JACC: Gait speed predicts outcomes in elderly CABG patients
Gait speed, a marker of frailty, can help predict mortality and major morbidity in subsets of elderly patients undergoing cardiac surgery, according to a study published Nov. 9 in the Journal of the American College of Cardiology.

“Elderly patients account for half of the cardiac surgeries performed in North American and as many as 78 percent of the major complications and deaths,” the authors wrote. “It is increasingly difficult to predict the elderly patient’s risk posed by cardiac surgery because existing risk assessment tools are incomplete.”

To evaluate the value of gait speed in clinical practice, Jonathan Afilalo, MD, MSc, of the SMBD-Jewish General Hospital and McGill University in Montreal, and colleagues assessed 131 elderly patients undergoing cardiac surgery at four tertiary care hospitals between 2008 and 2009.

Patients included in the analysis were aged 70 years or older and scheduled to undergo CABG surgery and/or valve repair or replacement. The researchers used a composite of in-hospital post-operative mortality and major morbidity as the trial’s primary endpoint and its primary predictor was slow gait speed, which was defined as taking six seconds or more to walk 5 meters.

The researchers found that 23 percent of the patients experienced the primary composite endpoint. Women and diabetic patients were slower walkers compared to other patients: 43 versus 25 percent, and 50 versus 28 percent, respectively. Sixty patients were classified as having a slow gait speed prior to cardiac surgery.

Afilalo and colleagues noted that slow gait speeds were an independent predictor of the composite endpoints after adjusting for Society of Thoracic Surgeons (STS) risk scores.

Additionally, the researchers found that a slow gait speed led to better models of performance and could accurately predict patients who were more likely to experience major adverse events, who needed to be discharged to a healthcare facility for ongoing treatment and those who would have longer hospital stays.

“The principal finding of this study is that 5-m gait speed is an incremental predictor of mortality and major morbidity in elderly patients undergoing cardiac surgery, associated with a two- to three-fold increase in risk,” the authors wrote. “This simple, rapid and inexpensive test effectively stratifies patients beyond traditional estimates of risk, which tend to be inaccurate in the elderly.”

The researchers noted that one potential limitation could be the endpoints where measured in-hospital rather than long-term, leaving out data on hospital discharges and transfers.

“Gait speed has the advantage of being applied in daily practice with minimal investment,” the authors concluded.

The "new screening tool, consisting of an observer, a stopwatch and a well-lit hallway, is reproducible, and I believe will be extraordinarily cost effective," Joseph C. Cleveland, Jr., MD, of the University of Colorado Health Sciences Center in Denver, wrote in an accompanying editorial.

"Most importantly, it replaces such subjective tests such as the 'eyeball test,' which only substantiated that the judgment of clinicians varied greatly in selecting elderly patients for cardiac operations."

However, Cleveland wrote that it is inappropriate to conclude that a patient would not be a candidate for surgery solely based on a 5-m gait speed.