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Journal of the American College of Cardiology Vol. 43, No. 10, 2004© 2004 by the American College of Cardiology Foundation ISSN 0735-1097/04/$30.00Published by Elsevier Inc. doi:10.1016/j.jacc.2004.02.024

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DITORIAL COMMENT

oes Hospital Coronaryntervention Volume

atter in Predicting Mortality?*lan C. Yeung, MDalo Alto, California

n the late 1990s, the Institute of Medicine pointed out thathe health care system in the U.S. performs far belowbtainable levels of patient safety and overall values. It isstimated that 44,000 to 98,000 Americans die each year asresult of medical errors. In 1998, the Leapfrog Group (1)as formed by a number of large U.S. health care purchasers

o initiate breakthroughs in the safety and the overall valuef health care to U.S. consumers. One of the three initialethods to improve patient safety is evidence-based hospi-

al referral (2):

“One marker of how well a hospital is likely to perform isthe experience of the hospital and its surgical team. In theabsence of data to compare hospitals on their complicationsand survival rates, one can begin evaluating experience bylooking at the number of high risk treatments and proce-dures a hospital performs each year. Referrals to institutionswith a lot of experience treating certain conditions offer thebest survival odds. For example, Evidence-Based HospitalReferral for certain conditions show strong statistical rela-tionships between patient survival and a hospital’s annualvolume of such procedures.”

ne such procedure is percutaneous coronary interventionPCI). Based on the guideline set by the American Collegef Cardiology/American Heart Association (3), the Leap-rog group has established a minimum institutional volumeequirement of 400 cases per year for hospitals offering PCI.

See page 1755

his volume threshold was set using the data based ontudies published in the late 1980s and early 1990s usingalloon angioplasty as the primary technology. These stud-es show that there is an increased mortality risk for patientsreated at hospitals with annual PCI volumes of fewer than00 cases (4). However, with the advent of widespreadoronary stenting, the use of IIb/IIIa antagonists and oraldenosine diphosphate antagonists, PCI appears to be

*Editorials published in the Journal of the American College of Cardiology reflect theiews of the authors and do not necessarily represent the views of JACC or themerican College of Cardiology.From the Division of Cardiovascular Medicine (Clinical) and Cardiac Catheter-

zation and Coronary Interventional Laboratories, Stanford University Medical

enter, Palo Alto, California.

ignificantly safer for a large range of patients. Whether theld volume criterion is still valid is unclear. In this issue ofhe Journal, Epstein et al. (5) describe a study that evaluatedhether the current volume standard still holds in the stent

ra.The authors studied the in-hospital mortality among

62,748 patients in the Agency for Healthcare Research anduality National In-patient Sample hospital discharge da-

abase. The hospitals were separated into low- (5 to 199ases/year), medium- (200 to 399 cases/year), high- (400 to99 cases/year), and very high- (1,000 cases or more/year)olume centers. Compared with patients treated in high-olume hospitals, patients treated in low-volume hospitalsemained at increased risk after adjustment for patientharacteristics. However, patients treated at medium-olume hospitals had a similar risk as high-volume centers.hus, is it time to change the American College ofardiology/American Heart Association volume criteria?Not so fast! This study (5) certainly suggests that the 400

ases/year figure may be high in the stent era, but low-olume centers should still be concerned about quality. Thenadjusted mortality rate is 1.58, 1.12, 1.00, and 0.84mong the hospitals with increased patient volume. Aftereing adjusted for clinical variables, the difference becamemaller, mainly because there is a larger proportion ofatients with myocardial infarction and smaller proportionsf elective admissions and patients who arrived by inter-ospital transfer in the low-volume centers. However, noccount was taken of the angiographic characteristics oresion complexity. It is common that large and very largeenters do indeed perform “high-risk rejects” from otherospitals and that small-volume hospitals may not performCI in multivessel disease patients (5). Thus, the adjust-ent for clinical risks may or may not mask the real

ifference between the hospitals.The volume criteria may indeed need to be re-examined, but

areful review of patient populations is prudent. This study alsoas not taken into account whether operator volume affectsutcome, especially in the low-volume centers. Thus, bothospital volume data and operator volume probably will be

mportant if the best outcome is to be achieved.

eprint requests and correspondence: Dr. Alan C. Yeung,ivision of Cardiovascular Medicine, Stanford University Medicalenter, 300 Pasteur Drive, H2103, Palo Alto, California 94304-203 E-mail: ayeung@cvmed.stanford.edu.

EFERENCES

. Milstein A, Galvin RS, Delbanco SF, Salber K, Buck CRJ. Improvingthe safety of healthcare: the Leapfrog Initiative. Eff Clin Pract 2000;6:313–6.

. The Leapfrog Group. Evidence-based hospital referral. The LeapfrogGroup. Available at: http://www.leapfroggroup.org/FactSheets/

EHR_FactSheet.PDF. Accessed March 4, 2004.

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1764 Yeung JACC Vol. 43, No. 10, 2004Editorial Comment May 19, 2004:1763–4

. Smith SC, Dove JT, Jacobs AK, et al. ACC/AHA guidelines forpercutaneous coronary intervention: a report of the American College ofCardiology/American Heart Association Task Force on PracticeGuidelines (Committee to Revise the 1993 Guidelines for PercutaneousTransluminal Coronary Angioplasty). J Am Coll Cardiol 2001;37:2215–39.

. Jollis JG, Peterson ED, DeLong ER, et al. The relation between the

volume of coronary angioplasty procedures at hospitals treating Medi-care beneficiaries and short-term mortality. N Engl J Med 1994;331:1625–9.

. Epstein AJ, Rathore SS, Volpp KGM, Krumholz HM. Hospitalpercutaneous coronary intervention volume and patient mortality, 1998to 2000: does the evidence support current procedure volume mini-mums? J Am Coll Cardiol 2004;43:1755–62.