosis (CS) by published guidelines; however, the sporadic nature of the disease may produce false negative biopsy results, causing CS to be underdiagnosed. We sought to establish a clinical category of CS absent histologic findings. Patients evaluated for CS were stratified into 3 groups: probable CS and definite CS based on Heart Rhythm Society (HRS) criteria and presumed CS, ie, patients without any histologic evidence of sarcoidosis, but with unexplained high-grade atrioventricular block or ventricular arrhythmia and findings suggestive of CS on either cardiac magnetic resonance imaging or positron emission tomography. The primary end point was hospitalization-free and overall survival at 10 years. A total of 383 patients were included in the study: 59, definite CS; 223, probable CS; and 101, presumed CS (62, isolated CS and 39, systemic CS). Compared with patients meeting HRS criteria for CS, patients with presumed CS had lower odds of New York Heart Association class III or IV symptoms (odds ratio [OR], 0.44 [95% CI, 0.23–0.83]; P =.01) but greater odds of previous ventricular tachycardia (OR, 2.4 [95% CI, 1.4–4.0]; P =.001) or history of resuscitated sudden cardiac arrest (OR, 2.9 [95% CI, 1.0–8.6]; P =.05). Hospitalization-free and overall survival were similar among groups (P =.51 and P =.71, respectively). Clinical categorization of patients with presumed CS identified a high-risk cohort comparable to patients with histologic evidence of disease, although caution should be exercised in reaching this diagnosis without paying due diligence to the differential diagnosis. • Cardiac sarcoidosis (CS) may be underdiagnosed. • A "presumed" CS category incorporates characteristic clinical and imaging findings. • The presumed cohort has similar presentation and symptomatology. • No difference in a composite CV outcome was identified among the cohorts. • Cardiac sarcoid diagnosis absent histology identifies patients warranting treatment. [ABSTRACT FROM AUTHOR]