KCCQ-OS Superior Model in Classifying Cardiovascular Conditions

Stephen Greene, MD

The debate of the best classifying model for cardiology outcomes continues.

A team, led by Stephen J. Greene, MD, Duke Clinical Research Institute, characterized the longitudinal changes and concordance between New York Heart Association (NYHA) class and the Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OS) and their associations with overall clinical outcomes.

Going into the study it was unclear how New York Heart Association functional class compares with patient-reported outcomes among patients with heart failure in contemporary US clinical practice.

The study included 2872 US outpatients with chronic heart failure with reduced ejection fraction across 145 practices enrolled in the CHAMP-HF registry between December 2015 and October 2017. The median age of the patient population was 68 years old.

The baseline proportion of patients included 312 patients (10.9%) at NYHA class I, 1710 patients (59.5%) at class II, 804 patients (28.0%) at class III, and 46 patients (1.6%) at class IV.

The Models

Each patient completed a NYHA class. The investigators collected KCCQ-OS data at baseline and 12 months and examined the longitudinal changes and correlations between the 2 measures.

The research team also evaluated the associations between improvement in NYHA and KCCQ-OS from baseline to 12 months with clinical outcomes occurring from months 12-24 using multivariable models landmarked at 12 months.

The investigators sought main outcomes of all-cause mortality, heart failure hospitalizations, and mortality or heart failure hospitalization.

The results for KCCQ-OS show, 1131 patients (39.4%) scored 75-100 (best health status), 967 patients (33.7%) scored 50-74, 612 patients (21.3%) scored 25-49, and 162 patients (5.6%) scored 0-24 (worst health status).

Improvement

These scores improved at 12 months.

There were 1002 patients (34.9%) that had a change in NYHA class (599 [20.9%] with improvement; 403 [14.0%] with worsening) and 2158 patients (75.1%) had a change of 5 or more points in KCCQ-OS (1388 [48.3%] with improvement; 770 [26.8%] with worsening) at 12 months.

“The most common trajectory for NYHA class was no change (1870 [65.1%]), and the most common trajectory for KCCQ-OS was an improvement of at least 10 points (1047 [36.5%]),” the authors wrote.

Adjustments

Following an adjustment, the researchers found improvement in NYHA class was not associated with subsequent clinical outcomes.

However, an improvement of 5 or more points in KCCQ-OS was independently associated with decreased mortality (HR, 0.59; 95% CI, 0.44-0.80; P < .001) and mortality or heart failure hospitalization (HR, 0.73; 95% CI, 0.59-0.89; P = .002).

“Findings of this cohort study suggest that, in contemporary US clinical practice, compared with NYHA class, KCCQ-OS is more sensitive to clinically meaningful changes in health status over time,” the authors wrote. “Changes in KCCQ-OS may have more prognostic value than changes in NYHA class.”

The study, “Comparison of New York Heart Association Class and Patient-Reported Outcomes for Heart Failure With Reduced Ejection Fraction,” was published online in JAMA Cardiology.