Category Archives: Publications

Unexplained exertional dyspnea caused by low ventricular filling pressures: results from clinical invasive cardiopulmonary exercise testing

Pulmonary Circulation, March 2016, Vol. 6 Issue: Number 1
p55-62, 8p;

Abstract: To determine whether low ventricular filling
pressures are a clinically relevant etiology of unexplained dyspnea on
exertion, a database of 619 consecutive, clinically indicated invasive
cardiopulmonary exercise tests (iCPETs) was reviewed to identify
patients with low maximum aerobic capacity (V̇o2max) due to inadequate
peak cardiac output (Qtmax) with normal biventricular ejection
fractions and without pulmonary hypertension (impaired: n= 49, V̇o2max
= 53% predicted [interquartile range (IQR): 47%–64%], Qtmax = 72%
predicted [62%–76%]). These were compared to patients with a normal
exercise response (normal: n= 28, V̇o2max = 86% predicted [84%–97%],
Qtmax = 108% predicted [97%–115%]). Before exercise, all patients
received up to 2 L of intravenous normal saline to target an upright
pulmonary capillary wedge pressure (PCWP) of ≥5 mmHg. Despite this
treatment, biventricular filling pressures at peak exercise were lower
in the impaired group than in the normal group (right atrial pressure
[RAP]: 6 [IQR: 5–8] vs. 9 [7–10] mmHg, P= 0.004; PCWP: 12 [10–16] vs.
17 [14–19] mmHg, P< 0.001), associated with decreased stroke volume
(SV) augmentation with exercise (+13 ± 10 [standard deviation (SD)] vs.
+18 ± 10 mL/m2, P= 0.014). A review of hemodynamic data from 23
patients with low RAP on an initial iCPET who underwent a second iCPET
after saline infusion (2.0 ± 0.5 L) demonstrated that 16 of 23 patients
responded with increases in Qtmax ([+24% predicted [IQR: 14%–34%]),
V̇o2max (+10% predicted [7%–12%]), and maximum SV (+26% ± 17% [SD]).
These data suggest that inadequate ventricular filling related to low
venous pressure is a clinically relevant cause of exercise

Exercise Testing: Who, When, and Why?

Nelson, Nicole; Asplund,
Chad A.. PM&R:

Journal of Injury Function and Rehabilitation, March
2016, Vol. 8 Issue: Number 3, Number 3 Supplement 1 pS16-S23, 8p;

Abstract: There are different modalities of exercise testing that can
provide valuable information to physicians about patient and athlete
fitness and cardiopulmonary status. Cardiopulmonary exercise testing
(CPX) is a form of exercise testing that measures ventilatory and gas
exchange, heart rate, electrocardiogram, and blood pressures to provide
detailed information on the cardiovascular, pulmonary, and muscular
systems. This testing allows an accurate quantification of functional
capacity/measure of exercise tolerance, diagnosis of cardiopulmonary
disease, disease-progression monitoring or response to intervention,
and the prescription of exercise and training. CPX directly measures
inhaled and exhaled ventilator gases to determine the maximal oxygen
uptake, which reflects the body’s maximal use of oxygen and defines the
limits of the cardiopulmonary system.

Randomized clinical trial of prehabilitation before planned liver resection

Dunne, D. F. J.; Jack, S.; Jones, R. P.; Jones, L.;
Lythgoe, D. T.; Malik, H. Z.; Poston, G. J.; Palmer, D. H.; Fenwick, S.

British Journal of Surgery: BJS, April 2016, Vol. 103 Issue: Number
5 p504-512, 9p;

Abstract: Patients with low fitness as assessed by
cardiopulmonary exercise testing (CPET) have higher mortality and
morbidity after surgery. Preoperative exercise intervention, or
prehabilitation, has been suggested as a method to improve CPETvalues
and outcomes. This trial sought to assess the capacity of a 4‐week
supervised exercise programme to improve fitness before liver resection
for colorectal liver metastasis. This was a randomized clinical trial
assessing the effect of a 4‐week (12 sessions) high‐intensity cycle,
interval training programme in patients undergoing elective liver
resection for colorectal liver metastases. The primary endpoint was
oxygen uptake at the anaerobic threshold. Secondary endpoints included
other CPETvalues and preoperative quality of life (QoL) assessed using
the SF‐36®. Thirty‐eight patients were randomized (20 to
prehabilitation, 18 to standard care), and 35 (25 men and 10 women)
completed both preoperative assessments and were analysed. The median
age was 62 (i.q.r. 54–69) years, and there were no differences in
baseline characteristics between the two groups. Prehabilitation led to
improvements in preoperative oxygen uptake at anaerobic threshold (+1·5
(95 per cent c.i. 0·2 to 2·9) ml per kg per min) and peak exercise
(+2·0 (0·0 to 4·0) ml per kg per min). The oxygen pulse (oxygen uptake
per heart beat) at the anaerobic threshold improved (+0·9 (0·0 to 1·8)
ml/beat), and a higher peak work rate (+13 (4 to 22) W) was achieved.
This was associated with improved preoperative QoL, with the overall
SF‐36® score increasing by 11 (95 per cent c.i. 1 to 21) (P= 0·028) and
the overall SF‐36® mental health score by 11 (1 to 22) (P= 0·037). A
4‐week prehabilitation programme can deliver improvements in CPETscores
and QoLbefore liver resection. This may impact on perioperative

