ORLANDO — Off-pump coronary artery revascularization surgery results in similar mortality but significantly less morbidity than on-pump procedures, said Dr. George Palmer at the annual meeting of the Southern Thoracic Surgical Association.
Using prospectively collected data for 1,208 consecutive patients who received coronary artery bypass grafts (CABGs) between February 2004 and July 2004, Dr. Palmer and colleagues in the multicenter Coronary Artery Revascularization Evaluation (CARE) study compared the outcomes of the 577 patients who had off-pump surgery and the 631 patients who had on-pump procedures. “The patients were not randomized. They were assigned to either off-pump or on-pump [by the respective surgeons],” said Dr. Palmer of Central Florida Regional Hospital in Sanford.
Data analysis using chi-squared statistics and t tests showed that patients in both study groups had similar predicted risks of mortality based on the Society of Thoracic Surgeons operative risk assessment model.
Preoperative medication use, including aspirin, β-blockers, ACE inhibitors, and inotropes, was similar in both groups. In terms of preoperative risk factors, there was no statistical difference between the two groups for mean age, gender, smoking, incidence of diabetes of renal failure, congestive heart failure, lung disease, myocardial infarction, or cerebrovascular disease.
There were statistical differences in the number of re-operations, with 38 in the on-pump group and 18 in the off-pump group, and in the ejection fraction, which measured 48.6% on pump and 51.0% off pump, though Dr. Palmer noted that the ejection fraction difference “was not likely of clinical significance.
There was no difference in operative mortality between the two groups, with rates of 1.7% and 1.9% for on-pump and off-pump, respectively, but on-pump procedures had statistically significant differences in rates of prolonged ventilation (9.8% vs. 3.1% for off-pump), atrial fibrillation (24.2% vs. 14.6%), blood product usage (50.6% vs. 34.2%), and renal failure (4.4% vs. 1.7%). The mean length of stay for on-pump surgery was 7.6 days, compared with 6.1 days for off-pump, Dr. Palmer said.
“These findings … suggest that off-pump coronary artery bypass surgery is a safe and less-expensive alternative to conventional CABG and may improve quality of life in some patients by reducing perioperative morbidity,” he said.
The CARE study is sponsored by HCA Inc., Guidant Corp., and Medtronic Inc.