A cutoff point for peak oxygen consumption in the prognosis of heart failure patients with beta-blocker therapy

• Published in: International journal of cardiology Vol. 145; no. 1; pp. 75 - 77
• Main Authors: Guimaraes, Guilherme V., d'Avila, Veridiana M., Silva, Mario S., Ferreira, Silvia A., Ciolac, Emmanuel G., Carvalho, Vitor O., Bocchi, Edimar A.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 05.11.2010; Elsevier
• Subjects: Adrenergic beta-Antagonists - pharmacology; Adrenergic beta-Antagonists - therapeutic use; Adult; Aged; Beta-blockers; Biological and medical sciences; Cardiology. Vascular system; Cardiopulmonary exercise test; Cardiovascular; Exercise Test - drug effects; Exercise Test - methods; Exercise Test - standards; Female; Follow-Up Studies; Heart; Heart failure; Heart Failure - diagnosis; Heart Failure - drug therapy; Heart Failure - physiopathology; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Humans; Male; Medical sciences; Middle Aged; Oxygen Consumption - drug effects; Oxygen Consumption - physiology; Peak oxygen consumption; Prognosis; Treatment Outcome; Heart failure; Cardiopulmonary exercise test; Beta-blockers; Peak oxygen consumption; Physical exercise; Human; Prognosis; Cardiopulmonary; Oxygen consumption; Patient; Cardiovascular disease; Treatment; Heart disease; Exercise tolerance test; Peak; Cardiology
• ISSN: 0167-5273; 1874-1754; 1874-1754
• DOI: 10.1016/j.ijcard.2009.05.001

Beta-blockers (BB) have shown to improve outcomes among heart failure patients (HF). Adequate risk stratification is still a major concern for HF. The prognostic indexes have been detected, but only few parameters maintain consistently high power in predicting progression of disease and mortality. Peak oxygen consumption (VO 2 peak, ml kg − 1 min − 1 ) is traditionally used for risk stratification in HF, however, there is limited evidence regarding predictive value of VO 2 peak in patients taking BB. Two hundred twenty nine patients, aged 49 ± 13 years with diagnosed HF for more than 6 months due to ischemic ( n = 73), idiopathic dilated ( n = 149) and Chagas disease ( n = 7) underwent a cardiopulmonary exercise test (CPX). The ejection fraction was 38 ± 10%; clinical stability was defined as no change in the NYHA class or absence of hospitalization for heart failure and stable medical treatment during 3 months prior to CPX. Subjects were tracked for cardiac-related mortality after CPX. The mean follow-up period was 2.5 ± 1.1 years and means value for VO 2 peak was 16.3 ± 4. Current BB therapy included carvedilol (83.4%), metoprolol (7.8%), bisoprolol (3.9%) and others (4.8%). The area under the ROC curve for VO 2 peak was 0.80 (95% CI: 0.69–0.90, optimal threshold: 12.5 and 82% sensitivity/26% specificity, p < 0.001). Kaplan–Meier analysis that revealed event-free survival for subjects in < and > 12.5 was 28% and 2.8%, respectively (long-rank 34.8; p < 0.001). VO 2 peak seems to maintain prognostic value in HF patients BB therapy. The present study also provides new evidence that optimal threshold value for VO 2 peak in the BB era is 12.5 ml kg − 1 min − 1 .