Validation of preoperative cardiopulmonary exercise testing-derived variables to predict in-hospital morbidity after major colorectal surgery

M. A. West R. Asher, M. Browning, G. Minto, M. Swart, K. Richardson,
L. McGarrity, S. Jack and M. P. W. Grocott on behalf of the Perioperative Exercise Testing
and Training Society

British Journal Surgery 2016 (On line)

BACKGROUND: In single-centre studies, postoperative complications are associated with reduced fitness. This study explored the relationship between cardiorespiratory fitness variables derived by cardiopulmonary exercise testing (CPET) and in-hospital morbidity after major elective colorectal surgery. METHODS: Patients underwent preoperative CPET with recording of in-hospital morbidity. Receiver operating characteristic (ROC) curves and logistic regression were used to assess the relationship between CPET variables and postoperative morbidity. RESULTS: Seven hundred and three patients from six centres in the UK were available for analysis (428 men, 275 women). ROC curve analysis of oxygen uptake at estimated lactate threshold (V o2 at theta^L ) and at peak exercise (V o2peak ) gave an area under the ROC curve (AUROC) of 0.79 (95 per cent c.i. 0.76 to 0.83; P < 0.001; cut-off 11.1 ml per kg per min) and 0.77 (0.72 to 0.82; P < 0.001; cut-off 18.2 ml per kg per min) respectively, indicating that they can identify patients at risk of postoperative morbidity. In a multivariable logistic regression model, selected CPET variables and body mass index (BMI) were associated significantly with increased odds of in-hospital morbidity (V o2 at theta^L 11.1 ml per kg per min or less: odds ratio (OR) 7.56, 95 per cent c.i. 4.44 to 12.86, P < 0.001; V o2peak 18.2 ml per kg per min or less: OR 2.15, 1.01 to 4.57, P = 0.047; ventilatory equivalents for carbon dioxide at estimated lactate threshold (V E /V co2 at theta^L ) more than 30.9: OR 1.38, 1.00 to 1.89, P = 0.047); BMI exceeding 27 kg/m2 : OR 1.05, 1.03 to 1.08, P < 0.001). A laparoscopic procedure was associated with a decreased odds of complications (OR 0.30, 0.02 to 0.44; P = 0.033). This model was able to discriminate between patients with, and without in-hospital morbidity (AUROC 0.83, 95 per cent c.i. 0.79 to 0.87). No adverse clinical events occurred during CPET across the six centres. CONCLUSION: These data provide further evidence that variables derived from preoperative CPET can be used to assess risk before elective colorectal surgery.

Preoperative Nutrition and Prehabilitation

Gupta, Ruchir; Gan, Tong J..

Anesthesiology Clinics, March 2016, Vol. 34 Issue: Number 1
p143-153, 11p;

Abstract: Enhanced recovery after surgery is the natural
evolution of what were previously referred to as fast track programs
and seeks to implement a series of interventions to improve and enhance
recovery after major surgical procedures. Two important preoperative
aspects are nutrition and prehabilitation. Identifying nutritionally
deficient patients allows preoperative intervention to optimize their
nutritional status. The contribution of cardiopulmonary exercise
testing to the evaluation of perioperative risk, subsequent development
of a training program, and the use of indices to risk stratify and
measure improvement after a training program allow a personalized
preoperative program to be developed for each patient.

Cardiopulmonary exercise testing is predictive of return to work in cardiac patients after multicomponent rehabilitation

Salzwedel, Annett; Reibis, Rona; Wegscheider, Karl; Eichler, Sarah; Buhlert,
Hermann; Kaminski, Stefan; Völler, Heinz.

