Category Archives: Publications

Using predicted 30 day mortality to plan postoperative colorectal surgery care: a cohort study.

Swart M, Carlisle JB, Goddard J

Br J Anaesth. 2017 Jan;118(1):100-104. doi: 10.1093/bja/aew402.

BACKGROUND: Preoperative identification of high-risk surgical patients might help
to reduce postoperative morbidity and mortality. Using a patient’s predicted
30 day mortality to plan postoperative high-dependency unit (HDU) care after
elective colorectal surgery might be associated with reduced postoperative
morbidity.
METHODS: The 30 day postoperative mortality was predicted for 504 elective
colorectal surgical patients in a preoperative clinic. The prediction was used to
determine postoperative surgical ward or HDU care. Those with a predicted 30 day
mortality of 1-3% mortality, and thus deemed at intermediate risk, had either
planned HDU care (n=68) or planned ward care (n=139). The main outcome measures
were emergency laparotomy and unplanned critical care admission.
RESULTS: There were more emergency laparotomies and unplanned critical care
admissions in patients with a predicted 30 day mortality of 1-3% who went to an
HDU after surgery compared with patients who went to a ward: 0 vs 14 (10%),
P=0.0056 and 0 vs 22 (16%), P=0.0002, respectively.
CONCLUSIONS: Planned postoperative critical care was associated with a lower rate
of complications after elective colorectal surgery.

The Obesity Factor: How Cardiorespiratory Fitness is Estimated More Accurately in People with Obesity.

Königstein K, Klenk C, Rossmeissl A, Baumann S, Infanger D, Hafner
B, Hinrichs T, Hanssen H, Schmidt-Trucksäss A

Obesity (Silver Spring). 2018 Feb;26(2):291-298. doi: 10.1002/oby.22078. Epub
2017 Dec 12.

OBJECTIVE: Cardiopulmonary exercise testing is clinically used to estimate
cardiorespiratory fitness (CRF). The relation to total body mass (TBM) leads to
an underestimation of CRF in people with obesity and to inappropriate prognostic
and therapeutic decisions. This study aimed to determine body composition-derived
bias in the estimation of CRF in people with obesity.
METHODS: Two hundred eleven participants (58.8% women; mean BMI 35.7 kg/m2
[± 6.94; 20.7-58.6]) were clinically examined, and body composition (InBody720;
InBody Co., Ltd., Seoul, South Korea) and spiroergometrical peak oxygen
consumption (VO2 peak) were assessed. The impacts of TBM, lean body mass (LBM),
and skeletal muscle mass (SMM) on CRF estimates were analyzed by the application
of respective weight models. Linear regression and plotting of residuals against
BMI were performed on the whole study population and two subgroups (BMI < 30
kg/m2 and BMI ≥ 30 kg/m2 ).
RESULTS: For every weight model, Δmean VO2 peak (expected - measured) was
positive. LBM and SMM had a considerable impact on VO2 peak demand (P = 0.001;
ΔR2  = 2.3%; adjusted R2  = 56% and P = 0.001; ΔR2 = 2.7%; adjusted R2  = 56%),
whereas TBM did not. Confounding of body composition on VO2 peak did not differ
in LBM and SMM.
CONCLUSIONS: TBM-adjusted overestimation of relative VO2 demand is much higher in
people with obesity than in those without. LBM or SMM adjustment may be superior
alternatives, although small residual body composition-derived bias remains.

Determining Cardiorespiratory Fitness with Precision: Compendium of Findings from the FRIEND Registry.

Kaminsky LA; Myers J; Arena R;

Progress In Cardiovascular Diseases [Prog Cardiovasc Dis] 2018 Oct 29. Date of Electronic Publication: 2018 Oct 29.

