Impact of cardiac catheterization volume on clinical and financial outcomes in patients with type A aortic dissection

Purpose: Institutional cardiac catheterization capabilities are often utilized as a surrogate measure to evaluate cardiovascular management. Thus, patients experiencing acute type A aortic dissection (TAAD) are frequently directed to such facilities, regardless of their expertise in aortic operation. We sought to evaluate institutional catheterization volume on patients with TAAD.

Methods: Using the 2017-2020 Nationwide Readmission Database, all adult patients undergoing repair for TAAD were identified. Diagnoses and procedures were identified using the International Classification of Diseases, Tenth Revision (ICD-10) codes. A logistic regression model for mortality was utilized with the inclusion of an annual percutaneous coronary intervention (PCI) caseload annually. The annual institutional PCI caseload corresponding to the volume (N=321) at the inflection point of the spline was utilized to categorize hospitals as low-volume (LVH) or high-volume (HVH) hospitals. Additionally, the annual institutional volume of TAAD repair was used to measure aortic operative volume. Patients were stratified into those managed at LVH or HVH. Chi-square or adjusted Wald tests were used to compare categorical and continuous variables, respectively. Multivariable regression was used to assess factors associated with HVH status on mortality, duration of hospitalization (LOS), hospitalization costs, non-home discharge and 90-day readmission.

Results: Of an estimated 4,387 patients undergoing thoracic aortic repair for TAAD, 1,584 (36.1%) were treated at HVH. Compared to those at LVH, patients with TAAD undergoing management at HVH had comparable age (62 [51-71] vs 60 [49-70], P=0.06), sex (Female: 35.5 vs 36.6%, P=0.59) and rates of transfer from another acute care facility (3.4 vs 3.4%, P=0.98). Relative to those managed at LVH, patients managed at HVH had lower mortality and index hospitalization cost (Table). After risk adjustment, HVH status was associated with reduced mortality (Adjusted Odds Ratio [AOR] 0.54, 95% Confidence Interval [95%CI] 0.41-0.70). Furthermore, management at HVH was associated with reduced hospital duration of stay by 0.7 days (95%CI 0.4-1.1 days) and hospitalization cost by $1,800 (95%CI $1,000-2,500). As shown in Figure, both an increase in institutional thoracic aortic repair volume and PCI volume were associated with reduced costs of TAAD management. The odds of perioperative complications and 90-day readmission were not significantly associated with HVH status. Patients managed at HVH had a greater risk of non-home discharge (AOR 1.46, 95%CI 1.18-1.80).

Conclusion: Increased cardiac catheterization volume was significantly associated with lower mortality rates. Furthermore, both increased cardiac catheterization and thoracic aortic repair volumes have been associated with reduced index hospitalization costs. Given these findings, routing patients with TAAD to hospitals with high PCI volume centers will likely benefit early evaluation and management.

Identify the source of the funding for this research project: None