Clinical Research in Cardiology, March 2016, Vol. 105 Issue: Number 3 p257-267, 11p;

Abstract: Return to work (RTW) is  a pivotal goal of cardiac
rehabilitation (CR) in patients after acute cardiac event. We aimed to
evaluate cardiopulmonary exercise testing (CPX) parameters as
predictors for RTW at discharge after CR.                   We analyzed
data from a registry of 489 working-age patients (51.5 ± 6.9 years,
87.9 % men) who had undergone inpatient CR predominantly after
percutaneous coronary intervention (PCI 62.6 %), coronary artery bypass
graft (CABG 17.2 %), or heart valve replacement (9.0 %).
Sociodemographic and clinical parameters, noninvasive cardiac
diagnostic (2D echo, exercise ECG, 6MWT) and psychodiagnostic screening
data, as well as CPX findings, were merged with RTW data from the
German statutory pension insurance program and analyzed for prognostic
ability.                   During a mean follow-up of
26.5 ± 11.9 months, 373 (76.3 %) patients returned to work, 116
(23.7 %) did not, and 60 (12.3 %) retired. After adjustment for
covariates, elective CABG (HR 0.68, 95 % CI 0.47–0.98; p= 0.036) and
work intensity (per level HR 0.83, 95 % CI 0.73-0.93; p= 0.002) were
negatively associated with the probability of RTW. Exercise capacity in
CPX (in Watts) and the VE/VCO2-slope had independent prognostic
significance for RTW. A higher work load increased (HR 1.17, 95 % CI
1.02–1.35; p= 0.028) the probability of RTW, while a higher
VE/VCO2slope decreased (HR 0.85, 95 % CI 0.76–0.96; p= 0.009) it. CPX
also had prognostic value for retirement: the likelihood of retirement
decreased with increasing exercise capacity (HR 0.50, 95 % CI
0.30–0.82; p= 0.006).

CPX is a valid tool for
assessing patients’ ability to return to work. Therefore, it may be an
essential part of functional assessment during CR for predicting
participation in employment.

Phenotyping Exercise Limitation in Systemic Sclerosis: The Use of Cardiopulmonary Exercise Testing

Boutou, Afroditi K.; Pitsiou,
Georgia G.; Siakka, Panagiota; Dimitroulas, Theodoros; Paspala,
Asimina; Sourla, Evdokia; Chavouzis, Nikolaos; Garyfallos, Alexandros;
Argyropoulou, Paraskevi; Stanopoulos, Ioannis.

Respiration, February  2016, Vol. 91 Issue: Number 2 p115-123, 9p;

AbstractBackground:Exercise impairment is a common symptom of systemic
sclerosis (SSc), a disorder which is frequently complicated by
cardiopulmonary involvement.

Objectives:This study’s aims were: (a) to
define the prevalence and the potential causes of limited exercise
capacity and (b) to study potential differences in clinical,
radiological and functional characteristics and blood serology among
SSc patients with exercise limitation of different etiology.
Methods:Prospectively collected data on SSc patients who had conducted
full lung function testing, blood serology, thorax high-resolution
computed tomography, Doppler echocardiogram and a maximal
cardiopulmonary exercise testing (CPET) were retrospectively analyzed.
Using a CPET algorithm, patients were characterized as having normal or
subnormal exercise capacity (N), respiratory limitation (RL), left
ventricular dysfunction (LVD) or pulmonary vasculopathy (PV). Group
comparisons were conducted using either one-way ANOVA or the
Kruskal-Wallis test. A p value <0.05 was considered significant.
Results:The study population consisted of 78 patients (53.7 ± 13.7
years old; 10.3 male). PV was present in 32.1, LVD in 25.6 and RL in
10.2, while 32.1 of the patients constituted the N group. The presence
of antisclero-70 antibodies, low anaerobic threshold and low peak
exercise capacity measures could discriminate LVD from the other
groups. Low end-tidal carbon dioxide pressure and its change from rest
to anaerobic threshold could discriminate between the PV, LVD and N
groups, while respiratory restriction along with ventilatory
inefficiency indices could differentiate the RL group from the rest.

Conclusions:The combined evaluation of CPET gas exchange patterns with
baseline measurements could discriminate the causes of exercise
limitation among SSc patients.

Role of cardiopulmonary exercise testing as a risk-assessment method in patients undergoing intra-abdominal surgery: a systematic review

Moran J, Wilson F, Guinan E, McCormick P, Hussey J, Moriarty J.

Br J Anaesth. 2016;116(2):177-91.

BACKGROUND: Cardiopulmonary exercise testing (CPET) is used as a preoperative risk-stratification tool for patients undergoing non-cardiopulmonary intra-abdominal surgery. Previous studies indicate that CPET may be beneficial, but research is needed to quantify CPET values protective against poor postoperative outcome [mortality, morbidity, and length of stay (LOS)].

METHODS: This systematic review aimed to assess the ability of CPET to predict postoperative outcome. The following databases were searched: PubMed, EMBASE, PEDro, The Cochrane Library, Cinahl, and AMED. Thirty-seven full-text articles were included. Data extraction included the following: author, patient characteristics, setting, surgery type, postoperative outcome measure, and CPET outcomes.

