Tuan SH;  National Cheng Kung University, Tainan 701,Taiwan
Huang IC; Huang WC; Chen GB; Sun SF; Lin KL;

Life (Basel). 2024 Nov 6;14(11):1429. doi: 10.3390/life14111429.

(1) Background: Heart failure (HF) leads to functional disability and major cardiovascular events (MACEs). Cardiopulmonary exercise testing (CPET) is the gold standard for assessing aerobic capacity and prognostic stratification. This study aimed to evaluate the predischarge CPET variables in patients with acute decompensated HF and identify the submaximal CPET variables with prognostic value.
(2) Methods: A retrospective cohort study was conducted at a tertiary center in Taiwan. Patients surviving their first episode of decompensated HF and undergoing predischarge CPET (February 2017 to January 2023) were analyzed. Follow-up was conducted until a MACE or administrative censoring (up to 5 years). Cox regression identified the significant predictors of MACE.
(3) Results: The study included 553, 485, and 267 patients at the 3-month, 1-year, and 5-year follow-ups, respectively. MACE rates were 15.0%, 34.2%, and 50.9%. The VE/VCO2 slope was a significant predictor of MACE at all intervals. A VE/VCO2 slope >38.95 increased the risk of MACE by 2.49-fold at 3 months and 1.81-fold at 1 year (both p < 0.001). A slope > 37.35 increased the 5-year MACE risk by 1.75-fold (p = 0.002).
(4) Conclusions: The VE/VCO2 slope is a significant submaximal CPET predictor of MACE in patients post-acute decompensated HF for both short- and long-term outcomes.

Eysenck W; London Bridge Hospital UK
Sulke N; Patel N; Furniss S; Veasey R; Freemantle N; Bodagh N;

The British journal of cardiology [Br J Cardiol] 2024 Apr 16; Vol. 31 (2), pp. 014.
Date of Electronic Publication: 2024 Apr 16 (Print Publication: 2024).

Our objective was to compare the efficacy of atrial fibrillation (AF) ablation versus permanent pacemaker (PPM) with atrioventricular node ablation (AVNA) versus direct current cardioversion (DCCV) for persistent AF in patients ≥65 years old. Seventy-seven patients (aged 66-86, mean 75.4 years) with persistent AF were randomised (1:1:1) to AF ablation + amiodarone (± DCCV), PPM with AVNA (+DCCV) or DCCV + amiodarone. The primary end point was persistent AF recurrence, measured with an implanted cardiac monitor or PPM.
Cardiopulmonary exercise testing (CPET) was performed at baseline and six months. Symptom questionnaires were completed monthly. Follow-up was 12 months. The primary end point occurred in fewer patients following AF ablation + amiodarone than DCCV + amiodarone (seven patients, 28% vs. 15 patients, 60%; hazard ratio [HR] 0.559, 95% confidence interval [CI] 0.293 to 1.065, p=0.073) with no differences between DCCV + amiodarone and PPM with AVNA (HR 0.990, 95%CI 0.539 to 1.818, p=0.973). AF ablation + amiodarone resulted in a lower AF burden at 12 months compared with DCCV + amiodarone (17.0 ± 37.9% vs. 61.7 ± 48.6%, p<0.0001). Modified European Heart Rhythm Association (EHRA) symptom class improved in all patients (baseline 2.4 ± 0.495 vs. 12-month follow-up 1.84 ± 0.081, p=0.00001). Six-month CPET demonstrated a higher VO ₂ peak in sinus rhythm (SR) compared with baseline in AF (12.1 ± 4.2 ml/kg/min at baseline to 15.3 ± 4.2 ml/kg/min at six months, p=0.013). In conclusion, in older patients with persistent AF, ablation + amiodarone resulted in a lower AF burden at 12 months than DCCV + amiodarone. There was a non-significant trend toward reduced recurrence of device detected persistent AF episodes. All therapies improved symptoms despite DCCV restoring SR in <50% of patients at 12 months. CPET demonstrated improved VO ₂ peak with SR restoration.

Faigenbaum AD; Department of Kinesiology and Health Sciences, The College of New Jersey, Ewing, NJ, USA.
Kang J; Ingui J; Fish A; Dimatteo J;Leazier I; Bush JA; DeRatamess NA;

International journal of exercise science [Int J Exerc Sci] 2024 Nov 01; Vol. 17 (4), pp. 1530-1539.
Date of Electronic Publication: 2024 Nov 01 (Print Publication: 2024).

