Cardiopulmonary Exercise Testing and Surgery

Exercise testing in patients with tricuspid regurgitation undergoing transcatheter tricuspid valve intervention

BACKGROUND

Transcatheter tricuspid valve intervention (TTVI) has shown promising results with persistent reduction of tricuspid regurgitation (TR) and improvements in functional class and quality of life (QOL).

OBJECTIVES

To analyze the impact of TTVI on maximal and submaximal exercise capacity (SEC).

METHODS

Constant work-rate exercise-time (CWRET) testing reflects SEC, which is more likely to be relevant for daily life activities and provides more differentiated physiological insight into the nature of exercise intolerance. Thus, 30 patients undergoing TTVI (21 direct annuloplasty and 9 edge-to-edge repair) received cardiopulmonary exercise testing (CPET) and CWRET (at 75% of maximum work rate in the initial CPET) before and 3 months after TTVI.

RESULTS

Patients' age was 80.5 [74.8-82.3] years and 53.3% were female. TR reduction ≥ 2 grades was achieved in 93.3% (TR grade ≤ moderate in 83.3%). Echocardiography revealed improved right ventricular (RV) characteristics with decreased RV basal diameter (47.0 mm [43.0-54.3] vs. 41.5 mm [36.8-48.0]; p < 0.001) and decreased inferior caval vein diameter. CWRET testing showed a significantly improved SEC (246.5 s [153.8-416.8] vs. 338.5 s [238.8-611.8] p = 0.001). Maximum oxygen uptake showed a positive trend without statistically significant differences (9.9 ml/min/kg [8.6-12.4] vs. 11.7 ml/min/kg [9.7-13.3]; p = 0.31). In contrast to the six-minute-walking distance (6MWD), SEC correlated moderately with effective regurgitation orifice area reduction (r = 0.385; p = 0.036), increased cardiac output (r = 0.378; p = 0.039), and improved QOL (r = 387; p = 0.035).

CONCLUSION

Improvements in exercise capacity after TTVI mainly occur in the submaximal rather than in the maximal exercise range and correlate with hemodynamic effects and QOL. This may have a methodological impact on assessment of exercise capacity in these patients.

Sarcopenia is independently associated with poor preoperative physical fitness in patients undergoing colorectal cancer surgery

BACKGROUND

Accurate preoperative risk assessment for major colorectal cancer (CRC) surgery remains challenging. Body composition (BC) and cardiopulmonary exercise testing (CPET) can be used to evaluate risk. The relationship between BC and CPET in patients undergoing curative CRC surgery is unclear.

METHODS

Consecutive patients undergoing CPET prior to CRC surgery between 2010 and 2020 were identified between two different UK hospitals. Body composition phenotypes such as sarcopenia, myosteatosis, and visceral obesity were defined using widely accepted thresholds using preoperative single axial slice CT image at L3 vertebrae. Relationships between clinicopathological, BC, and CPET variables were investigated using linear regression analysis.

RESULTS

Two hundred eighteen patients with stage I-III CRC were included. The prevalence of sarcopenia, myosteatosis, and visceral obesity was 62%, 33%, and 64%, respectively. The median oxygen uptake at anaerobic threshold (VO2 at AT) was 12.2 mL/kg/min (IQR 10.6-14.2), and oxygen uptake at peak exercise (VO2 peak) was 18.8 mL/kg/min (IQR 15.4-23). On univariate linear regression analysis, male sex (P < 0.001) was positively associated with VO2 at AT. While ASA grade (P < 0.001) and BMI (P = 0.007) were negatively associated with VO2 at AT, on multivariate linear regression analysis, these variables remained significant (P < 0.05). On univariate linear regression analysis, male sex (P < 0.001) was positively associated with VO2 peak, whereas age (P < 0.001), ASA grade (P < 0.001), BMI (P = 0.003), sarcopenia (P = 0.015), and myosteatosis (P < 0.001) were negatively associated with VO2 peak. On multivariate linear regression analysis age (P < 0.001), ASA grade (P < 0.001), BMI (P < 0.001), and sarcopenia (P = 0.006) were independently and negatively associated with VO2 peak.

CONCLUSIONS

The novel finding that sarcopenia is independently associated with reduced VO2 peak performance in CPET supports the supposition that reduced muscle mass relates to poor physical function in CRC patients. Further work should be undertaken to assess whether sarcopenia diagnosed on CT can act as suitable surrogate for CPET to further enhance personalized risk stratification.

