Causes and predictors of mortality in systematic sclerosis at a tertiary Southern Gauteng Hospital

Abstract

Background Systemic sclerosis (SSc) is a chronic systemic autoimmune disease primarily affecting skin and internal organs. It is characterized by excessive fibrosis, vasculopathy and chronic inflammation. The disease is associated with increased morbidity and mortality, but to date, there have been no studies on causes of death and predictors thereof in Sub-Saharan Africa. Objective To determine the spectrum of causes of death in SSc patients attending the Connective Tissue Disease Clinic at the Chris Hani Baragwanath Academic Hospital. Methods A retrospective record review of patients meeting the ACR/EULAR (full criteria attending the Connective Tissue Disease Clinic at Chris Hani Baragwanath Academic Hospital between Jan 1990 to Dec 2015). Results Of the 282 records reviewed, 174 patients met the inclusion criteria. The majority of patients were Black African (92.5%), with a female to male ratio of 7:1. The mean (SD) age at diagnosis and follow up period were 41.8 (13.1) years and 65.8 (66.4) months respectively at last visit. Only 53 were known to be alive at the end of the study, 63 were lost and/or could not be found during follow-up, and there were 58 known deaths. The major known causes of death were disease-related: cardiopulmonary in 24 (41.4%) and SRC in 1 patient (1.7%). The disease-unrelated causes included infection in 5 patients (8.6%) and malignancy in 2 patients (3.5%).

Predictors of mortality included serositis, renal dysfunction, digital ulcers, proteinuria, and a raised C-reactive protein (CRP). The estimated survival rates were 56.3% at 5 years and 35.8% at 10 years – censored for patients lost to follow up. Conclusion In the present study, SSc was associated with a high morbidity and mortality especially cardiorespiratory complications. The cause of death in our study was predominantly disease related, which is in accordance with that reported in other studies. Cardiopulmonary causes remain the leading causes of death in our population comparable to that reported in studies done in other countries.