The aim of this study was to compare the warm-up effects of a treadmill walking warm-up (TW) with a dynamic warm-up (DW) on the responses to cardiopulmonary exercise testing (CPET) in youth. A sample of 16 active youth (age 13.6 ± 1.8 yr) were tested for peak oxygen uptake (VO ₂ peak) using the Fitkids treadmill test protocol on 2 nonconsecutive days following different 6-min warm-up procedures. The TW consisted of walking on a treadmill at 2.2 mph and 0% grade whereas the DW consisted of 12 bodyweight exercises with a 2 kg medicine ball. Maximal heart rate (HR) was significantly higher following DW vs TW (200.8 ± 6.16 vs. 197.9 ± 7.3 bpm, respectively; p < 0.05), whereas no significant differences were found between DW and TW for VO ₂ peak (50.5 ± 9.9 vs 50.6 ± 11.1 ml/kg/min), maximal minute ventilation (V _E ; 93.0 ±21.4 vs. 92.7 ±21.2 L/min), maximal respiratory exchange ratio (1.19 ± 0.08 vs 1.22 ± 0.08), and total exercise test time (668.1 ± 103.5 vs 686.3 ± 97.0 s), respectively. During the Fitkids treadmill test protocol HR and V _E were significantly higher following DW vs TW at stage 1, stage 2, stage 3 and stage 4, and oxygen uptake was significantly higher following DW vs TW during stage 1 (all p < 0.05). Findings indicate a DW elicits a higher maximal HR and higher submaximal HR, V _E , and oxygen uptake values than TW during CPET in youth, although no differences in VO ₂ peak were observed.

Hughes DL; Division of Gastroenterology and Hepatology, Northwestern University, Chicago, IL.
Lizaola-Mayo B; Wheatley-Guy CM; Vargas HE; Bloomer PM; Wolf C; Carey EJ; Forman DE; Duarte-Rojo A;

Transplantation direct [Transplant Direct] 2024 Nov 15; Vol. 10 (12), pp. e1725.
Date of Electronic Publication: 2024 Nov 15 (Print Publication: 2024).

Background: Cardiovascular disease and physical decline are prevalent and associated with morbidity/mortality in liver transplant (LT) patients. Cardiopulmonary exercise testing (CPX) provides comprehensive cardiopulmonary and exercise response assessments. We investigated cardiorespiratory fitness (CRF) and cardiac stress generated during CPX in LT candidates.
Methods: LT candidates at 2 centers underwent CPX. Standard-of-care cardiac stress testing (dobutamine stress echocardiography, DSE) results were recorded. Physical function was assessed with liver frailty index and 6-min walk test. CPX/DSE double products were calculated to quantify cardiac stress. To better study the association of CPX-derived metrics with physical function, the cohort was divided into 2 groups based on 6-min walk test median (372 m).
Results: Fifty-four participants (62 ± 8 y; 65% men, Model for End-Stage Liver Disease-Na 14 [10-18]) underwent CPX. Peak oxygen consumption was 14.1 mL/kg/min for an anerobic threshold of 10.2 mL/kg/min, with further CRF decline in the lower 6MWT cohort despite lack of liver frailty index-frailty in 90%. DSE was nondiagnostic in 18% versus 4% of CPX ( P  = 0.058). All CPX were negative for ischemia. A double product of ≥25 000 was observed in 32% of CPX and 11% of DSE ( P  = 0.020). Respiratory function testing was normal. No patient presented major cardiovascular events at 30 d post-LT.
Conclusions: CPX provided efficient and effective combined cardiopulmonary risk and frailty assessments of LT candidates in a 1-stop test. The CRF was found to be very low despite preserved physical function or lack of frailty.

Tashiro M; Department of Cardiovascular Medicine, Kyorin University Hospital, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
Goda A; Yanagisawa Y; Nakamaru R; Funabashi S; Takeuchi S;Soejima K; Kohno T;

Clinical research in cardiology : official journal of the German Cardiac Society [Clin Res Cardiol] 2024 Nov 18.
Date of Electronic Publication: 2024 Nov 18.

