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.