Objective New York Heart Association (NYHA) functional class plays a central role in heart failure (HF) assessment but might be unreliable in mild presentations. We compared objective measures of HF functional evaluation between patients classified as NYHA I and II in the Rede Brasileira de Estudos em Insuficiência Cardíaca (ReBIC)-1 Trial.
Methods The ReBIC-1 Trial included outpatients with stable HF with reduced ejection fraction. All patients had simultaneous protocol-defined assessment of NYHA class, 6 min walk test (6MWT), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and patient’s self-perception of dyspnoea using a Visual Analogue Scale (VAS, range 0–100).
Results Of 188 included patients with HF, 122 (65%) were classified as NYHA I and 66 (35%) as NYHA II at baseline. Although NYHA class I patients had lower dyspnoea VAS Scores (median 16 (IQR, 4–30) for class I vs 27.5 (11–49) for class II, p=0.001), overlap between classes was substantial (density overlap=60%). A similar profile was observed for NT-proBNP levels (620 pg/mL (248–1333) vs 778 (421–1737), p=0.015; overlap=78%) and for 6MWT distance (400 m (330–466) vs 351 m (286–408), p=0.028; overlap=64%). Among NYHA class I patients, 19%–34% had one marker of HF severity (VAS Score >30 points, 6MWT <300 m or NT-proBNP levels >1000 pg/mL) and 6%–10% had two of them. Temporal change in functional class was not accompanied by variation on dyspnoea VAS (p=0.14).
Conclusions Most patients classified as NYHA classes I and II had similar self-perception of their limitation, objective physical capabilities and levels of natriuretic peptides. These results suggest the NYHA classification poorly discriminates patients with mild HF.
- heart failure with reduced ejection fraction
Statistics from Altmetric.com
MB and AZ contributed equally.
Contributors All authors contributed to the design and conduct of the study, data collection, analysis and preparation of the manuscript. LER supervised the study and is the guarantor.
Funding This study was supported in part by the 'Instituto de Avaliação em Tecnologia em Saúde (IATS)' and funded by the National Council for Scientific and Technological Development (CNPq, Brazil) with grants for the establishment of the Brazilian Research Network in Heart Failure (# 467110/2014-0). LER received a research fellowship from CNPq (# 30833/2017-1).
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval The study was approved by the institutional review board at each site and was registered at ClinicalTrials.gov (NCT02689180).
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement De-identified participant data are available upon reasonable request.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.