ROCHESTER, Minn. -- Mayo Clinic researchers discovered it is safe -- and much more convenient and less costly -- for many patients to undergo coronary angiography and elective valve surgery on the same day, it is reported in the current issue of Mayo Clinic Proceedings.
"We have developed a protocol to allow patients to safely have coronary angiography on the same day as their elective surgery," says David Holmes Jr., M.D., a cardiologist at Mayo Clinic and one of the study authors. "For patients, we are providing quality care and saving them the time and money it takes to make two trips to the hospital for the test and then surgery."
The impact of this research could be significant: Nearly 48,000 heart valve replacement or repair surgeries were registered with the Society of Thoracic Surgeons National Database in 2005, the researchers point out.
Coronary angiography, which is recommended preoperatively for all patients who are considered at risk for coronary artery disease, is frequently done several days or even weeks before surgery; the patient goes home and then returns for surgery. With coronary angiography, a dye is injected into the blood vessels through a thin, flexible tube; the dye or contrast medium allows the physician to see narrowing or blockage.
One of the primary concerns of performing coronary angiography the same day as surgery is the risk of acute kidney failure, an independent predictor of death after cardiac surgery; mortality rates have been reported as high as 44.4 percent to 63.7 percent, the researchers report. The dye used in angiography is associated with radiocontrast-induced nephropathy, which can cause kidney failure.
When worsening kidney function occurs, serum creatinine levels begin to increase after 24 to 72 hours, peak within three to five days and return to normal within another three to five days, thus the reason for the delay between the angiography and surgery, Dr. Holmes says.
To make it possible to do angiography and surgery on the same day and largely diminish the possibility of renal failure, Mayo physicians use other contrast agents. They minimize the total amount of contrast and carefully screen patients at risk for kidney disease. Different agents are used based on the patient's kidney function, Dr. Holmes says.
"In addition, deciding which patients may benefit from this streamlined approach is dependent on careful patient assessment and collaboration between the cardiologist and cardiovascular surgeon," he says.
Mayo researchers evaluated the medical records of 226 consecutive patients who had undergone cardiac catheterization on the day of elective valve repair or replacement between August 2000 and August 2004. The average age of the patient was 65 years old and 33 percent were female. Of the 226, angiography showed that 28.3 percent had severe enough coronary artery disease to also require bypass surgery, in addition to valve surgery. One patient died within 30 days following surgery, and four of the patients had transient renal failure.
A peer-review journal, Mayo Clinic Proceedings publishes original articles and reviews dealing with clinical and laboratory medicine, clinical research, basic science research and clinical epidemiology. Mayo Clinic Proceedings is published monthly by Mayo Foundation for Medical Education and Research as part of its commitment to the medical education of physicians. The journal has been published for more than 80 years and has a circulation of 130,000 nationally and internationally. Articles are available online at www.mayoclinicproceedings.com.