Variability in surgeons' perioperative practices may influence the incidence of low-output failure after coronary artery bypass grafting surgery

Circ Cardiovasc Qual Outcomes. 2012 Sep 1;5(5):638-44. doi: 10.1161/CIRCOUTCOMES.112.967091. Epub 2012 Jul 24.


Background: Postoperative low-output failure (LOF) is an important contributor to morbidity and mortality after coronary artery bypass grafting surgery. We sought to understand which pre- and intra-operative factors contribute to postoperative LOF and to what degree the surgeon may influence rates of LOF.

Methods and results: We identified 11 838 patients undergoing nonemergent, isolated coronary artery bypass grafting surgery using cardiopulmonary bypass by 32 surgeons at 8 centers in northern New England from 2001 to 2009. Our cohort included patients with preoperative ejection fractions >40%. Patients with preoperative intraaortic balloon pumps were excluded. LOF was defined as the need for ≥2 inotropes at 48 hours, an intra- or post-operative intraaortic balloon pumps, or return to cardiopulmonary bypass (for hemodynamic reasons). Case volume varied across the 32 surgeons (limits, 80-766; median, 344). The overall rate of LOF was 4.3% (return to cardiopulmonary bypass, 2.6%; intraaortic balloon pumps, 1.0%; inotrope usage, 0.8%; combination, 1.0%). The predicted risk of LOF did not differ across surgeons, P=0.79, and the observed rates varied from 1.1% to 10.2%, P<0.001. Patients operated by low-rate surgeons had shorter clamp and bypass times, antegrade cardioplegia, longer maximum intervals between cardioplegia doses, lower cardioplegia volume per anastomosis or minute of ischemic time, and less hot-shot use. Patients operated on by higher LOF surgeons had higher rates of postoperative acute kidney injury.

Conclusions: Rates of LOF significantly varied across surgeons and could not be explained solely by patient case mix, suggesting that variability in perioperative practices influences risk of LOF.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cardiac Output, Low / epidemiology*
  • Cardiac Output, Low / therapy
  • Cardiopulmonary Bypass
  • Cardiotonic Agents / therapeutic use
  • Chi-Square Distribution
  • Clinical Competence / statistics & numerical data
  • Coronary Artery Bypass / adverse effects*
  • Female
  • Heart Failure / epidemiology*
  • Heart Failure / therapy
  • Humans
  • Incidence
  • Intra-Aortic Balloon Pumping
  • Logistic Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • New England / epidemiology
  • Perioperative Care / statistics & numerical data*
  • Practice Patterns, Physicians' / statistics & numerical data*
  • Prospective Studies
  • Registries
  • Reoperation
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Treatment Outcome


  • Cardiotonic Agents