Category Archives: Abstracts

Cardiopulmonary exercise testing for identification of patients with hyperventilation syndrome.

Brat K(, Stastna N, Merta Z, Olson LJ, Johnson BD, CundrleI Jr

PLoS One. 2019 Apr 23;14(4):e0215997. doi: 10.1371/journal.pone.0215997.
eCollection 2019

INTRODUCTION: Measurement of ventilatory efficiency, defined as minute
ventilation per unit carbon dioxide production (VE/VCO2), by cardiopulmonary
exercise testing (CPET) has been proposed as a screen for hyperventilation
syndrome (HVS). However, increased VE/VCO2 may be associated with other disorders
which need to be distinguished from HVS. A more specific marker of HVS by CPET
would be clinically useful. We hypothesized ventilatory control during exercise
is abnormal in patients with HVS.
METHODS: Patients who underwent CPET from years 2015 through 2017 were
retrospectively identified and formed the study group. HVS was defined as dyspnea
with respiratory alkalosis (pH >7.45) at peak exercise with absence of acute or
chronic respiratory, heart or psychiatric disease. Healthy patients were selected
as controls. For comparison the Student t-test or Mann-Whitney U test were used.
Data are summarized as mean ± SD or median (IQR); p<0.05 was considered
significant.
RESULTS: Twenty-nine patients with HVS were identified and 29 control subjects
were selected. At rest, end-tidal carbon dioxide (PETCO2) was 27 mmHg (25-30) for
HVS patients vs. 30 mmHg (28-32); in controls (p = 0.05). At peak exercise PETCO2
was also significantly lower (27 ± 4 mmHg vs. 35 ± 4 mmHg; p<0.01) and VE/VCO2
higher ((38 (35-43) vs. 31 (27-34); p<0.01)) in patients with HVS. In contrast to
controls, there were minimal changes of PETCO2 (0.50 ± 5.26 mmHg vs. 6.2 ± 4.6
mmHg; p<0.01) and VE/VCO2 ((0.17 (-4.24-6.02) vs. -6.6 (-11.4-(-2.8)); p<0.01))
during exercise in patients with HVS. The absence of VE/VCO2 and PETCO2 change
during exercise was specific for HVS (83% and 93%, respectively).
CONCLUSION: Absence of VE/VCO2 and PETCO2 change during exercise may identify
patients with HVS.

The association between preoperative cardiopulmonary exercise-test variables and short-term morbidity after esophagectomy: A hospital-based cohort study.

Lam S, Alexandre L, Hardwick G, Hart AR

Surgery. 2019 Apr 10. pii: S0039-6060(19)30058-3. doi:
10.1016/j.surg.2019.02.001. [Epub ahead of print]

BACKGROUND: Postoperative complications after esophagectomy are thought to be
associated with reduced fitness. This observational study explored the
associations between aerobic fitness, as determined objectively by preoperative
cardiopulmonary exercise testing (CPEX), and 30-day morbidity after
esophagectomy.
METHODS: We retrospectively identified 254 consecutive patients who underwent
esophagectomy at a single academic teaching hospital between September 2011 and
March 2017. Postoperative complication data were measured using the Esophageal
Complications Consensus Group definitions and graded using the Clavien-Dindo
classification system of severity (blinded to cardiopulmonary exercise testing
values). Associations between preoperative cardiopulmonary exercise testing
variables and postoperative outcomes were estimated using logistic regression.
RESULTS: A total of 206 patients (77% male) were included in the analyses, with a
mean age of 67 years (SD 9). The mean values for the maximal oxygen consumed at
the peak of exercise (VO2peak) and the anaerobic threshold were 21.1 mL/kg/min
(SD 4.5) and 12.4 mL/kg/min (SD 2.8), respectively. The vast majority of patients
(98.5%) had malignant disease-predominantly adenocarcinoma (84.5%), for which
most received neoadjuvant chemotherapy (79%) and underwent minimally invasive
Ivor Lewis esophagectomy (53%). Complications at postoperative day 30 occurred in
111 patients (54%), the majority of which were cardiopulmonary (72%). No
associations were found between preoperative cardiopulmonary exercise testing
variables and morbidity for either VO2peak (OR 1.00, 95% CI 0.94-1.07) or
anaerobic threshold (OR 0.98, 95% CI 0.89-1.09).
CONCLUSION: Preoperative cardiopulmonary exercise testing variables were not
associated with 30-day complications after esophagectomy. The findings do not
support the use of cardiopulmonary exercise testing as an isolated preoperative
screening tool to predict short-term morbidity after esophagectomy. This modestly
sized observational work highlights the need for larger studies examining
associations between preoperative cardiopulmonary exercise testing and outcomes
after esophagectomy to look for consistency in our findings.

