Impact of cardiac resynchronisation therapy in patients with cardiac sarcoidosis
Authors: Ahmed R , Shi R , Pan J , Okafor J , Azzu A , Qadeer A , Khattar R , Baksi J , Wechalekar K , Wells A , Kouranos V , Sharma R 
Published: October 2022

Abstract

Background
Implantation of a device is usually required in cardiac sarcoidosis (CS) patients presenting with advanced conduction abnormalities or ventricular arrhythmias. A cardiac resynchronisation therapy (CRT) device is often chosen in patients with concomitant left ventricular systolic impairment. The role of CRT in CS is not well established.

Purpose
To describe the cohort of CS patients with CRT device in situ in our hospital focusing on the short-term effect in serial echocardiography and long-term outcomes on morbidity and mortality.

Methods
All consecutive CS patients with a CRT device in situ were identified in our CS database (2005–2022). A confident CS diagnosis was provided after review of all relevant clinical and imaging baseline data in our CS multi-disciplinary meeting and a consensus decision for CRT-D implantation was made based on international guidelines. All patients were followed up for at least 6 months with serial echocardiography. Serial data regarding symptoms, rhythm disturbance and echocardiographic parameters were obtained and comparisons were performed using Wilcoxon signed rank test.

Results
A total of 51 CS patients with CRT-D were identified (mean age: 57±10 years old). Patients were male predominant (64.7%) and Caucasian in origin (86.2%). Extra-cardiac sarcoidosis was confirmed histologically in 33 (64.7%) patients. The prevalence of smoking, diabetes, hypertension and ischaemic heart disease was 27.5%, 21.6%, 49.0% and 7.8% respectively. At the time of device implantation or during follow-up, 43 (84.3%) patients were found to have active cardiac sarcoidosis on cardiac PET.
Post CRT implantation there was a significant difference in LV ejection fraction (35.9±15.0% vs 42.2±14.1%, p&lt;0.001), LV end-systolic diameter (4.90±1.46 cm vs 4.62±1.32 cm, p=0.012) and LV end-diastolic diameter (5.99±1.18 cm vs 5.66±1.06 cm, p&lt;0.001). No significant changes were observed in the right ventricular function (p=0.09) and severity of mitral regurgitation (p=0.40). There was one patient who experienced acute heart failure decompensation admission within six months of CRT-D implantation. The New York Heart Association (NYHA) class improved in 26 patients (51.0%), worsened in 4 (7.8%) patients and remained the same in 21 (41.2%) patients at 6 months post CRT-implantation. During the mean follow up of 47.6 months, the composite end-point of death and cardiac transplantation was reached in 9 (17.6%) patients (8 deaths and 1 cardiac transplantation). 5 patients had major complications including a large haematoma, a small atrio-septal defect, haemothorax, device associated endocarditis and lead fracture. Minor wound infections were seen in 3 patients and 4 patients received inappropriate shock or anti-tachycardia pacing.

Conclusions
CRT in cardiac sarcoidosis patients is associated with short-term improvement in LV remodelling and functional status but over a four year follow up, morbidity and mortality are common.

Funding Acknowledgement
Type of funding sources: None.