P13
Exercise oscillatory breathing and increased ventilation to carbon dioxide production in women with cronic heart failure and type 2 diabetes mellitus
A Ascione1, M Borgia2, A Sciarappa1, M Aversa1
1
Buon Consiglio Fatebenefratelli Hospital, Naples, Italy, 2Vincenzo Monaldi Hospital, Naples, Italy
Topic: Exercise physiology, testing and training
Background: Cardiopulmonary exercise test with determination 02 consumption (CPET) is generally used for assessing patients with heart failure (HF). Increased slope of exercise ventilation to carbon dioxide production (VE/VCO2) is an established prognosticator in patients with heart failure. Recently, the occurrence of exercise oscillatory breathing (EOB) has emerged as an additional strong predictor even more powerful than VE/VCO2 slope.
Objective: the aim of this study is to define the respective prognostic significance of these variables in female patients with type 2 diabetes mellitus.
Methods: One hundred (100) women were recruited (mean age 54± 12 years, of whom 80NYHA class II and 20 NYHA class III). As diabetics, these women were being treated with insulin and/or oral hypoglycaemic drugs. All patients were receiving optimised therapy with beta-blockers, statins, nitro-derivatives, ACE-inhibitors and platelet anti-aggregants, and all had stable sinus rhythms. these women had been recruited in order to undergo CPETs and echocardiograms within a maximum period of 14 days. the CPETs were conducted utilising a protocol calling for testing on a cyclette with increments of 10 Watts per minute. None of them were obese. they were in stable chronic HF (average left ventricular ejection fraction, 33 +/– 13%). We analyzed the prognostic relevance of VE/VCO2 slope, EOB, 02 pulse and peak Vo2 was evaluated by multivariate Cox regression.
Results: During a mean interval of 22 months, 22 patients died of cardiac reasons. Fifty-five percent presented with EOB. Among patients exhibiting EOB, 54% had an elevated VE/VCO2 slope and poor 02 pulse. the optimal threshold value for the VE/VCO2 slope identified by receiver operating characteristic analysis was >36.2 or >36.2 (sensitivity, 77%; specificity, 64%; P<.001). Univariate predictors of death included low left ventricular ejection fraction, low peak Vo2, high VE/VCO2 slope, and EOB presence. the VE/VCO2 slope (threshold, >36.2 or >36.2) was the only other exercise test variable retained in the regression. the hazard ratio for subjects with EOB and a VE/VCO2 slope >36.2 was 14.4(95% confidence interval, 4.9–26.5; P < .001).
Conclusion: these findings identify EOB as a strong survival predictor even more powerful than VE/VCO2 slope in diabetic women with HF. Even more in these patients EOB presence does not necessarily imply an elevated VE/VCO2 slope, but combination of either both yields to a burden of high risk.
P245
Long-term physical exercise training in patients with end-stage chronic heart failure (NHYA IIIb): Sustained benefit on hemodynamics and exercise capacity after one year
R Hoellriegel1, S Erbs1, A Linke1, V Adams1, M Sandri1, E Beck1, R Hambrecht1, G Schuler1
1
University of Leipzig-Heart Center, Leipzig, Germany, 2Klinikum Links der Weser, Department of Cardiology and Angiology, Bremen, Germany
Topic: Exercise physiology, testing and training
In patients with stable, moderate chronic heart failure (CHF), exercise training (ET) is well established to enhance exercise capacity without harmful side effects. In contrast, the data about ET, especially for a long-term period, are limited in patients with end-stage CHF (NYHA III b). therefore, aim of the present study was to determine, whether long-term physical ET for a period of 12 months improves central hemodynamics and exercise capacity in patients with end-stage CHF.
Methods: 37 pts with CHF (LVEF 24±2 %, NYHA class IIIb) were randomized to 12 months of ET (30 min bicycle ergometer training daily at 50–60% of maximal work load) or sedentary lifestyle (C). At begin, after 3, 6 and 12 months patients a spiroergometry and an echocardiography were performed.
Results: Patients of the training group had a continuous increase in left ventricular ejection fraction (D after 3 months +9.4±1.5%; after 6 months + 15.5±2.0%; after 12 months ±14.3±2.1%; p>0.05 for Δ versus C). the positive effects on left ventricular performance were associated with a decline in end-diastolic diameter after 3, 6 and 12 months (Δ after 3 months –6.6±1.2mm; after 6 months –7.6±1.1mm; after 12 months –9.7±1.9mm; p>0.05 for Δ versus C).
