Introduction: Post-operative stroke (POS) is associated with vascular and cardiac surgery, but this finding has mainly been reported among populations receiving vascular and cardiac procedures. We investigated the association between type of surgery and risk of POS in a large, generalizable inpatient cohort from the American College of Surgeons National Surgical Quality Initiative Program (NSQIP) database.
Hypothesis: Cardiac and vascular procedures are associated with an increased risk of POS.
Methods: We identified patients that underwent surgery between the years of 2000 and 2010. Our primary outcome was POS within 30 days of surgery. Using a hierarchical model adjusted for age, race, sex, medical comorbidities and dichotomized functional status, we assessed for clustering between type of surgery and POS. We then determined risk factors for POS while adjusting for clustering. Each surgical type was compared against all other surgical types.
Results: We identified 729,886 patients, of whom 2,703 (0.3%) developed POS. In the hierarchical analysis, cardiac surgery (incidence rate ratio (IRR) 6.38, 95%CI 5.37-7.55), vascular surgery (IRR 4.41, 95%CI 4.08-4.76), and neurosurgery (IRR 2.05, 95%CI 1.69-2.48) were associated with increased risk of POS. The only patient-level factor associated with surgery type was poor preoperative functional status. Accounting for clustering, patients with poor pre-operative functional status (OR 4.11, 95%CI 3.60-4.69), history of stroke (OR 2.35 95%CI 2.06-2.69), history of transient ischemic attack (OR 2.49 95%CI 2.19-2.83), active smoking (OR 1.20, 95%CI 1.08-1.32), and COPD (OR 1.39 95%CI 1.21-1.59) were at higher risk of POS. There was no interaction between preoperative functional status and type of surgery.
Conclusions: In a large cohort of surgical inpatients, we found that the risk of POS was significantly associated with cardiac, vascular, and neurosurgical procedures. Certain patient populations, such as those with a dependent pre-operative functional status, may be at a higher risk of POS and may be more likely to undergo cardiac, vascular, or neurosurgical procedures. Further studies are needed to elucidate the relationship between pre-surgical functional status and type of surgery.