By: Ed Susman
SAN DIEGO, CA – A California database that tracks outcomes in coronary artery bypass graft surgery suggests that patients who undergo “off-pump” procedures do not fare as well as patients who undergo conventional surgery aided by heart-lung machines, researchers said at the 47th Annual Meeting of the Society of Thoracic Surgeons.
“Off-pump techniques were designed to protect patients from harm that is sometimes experienced with use of the heart-lung machine,” said Joseph Carey, MD, University of California Irvine, Orange, California. “But there still appear to be problems with off-pump surgery, particularly in the need for re-interventions.”
In his poster presentation, Dr. Carey explained that he and his colleagues reviewed data in the California Society of Thoracic Surgeons database that reflect all cardiac surgery and percutaneous coronary intervention procedures. They also interrogated the hospitalised patient discharge database of the California Office of Statewide Health Planning and Development for the years 1997 through 2008.
Risk-adjusted in-hospital mortality — corrected for connected transfers to another facility — and incidence of rehospitalisation within 1 year for mortality, acute myocardial infarction, re-intervention, or stroke for any cardiac surgery or percutaneous coronary intervention were compared for procedures performed off-pump and those performed on-pump.
The researchers noted that between 1997 and 2008 there was a sharp decline in coronary artery bypass graft procedures — dropping from 28,104 in 1997 to 13,843 in 2008. Off-pump procedures peaked at 6,300 (25.8% of the total) in 2002 and totalled 3,534 (25.5%) in 2008. In-hospital mortality during 2007-2008 was slightly better foroff-pump compared with on-pump (2.10% vs 2.20%; P =.06) and in 90-day mortality (2.65% vs 2.75%; P =.09).
However, at 1-year the differences favoured on-pump treatment, with 4.03% of the off-pump patients dying compared with 3.86% of those treated on pump (P =.08).
However, the combination of 1-year mortality, acute myocardial infarction, re-intervention, and stroke favoured treatment with conventional surgery. About 11.33% of patients in the 2-year database experienced that endpoint if they were treated off-pump compared with 9.46% of patients treated on-pump (P =.00).
Patients required more re-intervention with off-pump procedures. The rate was 2.14% for the need for re-intervention in 90 days with off-pump procedures compared with 1.06% for on-pump operations (P <.0001). The trend was similar for 1-year re-intervention, with 4.83% of those getting an off-pump procedure requiring another operation compared with 3.05% of those who were treated with on-pump techniques (P <.0001).
“Off-pump coronary artery bypass graft represents about 25% of the isolated procedures in California,” Dr. Carey noted. “This has changed little over the past decade. Off-pump coronary artery bypass graft trends toward a lower early mortality, but this difference is not significant. Off-pump coronary artery bypass graft leads to significantly higher re-intervention at 90 days and 1 year as well as a greater risk of myocardial infarction at 1 year.”
He noted that 3.09% of off-pump patients subsequently experienced an myocardial infarction 1 year after the procedure compared with 2.51% of on-pump patients (P =.03).
- MFP Wire Services