乌鸦传媒

Patient screening using the instead of New York Heart Association (NYHA) classification could bring clinicians and trialists closer to choosing the right therapies and enrolling the right patients in studies, one group suggested.

A clear weakness of the NYHA system is that people with KCCQ Overall Summary (KCCQ-os) scores 80 or better -- indicating good to excellent self-reported health status -- fell under a wide range of NYHA classifications assigned by clinicians in various studies:

• : 26.4% deemed NYHA class I, 54.7% NYHA class II, 18.9% NYHA class III, none class IV
• : 80.9% NYHA class II, 18.9% NYHA class III, 0.1% NYHA class IV
• : 85.2% NYHA class I-II, 14.8% NYHA class III-IV

The paper was published online in .

"The traditional way of measuring health status is for clinicians to do an unstructured interview with patients and assign a NYHA class. What this paper shows is that means of quantifying health status is not very reflective of the symptoms, function and quality of life, as reported by patients," according to senior author John Spertus, MD, MPH, of St. Luke's Mid America Heart Institute in Kansas City, Missouri.

Of note, Spertus developed and validated the KCCQ instrument. He holds a patent and is paid royalties for its use.

"We believe that by using patients' reports of their health status, through tools like the KCCQ, we can enroll a more homogenous group of patients into the trial and that the results of the trial can be more accurately applied to future patients, based on patients' reports, rather than the NYHA," Spertus told 乌鸦传媒.

NYHA classification is already well recognized to be flawed, since it relies on physicians guessing what patients can do, according to Lynne Warner Stevenson, MD, of Vanderbilt University Medical Center in Nashville, Tennessee. "There's no question that almost anything is better than NYHA."

Nevertheless, she said she disagreed with using the KCCQ to identify eligible patients for heart failure trials.

One of her concerns with using the KCCQ is that it is not helpful in guiding the selection of patients or therapies: it "lumps" together many things, including activity, congestion, limitations of social function, and life satisfaction, such that "it's very hard to know how you would use it specifically, since we don't have therapies that improve all of these."

"What I need to do as a doctor is find out what makes you miserable and try to treat that," she said in an interview. "By using this one score, we're going to miss a lot of the nuance of what's limiting the patient ... As we and others have shown, some heart failure patients are limited not by heart failure, but arthritis and maybe things that are not even medical."

Ultimately, Stevenson suggested asking patients specifically what they can do (e.g., can they get dressed? Walk a block? Take care of their yard?) in assessing their health status or trial eligibility.

Spertus and his colleagues analyzed the types of participants enrolled in the observational registry KCCQINT (n=546), the HF-ACTION trial of exercise training (n=2,129), and the TOPCAT trial of spironolactone (n=1,725). TOPCAT participants from Russia and Georgia were excluded given the known problems of enrollment in those countries.

"Some limitations of our study include the age of the studies (although the accuracy of NYHA is unlikely to have changed over time), limited generalizability of examining only three studies, and lack of adjustment for other patient factors, although this should not be necessary for two assessments of the same underlying construct," they acknowledged.

"These findings have important implications for clinical trials seeking to enroll patients who are homogenously ill, including the potential for some with high KCCQ-os scores to not be able to improve (undermining power), some with low scores being too ill for potential treatment benefit, and great difficulty in translating the results to clinical practice," the investigators maintained.

If the KCCQ were to be accepted for routine clinical evaluation of heart failure patients, practices and hospitals would have to obtain annual licenses to use the instrument -- and not every practice may be able to spare the expense, Stevenson suggested.

"It's not very practical. Healthcare's already very expensive," she said.

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