Análise da capacidade vital forçada como preditor de mortalidade em pacientes com esclerose lateral amiotrófica: estudo longitudinal

Abstract

In Amyotrophic Lateral Sclerosis (ALS), a severe neurodegenerative disease, respiratory failure often leads to death. Respiratory parameters such as forced vital capacity (FVC) are essential for prognosis, assessing the need for ventilation and the effectiveness of treatment. The aim of this study was to determine whether FVC (%predicted) can be a predictor of mortality in an ALS clinical population in the city of Natal/RN. Methods: This is a retrospective longitudinal study in which patients with ALS were followed for a period of 5 years. During the evaluations, they underwent pulmonary function tests, application of the revised ALS Functional Rating Scale (ALSFRS-r) and maximum respiratory pressure tests (MIP, MEP and SNIP). The data was analyzed using a logistic regression test and the area under the ROC curve was used to determine the FVC cut-off point (%predicted). Results: The mean age of the individuals was 57.21 (± 13.25) years, the majority were male (65.3%), with spinal onset ALS (50.7%) and 42.7% with a diagnosis of definite ALS. Twenty-four (33.8%) died during the five-year period of our study. The results of the logistic regression test showed that FVC(%predicted) was strongly associated with mortality (r= -0.328, p=0.008) and every 3% increase in FVC(%predicted) represented a 95.3% reduction in the chance of death (B= 3.065; p= 0.011; OR= 0.047; 95%CI: 0.004-0.497). Furthermore, ROC analysis showed that FVC < 63% could potentially be a predictor of death in ALS patients (ASC: 0.70; 95%CI: 0.57 - 0.83; p= 0.013). Conclusion: Our results indicate that the isolated measurement of FVC (%predicted) is significantly associated with survival, after controlling for confounding factors such as age and BMI, which can influence death. Our study showed that just a small increase in FVC(%predicted) can have a major impact on the survival of these patients, significantly reducing the chances of death.