Sudden cardiac death, arrhythmias and abnormal electrocardiography in systemic sclerosis: A systematic review and meta-analysis.

Objective: To calculate the frequency of sudden cardiac death(SCD), arrhythmia and conduction defects in SSc.
Methods: MEDLINE/EMBASE were searched to January 2023. English-language studies reporting the incidence/frequency of SCD, arrhythmia and electrocardiography(ECG) abnormalities in SSc were included. Odds ratios(OR), estimations of annual incidence or pooled frequencies were calculated.
Results: Seventy-nine studies(n = 13,609 participants with SSc) were included in the meta-analysis. Methodology and outcomes were heterogeneous. Ten studies included cohorts with known/suspected SSc-associated heart involvement(SHI), generally defined as clinically-manifest cardiac disease/abnormal cardiac investigations. The incidence of SCD in SHI was estimated to be 3.3% annually(n = 4 studies, 301PY follow-up). On ambulatory ECG, 18% of SHI cohorts had non-sustained ventricular tachycardia(NSVT; n = 4, 95%CI3.2-39.3%), 70% frequent premature ventricular complexes (PVCs; n = 1, 95%CI34.8-93.3%), and 8% atrial fibrillation (AF; n = 1, 95%CI4.2-13.6%). Nineteen studies included participants without SHI, defined as normal cardiac investigations/absence of cardiac disease. The estimated incidence of SCD was approximately 2.9% annually (n = 1, 67.5PY). Compared to healthy controls, individuals without SHI demonstrated NSVT 13.3-times more frequently (n = 2, 95%CI2-102), and paroxysmal supraventricular tachycardia 7-times more frequently (n = 4, 95%CI3-15). Other ambulatory ECG abnormalities included NSVT in 9% (n = 7, 95%CI6-14%), >1000 PVCs/24 h in 6% (n = 2, 95%CI1-13%), and AF in 7% (n = 5, 0-21%). Fifty studies included general SSc cohorts unselected for cardiac disease. The incidence of SCD was estimated to be 2.0% annually(n = 4 studies, 1646PY). Unselected SSc cohorts were 10.5-times more likely to demonstrate frequent PVCs (n = 2, 95%CI 2-59) and 2.5-times more likely to have an abnormal electrocardiography (n = 2, 95%CI1-4).
Conclusions: The incidence of SCD in SSc is estimated to be 1.0-3.3% annually, at least 10-fold higher than general population estimates. Arrhythmias including NSVT and frequent PVCs appear common, including amongst those without known/suspected SHI.
Competing Interests: Declaration of Competing Interest WS has received consulting fees from Boehringer Ingelheim. MN has received consulting fees from Janssen, Boehringer Ingelheim, Astra Zeneca and GSK, and honoraria from Janssen, Boehringer Ingelheim and GSK. PK has received consulting fees from Abbott Medical and honoraria from Abbott Medical and Biosense Webster. JF has received honoraria from Boehringer Ingelheim and conference sponsorship from Pfizer.
(Copyright © 2023. Published by Elsevier Inc.)