Preoperative cardiac stress test not vital for hip fracture patients

Researchers reported a very low rate of cardiac interventions, even when they diagnosed ischemia.

A study of patients with hip fractures found that preoperative cardiac stress testing resulted in low rates of cardiac intervention and significantly increased time until surgery.

"Cardiac stress evaluations provide information regarding the maximal heart rate before ischemia develops, and they also provide information regarding the function and efficiency of the heart during stress, but they don't help much in the preoperative evaluation of hip fracture patients," S. Andrew Sems, MD, said at the 23rd Annual Meeting of the Orthopedic Trauma Association in Boston.

Sems and his colleagues at the Mayo Clinic in Rochester, Minn, evaluated the frequency of cardiac stress testing among hip fracture patients, the frequency of cardiac intervention following stress testing and the impact of the tests on delaying fracture fixation. They also examined the mortality rate with and without stress testing.

Stress testing frequency

Of the 1,973 patients older than 65 years who were included in the study (1,010 hip fractures), 54 (5.5%) underwent preoperative cardiac stress testing. This consisted of either a dobutamine stress echocardiogram (DSE) or a sestamibi scan. There were 39 women and 15 men, with an average age of 81.7 years.

The control group consisted of the remaining 919 patients (665 women and 254 men; average age, 83.2 years).

The stress tests were positive for ischemia in 13 patients (24%); 12 of the 13 patients underwent DSE and one underwent a sestamibi scan. Only one patient (1.8%), however, underwent an interventional cardiac procedure: coronary artery bypass grafting prior to hip fracture fixation; this patient died within 2 months. No patients with sestamibi scans underwent any cardiac interventional procedures.

Overall mortality rates at 30 days, 90 days and 1 year were 7.2%, 13.9% and 27.7%, respectively. There were no differences between the stress testing group and the control group with regard to mortality, according to Sems.

Delays to surgery

"The average time from presentation to hip fracture surgery in the stress testing group was 2.76 days, compared to 1.41 days in the non-stress testing group [P<.0001]," Sems said. Among the stress testing group, the average time from presentation to stress test was approximately 1.6 days, and the time from stress test to hip fracture surgery was 1.2 days.

There was also a significantly longer hospital stay for those in the stress testing group (10.8 days vs. 8.4 days for the non-testing group).

"Stress tests provided no significant impact on the perioperative management of these patients, and in this group of patients, preoperative stress testing was associated with longer delays to surgery, longer hospital stays and no differences in perioperative mortality," he said.

"The very low rate of cardiac intervention in these patients, even among patients with results indicative of ischemia, also supports limiting the role that these tests play in routine management of hip fracture patients."

For more information:
S. Andrew Sems, MD, can be reached at Mayo Clinic, Dept of Orthopaedic Surgery, 200 First Street, SW, Rochester, MN 55905; 507-284-2511; e-mail: sems.stephen@mayo.edu.
Sems SA, Summers EC, Jurrens TL. Cardiac stress testing has limited value prior to hip fracture surgery. Paper #49. Presented at the 23rd Annual Meeting of the Orthopaedic Trauma Association. Oct. 18-20, 2007. Boston.