Mortality and morbidity in scleroderma renal crisis: A systematic literature review

Objectives: The objective of this study was to systematically review the mortality and morbidity associated with scleroderma renal crisis and to determine temporal trends. Methods: We searched MEDLINE, Embase and the Cochrane Database of Systematic Reviews from database inception to 10 February 2020. Bibliographies of selected articles were hand-searched for additional references. Data were extracted using a standardized extraction form. Study quality was assessed using the Newcastle-Ottawa scale. Results were analysed qualitatively. Results: Twenty studies with 14,059 systemic sclerosis subjects, of which 854 had scleroderma renal crisis and 4095 had systemic sclerosis-associated end-stage renal disease, met inclusion criteria. Study quality was generally moderate. Cumulative mortality in the post-angiotensin-converting enzyme inhibitor era was approximately 20% at 6 months, 30%-36% at 1 year, 19%-40% at 3 years and almost 50% at 10 years from scleroderma renal crisis onset. Although the introduction of angiotensin-converting enzyme inhibitors in the early 1970s resulted in a 50% improvement in scleroderma renal crisis mortality, there was no further improvement thereafter. Scleroderma renal crisis mortality rates were proportionally higher than mortality rates associated with other systemic sclerosis organ involvement. The rate of permanent dialysis after scleroderma renal crisis in the post-angiotensin-converting enzyme inhibitor era ranged from 19%-40%. Three to 17% of systemic sclerosis patients underwent renal transplant. Survival was better in patients post-renal transplant (54%-91%) compared to those on dialysis (31%-56%). Graft survival improved over time and appeared similar to that of patients with other types of end-stage renal disease. Conclusion: While there has been considerable improvement in scleroderma renal crisis-related outcomes since the introduction of angiotensin-converting enzyme inhibitors, morbidity and mortality remain high for affected patients without convincing evidence of further improvement in the post-angiotensin-converting enzyme inhibitor era. Novel treatments are required to improve outcomes of scleroderma renal crisis.