Objective: The objective of this study was to assess improved myocardial protection by performing coronary artery bypass grafting (CABG) on the beating heart. A case-matched study was conducted among patients who underwent CABG either on-pump (group 1), or off-pump (group 2).
Methods: Forty-five pairs of patients, having a similar clinical profile, were selected on the basis of five variables: age, gender, body surface area, ejection fraction, extent of coronary disease. Operative risk predicted by the The Society of Thoracic Surgeons national database was 1.80+/-0.35% in group 1, and 1.89+/-0.37% in group 2 (NS). Cold blood cardioplegia and 28 degrees C cardiopulmonary bypass were used in group 1. In group 2, beating heart coronary grafting was achieved with the Octopus 1 and 2 stabilizers. The average number of distal anastomoses was 2.8+/-0.1 in group 1 and 2.3+/-0.1 in group 2 (P=0.015).
Results: There was no significant difference among the groups regarding the trend in cardiac index, left and right ventricular stroke work indexes, and systemic and pulmonary vascular resistance indexes. However, heart rate trend was slower in group 2 (P=0.05). Pharmacological support was required in 65% of the patients in group 1, and in 33% in group 2 (P<0.001). The total amount of Dobutamine and/or Dopamine administered during the first 48 h was 3914+/-1306 gamma/kg in group 1 and 1645+/-697 gamma/kg in group 2 (P=0.049). Release of creatine kinase MB mass isoenzyme (CK-MB mass) was markedly reduced in group 2 (P<10(-4)).
Conclusions: Hemodynamic outcome following off-pump CABG is similar to on-pump CABG but the need for inotropic support is significantly reduced and CPK-MB mass release is markedly lower.