In patients of the training group, exercise capacity measured by VO2 max increased by +16 % after 3 months (from 15.3±0.8 to 17.8±0.8 ml/min/kg), by +24% after 6 months (to 18.8±0.8 ml/min/kg) and by +27% after 12 months (to 19.4±0.9 ml/min/kg; p>0.05 for 3, 6 and 12 months versus begin and C).
these changes were associated with an improvement in clinical symptoms evident by a decline in at least 1 NYHA-class in all patients of the training group after 3, 6 and 12 months. All the above-mentioned parameters remained unchanged in patients of the control group. Number of clinical events (cardiac decompensation, hospitalization, life-threatening arrhythmias, instable angina, revascularization, cardiovascular and all cause mortality) did not differ between the two groups.
Conclusion: To our knowledge, this trial shows for the first time a sustained improvement of hemodynamics and exercise capacity by long-term exercise training in patients with end-stage chronic heart failure (NYHA IIIb). these beneficial effects occurred in the absence harmful side effects like life-threatening arrhythmias or a higher incidence of cardiac decompensations in the training group.
P246
Red cell distribution width; a new marker of poor exercise tolerance in patients with chronic heart failure
E Van Craenenbroeck, P Beckers, N Possemiers, C Vrints, V Conraads
Antwerp University Hospital, Edegem, Belgium
Topic: Exercise physiology, testing and training
Purpose: Red cell distribution width (RDW) might be useful as a novel independent prognostic marker of mortality and morbidity in chronic heart failure (CHF). Preliminary evidence suggests that its prognostic power is equivalent to natriuretic peptides. Heterogeneity in red blood cell size is related to ineffective erythropoiesis or increased destruction of erythrocytes. the mechanisms for increased RDW in CHF patients are unknown but bone marrow dysfunction, systemic inflammation and nutritional deficiencies have been proposed. We aimed to study the relation between objective parameters of exercise intolerance and RDW in CHF patients. Moreover, we investigated the effect of exercise training, considered to be a highly effective strategy to improve physical capacity and to reduce morbidity, on RDW measures.
Methods: Sixty-eight CHF patients (60±10 yrs, VO2peak 19.5±5.3 ml/kg/min, LVEF 24.7±8.9%) were allocated to a 6-months exercise-training program. At baseline and after 6 months, patients underwent a cardio-pulmonary exercise test (CPET) and blood was sampled for analysis of complete blood count (CBC, including RDW) and NT-proBNP. Due to non-normality of data, non-parametric tests were used.
Results: At baseline, RDW correlated inversely with maximal exercise capacity (VO2 peak r=–0.428, p=0.0001; maximal workload r= –0.399, p=0.001). After multivariate analysis, including correction for age, NYHA class, LVEF and hemoglobin, RDW remained independently associated to VO2peak and maximal workload (p>0.05). Strong correlations were also observed between RDW and prognostic exercise parameters such as VE/VCO2 slope, circulatory power, and heart rate recovery 1 (all p>0.001). RDW measures were not related to LVEF, NYHA class, age or hemoglobin levels, but were correlated with NT-pro BNP values (r=0.310, p=0.013).
Following training, VO2peak improved (21.5 ± 5.5 ml/kg/min, p=0.0001) and RDW decreased from 13.9 ± 1.6 % to 13.4 ±1.7 %(p=0.017). the decrease in NT-proBNP (2102.3 ±113 pg/ml vs.1605.6 ±51 pg/ml, p=0.002) was not related to the decrease in RDW. Conclusion: We describe for the first time the relation between the novel prognostic marker RDW and objective parameters of exercise intolerance in CHF patients. A 6-months exercise-training program significantly reduced RDW.
P247
High intensity interval training in patients with chronic heart failure: acute cardior-espiratory responses and protocol optimization
P Meyer1, E Normandin1, M Gayda1, G Billon1, T Guiraud1, L Bosquet2, M Juneau1, A Nigam1
1
Montreal Heart Institute, Montreal, Canada, 2University of Montreal, Montreal, Canada
Topic: Exercise physiology, testing and training
Purpose: High-intensity aerobic interval training (HIIT) may be superior to conventional continuous moderate-intensity training for improving peak oxygen uptake (peak VO2) and cardiac function in patients with chronic systolic heart failure (HF). However, studies employing HIIT have generally used empiric training protocols with respect to interval duration and type of recovery (active vs. passive). We aimed to compare the acute cardiopulmonary responses to four different single bouts of HIIT in order to identify the most optimal protocol for HF patients.
Methods: After a maximal cardiopulmonary exercise test, 20 male subjects (mean age 57 yrs) with stage Cchronic HF (NYHA class I to III, mean LVEF 28%, mean VO2peak 17 mL/min/kg) participated in random fashion to 4 different single bouts of HIIT on ergocycle. Exercise intervals were all set at 100% of maximal aerobic workload (MAW) with variations in interval duration and type of recovery (Table 1). Each subject exercised until exhaustion or to a maximum of 30 min while gas exchange, ECG and blood pressure data were monitored continuously. the principal endpoints were total exercise time and time spent at a high percentage of peak VO2.
