The influence of aerobic fitness status on ventilatory efficiency in patients with coronary artery disease

Background: Previous studies have demonstrated that patients with coronary artery disease (CAD) have lower ventilatory efficiency (VE) during graded exercise test. However, there is scarce information whether the level of cardiorespiratory fitness might have association with lower VE observed in CAD patients. Purpose: To test the hypothesis that: 1) CAD patients with lower CF demonstrate a lower VE; and 2) CAD patients with lower CF exhibit greater responsiveness on improving VE after aerobic exercise training. Methods: 78 patients with CAD matched for age (60.2 + 6.2 years) were divided according to CF into 3 groups: Group 1 (n = 20, VO2 peak <17.5 ml/kg/min), Group 2 (n = 41, VO2 peak > 17.5 and < 24.5 ml/kg/min) and Group 3 (n = 17, VO2 peak > 24.5 ml/kg/min). All patients performed a graded exercise test on treadmill to determine ventilatory anaerobic threshold (VAT), respiratory compensation point and peak oxygen consumption (VO2 peak) before and after interventions. The VE was determined by the relationship between minute ventilation and carbon dioxide production at VAT (VE/VCO2@VAT). The exercise program consisted of 12-week, 3 times a week supervised moderate-intensity aerobic exercise training program. Results: The group 1 demonstrated both lower CF and VE when compared to other groups: Group 1 (VO2peak = 14.8±2,4; VEVCO2@VAT = 34,5±3,7); Group 2 (VO2peak = 20,2±1,9; VEVCO2@VAT = 30,9±3,5); group 3 (VO2peak = 27,7±2,5; VEVCO2@LAV = 29,7±1,9 respectively, p <0.05). After the intervention period, only group 1 has shown an increase in VE (p <0.05). Furthermore, group 1 demonstrated greater responsiveness in increasing both the CF and VE compared to the other groups: Group 1 (Δ VO2peak = 5.1; Δ VEVCO2@ VAT = -3,6); Group 2 (ΔVO2peak = 4.2; Δ VEVCO2@VAT = -1.5); Group 3 (Δ VO2peak = 2.2; ΔVEVCO2@ LAV = -1.3 respectively, p <0.05). Conclusion: These findings suggest that different levels of cardiorespiratory fitness may be an important determinant on responsiveness of increased in ventilatory efficiency after a period of exercise training in patients with coronary artery disease. Collectively, these data suggest a clinical significance for aerobic exercise program, since the low VE observed in patients with CAD has an important prognostic value for cardiovascular mortality.

The analysis of ventilatory efficiency in cardiopulmonary exercise testing has proven useful for assessing the presence and severity of cardiorespiratory diseases. During exercise, efficient pulmonary gas exchange is characterized by uniform matching of lung ventilation with perfusion. By contrast, mismatching is marked by inefficient pulmonary gas exchange, requiring increased ventilation for a given CO2 production. The etiology of increased and inefficient ventilatory response to exercise in heart disease is multifactorial, involving both peripheral and central mechanisms. Exercise training has been recommended as non-pharmacological treatment for patients with different chronic cardiopulmonary diseases. In this respect, previous studies have reported improvements in ventilatory efficiency after aerobic exercise training in patients with heart disease. Against this background, the primary objective of the present review was to discuss the pathophysiological mechanisms involved in abnormal ventilatory response to exercise, with an emphasis on both patients with heart failure syndrome and coronary artery disease. Secondly, special focus was dedicated to the role of aerobic exercise training in improving indices of ventilatory efficiency among these patients, as well as to the underlying mechanisms involved.

Effect of continuous and interval exercise training on the PETCO2 response during a graded exercise test in patients with coronary artery disease

OBJECTIVE To assess acute and chronic effects of surgical thromboendarterectomy on exercise capacity and ventilatory efficiency in patients with chronic thromboembolic pulmonary hypertension (CTEPH). DESIGN Cardiopulmonary exercise testing was performed in 20 patients with CTEPH before thromboendarterectomy (baseline), one month after (early phase), and four months after (late phase). Peak oxygen uptake (peakV˙o 2) and the ventilatory response to carbon dioxide production (V˙e-V˙co 2 slope) were measured for assessment of exercise capacity and ventilatory efficiency. Right heart catheterisation was performed in all patients before and one month after surgery. RESULTS Baseline peakV˙o 2 decreased andV˙e-V˙co 2 slope increased along with the increase in pulmonary vascular resistance in patients with CTEPH. After thromboendarterectomy, theV˙e-V˙co 2 slope decreased greatly from baseline to the early phase (mean (SD), 50 (9) to 37 (7), p &lt; 0.05) and reached a steady level thereafter. In contrast, a continued increase in peak V˙o 2 was noted from the early to the late phase (16.9 (4.1) to 21.1 (5.0) ml/kg/min, p &lt; 0.05). The decrease in theV˙e-V˙co 2 slope from baseline to the early phase, but not the increase in peakV˙o 2, correlated strongly with the decrease in pulmonary vascular resistance after surgery (r = 0.75, p &lt; 0.01). CONCLUSIONS Thromboendarterectomy may cause an immediate improvement in ventilatory efficiency, possibly through its beneficial haemodynamic effects. In contrast, exercise capacity may continue to improve towards the late phase, reflecting peripheral adaptation to exercise.

