The Role of Gas Exchange Variables in Cardiopulmonary Exercise Testing for Risk Stratification and Management of Heart Failure with Reduced Ejection Fraction

2018 ◽  
Vol 202 ◽  
pp. 116-126 ◽  
Author(s):  
Jonathan Wagner ◽  
Piergiuseppe Agostoni ◽  
Ross Arena ◽  
Romualdo Belardinelli ◽  
Daniel Dumitrescu ◽  
...  
2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
J.G Westphal ◽  
P.C Schulze

Abstract Background The prognostic value of cardiopulmonary exercise testing (CPET) is established for risk stratification in patients with heart failure (HF) and reduced ejection fraction (HFrEF). Since the introduction of HF with mid-range ejection fraction (HFmrEF) as an additional category in 2016, optimal management strategy and risk stratification for these patients is a field of ongoing research. Purpose Left ventricular ejection fraction (LVEF) is only one part of the picture when planning treatment and estimating long time risk for patients with HF. We planned to investigate the predictive long-term value of exercise intolerance as measured by CPET in patients with HFmrEF in comparison to HFrEF. Methods We performed a single-center retrospective cohort study of ambulatory consecutive patients that showed signs of heart failure (NYHA functional class II or III) and had a LVEF of 49% or below as measured by echocardiography at the time of CPET. All patients underwent CPET evaluation with an upright bicycle between 2015–2017. The primary endpoint of all-cause mortality as well as the secondary composite endpoint of all-cause mortality or heart transplant/ventricular assist device implantation (transplant/VAD free survival) were assessed. Results For the primary analysis, 253 patients (mean age 61.2±13.0 years, 82.6% male) were included. 68 patients showed an LVEF between 40 and 49% (HFmrEF) whereas 185 patients had an LVEF of below 40% (HFrEF). HF etiology was in 31.3% ischemic. Mean BNP values were 788±1061 pg/ml while HFmrEF patients had on average lower values than HFrEF (322±676 vs. 945±1121, p<0.001). Patients were followed up for a median of 4.2 years (IQR: 3.5–5.0 years). Over this period, the primary and secondary end-point occurred in 22.5%/30.8% of patients. Patients in the HFmrEF group showed a higher mean peak oxygen uptake compared to HFrEF (pVO2; 17.3±4.6 vs 14.2±3.7 ml/min/kg, p<0.001), peak exercise power (Pmax; 111±49 vs 91±38 Watt, p=0.02) and peak oxygen pulse (pO2/HR; 12.6±4.2 vs 10.4±4.1 ml/min/kg, p<0.001). The Kaplan-Meier-Estimate showed a significant difference in survival for both HFmrEF and HFrEF who had pVO2 below 14 ml/min/kg (Log Rank: Chi2: 4.45, p=0.035 and Chi2: 10.05, p=0.02). In univariate Cox regression, pVO2 was predictive of the primary endpoint (HR per +1 mL/kg/min: 0.81; CI: 0.71–0.93; p=0.002 and HR per +1 mL/kg/min: 0.84; CI: 0.77–0.92; p<0.001) in both groups as was Pmax and pO2/HR (p<0.05 for both variables in both groups). Conclusion As in HFrEF, CPET is a useful tool to stratify risk in HFmrEF as well. Our findings support the prognostic role of pVO2 as well as pO2/HR and Pmax in HF with mid-range LVEF. Using a cut off of pVO2 14 ml/min/kg selected patients at risk with similar long-term prognosis as in the HFrEF cohort. Further research to identify subgroups at risk within the heterogeneous group of HFmrEF is warranted for optimal risk stratification. FUNDunding Acknowledgement Type of funding sources: None.


Author(s):  
Reza Mazaheri ◽  
Mohammad Sadeghian ◽  
Mahshid Nazarieh ◽  
David Niederseer ◽  
Christian Schmied

Background: Peak oxygen consumption (VO2) measured by cardiopulmonary exercise testing (CPET) is a significant predictor of mortality and future transplantation in heart failure patients with severely reduced ejection fraction (HFrEF). The present study evaluated the differences in peak VO2 and other prognostic variables between treadmill and cycle CPETs in these patients. Methods: In this cross-over study design, thirty males with severe HFrEF underwent CPET on both a treadmill and a cycle ergometer within 2–5 days apart, and important CPET parameters between two exercise test modalities were compared. Results: Peak VO2 was 23.12% higher on the treadmill than on cycle (20.55 ± 3.3 vs. 16.69 ± 3.01, p < 0.001, respectively). Minute ventilation to carbon dioxide production (VE/VCO2) slope was not different between the two CPET modes (p = 0.32). There was a strong positive correlation between the VE/VCO2 slopes during treadmill and cycle testing (r = 0.79; p < 0.001). VE/VCO2 slope was not related to peak respiratory exchange ratio (RER) in either modality (treadmill, r = 0.13, p = 0.48; cycle, r = 0.25, p = 0.17). The RER level was significantly higher on the cycle ergometer (p < 0.001). Conclusion: Peak VO2 is higher on treadmill than on cycle ergometer in severe HFrEF patients. In addition, VE/VCO2 slope is not a modality dependent parameter and is not related to the patients’ effort during CPET.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
B.M.L Rocha ◽  
G.J Lopes Da Cunha ◽  
P.M.D Lopes ◽  
P.N Freitas ◽  
F Gama ◽  
...  

