Incidence and mortality of cardiac events in lumbar spine surgery.

STUDY DESIGN: Retrospective national database analysis.

OBJECTIVE: A population-based database was analyzed to characterize the incidence, mortality, and associated risk factors for cardiac events in lumbar spine surgery.

SUMMARY OF BACKGROUND DATA: Cardiac events are a leading cause of perioperative mortality in spinal surgery. The incidence of these complications after lumbar surgery is not well characterized on a national level.

METHODS: Data from the Nationwide Inpatient Sample was obtained from 2002 to 2009. Patients undergoing lumbar decompression or lumbar fusion for degenerative etiologies were identified. Patient demographics, incidence of cardiac complications, comorbidities, and mortality were assessed. Statistical analysis was performed using Student t test for discrete variables and χ test for categorical data. Logistic regression was used to identify independent predictors for cardiac complications.

RESULTS: A total of 578,457 lumbar spine procedures were identified in the Nationwide Inpatient Sample from 2002 to 2009. The overall incidence of cardiac complications was 6.7 per 1000 cases. Cardiac events occurred more frequently in the lumbar fusion group, with a rate of 9.3 per 1000 cases, than in the lumbar decompression group, with a rate of 4.0 per 1000 (P < 0.0005). Patients with cardiac events were significantly older than patients without complications by 9.4 years (P < 0.0005). Patients with cardiac complications had statistically increased hospitalizations, costs, and mortality when a cardiac event was present (P < 0.0005). Logistic regression analysis demonstrated independent predictors for cardiac events to include age 65 years or older, acute blood loss anemia, and several comorbidities.

CONCLUSION: Our results demonstrated an overall incidence of 6.7 cardiac complications per 1000 lumbar spine surgical procedures from 2002 to 2009. Patients undergoing lumbar fusion were more likely to experience cardiac events than lumbar decompression patients. Cardiac events tend to occur in patients with noted risk factors and result in increased hospitalizations, costs, and mortality. On the basis of these findings, we think that patients with specified risk factors should be monitored closely and medically optimized in the perioperative period.