Healthy living (HL) behaviors and characteristics are central to both preventing and treating a myriad of chronic diseases; a key HL characteristic is cardiorespiratory fitness (CRF). Knowing an individual’s CRF provides vital information when assessing health status and formulating a plan of care. Normative reference values as well as thresholds that denote varying degrees of health and future risk exist for measures of CRF. However, improving upon the precision of CRF reference standards according to key factors as well as precision in how CRF assessments can be used to assess health status and prognosis is needed. The current review will: 1) provide an overview of current approaches to CRF assessment and interpretations; 2) describe more recent efforts to improve upon the precision of CRF values; and 3) describe the Fitness Registry and the Importance of Exercise: A National Data Base (FRIEND) for the precision of CRF as a clinical measure.

High intensity interval training protects the heart during increased metabolic demand in patients with type 2 diabetes: a randomised controlled trial.

Suryanegara J; Cassidy S; Ninkovic V; Popovic D; Grbovic M; Okwose N; Trenell MI; MacGowan GG; Jakovljevic DG;

Acta Diabetologica [Acta Diabetol] 2018 Nov 01. Date of Electronic Publication: 2018 Nov 01.

Aim: The present study assessed the effect of high intensity interval training on cardiac function during prolonged submaximal exercise in patients with type 2 diabetes.
Methods: Twenty-six patients with type 2 diabetes were randomized to a 12 week of high intensity interval training (3 sessions/week) or standard care control group. All patients underwent prolonged (i.e. 60 min) submaximal cardiopulmonary exercise testing (at 50% of previously assess maximal functional capacity) with non-invasive gas-exchange and haemodynamic measurements including cardiac output and stroke volume before and after the intervention.
Results: At baseline (prior to intervention) there was no significant difference between the intervention and control group in peak exercise oxygen consumption (20.3 ± 6.1 vs. 21.7 ± 5.5 ml/kg/min, p = 0.21), and peak exercise heart rate (156.3 ± 15.0 vs. 153.8 ± 12.5 beats/min, p = 0.28). During follow-up assessment both groups utilized similar amount of oxygen during prolonged submaximal exercise (15.0 ± 2.4 vs. 15.2 ± 2.2 ml/min/kg, p = 0.71). However, cardiac function i.e. cardiac output during submaximal exercise decreased significantly by 21% in exercise group (16.2 ± 2.7-12.8 ± 3.6 L/min, p = 0.03), but not in the control group (15.7 ± 4.9-16.3 ± 4.1 L/min, p = 0.12). Reduction in exercise cardiac output observed in the exercise group was due to a significant decrease in stroke volume by 13% (p = 0.03) and heart rate by 9% (p = 0.04).
Conclusion: Following high intensity interval training patients with type 2 diabetes demonstrate reduced cardiac output during prolonged submaximal cardiopulmonary exercise testing. Ability of patients to maintain prolonged increased metabolic demand but with reduced cardiac output suggests cardiac protective role of high intensity interval training in type 2 diabetes.

 

Oxygen Consumption at Anaerobic Threshold Predicts Cardiac Events After Heart Transplantation.

Tsai HY; Tsai WJ; Kuo LY; Lin YS; Chen BY; Lin WH; Shen SL; Huang HY;

Transplantation Proceedings [Transplant Proc] 2018 Nov; Vol. 50 (9), pp. 2742-2746. Date of Electronic Publication: 2018 Mar 19.

Objectives: The ventilatory efficiency and functional capacity measured by the cardiopulmonary exercise test (CPET) have been used as important prognostic variables in congestive heart failure. This study sought to identify whether these predictors before heart transplantation (HTX) play a key role in predicting adverse events in patients with heart failure after HTX.
Methods: This was a retrospective cohort study design. HTX recipients were included for analysis. Ventilation to carbon dioxide production slope (VE/VCO2 slope) and oxygen consumption (VO2) during exercise were collected by CPET, which represented ventilator efficiency and functional capacity respectively. Cardiac-related events 2 years after HTX were recorded by chart review. We divided patients into 2 groups based on VE/VCO2 slope = 34, peak VO2 = 14 mL/kg/min and VO2 at aerobic threshold (AT) = 11 mL/kg/min. Kaplan-Meier survival curves was used to represent the events rate between groups and Log rank test was used to test significance.
Results: A total of 87 patients after HTX were included. Mean (SD) age was 48 (11) years and 73 were male; 28 subjects suffered from events, and 76 cardiac events were recorded. The mean (SD) data of peak VO2, VO2 at AT, and VE/VCO2 slope analyzed from CPET were 17.8 (5.6) mL/kg/min, 15.4 (4.4) mL/kg/min, and 33.1 (8.2) mL/kg/min, respectively. Lower VO2 at AT contributed to increase events rate (P < .05).
Conclusion: Aerobic capacity may better predict 2-year cardiac events in patients after HTX. Strategies to improve aerobic capacity should be focused on in the cohort.

