Peak Oxygen Consumption as a Predictor of Death in Patients With Heart Failure Receiving β-Blockers

Abstract

Background-Peak oxygen uptake (peak V O 2 ) is a strong predictor of mortality and is commonly used in the evaluation of patients for cardiac transplantation. ␤-Blockers reduce mortality in patients with heart failure, without influencing peak V O 2 , raising the possibility that peak V O 2 is no longer suitable as an indicator of prognosis in these patients. Methods and Results-We analyzed prospectively gathered data on 2105 patients referred for cardiopulmonary testing for all-cause mortality and for occurrence of death or transplantation. Patients receiving ␤-blockers were younger, more likely to have coronary disease, and had a greater mean ejection fraction but had a similar peak V O 2 . There were 555 deaths (26%) and 194 (9%) transplants during a median follow-up of 3.5 years. Peak V O 2 was a predictor of mortality irrespective of ␤-blocker use; a decrease of 1 mL · kg Ϫ1 · min Ϫ1 resulted in an adjusted hazard ratio (HR) of 1.13 (95% CI 1.09 to 1.17, PϽ0.0001) in patients not receiving ␤-blockers and 1.27 (95% CI 1.18 to 1.36, PϽ0.0001) in patients receiving ␤-blockers. Similar findings were noted when considering death or transplantation as an end point. ␤-Blocker use was associated with better outcomes until peak V O 2 values became very low (Ϸ10 mL · kg Ϫ1 · min Ϫ1 ), at which level survival rates were equally poor. Conclusion-Peak V O 2 is a determinant of survival in patients in heart failure even in the setting of ␤-blockade. Because of improved survival in patients treated with ␤-blockers, the cut point value of 14 mg · kg Ϫ1 · min Ϫ1 for referral for cardiac transplantation in these patients requires reevaluation, and a lower cut point may be more appropriate.

The clinical and research applications of aerobic capacity and ventilatory efficiency in heart failure: an evidence-based review

“…However, this threshold was proposed prior to the standard use of beta-blocker therapy which has been shown to improve survival without increasing peak VO 2 in HF. As a result, it has been suggested that the peak VO 2 threshold for prognostic purposes be reduced to \/C10 ml O 2 kg -1 min -1 in patients prescribed a betablocking agent [61]. The most commonly cited dichotomous threshold for the VE/VCO 2 slope is \/C34 [15,22,26].…”

Advanced chronic heart failure: A position statement from the Study Group on Advanced Heart Failure of the Heart Failure Association of the European Society of Cardiology

“…Regardless of its aetiology, it is usually characterised by all the features shown in Table 1 [5][6][7][8][9][10].…”

Cardiopulmonary exercise testing in heart failure: from ugly duckling to swan

“…Nevertheless, there are some concerns about this VE-related parameter, given that a large prospective study conducted by the Cleveland Clinic on 2,015 CHF patients finds that it is not predictive of survival, while a low peak VO 2 value may be an even more powerful predictor in patients receiving b-blocker therapy than in those treated without b-blocker therapy. [2] For all these considerations, we read with interest Scardovì et al's paper entitled ''Prognostic value of brain natriuretic peptide and enhanced ventilatory response to exercise in patients with chronic heart failure'' [3]. Their study, conducted on a sample of 156 consecutive stable CHF outpatients, had an ambitious aim since it attempted to investigate potential additive value of CPET-derived data in CHF prognostic evaluation by developing a multiparametric model including several clinical, echocardiographic and neurohormonal ones.…”