Department of Cardiothoracic Surgery, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6629HX Maastricht, Limburg, The Netherlands.
Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 50, Maastricht, PO Box 616, 6200 MD, Maastricht, The Netherlands.
Eur Heart J. 2023 Nov 1;44(41):4357-4372. doi: 10.1093/eurheartj/ehad551.
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.
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.
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].
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.
本研究提出了一种新的基于体积-结果（V-O）的荟萃分析方法，以确定需要集中化的心血管介入治疗的最佳年度医院病例量阈值。该新方法应用于急性 A 型主动脉夹层（ATAAD）手术作为说明性示例。
系统检索了三个电子数据库（2012 年 1 月 1 日至 2023 年 3 月 29 日）。主要结局是与年度医院病例量相关的早期死亡率。数据以体积四分位数（Qs）呈现。限制性立方样条用于显示 V-O 关系，应用肘部法确定最佳病例量。为了临床解释，计算了需要治疗的人数（NNTs）。
共纳入 140 项研究，包含 38276 例患者。观察到显著的非线性 V-O 效应（P<0.001），早期死亡率存在明显的四分位间差异[10.3%（Q4）比 16.2%（Q1）]。最佳年度病例量确定为 38 例/年[95%置信区间（CI）37-40 例/年，与最佳体积中心相比，每年挽救 1 条生命的 NNT 为 10 例/年=21]。长期生存率观察到更显著的四分位间生存差异[10 年生存率（Q4）69%比（Q1）51%，P<0.01，调整后的危险比 0.83，95%CI 每四分位为 0.75-0.91，与低体积（Q1）中心相比，每年挽救 1 条生命的 NNT 为高体积（Q4）中心=6]。
使用这种新方法，统计学上确定了最佳医院病例量阈值。将 ATAAD 护理集中到高容量中心可能会改善结果。该方法可应用于需要集中化的各种其他心血管手术。
