PHILADELPHIA — Performing coronary bypass surgery off-pump helps preserve renal function in patients who have renal insufficiency before surgery, according to results from a randomized study with 116 patients.
The benefit from off-pump surgery was greatest in two subsets of patients: diabetics and hypertensives, Dr. Lokeswara R. Sajja said at the annual meeting of the American Association for Thoracic Surgery.
“Off-pump surgery is renal protective in patients who are not on dialysis. Preoperative assessment of renal function by GFR [glomerular filtration rate] is needed to risk stratify patients” and identify patients who need off-pump surgery to maintain their renal function, said Dr. Sajja, a cardiac surgeon at CARE Hospital in Hyderabad, India.
The study enrolled patients at CARE Hospital who required coronary-artery bypass surgery and had stage 3 or 4, non-dialysis dependent renal insufficiency during August 2004–October 2005. All patients had a calculated GFR of 60 mL/min per 1.73 m
In patients who had on-pump surgery, the GFR fell from an average of 51.7 mL/min per 1.73 m
By contrast, among those patients whose surgery was done off pump, GFR fell from an average of 52.2 mL/min per 1.73 m
The impact of bypass surgery was more dramatic in those patients who had diabetes or hypertension.
In the subgroup with diabetes, among the 32 patients treated with on-pump surgery 84% had a 20% or greater rise in their serum creatinine level, compared with 48% of the 33 patients who underwent off-pump bypass surgery.
A 20% or greater drop in GFR occurred in 56% of the diabetic patients treated with on-pump surgery compared with 36% of those treated with off-pump surgery.
In the subgroup with hypertension, of the 46 patients treated with on-pump surgery 65% had a 20% or greater rise in serum creatinine levels, compared with 35% of the 37 the hypertensive patients who received off-pump surgery.