The impact of cardiopulmonary manifestations on the mortality of SSc: a systematic review and meta-analysis of observational studies

Objectives. Internal organ involvement reduces the life expectancy of SSc patients. Cardiopulmonary manifestations are currently the primary cause of death. We aimed to perform a systematic review and meta-analysis to define more precise effect estimates of different cardiopulmonary manifestations and to verify trends in the mortality of SSc. Methods. A systematic literature search was performed to identify relevant cohort studies. Reports analyzing the role of the organ manifestations in mortality or analysing survival compared with the control population were included. The outcome parameters were pooled with the random-effect model via generic inverse-variance weighting in conventional and cumulative meta-analysis. Results. Eighteen studies comprising a total of 12 829 patients qualified. The reported causes of death were as follows: 19.7% cardiac, 16.8% interstitial pulmonary disease, 13.1% pulmonary hypertension and 13.8% renal disease. The risk of death was significantly increased in patients with cardiac involvement [hazard ratio (HR) 3.15], with pulmonary interstitial disease (HR 2.58), with pulmonary hypertension (HR 3.50) and with renal manifestations (HR 2.76). A trend for survival improvement (R-2 = 0.4295, P = 0.04) was found, and the difference in survival between the diffuse and limited scleroderma subgroups was diminishing (R-2 = 0.4119. P = 0.02). Conclusion. Meta-analysis of observational studies indicates a trend for improvement over the last decades in which the life expectancy of SSc patients approaches that of the general population. A decreasing tendency in the survival differences between the limited and diffuse SSc subgroups was also verified. Internal organ involvements have similarly unfavourable predictive impact on survival.