Chronotropic incompetence predicts impaired response to exercise training in heart failure patients in sinus rhythm

Background: In most patients with chronic heart failure (CHF), endurance training improves exercise capacity. However, some patients do not respond favourably. The purpose of this study was to explore the reasons of non-response and to determine their predictive value.Methods: We studied a cohort of 120 consecutive CHF patients with sinus rhythm (mean age 57 ± 12 years, ejection fraction 29.3 ± 9.9%, peak VO2 17.3 ± 5.1 ml/min/kg), participating in a 3-month outpatient cardiac rehabilitation programme. Responders were defined as subjects who improved peak VO2 by more than 5%, work load by more than 10%, or VE/VCO2 slope by more than 5%. Subjects who did not fulfil at least one of the above criteria were characterized as non-responders. Multivariate regression analyses were performed to identify parameters that were predictive for a response. Receiver operating characteristic (ROC) analyses were performed for predictive parameters to identify thresholds for response or non-response.Results: Multivariate regression analyses revealed heart rate (HR) reserve, HR recovery at 1 min, and peak HR as significant predictors for a positive training response. ROC curves revealed the optimal thresholds separating responders from non-responders at less than 30 bpm for HR reserve, less than 6 bpm for HR recovery and less than 101 bpm for peak HR.Conclusions: The presence of impaired chronotropic competence is a major predictor of poor training response in CHF patients with sinus rhythm

Exercise training reverses exertional oscillatory ventilation in heart failure patients

Exertional oscillatory ventilation (EOV) is an ominous prognostic sign in chronic heart failure (CHF), but little is known about the success of specific therapeutic interventions. Our aim was to study the impact of an exercise training on exercise capacity and cardiopulmonary adaptation in stable CHF patients with left ventricular systolic dysfunction and EOV. 96 stable CHF patients with EOV were included in a retrospective analysis (52 training versus 44 controls). EOV was defined as follows: 1) three or more oscillatory fluctuations in minute ventilation (V'(E)) during exercise; 2) regular oscillations; and 3) minimal average ventilation amplitude ≥5 L. EOV disappeared in 37 (71.2%) out of 52 patients after training, but only in one (2.3%) out of 44 without training (p<0.001). The decrease of EOV amplitude correlated with changes in end-tidal carbon dioxide tension (r= -0.60, p<0.001) at the respiratory compensation point and V'(E)/carbon dioxide production (V'(CO(2))) slope (r=0.50, p<0.001). Training significantly improved resting values of respiratory frequency (f(R)), V'(E), tidal volume (V(T)) and V'(E)/V'(CO(2)) ratio. During exercise, V'(E) and V(T) reached significantly higher values at the peak, while f(R) and V'(E)/V'(CO(2)) ratio were significantly lower at submaximal exercise. No change was noted in the control group. Exercise training leads to a significant decrease of EOV and improves ventilatory efficiency in patients with stable CHF

Influence of exertional oscillatory ventilation on exercise performance in heart failure

BACKGROUND: Exertional oscillatory ventilation (EOV) in heart failure may potentiate the negative effects of low cardiac output and high ventilation on exercise performance. We hypothesized that the presence of EOV might, per se, influence exercise capacity as evaluated by maximal cardiopulmonary exercise test. METHODS AND RESULTS: We identified 78 severe chronic heart failure patient pairs with and without EOV. Patients were matched for sex, age and peak oxygen consumption (VO2). Patients with EOV showed, for the same peak VO2, a lower workload (WL) at peak (DeltaWatts=5.8+/-23.0, P=0.027), a less efficient ventilation (higher VE/VCO2 slope: 38.0+/-8.3 vs. 32.8+/-6.3, P<0.001), lower peak exercise tidal volume (1.49+/-0.36 L vs. 1.61+/-0.46 L, P=0.015) and higher peak respiratory rate (34+/-7/min vs. 31+/-6/min, P=0.002). In 33 patients, EOV disappeared during exercise, whereas in 45 patients EOV persisted. Fifty percent of EOV disappearing patients had an increase in the VO2/WL relationship after EOV regression, consistent with a more efficient oxygen delivery to muscles. No cardiopulmonary exercise test parameter was associated with the different behaviour of VO2/WL. CONCLUSION: The presence of EOV negatively influences exercise performance of chronic heart failure patients likely because of an increased cost of breathing. EOV disappearance during exercise is associated with a more efficient oxygen delivery in several cases

Prognostic Value of the Change in Heart Rate From the Supine to the Upright Position in Patients With Chronic Heart Failure

BACKGROUND: The prognostic value of the change in heart rate from the supine to upright position (∆HR) in patients with chronic heart failure (HF) is unknown. METHODS AND RESULTS: ∆HR was measured in patients enrolled in the Trial of Intensified Medical Therapy in Elderly Patients with Congestive Heart Failure (TIME‐CHF) who were in sinus rhythm and had no pacemaker throughout the trial (n=321). The impact of ∆HR on 18‐month outcome (HF hospitalization‐free survival) was assessed. In addition, the prognostic effect of changes in ∆HR between baseline and month 6 on outcomes in the following 12 months was determined. A lower ∆HR was associated with a higher risk of death or HF hospitalization (hazard ratio 1.79 [95% confidence interval {95% CI} 1.19‐2.75] if ∆HR ≤3 beats/min [bpm], P=0.004). In the multivariate analysis, lower ∆HR remained an independent predictor of death or HF hospitalization (hazard ratio 1.75 [95% CI, 1.18‐2.61] if ∆HR ≤3 bpm, P=0.004) along with ischemic HF etiology, lower estimated glomerular filtration rate, presence and extent of rales, and no baseline β‐blocker use. In patients without event during the first 6 months, the change in ∆HR from baseline to month 6 predicted death or HF hospitalization during the following 12 months (hazard ratio=2.13 [95% CI 1.12–5.00] if rise in ∆HR <2 bpm; P=0.027). CONCLUSIONS: ∆HR as a simple bedside test is an independent prognostic predictor in patients with chronic HF. ∆HR is modifiable, and changes in ∆HR also provide prognostic information, which raises the possibility that ∆HR may help to guide treatment. CLINICAL TRIAL REGISTRATION INFORMATION: URL: www.isrctn.org. Unique identifier: ISRCTN43596477

Differential prognostic impact of resting heart rate in older compared with younger patients with chronic heart failure--insights from TIME-CHF

BACKGROUND: There is little information regarding the prognostic role of resting heart rate (HR) in older compared with younger patients with chronic heart failure (HF). METHODS AND RESULTS: In patients enrolled in the Trial of Intensified Medical Therapy in Elderly Patients With Congestive Heart Failure (TIME-CHF) with sinus rhythm, effects of baseline HR (≥70 vs <70 beats/min [bpm]) on 18-month outcomes were compared between older (≥75 years; n = 186) and younger (<75 years; n = 141) patients. Older patients with lower (61 ± 6 bpm) and higher (83 ± 9 bpm) HR had similar left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) functional class, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and survival and HF hospitalization-free survival. In contrast, younger patients with higher HR (81 ± 7 bpm) had higher NT-proBNP and NYHA functional class, lower LVEF, and a higher risk of death (hazard ratio 4.01 [95% confidence interval (CI) 1.17 -13.69]; P = .02) and death or HF hospitalization (hazard ratio 2.35 [95% CI 1.01-5.50]; P = .04) than those with lower HR (62 ± 5 bpm), with the association between higher HR and survival remaining significant after adjustment for NYHA functional class, LVEF, and NT-proBNP. CONCLUSIONS: In contrast to HF patients aged <75 years, we found no association between HR and worse outcomes in HF patients aged ≥75 years