The following is the summary of “Widening volume and persistent outcome disparity in valve operations: New York statewide analysis, 2005-2016” published in the December 2022 issue of Thoracic and cardiovascular surgery by Shang, et al.

It has been noted that high-volume facilities do a disproportionate share of sophisticated noncardiac surgeries, but whether this trend holds for cardiac surgery is still being determined. Between 2005 and 2016, researchers analyzed data from New York State to determine if there was a correlation between volume concentration and death rates following valve surgery and coronary artery bypass grafting (CABG).

 From 2005 to 2016, researchers looked at New York’s solitary CABG and isolated or contemporaneous valve operation case volumes and risk-adjusted mortality rates (RAMRs), all made publicly available by hospitals. Researchers evaluated the percentage market share changes and outcomes between hospitals in the top and lowest volume quartiles for each treatment type. The statistical significance of the trend over time was assessed using bivariate and univariate longitudinal analysis. The percentage of the market held by the top quartile of volume centers among 36 hospitals climbed from 54.4% to 59.4% for valve cases and 41.4% to 44.3% for CABG procedures. The bottom quartile’s market share has not budged noticeably. Both valve procedures (RAMR: 0.261%/year, P<.001) and CABG (RAMR: 0.071%/year, P=.018) showed statistically significant trends toward improved outcomes in the highest volume quartile over the research period. 

No clear patterns emerged in the lowest-performing 25% of either method. Over the past decade in New York, the hospitals performing the most valve surgeries have expanded their market share while retaining lower death rates than those performing the fewest. Given the persisting outcome difference between the highest- and lowest-volume hospitals, the trend toward regionalization in valve volume raises the possibility that recommendations for specialized cardiac treatments based on volume could reduce surgical mortality.

Source: sciencedirect.com/science/article/abs/pii/S0022522320331834