Changes in Cardiopulmonary Capacity Parameters after Surgery: A Pilot Study Exploring the Link between Heart Function and Knee Surgery

Background: A knee injury in an athlete leads to periods of forced exercise interruption. Myocardial work (MW) assessed by echocardiographic and cardiopulmonary exercise testing (CPET) are two essential methods for evaluating athletes during the period following injury. However, compared to pre-surgery evaluations, the variations in cardiovascular parameters and functional capacity assessed by these methods after surgery remain unclear. Methods: We evaluated 22 non-professional athletes aged 18-52, involved in prevalently aerobic or alternate aerobic/anaerobic sports activities, who were affected by a knee pathology requiring surgical treatment. The evaluation was performed at rest using transthoracic echocardiography, including MW assessment, and during exercise using CPET. Each athlete underwent the following two evaluations: the first before surgery and the second after surgery (specifically at the end of the deconditioning period). Results: Resting heart rate (HR) increased significantly (from 63.3 ± 10.85 to 71.2 ± 12.52 beats per minute, p = 0.041), while resting diastolic and systolic blood pressure, forced vital capacity, and forced expiratory volume in the first second did not show significant changes. Regarding the echocardiographic data, global longitudinal strain decreased from -18.9 ± 1.8 to -19.3 ± 1.75; however, this reduction was not statistically significant (p = 0.161). However, the global work efficiency (GWE) increased significantly (from 93.0% ± 2.9 to 94.8% ± 2.6, p = 0.006) and global wasted work (GWW) reduced significantly (from 141.4 ± 74.07 to 98.0 ± 50.9, p = 0.007). Additionally, the patients were able to perform maximal CPET at both pre- and post-surgery evaluations, as demonstrated by the peak respiratory exchange ratio and HR. However, the improved myocardial contractility (increased GWE and decreased GWW) observed at rest did not translate into significant changes in exercise parameters, such as peak oxygen consumption and the mean ventilation/carbon dioxide slope. Conclusions: After surgery, the athletes were more deconditioned (as indicated by a higher resting HR) but exhibited better resting myocardial contractility (increased GWE and reduced GWW). Interestingly, no significant changes in exercise capacity parameters, as evaluated by CPET, were found after surgery, suggesting that the improved myocardial contractility was offset by a greater degree of muscular deconditioning.

Ventilatory efficiency as a prognostic factor for postoperative complications in patients undergoing elective major surgery: a systematic review

BACKGROUND

Major surgery is associated with high complication rates. Several risk scores exist to assess individual patient risk before surgery but have limited precision. Novel prognostic factors can be included as additional building blocks in existing prediction models. A candidate prognostic factor, measured by cardiopulmonary exercise testing, is ventilatory efficiency (VE/VCO2). The aim of this systematic review was to summarise evidence regarding VE/VCO2 as a prognostic factor for postoperative complications in patients undergoing major surgery.

METHODS

A medical library specialist developed the search strategy. No database-provided limits, considering study types, languages, publication years, or any other formal criteria were applied to any of the sources. Two reviewers assessed eligibility of each record and rated risk of bias in included studies.

RESULTS

From 10,082 screened records, 65 studies were identified as eligible. We extracted adjusted associations from 32 studies and unadjusted from 33 studies. Risk of bias was a concern in the domains 'study confounding' and 'statistical analysis'. VE/VCO2 was reported as a prognostic factor for short-term complications after thoracic and abdominal surgery. VE/VCO2 was also reported as a prognostic factor for mid- to long-term mortality. Data-driven covariable selection was applied in 31 studies. Eighteen studies excluded VE/VCO2 from the final multivariable regression owing to data-driven model-building approaches.

CONCLUSIONS

This systematic review identifies VE/VCO2 as a predictor for short-term complications after thoracic and abdominal surgery. However, the available data do not allow conclusions about clinical decision-making. Future studies should select covariables for adjustment a priori based on external knowledge.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42022369944).

Assessment of cardiopulmonary capacity in deconditioned athletes because of knee injury

BACKGROUND

An athlete's career inevitably goes through periods of forced physical exercise interruption like a knee injury. Advanced echocardiographic methods and cardiopulmonary exercise testing (CPET) are essential in evaluating athletes in the period elapsing after the injury. However, the feasibility of a maximal pre-surgery CPET and the capacity of resting advanced echocardiographic techniques to predict cardiorespiratory capacity still need to be clarified.