Effect of prehabilitation on ventilatory efficiency in non-small cell lung cancer patients: A cohort study.

Gravier FE, Bonnevie T, Boujibar F, Médrinal C, Prieur G, Combret Y, Muir JF, Cuvelier A, Baste JM, Debeaumont D

J Thorac Cardiovasc Surg. 2019 Feb 19. pii: S0022-5223(19)30448-9

OBJECTIVE: Cardiopulmonary exercise testing (CPET) for patients awaiting lung
resection for non-small cell lung cancer (NSCLC) has developed considerably in
recent years. Pulmonary rehabilitation before surgery (prehabilitation) improves
postoperative risk factors such as forced expiratory volume in 1 second and peak
oxygen consumption (VO2peak). Ventilatory inefficiency assessed according to the
linear regression of the ratio between the increase in minute ventilation and the
expired carbon dioxide flow during CPET (VE/VCO2 slope) >35, is a high-risk
factor for postoperative complications. Our objective was to assess the effect of
prehabilitation on VE/VCO2 slope, and its relationship with VO2peak.
METHODS: This retrospective cohort study was performed between January 1, 2014
and December 31, 2017 at Rouen University Hospital. One hundred fifty-two
patients with NSCLC awaiting lung surgery who underwent CPET were screened. A
total of 50 patients who underwent CPET before and after prehabilitation were
included.
RESULTS: VE/VCO2 slope did not change significantly after prehabilitation
(median, 37.1 [25th-75th percentile, 33.8-43.4] vs median, 35.4 [25th-75th
percentile, 31.1-40.5]; P = .09), whereas VO2peak increased significantly (from a
median of 13.2 [25th-75th percentile, 11.9-14.7] to a median of 14.8 [25th-75th
percentile, 13.1-16.4] mL/kg/min). The number of patients with a high risk of
postoperative complications (ie, VE/VCO2 slope >35) did not change significantly
after prehabilitation. Cardiorespiratory parameters improved significantly more
in patients who underwent at least 15 sessions of ambulatory prehabilitation.
CONCLUSIONS: VE/VCO2 slope, a known predictor of favorable surgical outcomes in
patients with NSCLC, did not change with the prehabilitation program used in this
study, despite clear improvements in VO2peak and other CPET measures. Larger,
prospective studies are needed to confirm the results of this study.

Effect of carvedilol on heart rate response to cardiopulmonary exercise up to the anaerobic threshold in patients with subacute myocardial infarction.

Nemoto S; Kasahara Y; Izawa KP; Watanabe S; Yoshizawa K; Takeichi N; Kamiya K; Suzuki N; Omiya K; Matsunaga A; Akashi YJ;

Heart And Vessels [Heart Vessels] 2019 Jan 02. Date of Electronic Publication: 2019 Jan 02.

Resting heart rate (HR) plus 20 or 30 beats per minute (bpm), i.e., a simplified substitute for HR at the anaerobic threshold (AT), is used as a tool for exercise prescription without cardiopulmonary exercise testing data. While resting HR plus 20 bpm is recommended for patients undergoing beta-blocker therapy, the effects of specific beta blockers on HR response to exercise up to the AT (ΔAT HR) in patients with subacute myocardial infarction (MI) are unclear. This study examined whether carvedilol treatment affects ΔAT HR in subacute MI patients. MI patients were divided into two age- and sex-matched groups [carvedilol (+), n = 66; carvedilol (-), n = 66]. All patients underwent cardiopulmonary exercise testing at 1 month after MI onset. ΔAT HR was calculated by subtracting resting HR from HR at AT. ΔAT HR did not differ significantly between the carvedilol (+) and carvedilol (-) groups (35.64 ± 9.65 vs. 34.67 ± 11.68, P = 0.604). Multiple regression analysis revealed that old age and heart failure after MI were significant predictors of lower ΔAT HR (P = 0.039 and P = 0.013, respectively), but not carvedilol treatment. Our results indicate that carvedilol treatment does not affect ΔAT HR in subacute MI patients. Therefore, exercise prescription based on HR plus 30 bpm may be feasible in this patient population, regardless of carvedilol use, without gas-exchange analysis data.

