title: Operator volume and outcomes in 12,998 percutaneous coronary interventions. Northern New England Cardiovascular Disease Study Group.
abstract: OBJECTIVE
  We sought to determine whether there is a relation between operator volume and outcomes for percutaneous coronary interventions (PCIs).
  
  
  BACKGROUND
  A 1993 American College of Cardiology/American Heart Association task force stated that cardiologists should perform > or = 75 procedures/year to maintain competency in PCIs; however, there were limited data available to support this statement.
  
  
  METHODS
  Data were collected from 1990 through 1993 on 12,988 PCIs (12,118 consecutive hospital admissions) performed by 31 cardiologists at two hospitals in New Hampshire and two in Maine and one hospital in Massachusetts supporting these procedures. Operators were categorized into terciles based on annualized volume of procedures. Univariate and multivariate regression analyses were used to control for case-mix. Successful outcomes included angiographic success (all lesions attempted dilated to < 50% residual stenosis) and clinical success (at least one lesion dilated to < 50% residual stenosis and no adverse outcomes). In-hospital adverse outcomes included coronary artery bypass graft surgery (CABG), myocardial infarction (MI) and death.
  
  
  RESULTS
  After adjustment for case-mix, higher angiographic (low, middle and high terciles: 84.7%, 86.1% and 90.3%, p-trend 0.006) and clinical success rates (85.8%, 88.0% and 90.7%, p-trend 0.025), with fewer referrals to CABG (4.54%, 3.75% and 2.49%, p-trend <0.001), were seen as operator volume increased. There was a trend toward higher MI rates for high volume operators (2.00%, 1.98% and 2.57%, p-trend 0.06); all terciles had similar in-hospital mortality rates (1.09%, 0.96% and 1.05%, p-trend 0.8).
  
  
  CONCLUSIONS
  There is a significant relation between operator volume and outcomes in PCIs. Efforts should be directed toward understanding why high volume operators are more successful and encounter fewer adverse outcomes.
authors.affiliation: Department of Medicine, Maine Medical Center, Portland 04102, USA.
authors.forename: P D
authors.initials: PD
authors.lastname: McGrath
authors.forename: D E
authors.initials: DE
authors.lastname: Wennberg
authors.forename: D J
authors.initials: DJ
authors.lastname: Malenka
authors.forename: M A
authors.initials: MA
authors.lastname: Kellett
authors.forename: T J
authors.initials: TJ
authors.lastname: Ryan
authors.forename: J R
authors.initials: JR
authors.lastname: O'Meara
authors.forename: W A
authors.initials: WA
authors.lastname: Bradley
authors.forename: M J
authors.initials: MJ
authors.lastname: Hearne
authors.forename: B
authors.initials: B
authors.lastname: Hettleman
authors.forename: J F
authors.initials: JF
authors.lastname: Robb
authors.forename: S
authors.initials: S
authors.lastname: Shubrooks
authors.forename: P
authors.initials: P
authors.lastname: VerLee
authors.forename: M W
authors.initials: MW
authors.lastname: Watkins
authors.forename: F L
authors.initials: FL
authors.lastname: Lucas
authors.forename: G T
authors.initials: GT
authors.lastname: O'Connor
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects* / Q000706:statistics & numerical data*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000706:statistics & numerical data; D015986:Confounding Factors, Epidemiologic; D003953:Diagnosis-Related Groups; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012044:Regression Analysis