Backgrounds: Heart rate (HR) and stroke volume (SV)-the components of cardiac output-have a complementary relationship. Poor HR increase during exercise is associated with poor exercise tolerance in heart failure (HF) with preserved ejection fraction (HFpEF), but its prognostic impact remains unclear. Furthermore, whether the compensation for poor HR increase with SV during exercise is associated with prognosis remains unknown.
Methods: We evaluated 129 consecutive hospitalized HF patients with sinus rhythm and left ventricular ejection fractions > 40% who underwent cardiopulmonary exercise testing before discharge from the index hospitalization.
Results: Patients (age: 66 [55-74] years; 73% male) were divided into four groups by median HR reserve (HRR; peak-rest HR: 34 bpm) and O ₂ pulse, a surrogate for SV, reserve (peak-rest O ₂ pulse: 4.8 mL/beat). During a mean follow-up of 562 [294-961] days, cardiovascular events (cardiovascular death and/or HF rehospitalizations) occurred in 24 patients. Kaplan-Meier analysis identified significant differences in outcomes among the four groups (χ ²  = 27.3, p < 0.001). Using the preserved HRR/preserved O ₂ pulse reserve group (n = 33) as a reference, the impaired HRR/impaired O ₂ pulse reserve group (n = 37) was associated with poor outcomes (adjusted hazard ratio: 5.66, 95% CI 1.15-27.74, p = 0.033), whereas the impaired HRR/preserved O ₂ pulse reserve group (n = 31) was not (adjusted hazard ratio: 0.38, 95% CI 0.03 to 4.76, p = 0.455).
Conclusion: The overlap of lower increases in HR and O ₂ pulse, a surrogate for SV, during exercise was associated with an extremely poor prognosis in HFpEF.

Dmytriiev K; Division of Pulmonary Medicine,  Edmonton, Alberta T6G 2G3, Canada.
Stickland MK; Weatherald J;

Heart failure clinics [Heart Fail Clin] 2025 Jan; Vol. 21 (1), pp. 51-61. Date of Electronic Publication: 2024 Oct 15.

Heart failure clinics [Heart Fail Clin] 2025 Jan; Vol. 21 (1), pp. 51-61.
Date of Electronic Publication: 2024 Oct 15.

Pulmonary arterial hypertension (PAH) is a progressive pulmonary vascular disease that has a high impact on patients’ quality of life, morbidity and mortality. PAH is characterized by extensive pulmonary vascular remodeling that results in an increase in pulmonary vascular resistance and right ventricular afterload, and can lead to right heart failure. Patients with PAH exhibit inefficient ventilation, high dead space ventilation, dynamic hyperinflation, and ventricular-arterial uncoupling, which can contribute to high dyspnea and low exercise tolerance. Cardiopulmonary exercise testing can help to diagnose PAH, define prognosis and treatment response in PAH, as well as discriminate between different pulmonary vascular diseases.
Competing Interests: Disclosure K. Dmytriiev has nothing to disclose; M.K. Stickland has nothing to disclose, J. Weatherald has received grants or contracts to his institution from Astra Zeneca, Bayer, Janssen, Sanofi, and Merck; consulting fees from Janssen and Merck; honoraria from Janssen and Merck; advisory board payments from Janssen and Merck, payment for expert testimony from Sprigings Intellectual Property Law; travel support from Janssen; participation on Data Safety and Monitoring Board for the Université de Laval; and has unpaid leadership role at the Pulmonary Hypertension Association of Canada.

Landsteiner I; Cardiology Division and Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02114, USA.
Ikoma T; Lewis GD;

Heart failure clinics [Heart Fail Clin] 2025 Jan; Vol. 21 (1), pp. 35-49.
Date of Electronic Publication: 2024 Oct 18.

Cardiopulmonary exercise testing (CPET) permits the assessment of gas exchange, electrocardiogram, and hemodynamic patterns throughout exercise, providing a window into multi-organ physiologic reserve during exercise. CPET provides risk stratification and informs management of advanced heart failure (HF). Increasingly, CPET is combined with echocardiography, or invasive right heart catheterization, which enables high-resolution assessment of cardiac and extracardiac limitations to exercise. CPET also represents a cornerstone in the evaluation process for advanced HF interventions. This review underscores the importance and utility of CPET in managing patients with advanced HF.

Bin Saif A; The Dudley Group NHS Foundation Trust, Dudley, UK.
Summerour V; Al-Saadi N; Arif A; Newman J; Wall M

Annals of Vascular Surgery. 109:522-530, 2024 Dec.

BACKGROUND: To investigate and analyze various aspects related to patients
who have been placed on a “turndown list” for elective or emergency repair
of abdominal aortic aneurysms.