Cardiorespiratory fitness data from 18,189 participants who underwent treadmill cardiopulmonary exercise testing in a Brazilian population.

Rossi Neto JM; Tebexreni AS; Alves ANF; Smanio PEP; de Abreu FB; Thomazi MC; Nishio PA; Cuninghant IA;

Plos One [PLoS One] 2019 Jan 09; Vol. 14 (1), pp. e0209897. Date of Electronic Publication: 20190109 (Print Publication: 2019).

Purpose: Cardiorespiratory fitness is inversely associated with a high risk of cardiovascular disease, all-cause mortality, and mortality attributable to various cancers. It is often estimated indirectly using mathematical formulas for estimating oxygen uptake. Cardiopulmonary exercise testing, especially oxygen uptake, represents the “gold standard” for assessing exercise capacity. The purpose of this report was to develop reference standards for exercise capacity by establishing cardiorespiratory fitness values derived from cardiopulmonary exercise testing in a Brazilian population. We focused on oxygen uptake standards and compared the maximal oxygen uptake [mLO2·kg-1·min-1] values with those in the existing literature.
Methods: A database was constructed using reports from cardiopulmonary exercise testing performed at Fleury laboratory. The final cohort included 18,189 individuals considered to be free of structural heart disease. Percentiles of maximal oxygen uptake for men and women were determined for six age groups between 7 and 84 years. We compared the values with existing reference data from patients from Norway and the United States.
Results: There were significant differences in maximal oxygen uptake between sexes and across the age groups. In our cohort, the 50th percentile maximal oxygen uptake values for men and women decreased from 44.7 and 36.3 mLO2·kg-1·min-1 to 28.4 and 22.3 mLO2·kg-1·min-1 for patients aged 20-29 years to patients aged 60-69 years, respectively. For each age group, both Norwegian men and women had greater cardiorespiratory fitness than cohorts in the United States and Brazil.
Conclusion: To our knowledge, our analysis represents the largest reference data for cardiorespiratory fitness based on treadmill cardiopulmonary exercise testing. Our findings provide reference values of maximal oxygen uptake measurements from treadmill tests in Brazilian populations that are more accurate than previous standard values based on workload-derived estimations. This data may also add information to the global data used for the interpretation of cardiorespiratory fitness.

A cross-sectional survey of Australian anesthetists’ and surgeons’ perceptions of preoperative risk stratification and prehabilitation.

Li MH; Bolshinsky V;Ismail H; Burbury K; Ho KM; Amin B; Heriot A; Riedel B;

Canadian Journal Of Anaesthesia = Journal Canadien D’anesthesie [Can J Anaesth] 2019 Apr; Vol. 66 (4), pp. 388-405. Date of Electronic Publication: 2019 Jan 28.

Purpose: Preoperative fitness training has been listed as a top ten research priority in anesthesia. We aimed to capture the current practice patterns and perspectives of anesthetists and colorectal surgeons in Australia and New Zealand regarding preoperative risk stratification and prehabilitation to provide a basis for implementation research.
Methods: During 2016, we separately surveyed fellows of the Australian and New Zealand College of Anaesthetists (ANZCA) and members of the Colorectal Society of Surgeons in Australia and New Zealand (CSSANZ). Our outcome measures investigated the responders’ demographics, practice patterns, and perspectives. Practice patterns examined preoperative assessment and prehabilitation utilizing exercise, hematinic, and nutrition optimization.
Results: We received 155 responses from anesthetists and 71 responses from colorectal surgeons. We found that both specialty groups recognized that functional capacity was linked to postoperative outcome; however, fewer agreed that robust evidence exists for prehabilitation. Prehabilitation in routine practice remains low, with significant potential for expansion. The majority of anesthetists do not believe their patients are adequately risk stratified before surgery, and most of their colorectal colleagues are amenable to delaying surgery for at least an additional two weeks. Two-thirds of anesthetists did not use cardiopulmonary exercise testing as they lacked access. Hematinic and nutritional assessment and optimization is less frequently performed by anesthetists compared with their colorectal colleagues.
Conclusions: An unrecognized potential window for prehabilitation exists in the two to four weeks following cancer diagnosis. Early referral, larger multi-centre studies focusing on long-term outcomes, and further implementation research are required.

