Worse Cardiac Surgery Outcomes Seen in Patients With Myasthenia Gravis

Patients who required coronary artery bypass grafting (CABG) surgery had worse outcomes when they were living with myasthenia gravis (MG), according to a new study published in BMC Anesthesiology.¹ This included experiencing greater morbidity, an increase in health care costs, and an extended length of stay.

Characteristics of MG, an autoimmune neuromuscular disorder, include weakness of ocular and limb muscles, among other muscle weaknesses. Some studies have previously found that there is cardiac involvement in MG, which may cause cardiac problems along with the other symptoms of MG.² CABG is a high-risk surgery to address cardiac problems in certain patients, but those with MG may experience a significantly higher risk due to the weakened neuromuscular relationship.¹ The relationship between outcomes of cardiac surgery in those with MG has not been studied as extensively. This study aimed to assess the association between MG and in-hospital outcomes in patients undergoing cardiac surgery.

The researchers used the Nationwide Inpatient Sample to collect data for the study. This database includes a sample of discharges across 44 participating states, primarily across community hospitals, equaling approximately 8 million unweighted hospitalizations per year. Patient- and hospital-level variables were included in the database as well, which included demographics, length of stay (LOS), and the characteristics of the institution itself.

Any patient aged 18 years or older who had cardiac surgery between 2005 and 2020 was eligible for the study. Participants were included if they were aged 18 years or older and had undergone at least 1 cardiac surgical procedure. In-hospital mortality, LOS, hospital costs, discharge disposition, and postoperative complications were the primary outcomes studied in this analysis. Age, race/ethnicity, sex, household income, insurance status, and the type of admission were all considered as covariates.

There were 4115 patients included in the study, of which 823 were living with MG and 3292 were controls. The mean age was 71.5 years, and 79% of the patients were men. The majority of the cohort were also White (80%) and were enrolled in Medicare or Medicaid (62%). Most of the patients had ischemic heart disease (approximately 85%) or hypertension (79%). A total of 63% of the patients had CABG, with the remainder having combined CABG and valve surgery, valve surgery, or aortic repair.

MG was significantly associated with a longer LOS (adjusted Beta [aBeta], 0.89; 95% CI, 0.56-1.23), greater total hospital costs (aBeta, 15.21; 95% CI, 11.75-18.68), higher odds of non-routine discharge (adjusted OR [aOR], 1.35; 95% CI, 1.12-1.63), and had higher odds of a postoperative complication (aOR, 1.30; 95% CI, 1.08-1.56).

As far as the postoperative complications, there were some that were more likely in patients with MG than others. Dysphagia (aOR, 2.39; 95% CI, 1.63-3.49), acute respiratory failure (aOR, 1.39; 95% CI, 1.14-1.70), and prolonged mechanical ventilatory support (aOR, 1.30; 95% CI, 1.02-1.65) were particular complications that were associated with patients with MG. Increased odds of infection were also found (aOR, 1.46; 95% CI, 1.13-1.88).

There were some limitations to this study. The researchers could not make causal inferences due to the study being retrospective and observational. The study used administrative codes to get information on exposures, comorbidities, procedures, and outcomes, which can be subject to misclassification. Hospitals with missing key variables were excluded. There was a lack of clinical granularity, and intraoperative variables were not captured. There were a limited number of cases of MG.

The researchers concluded that “MG is independently associated with greater perioperative morbidity and resource utilization among patients undergoing cardiac surgery, including significantly longer hospital stays, higher hospitalization costs, and increased likelihood of non-routine discharge.” Future studies should utilize detailed MG phenotyping and long-term outcomes to more accurately predict risks in those with MG who require cardiac surgery.

References

1. Chen PC, Masud JHB, Chung CC. Associations between myasthenia gravis and outcomes following cardiac surgery: an analysis of the nationwide impatient sample. BMC Anesthesiol. Published online February 13, 2026. doi:10.1186/s12871-026-03676-4
2. Elmati PR, Jagirdhar GSK, Surani S. Cardiac implications in myasthenia gravis. World J Clin Cases. 2024;12(26):5863-5867. doi:10.12998/wjcc.v12.i26.5863