Coronary Revascularization Trends in the United States, 2001-2008

Study Questions:

What are the national trends in the rates and type of coronary revascularization procedures in the United States over a decade?

Methods:

This was an examination of administrative databases, primarily the Nationwide Inpatient Sample (NIS), between 2001 and 2008. This data set was examined for procedure codes identifying percutaneous coronary intervention (PCI) with or without drug-eluting stents (DES) and coronary artery bypass grafting (CABG). The NIS is a 20% stratified random sample of US hospitals, and the procedure rate for the US adult population was therefore extrapolated from this sample. Known previous work has suggested that 6-18% of PCIs are performed on outpatient stays. Because the NIS primarily reflects inpatient discharge data, in order to include this outpatient group, Medicare data from the Centers for Medicare and Medicaid Services procedure claims were then used.

Results:

The annual US rate of coronary revascularization decreased by 15% from 2001 to 2008. There was a 38% reduction in annual CABG volume (p < 0.001), but no significant difference in PCI rate (p = 0.74). In essence, this projection suggested approximately 130,000 fewer CABG procedures in 2008 compared to 2001. In contrast, there was an increase in the number of hospitals providing CABG surgery, from 212 to 241 (p = 0.03). Concomitantly, there was a 26% increase in the number of hospitals providing PCI (246 vs. 331, p < 0.01). Overall, this provided a 28% decrease in the median case load per hospital for CABG, and a substantial increase in the number of hospitals providing fewer than 100 CABG procedures per year (23 vs. 62, p < 0.01). The use of DES dramatically increased from 2001 to 2005, at which point 90% of all PCI procedures used DES. However, thereafter, the volume subsequently decreased such that by 2008, DES were used in 68% of procedures.

Conclusions:

This study demonstrates that CABG procedural volume has markedly decreased within a decade, but PCIs remain unchanged. In addition, initial dramatic enthusiasm for DES has been tempered over time.

Perspective:

This is a very interesting study confirming what we all know as practitioners, namely the slow erosion of CABG volume. In examining these data, this is a linear decrease throughout the 8-year period, and was not triggered by a single event. It is likely, though not verified in the data, that the maintenance of stability of PCI has likely been at the expense of CABG volume. It appears that the recent SYNTAX trial suggesting superiority of CABG for three-vessel disease or left main coronary artery disease, even in the DES era, did not necessarily affect the utilization of different therapeutic modalities in the US. The current study is obviously limited in being able to determine whether the rates of CABG in those specific indications stabilized or increased, however. I believe, however, that the most important findings in this study were the following: The first is the identified rapid increase in DES use despite inadequate data in patients undergoing PCI. Obviously, the concerns about stent thrombosis after DES use tempered the enthusiasm over time. I believe the second and equally important finding in this study is that the volume of total coronary revascularization procedures has decreased over the last decade. Whether this means that medical therapy has improved despite an increase in comorbidities such as diabetes or hypertension in the US remains to be further elucidated.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Aortic Surgery, Interventions and Coronary Artery Disease

Keywords: Coronary Artery Disease, Centers for Medicare and Medicaid Services (U.S.), Coronary Artery Bypass, United States, Percutaneous Coronary Intervention


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