PHILADELPHIA – U.S. cardiac surgeons increasingly performed coronary artery bypass surgery on more complex patients during 2000-2009, yet significant drops in the rates of perioperative deaths and strokes were seen during those years, according to a review of more than 1.4 million procedures.
"The major implication of this study is that we are operating on a more complex cohort of patients, and we’re doing a better job, with less death and stroke than [was the case] not too long ago. This has implications for how we stratify patients for revascularization therapy," said Dr. Andrew W. ElBardissi at the annual meeting of the American Association for Thoracic Surgery.
"A lot of the patterns that we are seeing reflect the results from some of the more rigorous prospective studies that have dictated practice. We have seen improvements in process and surgical decision making, including more optimal medical management when patients go to surgery – not just in the operating room, but throughout the perioperative period (preop, op, and the ICU). Not only have outcomes improved, but we seem to be operating on the correct cohort of patients," said Dr. ElBardissi, a cardiac surgeon at Brigham and Women’s Hospital in Boston.
"These outcomes appear to reflect improvements in perioperative surgical care as they continue to be significant after adjustment for patient risk," he added.
Dr. T. Bruce Ferguson Jr. concurred with Dr. ElBardissi’s assessment. "This study clearly documented continued improvement in CABG [coronary artery bypass grafting], particularly in the CABG-PCI [percutaneous coronary intervention] era of the last decade. These are clearly more technically difficult operations, with increased rates of prior PCI, left main disease, and distal anastomoses," said Dr. Ferguson, professor of surgery and chairman of cardiovascular sciences at East Carolina University in Greenville, N.C.
Dr. ElBardissi’s analysis used data that were collected on more than 1.4 million patients who underwent first-time, isolated CABG surgery at a hospital participating in the Society of Thoracic Surgeons’ adult cardiac surgery database. The data he presented compared 136,513 patients who underwent CABG in 2000 vs. 160,905 patients who had this surgery in 2009.
Major shifts during those years included a statistically significant drop in the prevalence of recent smoking (from 60% in 2000 to 30% in 2009), but significant increases in the prevalence of patients with hypercholesterolemia (84% in 2009 vs. 60% in 2000), hypertension (85% vs. 71%), and chronic obstructive pulmonary disease (23% vs. 16%). The percentage of patients who were previously treated by PCI also jumped to 26% in 2009, compared with 19% in 2000.
Significant rises in the rate of preoperative treatment with cardioprotective drugs were also seen, notably in the use of aspirin, beta-blockers, ACE inhibitors, and statins. Beta-blocker use jumped from 61% of patients in 2000 to 81% in 2009.
The prevalence of left main coronary artery stenosis rose from 23% of patients in 2000 to 32% in 2009.
The statistics also documented meaningful changes in how CABG occurred. Use of an internal mammary artery graft rose from 84% of cases in 2000 to 95% in 2009, and off-pump surgery increased from 14% of cases to 21%.
Elective procedures dropped from 58% in 2000 to 41% in 2009. The largest subgroup of patients shifted to urgent cases, which rose from 38% of patients in 2000 to 54% in 2009.
Mortality during 30-day follow-up fell significantly, from 2.4% in 2000 to 1.9% in 2009 – a 24% relative rate reduction after adjustment for differences in patient risk. Among elective and urgent cases, 30-day mortality fell from 2.1% in 2000 to 1.6% in 2009.
The rate of 30-day stoke in all patients dropped from 1.6% in 2000 to 1.2% in 2009, a statistically significant decline. The risk-adjusted analysis showed this as a 26% relative fall in stroke rates. In elective and urgent cases, the rate declined from 1.6% to 1.1%.
The 30-day outcome results also showed significant declines in deep sternal wound rates (from 0.55% in 2000 to 0.37% in 2009), and in the need for reoperations because of bleeding (2.5% vs. 2.2%). The statistics showed no significant changes in the rates of postoperative renal failure or new-onset atrial fibrillation.
Dr. ElBardissi and Dr. Ferguson said they had no disclosures.