Clinical success rates and safety are similar between surgical residents and staff surgeons performing heart surgery, according to a new long-term study reported in the Cardiovascular Surgery Supplement of Circulation: Journal of the American Heart Association.

In the study, surgical residents and staff surgeons performed two common heart operations - coronary artery bypass surgery (CABG) and aortic valve replacement (AVR) - or combined CABG and AVR.

The study found operations performed by properly supervised residents were as safe as those performed by staff surgeons. The analysis focused on 5,703 staff surgeon-performed cases and 1,011 resident-performed cases from 1998 to 2005 involving seven staff surgeons and six residents at the Maritime Heart Center in Halifax, Canada.

"There doesn't appear to be any significant difference in the long-term outcome comparing cases performed by residents as the primary surgeon or by staff as the primary surgeon," said Roger J. F. Baskett, M.D., senior author of the study and assistant professor of surgery at Dalhousie University in Halifax, Nova Scotia, Canada.

The study examined long-term clinical outcome, as measured by death, re-admission to the hospital for acute coronary syndrome, heart failure and repeat procedures. The findings showed that patient survival, without adverse events, was similar between heart surgery performed by residents and by staff surgeons. The resident-performed cases were not associated with late death or re-hospitalization.

The resident cases as a group were also sicker with greater co-morbidities when compared to the staff cases. Baskett said residents, who generally chose which cases they would operate on, tended to choose sicker patients and more complex cases because they felt the learning opportunities were greater.

Overall, the average age of the patients was 65 years old. About 25 percent were women. The patients also had other diseases that ranged from diabetes, high blood pressure and peripheral vascular disease to cerebrovascular disease, previous heart attack and previous atrial fibrillation. About 35 percent of the patients in both groups had diabetes. About 50 percent of the patients underwent elective surgery, while about 15 percent underwent urgent or emergency surgery. Of the procedures the majority of the patients received isolated CABG.

Event-free survival rates were:

• One year after surgery - 81.3 percent for staff cases vs. 79.1 for resident cases.
• Three years after surgery -68.2 percent for staff cases vs. 66.7 percent for resident cases.
• Five years after surgery - 58.6 percent for staff cases vs. 55.8 percent for resident cases.

None of these differences were statistically significant after considering that as a group the patients operated on by residents as primary surgeons were sicker.

The average follow-up time was three years, with a maximum of eight years.

Baskett emphasized the importance of supervised training of surgical residents, especially for the benefit of future generations of heart surgery patients.

"The important message is that it is safe to train residents if they are appropriately supervised," Baskett said. "It is not only safe, even with complex procedures, but it is very important. That should make patients very comfortable. It is critical that trainees operate because they're going to be the ones operating on the next generation - your kids."

Co-authors are: Serban C. Stoica, M.D.; Dimitri Kalavrouziotis, M.D.; Billlie-Jean Martin, M.D.; Karen J. Buth, M.Sc.; Gregory Hirsch, M.D.; and John A. Sullivan, M.D.