Heart failure prognosis over time: how the prognostic role of oxygen consumption and ventilatory efficiency during exercise has changed in the last 20 years.

Paolillo S; Veglia F; Salvioni E; MECKI Score Research Group

European Journal Of Heart Failure [Eur J Heart Fail] 2019 Feb; Vol. 21 (2), pp. 208-217. Date of Electronic Publication: 2019 Jan 11.

Aims: Exercise-derived parameters, specifically peak exercise oxygen uptake (peak VO2 ) and minute ventilation/carbon dioxide relationship slope (VE/VCO2 slope), have a pivotal prognostic value in heart failure (HF). It is unknown how the prognostic threshold of peak VO2 and VE/VCO2 slope has changed over the last 20 years in parallel with HF prognosis improvement.
Methods and Results: Data from 6083 HF patients (81% male, age 61 ± 13 years), enrolled in the MECKI score database between 1993 and 2015, were retrospectively analysed. By enrolment year, four groups were generated: group 1 1993-2000 (n = 440), group 2 2001-2005 (n = 1288), group 3 2006-2010 (n = 2368), and group 4 2011-2015 (n = 1987). We compared the 10-year survival of groups and analysed how the overall risk (cardiovascular death, urgent heart transplantation, or left ventricular assist device implantation) changed over time according to peak VO2 and VE/VCO2 slope and to major clinical and therapeutic variables. At 10 years, a progressively higher survival from group 1 to group 3 was observed, with no further improvement afterwards. A 20% risk for peak VO2 15 mL/min/kg (95% confidence interval 16-13), 9 (11-8), 4 (4-2) and 5 (7-4) was observed in group 1, 2, 3, and 4, respectively, while the VE/VCO2 slope value for a 20% risk was 32 (37-29), 47 (51-43), 59 (64-55), and 57 (63-52), respectively.
Conclusions: Heart failure prognosis improved over time up to 2010 in a HF population followed by experienced centres. The peak VO2 and VE/VCO2 slope cut-offs identifying a definite risk progressively decreased and increased over time, respectively. The prognostic threshold of peak VO2 and VE/VCO2 slope must be updated whenever HF prognosis improves.
(© 2019 The Authors. European Journal of Heart Failure © 2019 European Society of Cardiology.)

 

Role of Advanced Testing: Invasive Hemodynamics, Endomyocardial Biopsy, and Cardiopulmonary Exercise Testing.

Lanier GM; Fallon JT; Naidu SS;

Cardiology Clinics [Cardiol Clin] 2019 Feb; Vol. 37 (1), pp. 73-82. Date of Electronic Publication: 2018 Oct 29.

Hypertrophic cardiomyopathy affects 0.5% of the population. Advanced testing is considered, including cardiac catheterization, endomyocardial biopsy, and cardiopulmonary exercise testing. Right and left heart catheterization provides essential hemodynamic data, identifies patients who might benefit from septal reduction therapy, and assesses for comorbidities. Pathologic analysis reveals ventricular hypertrophy, myocardial disarray, and endocardial and interstitial fibrosis. Routine endomyocardial biopsy is not recommended unless other conditions that cause hypertrophy need to be ruled out. Cardiopulmonary exercise testing provides useful physiologic data, allows monitoring of the response to medication and surgical interventions, estimates prognosis, and guides referral for orthotopic heart transplantation.

Functional outcome in contemporary children and young adults with tetralogy of Fallot after repair.

Hock J; Häcker AL; Reiner B; Oberhoffer R; Hager A; Ewert P; Müller J;

Archives Of Disease In Childhood [Arch Dis Child] 2019 Feb; Vol. 104 (2), pp. 129-133. Date of Electronic Publication: 2018 Jul 03.

