title: A prospective evaluation of hemodynamic instability during off-pump coronary artery bypass surgery.
abstract: OBJECTIVE
  Despite recognized hemodynamic derangements during cardiac displacement, most patients appear to tolerate the off-pump procedure well. However, some patients unpredictably become hemodynamically unstable requiring emergency cardiopulmonary bypass or intra-aortic balloon pump support. After an experience of 5306 multivessel off-pump coronary artery bypasses (OPCABs), this study was undertaken to determine the factors that would identify the patients who were at a higher risk for the procedure.
  
  
  METHODS
  Prospective clinical investigation.
  
  
  METHODS
  Tertiary care academic cardiac care center.
  
  
  METHODS
  Five hundred consecutive patients undergoing multivessel OPCAB from September to December 2001.
  
  
  METHODS
  Various cardiac and extracardiac factors were charted in prespecified data-entry forms. Multiple logistic regression analysis was done to determine if any identifiable factors were predictors of a higher risk of unacceptable hemodynamic instability during OPCAB. Institution of IABP support or conversion to CPB were the endpoints of the study.
  
  
  RESULTS
  Of the 500 patients studied, significant hemodynamic instability developed in 24 (4.8%) patients. IABP support was instituted in 16 (3.2%) patients, and 8 (1.6%) were converted to CPB. Stepwise logistic regression identified ejection fraction <25% (p < 0.001), myocardial infarction of <1-month duration (p = 0.009), congestive heart failure (p = 0.016), and preoperative hemodynamic instability (p = 0.057) as predictors of conversion during OPCAB.
  
  
  CONCLUSIONS
  Patients with low left ventricular ejection fraction <25%, myocardial infarction of <1-month duration, congestive heart failure, or preoperative hemodynamic instability constitute the high-risk group for OPCAB.
authors.affiliation: Escorts Heart Institute and Research Centre, New Delhi, India. manishamishra@yahoo.com
authors.forename: Manisha
authors.initials: M
authors.lastname: Mishra
authors.forename: Shipra
authors.initials: S
authors.lastname: Shrivastava
authors.forename: Ajay
authors.initials: A
authors.lastname: Dhar
authors.forename: Ramesh
authors.initials: R
authors.lastname: Bapna
authors.forename: Anil
authors.initials: A
authors.lastname: Mishra
authors.forename: Zile Singh
authors.initials: ZS
authors.lastname: Meharwal
authors.forename: Naresh
authors.initials: N
authors.lastname: Trehan
mesh_terms: D000368:Aged; D000714:Anastomosis, Surgical; D001145:Arrhythmias, Cardiac / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D023921:Coronary Stenosis / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D003331:Coronary Vessels / Q000637:transplantation; D005260:Female; D006333:Heart Failure / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D015994:Incidence; D007423:Intra-Aortic Balloon Pumping; D008297:Male; D008323:Mammary Arteries / Q000637:transplantation; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D017534:Radial Artery / Q000637:transplantation; D012008:Recurrence; D012307:Risk Factors; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D014654:Vascular Patency / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery