Comorbidity burden on mortality in patients with systemic sclerosis

Abstract

Introduction: Systemic sclerosis (SSc) is a serious life-threatening tissue disease. A significant aspect of its mortality arises from comorbid conditions. Our study aimed at mapping out the prevalence of these comorbidities and their relation to mortality, thus creating a 'comorbidome'.

Methods: In our retrospective, single-centre observational study, we recorded each patient's data, including demographic informations, vital stats and SSc-related organ involvement, along with the presence or absence of 14 predefined comorbidities. We also documented the dates of their initial and most recent visits. To construct survival curves, we used the Kaplan-Meier method, followed by a Cox regression model for multivariate analysis.

Results: Our study involved 400 participants, 74 of whom unfortunately passed away. It is important to note that three specific comorbidities showed significant correlation to mortality: neoplasia, cardiovascular diseases and polypharmacy, as well as two SSc-specific organ involvements (lung and cardiac).

Conclusion: Our research led to the successful creation of the SSc comorbidome. Comorbidities are a major concern for patients suffering from SSc, particularly cardiovascular diseases and neoplasms. Our study highlights the effects of polypharmacy. The resultant comorbidome offers a comprehensive and analytical perspective on this complex issue and underscores the inter-relatedness of the data. Our study, however, was limited by a small sample size. Therefore, to confirm our findings, validation on a larger scale is necessary. This could potentially contribute to the creation of a future mortality scoring tool.

Keywords: Connective Tissue Diseases; Mortality; Scleroderma, Systemic.

Figure 1. Survival curves of each comorbidity using Kaplan-Meier model. CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease.

Figure 2. Adjusted HR for death for each comorbidity and systemic sclerosis (SSc) organ involvement. CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease.

Figure 3. Comorbidome of systemic sclerosis (SSc). The comorbidome is the graphic illustration of all the comorbidities studied in our cohort (one comorbidity=one circle), their prevalence (represented by the diameter of the circle) and their association with mortality in our patients with SSc (represented by the distance between the grey cross and the centre of the circle). All the comorbidities within the dotted circle are associated with a higher risk of death. All the comorbidities with a red star have a statistically significant association with an increased or decreased risk of death in our analysis. CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; CV, cardiovascular.