Objective: Functional outcome measures are of growing importance in the aftercare of patients with congenital heart disease. This study addresses the functional status with regard to exercise capacity, health-related physical fitness (HRPF) and arterial stiffness in a recent cohort of children, adolescents and young adults with tetralogy of Fallot (ToF) after repair.
Design: Single-centre, uncontrolled and prospective cohort study.
Setting: Outpatient department of the German Heart Centre Munich; July 2014-January 2018.
Patients: One hundred and six patients with ToF after repair (13.5±3.7 years, 40 females) were included. Data were compared with a recent cohort of healthy controls (HCs) (n=1700, 12.8±2.6 years, 833 females).
Main Outcome Measures: Patients underwent a symptom-limited cardiopulmonary exercise test, performed an HRPF test (FitnessGram) and had an assessment of their arterial stiffness (Mobil-O-Graph).
Results: Compared with HC, patients with ToF showed lower predicted [Formula: see text]O2 peak (ToF: 80.4% ± 16.8% vs HC: 102.6% ± 18.1%, p<0.001), impaired ventilatory efficiency (ToF: 29.6 ± 3.6 vs HC: 27.4 ± 2.9, p<0.001), chronotropic incompetence (ToF: 167 ± 17 bpm vs HC: 190 ± 17 bpm, p<0.001) and reduced HRPF (ToF z-score: -0.65 ± 0.87 vs HC z-score: 0.03 ± 0.65, p<0.001). Surrogates of arterial stiffness, central and peripheral systolic blood pressure, did not differ between the two groups.
Conclusions: Contemporary children, adolescents and young adults with ToF still have functional limitations. How impaired HRPF and limited exercise capacity interact and how they can be modified needs to be evaluated in further intervention studies.

Value of combined cardiopulmonary and echocardiography stress test to characterize the haemodynamic and metabolic responses of patients with heart failure and mid-range ejection fraction.

Pugliese NR; Fabiani I; Santini C; Rovai I; Pedrinelli R; Natali A; Dini FL;

European Heart Journal Cardiovascular Imaging [Eur Heart J Cardiovasc Imaging] 2019 Feb 11. Date of Electronic Publication: 2019 Feb 11.

Aims: To characterize heart failure (HF) with mid-range ejection fraction (HFmrEF), combining cardiopulmonary exercise test, and exercise stress echocardiography.
Methods and results: We studied 169 consecutive subjects (age 62.3 ± 11 years; 74% male): 30 healthy controls, 45 patients with HF and preserved EF (HFpEF), 40 HFmrEF, and 54 with HF and reduced EF (HFrEF). Left ventricular (LV) stroke volume (SV), EF, elastance, global longitudinal strain, E/E’, oxygen consumption (VO2), and arterial-venous oxygen content difference (AVO2diff) were measured in all exercise stages. HFmrEF revealed baseline features intermediate between HFrEF and HFpEF, except for B-type natriuretic peptide levels, which was similar to HFpEF and significantly lower than HFrEF. Peak VO2 was not significantly different between HF groups. HFrEF exhibited a significantly lower peak SV as compared to either HFpEF or HFmrEF (74.3 ± 21.8 mL vs. 88.0 ± 17.4 mL and 96.5 ± 25.1 mL; P < 0.01), whereas peak heart rate was not significantly different between HF groups. A significantly reduced AVO2diff at peak exercise was apparent in HFpEF and HFmrEF (15.2 ± 3.3 mL/dL and 13.3 ± 4.2 mL/dL) vs. HFrEF (17.±6.6 mL/dL; P < 0.01), whereas no significant difference was reported between HFpEF and HFmrEF. Multivariate analysis in the overall population and all groups revealed peak parameters as independent predictors of peak VO2 (R2 = 0.90, P < 0.0001); AVO2diff showed the largest standardized regression coefficient.
Conclusion: In HFpEF and HFmrEF, effort intolerance is predominantly due to peripheral factors (AVO2diff), whereas in HFrEF peak VO2 is restricted by low increases in SV. Individual therapy according to which component of VO2 is more impaired is advisable.