title: Effects of hospital volume of primary percutaneous coronary interventions on angiographic results and in-hospital outcomes for acute myocardial infarction.
abstract: BACKGROUND
  Several clinical studies have demonstrated an inverse relationship between hospital volume of primary percutaneous coronary interventions (PCI) and in-hospital mortality. However, the relationships among hospital primary PCI volume, angiographic results, and in-hospital prognosis in patients with acute myocardial infarction (AMI) have not been fully investigated in Japan.
  
  
  RESULTS
  Using the AMI-Kyoto Multi-Center Risk Study database between January 2000 and December 2005, hospitals were classified into quintiles based on their annual volume of primary PCI. The fifth quintile of hospitals was labeled as high-volume, and the other quintiles were combined and defined as low-volume. Although patients undergoing primary PCI in high-volume hospitals (high-volume group, n=764) had a larger number of diseased vessels at initial coronary angiography and lower Thrombolysis In Myocardial Infarction (TIMI) flow grade in the infarct-related artery before PCI, compared with those in low-volume hospitals (low-volume group, n=1,021), the rates of achieving TIMI flow grade 3 just after PCI in the high-volume group was significantly higher than that in the low-volume group. The overall in-hospital mortality did not differ between the 2 groups. On multivariate analysis, in AMI patients undergoing primary PCI, Killip class >or=3 at admission, multivessel disease or left main trunk (LMT) as culprit lesion, number of diseased vessels >or=2 or diseased LMT, and age were the independent positive predictors of in-hospital mortality, whereas the TIMI flow grade 3 after primary PCI and elapsed time <24 h were the negative ones, but not low-volume hospital.
  
  
  CONCLUSIONS
  Angiographic results of primary PCI in high-volume hospitals were superior to those in low-volume hospitals, but there was no significant difference in the in-hospital mortality between AMI patients in high-volume hospitals and those in low-volume hospitals.
authors.affiliation: Department of Cardiology, Kyoto First Red Cross Hospital, Honmachi, Higashiyama-ku, Kyoto 605-0981, Japan. sjun@msj.biglobe.ne.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Shiraishi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kohno
authors.forename: Takahisa
authors.initials: T
authors.lastname: Sawada
authors.forename: Masayasu
authors.initials: M
authors.lastname: Arihara
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hyogo
authors.forename: Takakazu
authors.initials: T
authors.lastname: Yagi
authors.forename: Takatomo
authors.initials: T
authors.lastname: Shima
authors.forename: Takashi
authors.initials: T
authors.lastname: Okada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Satoaki
authors.initials: S
authors.lastname: Matoba
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shirayama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tatsumi
authors.forename: Makoto
authors.initials: M
authors.lastname: Kitamura
authors.forename: Keizo
authors.initials: K
authors.lastname: Furukawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsubara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000401:mortality* / Q000706:statistics & numerical data; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D005260:Female; D006742:Hospital Bed Capacity / Q000706:statistics & numerical data*; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000628:therapy*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D011379:Prognosis; D012307:Risk Factors