Importance: Sparse data exist regarding how clinician-assigned New York Heart Association (NYHA) class compares with heart failure (HF)-specific Kansas City Cardiomyopathy Questionnaire (KCCQ) in acute HF.
Objective: To compare concordance between NYHA class and KCCQ overall summary score (KCCQ-OS) in acute HF and investigate associations of changes in NYHA class and KCCQ-OS with long-term outcomes.
Design, setting, and participants: In this cohort study, patients with HF were enrolled from 52 hospitals in China between August 2016 and May 2018. Among patients with NYHA class and KCCQ-OS at admission and 1 month, levels of each scale were categorized into 4 groups from worst to best. Mild and moderate to severe discordance were defined as NYHA class and KCCQ-OS differing by 1 level or 2 or more levels, respectively. Multivariable models evaluated associations between improvements in the 2 measures and outcomes. Analysis was conducted from January to March 2023.
Exposure: Changes in NYHA class and KCCQ-OS from admission to 1 month.
Main outcomes and measures: All-cause mortality, cardiovascular death, or first HF rehospitalization.
Results: A total of 2683 patients (1709 [63.7%] male; median [IQR] age, 66 [56-75] years) were included. NYHA class II, III, and IV were presented in 374 patients (13.9%), 1179 patients (44.0%), and 1130 patients (42.1%), respectively, and the median (IQR) KCCQ-OS was 44.4 (28.3-61.9). Concordance, mild discordance, and moderate to severe discordance between admission NYHA class and KCCQ-OS occurred in 954 patients (35.6%), 1203 patients (44.8%), and 526 patients (19.6%), respectively. For KCCQ-OS, kernel density overlaps were 73.6% between NYHA II and III, 63.8% between NYHA II and IV, and 88.3% between NYHA III and IV. Most patients experienced improvements in NYHA and KCCQ-OS from admission to 1 month. After adjustment, there was no significant association between improvements in NYHA class and 4-year all-cause mortality, whereas 5 or more point improvements in KCCQ-OS were independently associated with a lower risk of 4-year mortality (hazard ratio, 0.84; 95% CI, 0.74-0.96; P = .01). NYHA class and KCCQ-OS improvements were both associated with decreased risk of 1-year composite cardiovascular death or HF rehospitalization.
Conclusions and relevance: In this cohort study of acute HF, discordance between NYHA class and KCCQ was common, and KCCQ was more relevant to subsequent mortality than NYHA class.