Frailty was associated with a threefold increase in mortality risk 1 year after transcatheter aortic valve replacement, according to a single-center study published online Sept. 16 in JACC: Cardiovascular Interventions.
Researchers also found that there was no significant association between frailty status and the majority of post-TAVR procedural outcomes, suggesting that the current standard for patient selection is adequate, they wrote.
"We hope that the result will convince physicians to measure frailty," Dr. Philip Green, the study’s lead author, said in an interview. "Formally assessed frailty can be extremely useful for prognostic information."
Risk prediction for older adults undergoing cardiac surgery is somewhat tricky, said Dr. Green, because some of the well established measurement tools are based on studies that did not include many adults who were very old or at high risk.
"So the risk-prediction confidence intervals among the highest risk patients tend to get very wide," said Dr. Green, a fellow in cardiovascular medicine at Columbia University Medical Center, New York, where the study was conducted.
Frailty, which is the loss of resiliency and physiological reserve, helps predict the patients’ tolerance for certain procedures, their odds of survival, and their overall prognosis.
For an objective frailty score, Dr. Green said he and colleagues built on findings from previous studies and measured gait speed, grip strength, serum albumin, and activities of daily living to derive a frailty score in 159 very-high-risk patients with severe aortic stenosis who underwent TAVR at the Valve Center at Columbia University Medical Center/New York–Presbyterian Hospital.
They then broke down the patients into two groups based on their median frailty score: those who were frail and those who were not.
Patients’ mean age was 86 years, and half were men. Half of the patients had at least three comorbidities, although the frailty score was not associated with the number of comorbidities.
Overall, 76 patients had a frailty score higher than 5, and 83 had a score of 5 or less (considered not frail).
Patients whose frailty score was higher than 5 had longer hospital stays and were at a higher risk of in-hospital, life-threatening, or major bleeding events compared with the nonfrail group (JACC Cardiovasc. Interv. 2012;5:974-81).
Eight patients died during the first 30 days; however, frailty status was not associated with adverse periprocedural events such as vascular complications, stroke, or procedural mortality.
Meanwhile, 1-year follow-up showed that patients with a frailty score of more than 5 had a threefold increase in mortality after the procedure, compared with the nonfrail group (17 frail vs. 7 nonfrail; hazard ratio, 1.15).
"But it’s really important to distinguish between frailty and futility [of the procedure]," said Dr. Green. "Even the frail group had an 80% survival rate, and that suggests that even the most frail can tolerate and live for a long time after TAVR."
He added that the study did not address the patients’ quality of life, which could be a subject for another study.
The authors pointed out a few methodological issues.
For one, all the patients were carefully selected for TAVR, and hence it is not clear whether the findings can be generalized to unselected or lower-risk patients, or to patients who undergo surgical aortic valve replacement (SAVR).
Also, the components of the frailty score used are somewhat of a departure from the previously validated assessment tools.
"For our study, we had to raise the threshold for who’s frail," said Dr. Green. "We’re really talking about the frailest of the frail. Nevertheless we saw excellent outcome."
But for now, "the bottom line is measure frailty," advised Dr. Green. "Understand the functional status of your patients. Understand their abilities to perform activities and their nutritional status. It can shed light on patients who are thriving despite their heart disease and other comorbidities compared to those who are really limited on the basis of their diseases."
Dr. Green said that he had no relevant financial disclosures.