Effects of on-pump versus off-pump coronary artery bypass graft surgery on right ventricular function.
OBJECTIVE
Right ventricular dysfunction is a possible cause of cardiac failure after coronary surgery. The use of cardiopulmonary bypass is regarded as a major cause for its occurrence, and it has been postulated that performing coronary surgery without cardiopulmonary bypass might reduce ventricular dysfunction. Therefore, this prospective, randomized, controlled study tested the hypothesis that off-pump coronary surgery would better preserve right ventricular systolic and diastolic function than conventional bypass surgery.


METHODS
Fifty patients scheduled for elective coronary artery bypass surgery were randomly assigned to conventional or off-pump surgery. Right ventricular function was assessed by intraoperative transesophageal echocardiography immediately before and after coronary surgery. Right ventricular ejection fraction was used as a marker of global systolic function and tricuspid early/late (atrial) ratio as a marker of the global diastolic function. Peak systolic and early diastolic velocities of the lateral tricuspid annulus were studied to assess systolic and diastolic function in the area of the right ventricular free wall.


RESULTS
Surgery was completed according to randomization in 48 of 50 patients. Preoperative characteristics were similar in both groups. Intraoperative differences between the two groups included a higher volume of allogeneic blood transfusion in the conventional surgery group. At the end of surgery, global systolic right ventricular function was similarly maintained and diastolic function similarly impaired in both groups. There were no significant intergroup differences in any of the echocardiographic markers of right ventricular function.


CONCLUSIONS
Off-pump surgery did not better preserve right ventricular systolic and diastolic function than did conventional coronary surgery.
Michaux
Isabelle
I
Department of Anesthesia, University Hospital Basel, Basel, Switzerland. isabelle.Michaux@rean.ucl.ac.be
Filipovic
Miodrag
M
Skarvan
Karl
K
Schneiter
Stephan
S
Schumann
Regina
R
Zerkowski
Hans-Reinhard
HR
Bernet
Franziska
F
Seeberger
Manfred D
MD
D000368:Aged; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects; D003327:Coronary Disease / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018497:Ventricular Dysfunction, Right / Q000209:etiology*