Apical hypertrophic cardiomyopathy: what are the risks in our diverse military population?

Eveson LJ; Williams A;

Journal Of The Royal Army Medical Corps [J R Army Med Corps] 2018 Oct 12. Date of Electronic Publication: 2018 Oct 12.

We present the case of a 50-year-old, fit, asymptomatic gurkha officer. At a routine medical, an ECG showed T-wave inversion in the chest leads V3-6. Transthoracic echo showed left ventricular apical hypertrophy and cavity obliteration consistent with apical hypertrophic cardiomyopathy (ApHCM). Cardiac magnetic resonance imaging showed apical and inferior wall hypertrophy in the left ventricle with no aneurysm or scarring. A 24-hour monitor showed normal sinus rhythm with no evidence of non-sustained ventricular tachycardia. Eighteen-panel genetic testing revealed no specific mutations. Cardiopulmonary exercise testing demonstrated a V̇O2 max, anaerobic threshold and peak V̇O2 consistent with above average cardiopulmonary capacity. There was no family history of either ApHCM or sudden cardiac death (SCD). Risk of SCD by the European Society of Cardiology’s HCM calculator was low. This case generates discussion on the prognosis of ApHCM, factors that worsen prognosis, occupational limitation considerations and appropriate monitoring in this patient group.

Evaluation of cardiopulmonary exercise testing, heart function, and quality of life in children after allogenic hematopoietic stem cell transplantation.

Vandekerckhove K; De Waele K; Minne A; Coomans I; De Groote K; Panzer J; Dhooge C; Bordon V; De Wolf D;
Boone J;

Pediatric Blood & Cancer [Pediatr Blood Cancer] 2018 Oct 14, pp. e27499. Date of Electronic Publication: 2018 Oct 14.

Background: Physical fitness is an important determinant of quality of life (QOL) after hematopoietic stem cell transplantation. Cardiac function can influence exercise performance. The aim of this study was to assess these factors and their interrelationship.
Procedure: Children underwent cardiopulmonary exercise testing (CPET) at least 1 year after hematopoietic stem cell transplantation (HSCT) and were compared with healthy controls. Systolic and diastolic heart function and left ventricle (LV) wall dimensions were measured. Health-related QOL (HR-QOL) was evaluated using PedsQL questionnaires.
Results: Forty-three patients performed CPET (26 boys, 13.6 ± 3.4 years, weight 45.5 ± 13.3 kg, length 152.9 ± 17.5 cm, body surface area 1.35 ± 0.28). HSCT patients had lower maximal oxygen consumption (VO2peak/kg, 34.7 ± 8.4 vs 46.3 ± 7.1 mL/kg/min, P < 0.001), shorter exercise duration (9.1 ± 2.5 vs 12.9 ± 2.6 min, P < 0.001), and lower maximal load (%Ppeak 70.8 ± 19.7 vs 102.4% ± 15.9%, P < 0.001). Echocardiography demonstrated decreased interventricular septal wall thickness (interventricular septum in diastole [IVSd] Z-value -0.64 ± 0.69, P < 0.001), and more systolic (11% of patients) and diastolic dysfunction (high E/E’ Z-value 1.06 ± 1.13, P < 0.001). LV dilatation correlates with VO2max/kg (r = -0.364, P = 0.017). HR-QOL showed lower overall and emotional functioning scores (respectively, P = 0.016 and P = 0.001). Patients after anthracycline therapy have the lowest maximal exercise performance, but have no difference in QOL. Diminished exercise performance is not encountered as a QOL limitation. Total body irradiation influences the domain of psychosocial functioning.
Conclusions: LV (systolic and diastolic) and right ventricle dysfunctions justify the need for thorough cardiac follow-up in children after HSCT. Lower physical fitness levels and lower HR-QOL emphasize the importance of CPET and fitness programs.

