Type A aortic dissection: optimal annual case volume for surgery

• Published in: European heart journal Vol. 44; no. 41; pp. 4357 - 4372
• Main Authors: Kawczynski, Michal J, van Kuijk, Sander M J, Olsthoorn, Jules R, Maessen, Jos G, Kats, Suzanne, Bidar, Elham, Heuts, Samuel
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 01.11.2023
• Subjects: Aortic Dissection - surgery; Hospitals, High-Volume; Humans; Retrospective Studies; Treatment Outcome; Volume–outcome relationship; Hospital volume; Annual case volume; Optimal case volume; Cardiovascular interventions; Acute type A aortic dissection
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/ehad551

Abstract Background and Aims The current study proposes a novel volume–outcome (V–O) meta-analytical approach to determine the optimal annual hospital case volume threshold for cardiovascular interventions in need of centralization. This novel method is applied to surgery for acute type A aortic dissection (ATAAD) as an illustrative example. Methods A systematic search was applied to three electronic databases (1 January 2012 to 29 March 2023). The primary outcome was early mortality in relation to annual hospital case volume. Data were presented by volume quartiles (Qs). Restricted cubic splines were used to demonstrate the V–O relation, and the elbow method was applied to determine the optimal case volume. For clinical interpretation, numbers needed to treat (NNTs) were calculated. Results One hundred and forty studies were included, comprising 38 276 patients. A significant non-linear V–O effect was observed (P < .001), with a notable between-quartile difference in early mortality rate [10.3% (Q4) vs. 16.2% (Q1)]. The optimal annual case volume was determined at 38 cases/year [95% confidence interval (CI) 37–40 cases/year, NNT to save a life in a centre with the optimal volume vs. 10 cases/year = 21]. More pronounced between-quartile survival differences were observed for long-term survival [10-year survival (Q4) 69% vs. (Q1) 51%, P < .01, adjusted hazard ratio 0.83, 95% CI 0.75–0.91 per quartile, NNT to save a life in a high-volume (Q4) vs. low-volume centre (Q1) = 6]. Conclusions Using this novel approach, the optimal hospital case volume threshold was statistically determined. Centralization of ATAAD care to high-volume centres may lead to improved outcomes. This method can be applied to various other cardiovascular procedures requiring centralization. Structured Graphical Abstract Structured Graphical Abstract Overview of the process to determine the volume-outcome relation and the optimal annual case volume in surgery for acute type A aortic dissection. Grey line: first quartile, yellow line: second quartile, blue line: third quartile, and red line: fourth quartile. ATAAD, acute type A aortic dissection. Audio Abstract 10.1093/eurheartj/ehad551media1 Audio Abstract ehad551media1 6335404329112