It's widely assumed that hospitals are performing increasing numbers of percutaneous coronary interventions (PCIs) with stents, and vastly fewer invasive coronary artery bypass graft procedures.
But in a surprising study, Philadelphia researchers who looked at all-payer statistics from 2001 to 2008 found that although coronary artery bypass graft surgery (CABG) procedures have indeed decreased dramatically by nearly one-third, rates of PCIs have remained relatively stable.
"Stable PCI rates between 2001 and 2008 were unanticipated, because clinical trials consistently have reported that DES (drug-eleuting stents) reduces a recipient's likelihood of repeat target vessel revascularization due to lower rates of subsequent restenosis," wrote Andrew J. Epstein of the Philadelphia Veterans Affairs Medical Center and the University of Pennsylvania and colleagues in Wednesday's edition of the Journal of the American Medical Association.
CABG and PCI revascularization operations are the most common type of major medical procedure provided by U.S. healthcare facilities, with more than a million done annually, the report says.
Overall, there was a 15% decrease in total revascularization procedures of both types between 2001-2002 and 2007-2008.
The rate of CABG surgeries decreased from 1,742 per million adults in the 2001-2002 period to 1,081 in 2007-2008. PCI operations went from 3,827 per million adults in 2001-2002 to 3,667 in 2007-2008, a rate considered relatively stable.
The authors imply that PCI use did not balloon as expected because of safety concerns about drug-eluting stents, which became the preferred type over bare metal stents (BMS) after they received approval in 2003 from the U.S. Food and Drug Administration.
"Changes in PCI market share between DES and BMS have been previously reported among selected subsets of U.S. hospitals, and these changes possibly reflect a high level of clinician enthusiasm for DES in the years immediately following US Food and Drug Administration approval," the authors wrote.
But that enthusiasm was "followed by a 'cooling off' period after publication of data suggesting DES safety concerns (such as late in-stent thrombosis), as well as increasing clinician awareness of the imperative for DES patients’ adherence to long-duration anti-platelet therapy following DES implantation."
They added, "An important implication of this volatility is that thousands of patients may have received DES during the peak years (2004-2005) who would have instead received BMS in 2007-2008. Whether these patients were appropriately treated with DES instead of BMS during these years of high enthusiasm for DES is uncertain."
Interestingly, the number of hospitals performing CABG procedures increased dramatically signaling that greater numbers of patients "were obtaining CABG surgery at hospitals with low volumes of CABG surgery," they wrote. "Although there is controversy in the literature on whether low income hospitals inherently have worse CABG surgery outcomes, our findings highlight the increasing role of low-volume hospitals in the provision of CABG surgery."
The data were taken from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project sample of 1,000 hospitals and extrapolated the entire U.S. healthcare system.