SNOWMASS, COLO. – A structured frailty assessment has become an important tool for cardiologists in individualizing decisions regarding referral of elderly patients for heart procedures.
The frailty assessment aids in determining whether the procedure is likely to improve the individual’s long-term outcome, or if instead, multiple converging limitations unrelated to the cardiac condition are pushing the patient toward early functional losses and mortality from noncardiovascular causes.
More than 20 multidimensional frailty scales have been developed in the geriatrics literature during the past decade. For busy cardiologists, two of the simplest, fastest, and least expensive are walking speed and the Dalhousie Clinical Frailty Scale, Dr. Karen P. Alexander said at the annual cardiovascular conference at Snowmass sponsored by the American College of Cardiology.
Dr. Karen P. Alexander
Walking speed can be assessed by a nonphysician with a stopwatch and two marks on the hallway floor 4-6 meters apart, noted Dr. Alexander, a cardiologist with a special interest in geriatrics at Duke University, Durham, N.C.
The first prospective study of walking speed as a predictor of mortality and major morbidity in elderly patients scheduled for cardiac surgery involved 131 subjects at four university hospitals. Those classified as slow walkers as defined by taking 6 seconds or longer to cover 5 meters in the clinic hallway had a threefold increased rate of the composite endpoint of in-hospital mortality, stroke, renal failure, prolonged infection, deep sternal wound infection, or reoperation. That was true even after adjusting for the widely used Society of Thoracic Surgeons risk score.
Patients with a high STS risk score, of 15% or more, plus a 5-meter walk speed of 6 seconds or longer, had a 43% incidence of mortality or major morbidity. Those with an STS risk score below 15% and a walking speed of less than 6 seconds had an event rate of only 6% (J. Am. Coll. Cardiol. 2010;56:1668-76).
More recently, a pooled analysis of 9 cohort studies totaling nearly 35,000 community-dwelling seniors followed for 6-21 years concluded that gait speed was significantly associated with remaining years of life in both men and women.
Lead investigator Dr. Stephanie Studenski, director of research in the division of geriatric medicine at the University of Pittsburgh, noted that each 0.1-meter/second increment in walking speed was associated with a 12% increase in survival. A walking speed of 0.8 meters/second was associated with the median life expectancy for persons in that age category. She proposed that a walking speed of 0.6 meters/second would be a reasonable threshold for increased risk of early mortality, that a speed faster than 1.0 meters/second suggests better than average life expectancy, and a gait speed above 1.2 meters/second suggests exceptional life expectancy (JAMA 2011;305:50-8).
Dr. Alexander said the Clinical Frailty Scale developed by Dr. Kenneth Rockwood and his coworkers at Dalhousie University in Halifax, Nova Scotia, allows physicians to quickly judge where an individual patient fits on a nine-point frailty scale.
"It gets raters on the same page and improves upon the ‘I know frailty when I see it’ eyeball test," she added.
It appears, however, that cardiologists may be underutilizing frailty assessments. When session moderator Dr. Rick A. Nishimura of the Mayo Clinic, Rochester, Minn., asked for an audience show of hands as to how many routinely make a comment about frailty in elderly patients’ charts, only about 40% responded affirmatively.
Panelist Michael J. Mack, a surgeon who has played a major role in the introduction of transcatheter aortic valve replacement (TAVR) in the United States, said he views frailty assessment as indispensable in deciding whether a patient with aortic stenosis is best served by TAVR, surgical replacement, or no procedure.
Dr. Michael J. Mack
"On our heart team we spend a lot of time sorting out this matter of futility, where you can have a successful procedure but the patient dies anyway. We’re trying to sort out the patients who are dying with aortic stenosis from those that are dying from aortic stenosis," explained Dr. Mack, medical director of cardiovascular surgery for the Baylor Health Care System and director of cardiovascular research at the Heart Hospital in Plano, Tex.
At the Baylor heart team clinic, patients with aortic stenosis get a complete work-up in 1 day. It includes echocardiography, a CT scan, pulmonary function testing, determination of the STS risk score, and frailty testing. Four frailty tests are done routinely: a 5-meter walk test, grip strength, the Katz Activities of Daily Living, and a serum albumin. Then the surgeon and the cardiologist see the patient together.