Comparing outcomes of an 'early' versus 'late' diagnosis of cardiac sarcoidosis following a baseline presentation of high-grade atrioventricular block

Background: There is a paucity of evidence on impact of a delay in Cardiac Sarcoidosis (CS) diagnosis after high-grade atrioventricular-block (AVB) and this study aims to fill this void. Methods: Consecutive CS patients ( n = 77) with high grade AVB referred to one specialist hospital in London between February 2007 to February 2023 were retrospectively reviewed. The median time from AVB to diagnosing CS (112 days) was used to define the Early ( n = 38) and Late ( n = 39) cohorts. The primary endpoint was a composite of all -cause mortality, cardiac transplantation, ventricular arrhythmic events or heart failure hospitalisation. Secondary endpoints included difference in maintenance prednisolone dose, need for cardiac device upgrade and device complications. Results: The mean age of the cohort was 54.4 ( +/- 10.6) years of whom 64 % were male and 81 % Caucasian. After a mean follow up of 54.9 ( +/- 45.3) months, the primary endpoint was reached by more patients from the Late cohort (16/39 vs. 6/38, p = 0.02; multivariable HR 6.9; 95 %CI 1.5 -32.2, p = 0.01). Early Group were more likely to have received an Implantable Cardioverter Defibrillator or Cardiac Resynchronisation Therapy -defibrillator as index device after AVB (19/38 vs. 6/39; p < 0.01) and had fewer device upgrades (19/38 vs. 30/39, p = 0.01) and a trend towards fewer device complications (1 vs. 5, p = 0.20). The maintenance dose of prednisolone was significantly higher in Late Group [20.7( +/- 9.7) mg vs. 15.3( +/- 7.9) mg, p = 0.02]. Conclusion: A late diagnosis of CS was associated with more adverse events, a greater probability of needing a device upgrade and required higher maintenance steroid dose.