Vassileva Christina M, Boley Theresa, Markwell Stephen, Hazelrigg Stephen
Division of Cardiothoracic Surgery, Southern Illinois University School of Medicine, Springfield, IL 62794-9638, USA.
J Heart Valve Dis. 2012 Jan;21(1):41-7.
The aim of this investigation was to examine the impact of hospital annual mitral volume on mitral valve (MV) repair rates and mortality.
The 2005-2008 Nationwide Inpatient Sample (NIS) database was searched to identify patients who had undergone either MV repair (ICD-9-CM code 35.12) or MV replacement (ICD-9-CM codes 35.23 and 35.24). The hospitals were stratified into five categories based on the annual volume of all mitral procedures (< 10, 10-20, 21-40, 41-79, and > or = 80 cases/year). The relationship between hospital annual mitral procedure volume and MV repair rates, as well as hospital mortality for MV repair, was then examined for patients undergoing isolated MV surgery (excluding those aged < 30 years and those with congenital heart disease, concomitant coronary revascularization, ventricular aneurysm excision, heart transplant and other valvular interventions, except tricuspid). Chi-square tests of independence were used to test for differences between the mitral volume categories, and Cochran-Armitage tests to check for trends across the years.
The sample included a total of 12,857 patients from 603 hospitals. Mitral repair rates increased as a function of hospital mitral volume, ranging from 34% for hospitals with < 10 mitral cases/year to 53% for hospitals with > or = 80 mitral cases/year. Follow up comparisons revealed that an annual mitral volume of > 40 cases/year was associated with a significantly higher rate of MV repair (p < 0.005). There was a significant trend of increasing MV repair rates over time for hospitals with annual mitral volumes of 20-40 and 41-79 cases/year (p = 0.0001). The MV repair mortality ranged from 1.33% to 2.29%, and did not differ among hospitals as a function of the annual mitral volume (p = 0.2982).
Mortality after MV repair was low, and independent of the hospital annual mitral volume. A hospital annual mitral volume of fewer than 40 cases per year was associated with a lower rate of MV repair. Addressing the factors responsible for this finding constitutes an important area for future improvement in the care of patients with MV disease.
本研究旨在探讨医院每年二尖瓣手术量对二尖瓣修复率及死亡率的影响。
检索2005 - 2008年全国住院患者样本（NIS）数据库，以识别接受二尖瓣修复（国际疾病分类第九版临床修订本代码35.12）或二尖瓣置换（国际疾病分类第九版临床修订本代码35.23和35.24）的患者。根据所有二尖瓣手术的年手术量将医院分为五类（每年<10例、10 - 20例、21 - 40例、41 - 79例以及≥80例）。然后，针对接受单纯二尖瓣手术的患者（不包括年龄<30岁以及患有先天性心脏病、同期冠状动脉血运重建、心室壁瘤切除术、心脏移植及其他瓣膜干预的患者，但三尖瓣干预除外），研究医院每年二尖瓣手术量与二尖瓣修复率以及二尖瓣修复术后医院死亡率之间的关系。采用独立性卡方检验来检验二尖瓣手术量类别之间的差异，并用 Cochr an - Armitage检验来检查多年间的趋势。
样本包括来自603家医院的12857例患者。二尖瓣修复率随医院二尖瓣手术量增加而升高，每年二尖瓣手术量<10例的医院，修复率为34%；每年二尖瓣手术量≥80例的医院，修复率为53%。后续比较显示，每年二尖瓣手术量>40例与显著更高的二尖瓣修复率相关（p<0.005）。对于每年二尖瓣手术量为20 - 40例和41 - 79例的医院，二尖瓣修复率随时间有显著上升趋势（p = 0.0001）。二尖瓣修复术后死亡率在1.33%至2.29%之间，且在不同医院间，与每年二尖瓣手术量无关（p = 0.2982）。
二尖瓣修复术后死亡率较低，且与医院每年二尖瓣手术量无关。每年二尖瓣手术量少于40例的医院，二尖瓣修复率较低。探究导致这一结果的因素是未来改善二尖瓣疾病患者护理的重要领域。
