Trends and outcomes of valve surgery: 16-year results of Netherlands Cardiac Surgery National Database

Objectives: The aim was to describe procedural volumes, patient risk profile and outcomes of heart valve surgery in the past 16 years in Netherlands.

Methods: The Dutch National Database for Cardio-Thoracic Surgery includes approximately 200 000 cardiac operations performed between 1995 and 2010. Information on all valve surgeries (56 397 operations) was extracted. We determined trends for changes in procedural volume, demographics, risk profile and in-hospital mortality of valve operations. Because of incomplete data in the first years of registration, the total number of operations in those years was estimated using Poisson regression. For a subset from 2007 to 2010, follow-up data were available. Survival status was obtained through linkage with the national Cause of Death Registry, and survival analysis was performed using Kaplan-Meier method. Information on discharge and readmissions was obtained from the National Hospital Discharge Registry.

Results: The annual volume of heart valve operations increased by more than 100% from an estimated 2431 in 1995 to 5906 in 2010. Adjusted for population size in Netherlands, the number of operations per 100 000 adults increased from 20 in 1995 to 43 in 2010. In 2010, frequently performed valve surgery included the following: 34.6% isolated aortic valve (AoV) replacement, 21.8% AoV replacement and coronary artery bypass grafting (CABG), 14.6% isolated mitral valve surgery (repair or replacement) and 9.1% mitral valve and CABG. In AoV surgery, an increasing use of bioprostheses in all age categories is observed. In mitral valve surgery, 75.4% was performed by repair rather than replacement in 2010. In-hospital mortality for all valve surgery decreased significantly from 4.6% in 2007 to 3.6% in 2010, whereas the mean logistic EuroSCORE remained stable (median 5.8, P = 1.000). Thirty-day mortality after all valve surgery was 3.9% and 120-day mortality was 6.5%. At 1 year, survival after all valve surgery was 91.6% and a reoperation had been performed in 1.6%. The median postoperative length of stay was 7 days (interquartile range (IQR) 5-11) in the primary hospital and 11 days (IQR 8-16), including subsequent stay, in the secondary hospital.

Conclusions: The results of this study provide a comprehensive overview of valve surgery trends and outcomes in Netherlands. The number of heart valve operations performed in Netherlands has increased since 1995. The significant decrease in mortality and unchanged EuroSCORE between 2007 and 2010 might reflect a general improvement of the safety of valve surgery.