Role of Serial Measurement of Peak Oxygen Consumption for Prognosis Assessment in Heart Failure

Introduction: Peak oxygen consumption (VO 2 ) has a strong and independent prognostic value in systolic heart failure; in contrast no data support its prognostic role in hypertrophic cardiomyopathy (HCM). Hypothesis: We assess if peak VO 2 is a long-term predictor of outcome in HCM. Methods: We studied 92 HCM patients (40±15 years). Peak VO 2 was expressed as percentage (%) of the predicted value. Follow up was 76±57 months. The primary composite endpoint (CE) was atrial fibrillation, progression to NYHA class III or IV, myotomy-myectomy (MM), heart transplantation (HT) and cardiac death. An ancillary endpoint (HFE) included markers of heart failure (progression to NYHA class III or IV, MM and HT). Results: At baseline, 62% of patients were asymptomatic, 35% NYHA class II and 3% NYHA class III; 26% had left ventricular outflow tract obstruction. During follow up, 30 patients met CE with 43 events. By multivariate Cox survival analysis, we analyzed 2 models, using the CE, and in turn HFE. For CE, maximal left atrial diameter (LAD) (HR: 1.12; 95% CI: 1.04 to 1.22), maximal wall thickness (MWT) (HR: 0.14; 95% CI: 1.04 to 1.23) and % predicted peak VO 2 (HR: -0.03; 95% CI: 0.95 to 0.99) independently predicted outcome (overall, p<0.0001). For HFE, maximal LAD (HR:0.31; 95% CI: 1.09 to 1.70), MWT (HR: 0.35; 95% CI: 1.08 to 1.84) and % predicted peak VO 2 (HR: -0.06; 95% CI: 0.89 to 0.98) independently predicted outcome (overall, p<0.0001). Only 19% of mildly symptomatic or asymptomatic patients with % predicted peak VO 2 >80% had events, as opposed to 53% of them with % predicted peak VO 2 < 55% (p= 0.04). Event-free survival for both endpoints was significantly lower in patients with % predicted peak VO 2 < 55% as compared to those with it between 55 and 80 and >80% , Figure. Conclusion: In mildly or asymptomatic patients severe exercise intolerance may precede clinical deterioration. In HCM, peak VO 2 provides excellent risk stratification with a high event rate in patients with % predicted value <55%.

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Effect of Training on Peak Oxygen Consumption in Patients With Heart Failure With Preserved Ejection Fraction—Reply

JAMA ◽

10.1001/jama.2021.10061 ◽

2021 ◽

Vol 326 (8) ◽

pp. 772

Author(s):

Stephan Mueller ◽

Bernhard Haller ◽

Martin Halle ◽

Keyword(s):

Heart Failure ◽

Oxygen Consumption ◽

Ejection Fraction ◽

Peak Oxygen Consumption ◽

Preserved Ejection Fraction ◽

Patients With Heart Failure

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The acute physiological and perceptual effects of recovery interval intensity during cycling-based high-intensity interval training

European Journal of Applied Physiology ◽

10.1007/s00421-020-04535-x ◽

2020 ◽

Author(s):

Christopher R. J. Fennell ◽

James G. Hopker

Keyword(s):

Oxygen Consumption ◽

High Intensity ◽

Lactate Threshold ◽

Interval Training ◽

Peak Oxygen Consumption ◽

High Intensity Interval Training ◽

Active Recovery ◽

Recovery Interval ◽

High Intensity Interval

Abstract Purpose The current study sought to investigate the role of recovery intensity on the physiological and perceptual responses during cycling-based aerobic high-intensity interval training. Methods Fourteen well-trained cyclists ($$\dot{V}{\text{O}}_{{{\text{2peak}}}}$$ V ˙ O 2peak : 62 ± 9 mL kg−1 min−1) completed seven laboratory visits. At visit 1, the participants’ peak oxygen consumption ($$\dot{V}{\text{O}}_{{{\text{2peak}}}}$$ V ˙ O 2peak ) and lactate thresholds were determined. At visits 2–7, participants completed either a 6 × 4 min or 3 × 8 min high-intensity interval training (HIIT) protocol with one of three recovery intensity prescriptions: passive (PA) recovery, active recovery at 80% of lactate threshold (80A) or active recovery at 110% of lactate threshold (110A). Results The time spent at > 80%, > 90% and > 95% of maximal minute power during the work intervals was significantly increased with PA recovery, when compared to both 80A and 110A, during both HIIT protocols (all P ≤ 0.001). However, recovery intensity had no effect on the time spent at > 90% $$\dot{V}{\text{O}}_{{{\text{2peak}}}}$$ V ˙ O 2peak (P = 0.11) or > 95% $$\dot{V}{\text{O}}_{{{\text{2peak}}}}$$ V ˙ O 2peak (P = 0.50) during the work intervals of both HIIT protocols. Session RPE was significantly higher following the 110A recovery, when compared to the PA and 80A recovery during both HIIT protocols (P < 0.001). Conclusion Passive recovery facilitates a higher work interval PO and similar internal stress for a lower sRPE when compared to active recovery and therefore may be the efficacious recovery intensity prescription.

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