Results: Table 1.
Conclusions: Training modes with passive recovery intervals were associated with a longer total exercise time compared to those with active recovery intervals without compromising time spent near peak VO2. All training modes were safe without significant adverse effects or arrhythmias. Considering lower perceived exertion rating, better patient comfort and similar times spent at high levels of peak VO2, among the four modes tested, mode A was the optimal training mode in these patients.
Characteristics and acute responses to 4 modes of HIIT∗P >0.05
P248
Attenuated heart rate recovery is related to exercise intolerance early after left ventricular assist device implantation in CHF patients
S Dimopoulos1, G Tzanis1, A Bouchla1, A Tasoulis2, C Manetos1, L Samartzis1, N Diakos2, S Nanas1
1
Cardiopulmonary Rehabilitation Center, ‘Evgenideio’ Hospital, University of Athens, Athens, Greece, 2University of Athens, School of Medicine, 3rd Cardiology Dept, Athens, Greece
Topic: Exercise physiology, testing and training
Purpose: Heart rate recovery immediately after exercise (HRR1) is an index of parasympathetic activity and a strong independent predictor of mortality in CHF patients. Aim of this study was to evaluate HRR1 in relation to exercise capacity in CHF patients early after left ventricular assist device implantation (LVAD) implantation.
Methods: We enrolled 7 stable consecutive CHF patients (5 males/2 females, mean age: 45±16 years) after 1 month of LVAD (HeartMate II) implantation as destination therapy (N=4, Ischemic CHF) and as a bridge to transplantation/recovery (N=3, Non-ischemic CHF). All patients performed an incremental symptom-limited cardiopulmonary exercise testing. Main measurements included peak O2 uptake (VO2p), oxygen uptake at anaerobic threshold (AT), heart rate recovery [(HRR1, b/min): HR difference from peak to 1 min after exercise] and chronotropic response to exercise [chronotropic reserve (CR,%)=(peak HR-resting HR/220-age-resting HR)x100].
Results: Patients had a low VO2p (12.4±2, ml/kg/min) a low AT (7.8±1.8, ml/kg/min), while there was a significant reduction of CR (40±17, %) and HRR1 (14±8, bpm). HRR1 was significantly related to VO2p (r:0.95, p=0.001) and AT (r:0.89, p>0.01)
Conclusions: A delayed heart rate recovery immediately after exercise is related to exercise intolerance in CHF patients early after LVAD implantation.
P249
Are oxygen uptake kinetics in chronic heart failure limited by oxygen delivery or oxygen utilization?
HMC Kemps1, G Schep1, ML Zonderland2, HJM thijssen1, WR De Vries2, B Wessels3, PAFM Doevendan2, PFF Wijn3
1
Maxima Medical Centre, Veldhoven, Netherlands, 2University Medical Center Utrecht, Utrecht, Netherlands, 3Eindhoven University of Technology, Eindhoven, Netherlands
Topic: Exercise physiology, testing and training
Purpose: To examine the physiological background of the delay in oxygen uptake (Vo2) kinetics during and after submaximal exercise in moderately impaired patients with chronic heart failure (CHF) by comparing kinetics of cardiac output (Q) and Vo2.
Methods: Fourteen stable CHF patients (New York Heart Association class II-III, left ventricular ejection fraction =< 40%) and 8 healthy subjects, matched for age and body mass index, were included. All subjects performed a 6 minute submaximal constant-load exercise test at 80% of the ventilatory threshold to assess O2 uptake kinetics. Furthermore, in 10 CHF patients Q was measured by a radial artery pulse contour analysis method, which enabled the simultaneous modelling of exercise-related kinetics of Q and Vo2.
Results: Both O2 onset and recovery kinetics were delayed in CHF patients as compared to healthy controls (60 ± 25 versus 41 ± 23 sec, p = 0.02, and 55 ± 19 versus 35 ± 10 sec, p = 0.004, respectively). In the patient group, there were no significant differences between the time constants of Q and Vo2 during exercise-onset (62 ± 25 sec versus 59 ± 28 sec, p = 0.51) nor during recovery (61 ± 25 sec versus 57 ± 20 sec, p = 0.38). these results indicate that O2 delivery was not in excess of the metabolic demands in these patients, which is in contrast with previous observations in healthy individuals.