METHODS: This retrospective study analyzed data from the Black Country
Vascular Network. Multidisciplinary team meetings assessed abdominal
aortic aneurysm patients referred through National Abdominal Aortic
Aneurysm Screening Program or directly to vascular surgery. Patients
considered unfit for intervention were added to a prospectively kept
turndown list. Survival and cause of death data were collected, along with
cardiopulmonary exercise testing (CPET) results and British Aneurysm
Repair scores for some patients. The study covered a period from January
2015 to May 2023.

RESULTS: After exclusions, 247 (16%) patients were placed on the turndown
list with a median age of 85 years (interquartile range 8 years). The
mortality of turndown cases on medical grounds was 74.1%. Survival was
significantly higher for patients who completed CPET before being turned
down (P = 0.004). Gender analysis revealed a higher proportion of females
being turned down compared to males (P = 0.044). COVID-19 led to a notable
reduction in the number of discussed cases and interventions, while the
turndown rates remained consistent. Survival at 1 year in turndown
patients was 66%, at 3 years it was 29%, at 4 years it was 18%, and at 7
years it was 5%. Most patients whose cause of death was known died of
respiratory complications (30%) or malignancy (19%). British Aneurysm
Repair scores and aneurysm size were not significant predictors of
mortality.

CONCLUSIONS: Patients on the turndown list have a substantial mortality
rate. A significant proportion of female patients were being turned down
compared to men and the reasons for this are not clear. Patients who
completed CPET before being turned down had a longer survival time. While
COVID-19 impacted healthcare services reducing the number of
interventions, it did not influence turndown decisions. The study showed
that the cause of death for a significant number of patients was
respiratory complications or malignancy

Yanagi H; Toneyama Medical Center, Toyonaka, Osaka, 560-8552, Japan.
Miki K; Koyama K; Miyamoto S; Mihashi Y; Nagata Y; Hashimoto K;
Hashimoto H; Fukai M; Maekura T; Yonezawa R; Sakaguchi S; Nii T; Matsuki
T; Tsujino K; Kida H

BMC Pulmonary Medicine. 24(1):550, 2024 Oct 31.

BACKGROUND: In patients with chronic obstructive pulmonary disease (COPD),
the clinical use of the minute ventilation-carbon dioxide production
([Formula: see text]E-[Formula: see text]CO2) slope has been reported as a
measure of exercise efficiency, but the oxygen uptake efficiency slope
(OUES), i.e., the slope of oxygen uptake ([Formula: see text]O2) versus
the logarithmically transformed [Formula: see text]E, has rarely been
reported.

METHODS: We hypothesized that the [Formula: see text]E-[Formula: see
text]CO2 slope is more useful than OUES in clinical use for the
pathophysiological evaluation of COPD. Then, we investigated the
cardiopulmonary exercise testing parameters affecting each of these slopes
in 122 patients with all Global Initiative for Chronic Obstructive Lung
Disease (GOLD) COPD grades selected from our database.

RESULTS: Compared with the GOLD I-II group (n = 51), peak [Formula: see
text]O2 (p < 0.0001), OUES (p = 0.0161), [Formula: see text]E at peak
exercise (p < 0.0001), and percutaneous oxygen saturation (SpO2) at peak
exercise (p = 0.0004) were significantly lower in the GOLD III-IV group (n
= 71). The GOLD III-IV group was divided into two groups by the exertional
decrease in SpO2 from rest to peak exercise: 3% or less (the
non-desaturation group: n = 23), or greater than 3% (the desaturation
group: n = 48). OUES correlated only weakly with peak [Formula: see
text]O2, [Formula: see text]E at peak exercise, and the difference between
inspired and expired mean O2 concentrations (DELTAFO2) at peak exercise,
i.e., an indicator of oxygen consumption ability throughout the body, in
the GOLD III-IV group with exertional hypoxemia. In contrast, the
[Formula: see text]E-[Formula: see text]CO2 slope was significantly
correlated with DELTAFO2 at peak exercise, regardless of the COPD grade
and exertional desaturation. Across all COPD stages, there was no
correlation between the [Formula: see text]E-[Formula: see text]CO2 slope
and [Formula: see text]E at peak exercise, and stepwise analysis
identified peak [Formula: see text]O2 (p = 0.0345) and DELTAFO2 (p <
0.0001) as variables with a greater effect on the [Formula: see
text]E-[Formula: see text]CO2 slope.