Abstract Background Cardiopulmonary exercise testing (CPET) is recommended in the evaluation of selected patients with Heart Failure (HF). Notwithstanding, its prognostic significance has mainly been ascertained in those with left ventricular ejection fraction (LVEF) &lt;40% (i.e., HFrEF). The main goal of our study was to assess the role of CPET in risk stratification of HF with mid-range (40–49%) LVEF (i.e., HFmrEF) compared to HFrEF. Methods We conducted a single-center retrospective study of consecutive patients with HF and LVEF &lt;50% who underwent CPET from 2003–2018. The primary composite endpoint of death, heart transplant or HF hospitalization was assessed. Results Overall, 404 HF patients (mean age 57±11 years, 78.2% male, 55.4% ischemic HF) were included, of whom 321 (79.5%) had HFrEF and 83 (20.5%) HFmrEF. Compared to the former, those with HFmrEF had a significantly higher mean peak oxygen uptake (pVO2) (20.2±6.1 vs 16.1±5.0 mL/kg/min; p&lt;0.001), lower median minute ventilation/carbon dioxide production (VE/VCO2) [35.0 (IQR: 29.1–41.2) vs 39.0 (IQR: 32.0–47.0); p=0.002) and fewer patients with exercise oscillatory ventilation (EOV) (22.0 vs 46.3%; p&lt;0.001). Over a median follow-up of 28.7 (IQR: 13.0–92.3) months, 117 (28.9%) patients died, 53 (13.1%) underwent heart transplantation, and 134 (33.2%) had at least one HF hospitalization. In both HFmrEF and HFrEF, pVO2 &lt;12 mL/kg/min, VE/VCO2 &gt;35 and EOV identified patients at higher risk for events (all p&lt;0.05). In Cox regression multivariate analysis, pVO2 was predictive of the primary endpoint in both HFmrEF and HFrEF (HR per +1 mL/kg/min: 0.81; CI: 0.72–0.92; p=0.001; and HR per +1 mL/kg/min: 0.92; CI: 0.87–0.97; p=0.004), as was EOV (HR: 4.79; CI: 1.41–16.39; p=0.012; and HR: 2.15; CI: 1.51–3.07; p&lt;0.001). VE/VCO2, on the other hand, was predictive of events in HFrEF but not in HFmrEF (HR per unit: 1.03; CI: 1.02–1.05; p&lt;0.001; and HR per unit: 0.99; CI: 0.95–1.03; p=0.512, respectively). ROC curve analysis demonstrated that a pVO2 &gt;16.7 and &gt;15.8 mL/kg/min more accurately identified patients at lower risk for the primary endpoint (NPV: 91.2 and 60.5% for HFmrEF and HFrEF, respectively; both p&lt;0.001). Conclusions CPET is a useful tool in HFmrEF. Both pVO2 and EOV independently predicted the primary endpoint in HFmrEF and HFrEF, contrasting with VE/VCO2, which remained predictive only in latter group. Our findings strengthen the prognostic role of CPET in HF with either reduced or mid-range LVEF. Funding Acknowledgement Type of funding source: None


2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
P Garcia Bras ◽  
A Valentim Goncalves ◽  
J Reis ◽  
T Pereira Da Silva ◽  
R Ilhao Moreira ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cardiopulmonary exercise testing (CPET) is used for risk stratification in patients with chronic heart failure (CHF). However, there is a lack of information regarding CPET prognostic power in patients under new HF therapies such as sacubitril/valsartan, Mitraclip, IV iron or SGLT2 inhibitors. The aim of this study was to evaluate the prognostic value of CPET parameters in a contemporary subset of patients with optimal medical and device therapy for CHF. Methods Retrospective evaluation of patients with CHF submitted to CPET in a tertiary center. Patients were followed up for 24 months for the composite endpoint of cardiac death, urgent heart transplantation or left ventricular assist device. CPET parameters, including peak oxygen consumption (pVO2) and VE/VCO2 slope, were analysed and their predictive power was measured. HF events were stratified according to cut-off values defined by the International Society for Heart and Lung Transplantation (ISHLT) guidelines: pVO2 of ≤12 mL/Kg/min and VE/VCO2 slope of &gt;35. Results CPET was performed in 204 patients, from 2014 to 2018. Mean age was 59 ± 13 years, 83% male, with a mean left ventricular ejection fraction of 33 ± 8%, and a mean Heart Failure Survival Score of 8.6 ± 1.3. The discriminative power of CPET parameters is displayed in the Table. In patients with pVO2 ≤12 mL/Kg/min, the composite endpoint occurred in 18% of patients. A pVO2 value of ≤12 mL/Kg/min had a positive predictive power of 18% while pVO2 &gt;12 had a negative predictive power of 93%. Regarding VE/VCO2 slope &gt;35, the composite endpoint occurred in 13% of patients. A VE/VCO2 slope value of &gt;35 had a positive predictive power of 13% while VE/VCO2 slope &lt;35 had a negative predictive power or 94%. Conclusion Using ISHLT guideline cut-off values for advanced HF therapies patient selection, there was a reduced number of HF events (&lt;20%) at 24 months in patients under optimal CHF therapy. While pVO2 and VE/VCO2 slope are still valuable parameters in risk stratification, redefining cut-off values may be necessary in a modern HF population. Discriminative power of CPET parameters Parameters HR; 95% CI AUC p-value Peak VO2 0.824 (0.728-0.934) 0.781 0.001 Percent of predicted pVO2 0.942 (0.907-0.978) 0.774 0.002 VE/VCO2 slope 1.068 (1.031-1.106) 0.756 0.008 Cardiorespiratory optimal point 1.118 (1.053-1.188) 0.746 0.004 PETCO2 maximum exercise 0.854 (0.768-0.950) 0.775 0.003 Ventilatory Power 0.358 (0.176-0.728) 0.796 0.002 HR Hazard ratio, AUC: Area under the curve, PETCO2: end-tidal CO2 pressure


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