Prioritizing high-volume repair hospitals with ruptured abdominal aortic aneurysms, for rural and nonrural patients

Among patients who suffer a ruptured abdominal aortic aneurysm (rAAA), ≤35% die perioperatively despite advancements in endovascular repair and intensive care. Patient rurality and associated disparities in local health services portend poorer cardiovascular outcomes; however, the effect of patient rurality on rAAA outcomes is unknown. Conversely, high-volume repair hospitals are associated with improved mortality outcomes for cardiovascular operations; however, the effects for patients residing rurally are unknown. We evaluated the association between in-hospital mortality, patient rurality, transfer status, and rAAA hospital repair volume among patients undergoing rAAA repair.

Using Healthcare Cost and Utilization Project's State Inpatient Database (New York and Florida), we identified adults with a primary diagnosis of rAAA who underwent repair (2015-2020). Exposures of interest included (1) patient rurality, (2) transfer status before repair, and (3) hospital rAAA repair volume. The Rural Urban Community Area classified patient residence as rural (rural/small town/micropolitan) or nonrural (metropolitan), the State Inpatient Database provided transfer status from another facility, and the top 25% of hospital rAAA volume defined high-volume repair hospitals. The primary outcome was in-hospital mortality. A multivariable logistic regression adjusted for patient demographics, comorbidities, frailty (by validated the Risk Analysis Index), income quartiles, repair type, and hospital case mix with a variance estimation clustered by unique hospital. Interaction terms evaluated the association between hospital repair volume and mortality among exposure subgroups.

Of 1744 rAAA patients (median age, 75 years [interquartile range, 67-82 years]; 76.4% male; 78.8% White; 73.9% undergoing endovascular aneurysm repair), 148 (8.5%) resided in rural areas, 414 (23.7%) were transferred to a referral hospital for repair, and 1248 (71.6%) were repaired at high-volume hospitals. Rural patients were more often transferred in from another facility for repair (49.3% vs 21.4%; P < .001) and repaired at high-volume hospitals (82.6% vs 70.6%; P = .002). After multivariable adjustment, neither rurality (adjusted odds ratio [aOR], 0.78; 95% confidence interval [CI], 0.46-1.34) nor transfer status (aOR, 0.82; 95% CI, 0.61-1.10) were associated with in-hospital mortality; however, high-volume hospitals were associated with a 27% lower risk of in-hospital mortality (aOR, 0.73; 95% CI, 0.56-0.96). The association between high-volume repair hospitals and reduced in-hospital mortality was independent of rural residence and transfer status.

Despite rural patients having fewer local health care resources, rurality was not associated with an increased risk of in-hospital mortality after rAAA repair. High-volume rAAA repair hospitals were associated with a 27% decreased in in-hospital mortality, independent of transfer status or patient rurality. These data underscore the importance of considering rAAA repair at high-volume repair hospitals for patients stable enough to survive rapid transport.