CONCLUSIONS: The OUES may be less useful in advanced COPD with exertional
hypoxemia. The [Formula: see text]E-[Formula: see text]CO2 slope, which is
independent of [Formula: see text]E, focuses on oxygen consumption ability
and exercise tolerance in COPD, regardless of the exertional hypoxemia
level and COPD grade. Therefore, the [Formula: see text]E-[Formula: see
text]CO2 slope might be useful in establishing or evaluating tailor-made
therapies for individual patient’s pat

Gattoni C; The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
Abbasi A; Ferguson C; Lanks CW; Decato TW; Rossiter HB; Casaburi R; Stringer WW;

Respiratory physiology & neurobiology [Respir Physiol Neurobiol] 2024 Oct 28; Vol. 331, pp. 104362. Date of Electronic Publication: 2024 Oct 28.

Background: Long COVID patients present with a myriad of symptoms that can include fatigue, exercise intolerance and post exertional malaise (PEM). Long COVID has been compared to other post viral syndromes, including myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), where a reduction in day 2 cardiopulmonary exercise test (CPET) performance of a two-day CPET protocol is suggested to be a result of PEM. We investigated cardiopulmonary and perceptual responses to a two-day CPET protocol in Long COVID patients.
Methods: 15 Long COVID patients [n=7 females; mean (SD) age: 53(11) yr; BMI = 32.2(8.5) kg/m ² ] performed a pulmonary function test and two ramp-incremental CPETs separated by 24 hr. CPET variables included gas exchange threshold (GET), peak oxygen uptake (V̇O _2peak ) and peak work rate (WR _peak ). Ratings of perceived dyspnoea and leg effort were recorded at peak exercise using the modified 0-10 Borg Scale. PEM (past six months) was assessed using the modified DePaul Symptom Questionnaire (mDSQ). One-sample t-tests were used to test significance of mean difference between days (p<0.05).
Results: mDSQ revealed PEM in 80 % of patients. Lung function was normal. Responses to day 1 CPET were consistent with the presence of aerobic deconditioning in 40 % of patients (V̇O _2peak <80 % predicted, in the absence of evidence of cardiovascular and pulmonary limitations). There were no differences between day-1 and day-2 CPET responses (all p>0.05).
Conclusion: PEM symptoms in Long COVID patients, in the absence of differences in two-day CPET responses separated by 24 hours, suggests that PEM is not due to impaired recovery of exercise capacity between days.
Competing Interests: Declaration of Competing Interest Chiara Gattoni has no conflict of interest to declare. Asghar Abbasi is supported by awards from Johnny Carson Foundation and NIH (1R43 HL167289–01). Carrie Ferguson is supported by grants from NIH (R01HL166850). She reports consulting fees from Respira Therapeutics. She is involved in contracted clinical research with United Therapeutics, Genentech, Regeneron and Respira Therapeutics. She has received honoraria for teaching on the ACCP CPET live-learning course. She is a visiting Associate Professor at the University of Leeds, UK. Charles W. Lanks has no conflict of interest to declare. Thomas DeCato is supported by a grant from the NIH (R01HL166850). He reports consulting fees from MannKind Corporation and has received honoraria for teaching on the ACCP CPET live-learning course. Harry Rossiter is supported by grants from NIH (R01HL151452, R01HL166850, R01HL153460, P50HD098593, R01DK122767) and the Tobacco Related Disease Research Program (T31IP1666). He reports consulting fees from the NIH RECOVER-ENERGIZE working group (1OT2HL156812) and is involved in contracted clinical research with United Therapeutics, Genentech, Regeneron, Respira and Intervene Immune. He is a visiting Professor at the University of Leeds, UK. Richard Casaburi is involved in contracted research and is a consultant with Regeneron. He is an advisory board member for Inogen and a speaker bureau member for GlaxoSmithKline. William Stringer is involved in contracted clinical research with Genentech, Regeneron, Roche, AstraZeneca and the NIH Recover-Vital and Recover-Neuro clinical trials. He performs CPET Data Center activities for the NIH funded PETRACT study (UG3HL155798–01A1). He is a co-investigator on an NIH Small Business Innovation Award (1R43HL167289–01) and has been a site PI for the NIH RETHINC (5U01HL128954-04) and BLOCK-COPD (W81XWH-15–1–0705) studies. He performs Data Safety Monitoring Board activities for SYNEOS and CAPRICOR. He receives royalty payments from a CPET book from Wolters Kluwer. He is a paid consultant for Genentech, Verona and Regeneron. He owns stock in HIA. The current study was funded by the Pulmonary Education and Research Foundation.