OBJECTIVETo assess acute and chronic effects of surgical thromboendarterectomy on exercise capacity and ventilatory efficiency in patients with chronic thromboembolic pulmonary hypertension (CTEPH).DESIGNCardiopulmonary exercise testing was performed in 20 patients...

Cardiorespiratory fitness: an independent and additive marker of risk stratification and health outcomes.

Ventilatory efficiency as measured by VE vs VCO2 slope during cardiopulmonary exercise testing is a strong and independent predictor of outcome in patients with heart failure. We analysed the change of the VE vs VCO2 slope pre/post CRT in our own registry of 46 patients. Systems were implanted in the period from February 2001 to December 2004. CRT was performed in patients with left bundle branch block (LBBB) 0.02, two sided student-t-test). In addition we found a statistically significant improvement in VO2max and VO2AT. Conclusion CRT improves ventilatory efficiency in CHF. The improvement in ventilatory efficiency in patients undergoing CRT is proposed as a parameter to optimize CRT in CHF patients.

Exercise Capacity and Ventilatory Efficiency in Patients With Pulmonary Embolism After Short Duration of Anticoagulation Therapy

Effects of left ventricular assist device on cardiopulmonary exercise performance.

Funding Acknowledgements Type of funding sources: None. Introduction Exercise capacity and ventilatory efficiency are often altered in hypertrophic cardiomyopathy (HCM) and several factors have been advocated as possible causes. Aim This study investigates the determinants of cardiopulmonary exercise test (CPET) prognostic markers for HCM (VO2Peak, VE/VCO2 Slope and PETCO2 apex), by considering echocardiographic and cardiac magnetic resonance (CMR) parameters. Secondly, it scopes if myocardial fibrosis at CMR leads to clinical and functional differences. Methods 64 patients with HCM underwent a clinical assessment, including maximal CPET, echocardiography, and CMR. Exclusion criteria were the corrective surgery for cardiac hypertrophy and heart failure stage. Results The study included 66% males, age 40±17 years, NYHA class I or II 91%. Mean left ventricle (LV) ejection fraction was 63,8±7,7%, with a mean LV maximal wall thickness (MVT) of 20,2±5,6 mm; LVOT gradient was &amp;gt;30mmHg in 14% of patients. Late gadolinium enhancement (LGE) was described in 70,3% of cases with a mean LGE extension on bullseye plot of 11%. 39% of patients had a VO2 peak &amp;lt;80% of predicted, 35% a reduced PETCO2 apex and 26% an increased VE/VCO2 Slope. At the stepwise multivariate analysis, age (β=-0,33; p=0,00), BMI (β=-0,80; p=0,002), systolic blood pressure increase (β=0,22; p=0,02), left atrial volume (β=-0,15; p=0,02) and BB therapy (β=-0,45; p=0,00) were independently associated with VO2 peak (R2-adjusted index 0,95). Concerning ventilatory efficiency, sex (β=-0,41; p=0,03), left atrial volume (β=0,46; p=0,01) and LGE extension (β=0,33; p=0,01) were independently associated with VE/VCO2 Slope (R2-adjusted index 0,46). Similar data, with reversed correlations, emerged for PETCO2 apex. Patients with LGE had a LV mass index (mean 104,6 vs 82,7 g/m2, p=0,04), MWT (mean 21,8 vs 16,2 mm, p=0,00) and diastolic function (mean E/e’ 13,4 vs 10,0, p=0,01) worse that the counterpart. No differences were found in sex, age, therapy, CPET parameters and arrhythmic burden. BB+ patients were older, had more LV hypertrophy, worse diastolic parameters, and functional capacity while ventilatory efficiency was similar. Conclusions This study supports previous data about VO2 peak determinants. The correlation between the extension of the LGE and ventilatory efficiency in patients with HCM is an original finding. It confirms the pathophysiological explanation of a lung ventilation/perfusion mismatch due to the increased left atrium pressure that is secondary to a more severe LV diastolic disfunction in patients with LGE. The reduced VO2 in BB+ compared to BB- patients is not inferable given the different age and severity of disease. Moreover, the negative chronotropic effect of BB during exercise prolongs the diastolic filling time, thus, improving stroke volume and alleviating the LV filling pressures, thus normalising, in the less advanced stages of pathology, the ventilatory efficiency in HCM patients.