Conclusion: the delay in O2 onset and recovery kinetics in moderately impaired CHF patients is suggested to be due to limitations in O2 delivery. therefore, strategies aimed at improving exercise performance of these patients should focus more on improvements of O2 delivery than on O2 utilization.
P250
Leptin and exercise ventilatory efficiency in patients with chronic heart failure
E Straburzynska-Migaj, S Grajek
University of Medical Sciences, Poznan, Poland
Topic: Exercise physiology, testing and training
there is an increasing interest in the role of leptin in cardiovascular pathophysiology. Among others it is suggested that leptin may play role in the regulation of respiration. Ventilatory abnormalities in response to exercise are known important prognostic factors in patients with CHF. Many studies reported elevated levels of leptin in non-cachectic patients with CHF, however its role in CHF is still under investigation.
We analysed leptin levels in patients with CHF and systolic dysfunction in relation to CPET results.
there were 56 patients with stable CHF (50 ± 9 yrs, 19 CAD, 10 women, mean LVEF 26,6 ± 7,4, NYHA 2,6 ± 0,8, BMI 27,7 ± 4,4). All patients underwent anthropometric measurements (weight, height, waist circumference) and cardiopulmonary exercise treadmill test. the ventilatory response to exercise was calculated as VE/VCO2 slope. OUES was also calculated. Serum leptin levels were measured by RIA test.
In our study 24 patients had VE/VCO2 slope = 35. those patients in comparison to the rest had significantly higher leptin levels and leptin/BMI, lower peak VO2 and OUES. Leptin levels were significantly correlated with VE/VCO2 slope (r = 0,34; p = 0,009), peak VO2 (r = –0,36; p = 0,006), VE/VCO2 slope/peakVO2 (r = 0,42; p = 0,001), age (r = 0,28; p = 0,03), BMI (r = 0,40; p = 0,002), waist circumference (r = 0,42; p = 0,001), and FVC (r = –0,27; p = 0,047), FEV1 (r = –0,30; p = 0,02). there were no significant correlation with LVEF, OUES, HR rest and HR max. In multivariate regression analysis leptin was significantly correlated with VE/VCO2 slope independently of peak VO2, VE/VCO2 slope/peakVO2, and BMI.
Conclusion: Leptin is an independent predictor of VE/VCO2 slope, but not OUES in CHF patients.
P251
Microcirculatory abnormalities assessed by Near Infrared Spectroscopy in relation to CHF severity
C Manetos1, S Dimopoulos1, V Agapitou1, M Bonios2, G Tzanis1, E Karatzanos1, E Tseliou2, S Nanas1
1
Cardiopulmonary Rehabilitation Center, Evgenideio’ Hospital, University of Athens, Athens, Greece, 2University of Athens, School of Medicine, 3rd Cardiology Dept, Athens, Greece
Topic: Exercise physiology, testing and training
Purpose: Patients with chronic heart failure (CHF) present with microcirculation alterations, mainly due to endothelial dysfunction. In this study, we evaluated peripheral muscle microcirculation by Near Infra-Red Spectroscopy (NIRS) occlusion technique in relation to severity of CHF
Methods: Ninety-two CHF patients (80Males/12Females, mean age 54±13yrs, and 20 controls underwent NIRS evaluation and a symptom limited cardiopulmonary exercise testing on a cycle ergometer. Tissue O2 saturation defined as the percentage of hemoglobin saturation in the microvasculature compartments, was measured with a probe placed on the thenar muscle. A 3-min brachial artery occlusion technique was applied to evaluate microcirculatory function. Main measurement included the recovery slope (RS,%/min), as the first degree slope of the tissue reoxygenation rate after the release of the cuff, an indirect index of endothelial function. the gas exchange measurements served to calculate oxygen uptake at peak exercise (VO2 peak), at anaerobic threshold (AT) and the slope of the ventilatory equivalent for carbon dioxide output (VE/VCO2).
Results: CHF patients had a significant lower RS compared to controls (10±5 vs 13±6, p>0.05). CHF patients with RS>10 (n=50) had a decreased VO2 peak, anaerobic threshold (AT) and higher VE/VCO2 slope comparing with patients with RS=10(1.2±0.4vs 1.4±0.6, L/min, p>0.05 0.7±0.3 vs 0.9±0.3, L/min, p>0.05, 34.5±6.4 vs 31.5±5.5, p>0.05, respectively). RS after adjustment for age and CHF eziology was inversely correlated with VE/VCO2 slope (r=0,389) and was also correlated with VO2 peak and AT (r=0.3, p>0.01 and r=0.3, p>0.01, respectively).
Conclusions: Peripheral microcirculation of CHF patients measured by NIRS predict the severity of CHF patients. Further studies should evaluate NIRS predictive value.
