Detrended Fluctuation Analysis independently predicts all-cause mortality of patients with Sarcoidosis

Abstract

Patients with sarcoidosis (Sarc) may have autonomic dysfunction, which could be evaluated by heart rate variability (HRV). Nonlinear HRV parameters such as detrended fluctuation analysis (DFA) have been demonstrated to be an important predictor of mortality. Whether DFA is a prognostic factor for patients with sarcoidosis remains unclear. Purpose of this study was the evaluation of this hypothesis. Methods: Sarc patients were included and underwent a 24-hour Holter as well as lung function tests, cardiac ultrasound and MRI examination for the assessment. The study population was prospectively examined with all-cause mortality as an end-point. HRV analysis included short-term α1 and long-term α2 scaling exponents from detrended fluctuation analysis (DFA) and approximate entropy (ApEn), (ii) time-domain indices and frequency domain indices. Results: 173 patients, mean aged: 46.78±14.57 yo, with disease duration of 4.20±5.85 yrs were evaluated. During a median follow-up period of 51.5±21.3 months, 14 deaths occurred; Cox-regression analysis demonstrated that the strongest predictors of all-cause mortality were α1 (p Conclusion: The DFA α1 is a strong and independent predictor of mortality in Sarcoidosis. This study highlights the importance of the non-linear dynamic indices in prognosis in Sarcoid population.