CardioSource WorldNews – A new Cochrane review raises a warning regarding coronary artery bypass surgery (CABG) on the beating heart. In an analysis of 86 randomized trials involving 10,716 patients, off-pump CABG increased all-cause mortality compared with on pump CABG (3.7% vs 3.1%; RR 1.24, p = 0.04). In 10 trials (4,950 participants) that were considered to be at low risk of bias, the effect was more pronounced (6.2% versus 4.6%; RR 1.35, p = 0.01).

CABG has traditionally been performed with cardiopulmonary bypass and an arrested heart. However, development of cardiac stabilizers has made it possible to conduct the operation on the beating heart and thereby avoid cardiac arrest and cardiopulmonary bypass. It was hoped that this would reduce complications seen after CABG surgery.

The systematic review did not demonstrate any significant benefit of off-pump compared with on-pump CABG regarding the outcome measures of myocardial infarction, stroke, atrial fibrillation, renal insufficiency, or coronary reintervention. This was in contrast to the better long-term survival in the group of patients undergoing on-pump CABG with the use of cardiopulmonary bypass and cardioplegic arrest.

Knowing that apparently conclusive meta-analyses may be inconclusive, the authors performed trial sequential analysis adjustment to assess the risk of random error due to sparse data and to multiple updating of accumulating data. This analysis showed that the risk of random error on the result was unlikely.

The investigators said the data “raise a warning” regarding use of CABG surgery on the beating heart. Cardiac arrest and cardiopulmonary bypass seem less risky, they said. In patients with contraindications for cannulation of the aorta and cardiopulmonary bypass, CABG surgery on the beating heart may be a solution, they wrote, but there is a need for randomized clinical trials in these patients to identify the most beneficial approach.

Reference

1. Møller CH, Penninga L, Wetterslev J, Steinbrüchel DA, Gluud C. Off-pump versus on-pump coronary artery bypass grafting for ischaemic heart disease. Cochrane Database of Systematic Reviews 2012, Issue 3. Art. No.: CD007224. DOI: 10.1002/14651858.CD007224.pub2 Published Online: March 14, 2012.

Keywords: Outcome Assessment, Health Care, Myocardial Infarction, Stroke, Renal Insufficiency, Catheterization, Cardiopulmonary Bypass, Coronary Artery Bypass, Heart Arrest, Induced

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