RESULTS: Surgeries reviewed were hepatic transplant and resection (n=7), abdominal aortic aneurysm (AAA) repair (n=5), colorectal (n=6), pancreatic (n=4), renal transplant (n=2), upper gastrointestinal (n=4), bariatric (n=2), and general intra-abdominal surgery (n=12). Cardiopulmonary exercise testing-derived cut-points, peak oxygen consumption ([Formula: see text]), and anaerobic threshold (AT) predicted the following postoperative outcomes: 90 day-3 yr survival (AT 9-11 ml kg(-1) min(-1)) and intensive care unit admission (AT <9.9-11 ml kg(-1) min(-1)) after hepatic transplant and resection, 90 day survival after AAA repair ([Formula: see text] 15 ml kg(-1) min(-1)), LOS and morbidity after pancreatic surgery (AT <10-10.1 ml kg(-1) min(-1)), and mortality and morbidity after intra-abdominal surgery (AT 10.9 and <10.1 ml kg(-1) min(-1), respectively).

CONCLUSION: Cardiopulmonary exercise testing is a useful preoperative risk-stratification tool that can predict postoperative outcome. Further research is needed to justify the ability of CPET to predict postoperative outcome in renal transplant, colorectal, upper gastrointestinal, and bariatric surgery.

Does a 20-week aerobic exercise training programme increase our capabilities to buffer real-life stressors? A randomized, controlled trial using ambulatory assessment

Haaren, Birte; Ottenbacher, Joerg;
Muenz, Julia; Neumann, Rainer; Boes, Klaus; Ebner-Priemer, Ulrich.

European Journal of Applied Physiology, February 2016, Vol. 116 Issue:
Number 2 p383-394, 12p;

Abstract: The cross-stressor adaptation
hypothesis suggests that regular exercise leads to adaptations in the
stress response systems that induce decreased physiological responses
to psychological stressors. Even though an exercise intervention to
buffer the detrimental effects of psychological stressors on health
might be of utmost importance, empirical evidence is mixed. This may be
explained by the use of cross-sectional designs and non-personally
relevant stressors. Using a randomized controlled trial, we
hypothesized that a 20-week aerobic exercise training does reduce
physiological stress responses to psychological real-life stressors in
sedentary students.   Sixty-one students were  randomized to either a
control group or an exercise training group. The
academic examination period (end of the semester) served as a real-life
stressor. We used ambulatory assessment methods to assess physiological
stress reactivity of the autonomic nervous system (heart rate
variability: LF/HF, RMSSD), physical activity and perceived stress
during 2 days of everyday life and multilevel models for data analyses.
Aerobic capacity (VO2max) was assessed pre- and post-intervention via
cardiopulmonary exercise testing to analyze the effectiveness of the
intervention.   During real-life stressors, the exercise training group
showed significantly reduced LF/HF (β= −0.15,
t= −2.59, p= .01) and increased RMSSD (β= 0.15, t= 2.34, p= .02)
compared to the control group.
Using a randomized
controlled trial and a real-life stressor, we could show that exercise
appears to be a useful preventive strategy to buffer the effects of
stress on the autonomic nervous system, which might result into
detrimental health outcomes.

Impact of training methods and patient characteristics on exercise capacity in patients in cardiovascular rehabilitation

Reibis, Rona;
Salzwedel, Annett; Buhlert, Hermann; Wegscheider, Karl; Eichler, Sarah;
Völler, Heinz.

European Journal of Preventive Cardiology, March 2016,
Vol. 23 Issue: Number 5 p452-459, 8p;

Abstract: Aim  We aimed to
identify patient characteristics and comorbidities that correlate with
the initial exercise capacity of cardiac rehabilitation (CR) patients
and to study the significance of patient characteristics, comorbidities
and training methods for training achievements and final fitness of CR
patients.Methods  We studied 557 consecutive patients (51.7 ± 6.9
years; 87.9% men) admitted to a three-week in-patient CR.
Cardiopulmonary exercise testing (CPX) was performed at discharge.
Exercise capacity (watts) at entry, gain in training volume and final
physical fitness (assessed by peak O2utilization (VO2peak) were
analysed using analysis of covariance (ANCOVA) models.Results  Mean
training intensity was 90.7 ± 9.7% of maximum heart rate (81%
continuous/19% interval training, 64% additional strength training). A
total of 12.2 ± 2.6 bicycle exercise training sessions were performed.
Increase of training volume by an average of more than 100% was
achieved (difference end/beginning of CR: 784 ± 623 watts × min). In
the multivariate model the gain in training volume was significantly
associated with smoking, age and exercise capacity at entry of CR. The
physical fitness level achieved at discharge from CR as assessed by
VO2peakwas mainly dependent on age, but also on various factors related
to training, namely exercise capacity at entry, increase of training
volume and training method.

Conclusion  CR patients were trained in line
with current guidelines with moderate-to-high intensity and reached a
considerable increase of their training volume. The physical fitness
level achieved at discharge from CR depended on various factors
associated with training, which supports the recommendation that CR
should be offered to all cardiac patients.