Incidence of Cardiac Complications Following Hip Surgery: A Population‐Based Study

Background:

After coronary artery bypass grafting, hip surgery is the most commonly performed procedure in patients older than 65. In the current American College of Cardiology/American Heart Association (ACC/AHA) preoperative evaluation guideline, orthopedic surgical procedures are categorized as intermediate risk (combined myocardial infarction [MI] and death rate of < 5%). This categorization is based on pooled orthopedic surgical populations, yet reported mortality rates differ by procedure. In particular, mortality after surgical repair of hip fractures is significantly higher than that after any other orthopedic surgery. It is unknown how much of this excess mortality is due to cardiac events. The current aggregation of all orthopedic surgical procedures into 1 risk stratum may not adequately characterize the geriatric patient undergoing urgent hip fracture repair.

Methods:

This was a population‐based retrospective cohort of 1890 hip surgeries (elective replacement and hip fracture repair) received by 1609 patients from Olmsted County, Minnesota, between January 1988 and December 2002. Data were obtained through medical record review. MI was defined as biochemical or ECG evidence of a definite MI. Clinical documentation alone was not enough to call an event an MI. Congestive heart failure (CHF) was detected through the use of the Framingham criteria.

Results:

During hospitalization (mean length of stay 8.9 ± 5.5 days), the incidence of postoperative MI, CHF, and mortality was 4.6%, 1.9%, and 0.6%, respectively, following elective hip arthroplasty and 14.3%, 6.5%, and 4.7%, respectively, after hip fracture. After 1 year, the all‐cause mortality rate was 2.3% (95% CI: 1.3%, 3.7%) for elective hip arthroplasty patients and 24.0% (95% CI: 21.3%, 26.9%) for hip fracture patients. The incidence of the combined end point of postoperative MI or death was 7.5% (95% CI 5.6%, 9.8%) among patients undergoing elective hip arthroplasty compared to 34.2% (95% CI 30.9%, 37.6%) following hip fracture repair. After adjusting for age, sex, and ASA classification, hip fracture patients were 3.6 times more likely (95% CI 2.5, 5.2)to suffer an MI or death within 1 year of surgery than were those who underwent elective THA surgery.

Conclusions:

The ACC/AHA preoperative evaluation guideline calls for “establishment of optimal guidelines for selected patient subgroups, particularly the elderly.” Hip fracture patients should be considered a special subgroup. This study shows that the 1‐year combined outcome of MI and death following hip fracture repair far exceeds the current guideline's predicted rate of less than 5% for intermediate‐risk procedures (the classification for orthopedic surgeries). Even though fracture repair is urgent, it does not fall into the “emergency surgery” category within the published guideline. As such, there is time (up to 48 hours postfracture) to medically optimize the patient's condition, including cardiac status.

Author Disclosure:

J. Huddleston, None; P. Huddleston, None; D. Larson, None; R. Gullerud, None; S. Gabriel, None; L. J. Melton, None; V. Roger, None.