METHODS

We evaluated 28 non-professional athletes aged 18-52, involved in prevalently aerobic or alternate aerobic/anaerobic sports activities, affected by a knee pathology with indications for surgical treatment. The evaluation was performed at rest by trans-thoracic echocardiography, including global longitudinal strain (GLS) and myocardial work (MW) assessment, and during exercise by CPET.

RESULTS

The percent-predicted peak oxygen consumption (peak VO2%) was 82.8±13.7%, the mean respiratory exchange ratio was 1.16±0.08, and the mean ventilation/carbon dioxide (VE/VCO2) slope was 24.23±3.36. Peak VO2% negatively correlated with GLS (r=-0.518, P=0.003) and global wasted work (GWW) (r =-0.441, P=0.015) and positively correlated with global work efficiency (GWE) (r=0.455, P=0.012). Finally, we found that the VE/VCO2 slope during exercise was negatively correlated with GWE (r=-0.585, P=0.001) and positively correlated with GWW (r=0.499, P=0.005).

CONCLUSIONS

A maximal CPET can be obtained in deconditioned athletes because of a knee injury, allowing a comprehensive functional pre-surgery evaluation. In these patients, peak VO2 is reduced due to decreased physical activity after injury; however, a lower cardiopulmonary efficiency may be a concause of the injury itself. In addition, we demonstrated that the MW indexes obtained at rest could predict exercise capacity and ventilatory efficiency as evaluated by CPET.

How to interpret a cardiorespiratory fitness assessment - Key measures that provide the best picture of health, disease status and prognosis

Graded exercise testing is a widely accepted tool for revealing cardiac ischemia and/or arrhythmias in clinical settings. Cardiopulmonary exercise testing (CPET) measures expired gases during a graded exercise test making it a versatile tool that helps reveal underlying physiologic abnormalities that are in many cases only present with exertion. It also characterizes one's health status and clinical trajectory, informs the therapeutic plan, evaluates the efficacy of therapy, and provides submaximal and maximal information that can be used to tailor an exercise intervention. Practitioners can also modify the mode and protocol to allow individuals of all ages, fitness levels, and most disease states to perform a CPET. When used to its full potential, CPET can be a key tool used to optimize care in primary and secondary prevention settings.

Multimodal Prehabilitation for Patients Undergoing Endovascular Aortic Aneurysm Repair Surgery: A Feasibility Study

BACKGROUND

Elective treatment options for aortic abdominal aneurysms include open repair or the less-invasive endovascular aortic aneurysm repair (EVAR). Recovery from EVAR is generally considered easier and faster than open repair. Despite this, EVAR remains a major procedure, and average return to preoperative quality of life is at least 3 months. The purpose of this study is to determine the safety and feasibility of multimodal prehabilitation, a multidisciplinary preoperative optimization intervention, in patients undergoing EVAR and its impact on perioperative functional capacity and quality of life.

METHODS

Candidates for EVAR with an infra-renal abdominal aortic aneurysm <7.5cm were invited to participate in a 6-week multimodal prehabilitation program that included (1) supervised and home-based exercise, (2) nutritional support, (3) psychosocial support, and (4) smoking cessation. Functional capacity and quality of life were assessed at baseline, before surgery and 6 weeks postoperatively. Recruitment rate, safety, and compliance were also assessed.

RESULTS

A total of 24 patients were included, 17 males (70%) and 7 females (30%). No adverse events occurred during the program. Compliance to each component of the program (median [Q1-Q3]) was 66% [67] for supervised training, 100% [67] for home-based training, and 100% [100] for nutrition. The multimodal prehabilitation program elicited a significant increase in functional capacity and quality of life preoperatively.

CONCLUSION

Multimodal prehabilitation for patients awaiting EVAR is feasible and safe. Multimodal prehabilitation improves both functional capacity and quality of life preoperatively. Further research is needed to assess the impact of multimodal prehabilitation on postoperative quality of life and functional capacity.

CLINICAL IMPACT

Multimodal prehabilitation is safe and feasible in patients awaiting endovascular aneurysm repair. The importance of this finding is that multimodal prehabilitation can be safely delivered preoperatively in patients awaiting EVAR. Although further research is needed, multimodal prehabilitation seems to improve preoperative functional capacity and quality of life. This could have an impact for the future implementation of prehabilitation interventions in order to increase functional reserve and quality of life preoperatively so that this high-risk population can cope better with the surgical stress and return to their normal life faster postoperatively.

