Associations between myasthenia Gravis and outcomes following cardiac surgery: an analysis of the nationwide inpatient sample.

BACKGROUND: Myasthenia gravis (MG) is a chronic neuromuscular disorder associated with increased susceptibility to perioperative complications. However, large population-based studies have not clearly characterized its impact on cardiac surgery outcomes. We therefore aimed to assess the in-hospital outcomes of MG patients undergoing cardiac surgery using a nationally representative database. METHODS: This retrospective cohort study analyzed data from the Nationwide Inpatient Sample (NIS) between 2005 and 2020. Patients ≥ 18 years old who underwent coronary artery bypass grafting (CABG), valve surgery, or aortic repair were identified using ICD-9 and ICD-10 codes. Propensity score matching (PSM) was used to balance baseline characteristics. Multivariable regressions assessed associations between MG and in-hospital outcomes, including length of hospital stay (LOS), non-routine discharge, hospital costs, and complications. RESULTS: Following PSM, 823 patients with MG and 3,292 matched controls were included. After adjustment, patients with MG had significantly longer LOS (adjusted Beta [aBeta] = 0.89 days, 95% confidence interval [CI]: 0.56–1.23), greater risk of non-routine discharge (adjusted OR [aOR] = 1.35, 95% CI: 1.12–1.63), and higher total hospital costs (aBeta = 15.21, 95% CI: 11.75–18.68). They also had an increased risk of complications (aOR = 1.30, 95% CI: 1.08–1.56), including dysphagia (aOR = 2.39), respiratory failure (aOR = 1.39), mechanical ventilation (aOR = 1.30), and infection (aOR = 1.46). Furthermore, associations were most pronounced in patients undergoing isolated CABG, whereas estimates for valve and aortic procedures were less precise. CONCLUSION: Patients with MG undergoing cardiac surgery—particularly those receiving isolated CABG—experience greater morbidity, extended hospitalization, and increased healthcare costs. These findings support implementing enhanced perioperative protocols and multidisciplinary care pathways to mitigate excess complications, streamline recovery, and optimize resource use in this high-risk population.