Cardiopulmonary exercise testing provides additional prognostic information in cystic fibrosis.

Hebestreit H; Hulzebos EH; Schneiderman JE; Karila C; Boas SR; Kriemler S; Switzerland; Dwyer T; Sahlberg M;
Urquhart DS; Lands LC; Ratjen F; Takken T; Varanistkaya L; Rücker V; Hebestreit A; Usemann J; Radtke T;

American Journal Of Respiratory And Critical Care Medicine [Am J Respir Crit Care Med] 2018 Oct 15. Date of Electronic Publication: 2018 Oct 15.

Rationale: The prognostic value of cardiopulmonary exercise testing (CPET) for survival in cystic fibrosis (CF) in the context of current clinical management, when controlling for other known prognostic factors is unclear.
Objectives: To determine the prognostic value of CPET-derived measures beyond peak oxygen uptake (VO2peak) following rigorous adjustment for other predictors.
Measurements and Main Results: Data from 10 CF-centers in Australia, Europe and North America were collected retrospectively. 510 patients completed a cycle CPET between January 2000 and December 2007, of which 433 fulfilled the criteria for a maximal effort. Time to death/lung transplantation (LTx) was analyzed using Cox proportional hazards regression. In addition, phenotyping using hirarchical Ward’s clustering was performed to characterize high risk subgroups. Cox regression showed – even after adjustment for sex, forced expiratory volume in 1s (%predicted), body mass index (z-score), age at CPET, Pseudomonas aeruginosa status, and CF-related diabetes as covariates in the model – that VO2peak in %predicted, hazard ratio (HR) 0.964 [95%-CI: 0.944-0.986], peak work rate (%predicted, HR 0.969 [0.951-0.988], ventilatory equivalent for oxygen (VE/VO2peak) HR 1.085 [1.041-1.132], and carbon dioxide (VE/VCO2peak), HR 1.060 [1.007-1.115], all P<0.05) were significant predictors of death or LTx at 10 years follow-up. Phenotyping revealed that CPET-derived measures were important for clustering. We identified a high risk cluster characterized by poor lung function, nutritional status and exercise capacity.
Conclusions: In conclusion, CPET provides additional prognostic information to established predictors of death/LTx in CF. High risk patients may especially benefit from regular monitoring of exercise capacity and exercise counselling.

Exercise testing in patients with diaphragm paresis.

Bonnevie T, Gravier FE, Ducrocq A, Debeaumont D, Viacroze C,
Cuvelier A, Muir JF, Tardif C.

Respir Physiol Neurobiol. 2018 Jan;248:31-35.

PURPOSE: Diaphragm paresis (DP) is characterized by abnormalities of respiratory
muscle function. However, the impact of DP on exercise capacity is not well
known. This study was performed to assess exercise tolerance in patients with DP
and to determine whether inspiratory muscle function was related to exercise
capacity, ventilatory pattern and cardiovascular function during exercise.
METHODS: This retrospective study included patients with DP who underwent both
diaphragmatic force measurements, and cardiopulmonary exercise testing (CPET).
RESULTS: Fourteen patients were included. Dyspnea was the main symptom limiting
exertion (86%). Exercise capacity was slightly reduced (median VO2peak: 80%
[74.5%-90.5%]), mostly due to ventilatory limitation. Diaphragm and overall
inspiratory muscle function were correlated with exercise ventilation. Moreover,
overall inspiratory muscle function was related with oxygen consumption (r=0.61)
and maximal workload (r=0.68).
CONCLUSIONS: DP decreases aerobic capacity due to ventilatory limitation.
Diaphragm function is correlated with exercise ventilation whereas overall
inspiratory muscle function is correlated with both exercise capacity and
ventilation suggesting the importance of the accessory inspiratory muscles during
exercise for patients with DP. Further larger prospective studies are needed to
confirm these results.