Aim To evaluate the effect of sacubitril/valsartan on exercise capacity, cardiac structure, and function in patients with hypertrophic cardiomyopathy (HCM). Methods Phase II, randomised, open-label multicentre study enrolled adult patients with symptomatic non-obstructive HCM (NYHA class I–III) who were randomly assigned (2:1) to receive sacubitril/valsartan (target dose 97/103mg) or usual care for 16 weeks. Primary endpoint was a change in peak oxygen consumption (peak VO2). Secondary endpoints included echocardiography measures of cardiac structure and function, natriuretic peptides and other biomarkers, and Minnesota Living with Heart Failure quality of life (QoL). Results Between May 2018 and November 2021, 354 patients were screened for eligibility, 115 patients (mean age 58 years [SD 11], 37% women) met the study inclusion criteria and were randomly assigned to sacubitril/valsartan (N=79) or usual care (N=36). At 16 weeks, there was no significant change in peak VO2 from baseline in sacubitril/valsartan (15.3 [4.3] vs 15.9 [4.3] ml/kg/min, p=0.13), or usual care group (p=0.47). There was a significant reduction in ventilatory efficiency slope (30.1 [7] vs 28.4 [4.9], p=0.03), but not in the control group (p=0.09). No significant changes were found in systolic or diastolic function, cardiac structure, or plasma biomarkers. The QoL score decreased significantly in the sacubitril/valsartan by 6 points (p=0.005) but not in the usual care group (p=0.66). Conclusion In patients with hypertrophic cardiomyopathy, 16 weeks of treatment with sacubitril/valsartan was well tolerated and contributed to a significant improvement in ventilatory efficiency and quality of life but not in exercise capacity or cardiac function.

Summary : Lifelong exercise training maintains a youthful compliance of the left ventricle (LV), whereas a year of exercise training started later in life fails to reverse LV stiffening, possibly because of accumulation of irreversible advanced glycation end products. Alagebrium is a novel drug that breaks advanced glycation end product crosslinks and improves LV stiffness in aged animals. In this study, the authors prescribed alagebrium (200 mg daily) or placebo combined with aerobic exercise training or contact control in healthy, sedentary older individuals for 1 year. The authors evaluated overall cardiac function by the use of several modalities, including invasive pressure–volume measurements, exercise testing, and cardiac MRI before and after the training. To the authors’ knowledge, this is the first study to evaluate the effects of alagebrium and exercise training in healthy aged humans. After intervention, exercise training significantly increased exercise capacity, LV mass, and LV end-diastolic volume. Conversely, alagebrium had little effect on exercise capacity or LV geometry. However, alagebrium showed a modest improvement in LV stiffness compared with placebo. This favorable effect of alagebrium on LV stiffness was most prominent in individuals with combined alagebrium and exercise training. Conclusions : Alagebrium had no effect on hemodynamics, LV geometry, or exercise capacity in healthy, previously sedentary seniors. However, it did show a modestly favorable effect on age-associated LV stiffening.1 Summary : Maximum oxygen consumption (peak VO2) and efficiency of ventilation (VE) during exercise (VE/VCO2 slope) are known to stratify adults in heart failure for 1-year survival. On the basis of adult data, a recent American Heart Association scientific statement suggested that peak VO2<50% predicted for age and sex should be considered substantial impairment in exercise performance in children with heart disease and therefore a class I indication for heart transplant listing. This single-center study examined the association of …

Shifting Paradigms: Exercise Testing as a Metric of Long-Term Success in Surgery for Ebstein Anomaly.

Sodium-glucose linked transporter 2 inhibition recently emerged as a promising therapy for reducing the risk of heart failure (HF) in patients with type 2 diabetes mellitus (T2DM). However, there is a lack of data endorsing its role in symptomatic HF patients. We sought to evaluate the short-term effects of empagliflozin on maximal exercise capacity in these patients. We postulate tretament with empagliflozin may improve functional capacity in patients with T2DM and established HF. Nineteen T2DM patients with symptomatic HF were prospectively included and underwent cardiopulmonary exercise testing before and 30 days after initiation of empagliflozin therapy. A mixed-effects model for repeated measures was used. Median patient age was 72 years (interquartile range, 60-79 years); 42.1% were in New York Heart Association class III. Baseline mean (± SD) peak oxygen consumption (peak VO2 ) was 10.9 ± 4.0 mL/min/kg. Peak VO2 increased significantly at 30 days (∆: +1.21 [0.66 to 1.76] mL/min/kg; P < 0.001). A significant improvement in ventilatory efficiency during exercise, 6-minute walking distance, and quality of life, and a reduction in antigen carbohydrate 125, were also found. Estimated glomerular filtration rate and natriuretic peptides did not significantly change. In this pilot study, empagliflozin was associated with 1-month improvement in exercise capacity in T2DM patients with symptomatic HF. This beneficial effect was also found for other surrogates of severity.

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