Minimally Clinically Important Difference in Health Status Scores in Patients With HFrEF vs HFpEF

BACKGROUND

Differences in clinically important thresholds in patient-reported outcomes measures such as the Kansas City Cardiomyopathy Questionnaire (KCCQ) remain less well-established in patients with heart failure with preserved ejection fraction (HFpEF) versus heart failure with reduced ejection fraction (HFrEF).

OBJECTIVES

The purpose of this study was to estimate meaningful thresholds for improvement or deterioration in the KCCQ-Total Symptom Score (TSS) in patients with HFrEF versus HFpEF.

METHODS

This secondary analysis of EMPERIAL program used anchor- and distribution-based approaches to estimate thresholds for improvement or deterioration in the KCCQ-TSS using Patient Global Impression of Severity (PGIS) as the primary anchor. Mean change in KCCQ-TSS from baseline to week 12 was calculated for each PGIS.

RESULTS

A total of 312 HFrEF and 315 HFpEF patients were enrolled. At week 12, mean changes in KCCQ-TSS corresponding to PGIS changes of "any improvement," "1-category improvement," and "1-category deterioration" were 13 ± 17, 12 ± 17, -3 ± 16 points in HFrEF, and 15 ± 18, 13 ± 17, -7 ± 18 points in HFpEF. Threshold for meaningful within-patient change in KCCQ-TSS was ≥9 points in HFrEF and ≥7 points in HFpEF patients. Sensitivity and specificity of ≥9 points/≥7 points change was 0.65 and 0.70 for HFrEF and 0.64 and 0.66 for HFpEF. Cumulative distribution function curves of KCCQ-TSS change from baseline to week 12 showed a shift to higher scores in both HFrEF and HFpEF patients.

CONCLUSIONS

In the EMPERIAL program, a change in KCCQ-TSS of ≥9 points in HFrEF and ≥7 points in HFpEF represents the minimal clinically important difference for improvement, confirming the broad range of 5-10 points as meaningful thresholds.