Myths and methodologies: Cardiopulmonary exercise testing for surgical risk stratification in patients with an abdominal aortic aneurysm; balancing risk over benefit

The extent to which patients with an abdominal aortic aneurysm (AAA) should exercise remains unclear, given theoretical concerns over the perceived risk of blood pressure-induced rupture, which is often catastrophic. This is especially pertinent during cardiopulmonary exercise testing, when patients are required to perform incremental exercise to symptom-limited exhaustion for the determination of cardiorespiratory fitness. This multimodal metric is being used increasingly as a complementary diagnostic tool to inform risk stratification and subsequent management of patients undergoing AAA surgery. In this review, we bring together a multidisciplinary group of physiologists, exercise scientists, anaesthetists, radiologists and surgeons to challenge the enduring 'myth' that AAA patients should be fearful of and avoid rigorous exercise. On the contrary, by appraising fundamental vascular mechanobiological forces associated with exercise, in conjunction with 'methodological' recommendations for risk mitigation specific to this patient population, we highlight that the benefits conferred by cardiopulmonary exercise testing and exercise training across the continuum of intensity far outweigh the short-term risks posed by potential AAA rupture.

Training effects of set- and repetition-interval rest time on recumbent-boxing exercise: Could virtual reality improve further?

This study examined the influence of set-interval and repetition-interval rest time of virtual reality (VR) boxing game in supine-lying posture. Fifty healthy middle-aged adults were randomly assigned into VR and non-VR groups to perform six different exercise protocols with varying set-interval and repetition-interval rest times (S0R0, S0R1/3, S0R2/3, S40R0, S40R1/3, and S40R2/3). Analysis on the non-VR group showed significant differences between exercise protocols for average heart rate (p < 0.001), maximum ventilation volume (p < 0.001), respiratory quotient (p < 0.001), oxygen pulse (p < 0.001), and excess post-exercise oxygen consumption (EPOC) (p = 0.003). VR appeared to have no further improvement on physical training effects in middle-aged adults, while the participants reported negative experience that might be associated with the over-exertion. Future study might need to explore game design elements that can accommodate high-exertion exercises.

Use of Wearable Devices for Peak Oxygen Consumption Measurement in Clinical Cardiology: Case Report and Literature Review

BACKGROUND

Oxygen consumption is an important index to evaluate in cardiac patients, particularly those with heart failure, and is measured in the setting of advanced cardiopulmonary exercise testing. However, technological advances now allow for the estimation of this parameter in many consumer and medical-grade wearable devices, making it available for the medical provider at the initial evaluation of patients. We report a case of an apparently healthy male aged 40 years who presented for evaluation due to an Apple Watch (Apple Inc) notification of low cardiac fitness. This alert triggered a thorough workup, revealing a diagnosis of familial nonischemic cardiomyopathy with severely reduced left ventricular systolic function. While the use of wearable devices for the measurement of oxygen consumption and related parameters is promising, further studies are needed for validation.

OBJECTIVE

The aim of this report is to investigate the potential utility of wearable devices as a screening and risk stratification tool for cardiac fitness for the general population and those with increased cardiovascular risk, particularly through the measurement of peak oxygen consumption (VO2). We discuss the possible advantages of measuring oxygen consumption using wearables and propose its integration into routine patient evaluation and follow-up processes. With the current evidence and limitations, we encourage researchers and clinicians to explore bringing wearable devices into clinical practice.

METHODS

The case was identified at Sheba Medical Center, and the patient's cardiac fitness was monitored through an Apple Watch Series 6. The patient underwent a comprehensive cardiac workup following his presentation. Subsequently, we searched the literature for articles relating to the clinical utility of peak VO2 monitoring and available wearable devices.

RESULTS

The Apple Watch data provided by the patient demonstrated reduced peak VO2, a surrogate index for cardiac fitness, which improved after treatment initiation. A cardiological workup confirmed familial nonischemic cardiomyopathy with severely reduced left ventricular systolic function. A review of the literature revealed the potential clinical benefit of peak VO2 monitoring in both cardiac and noncardiac scenarios. Additionally, several devices on the market were identified that could allow for accurate oxygen consumption measurement; however, future studies and approval by the Food and Drug Administration (FDA) are still necessary.

CONCLUSIONS

This case report highlights the potential utility of peak VO2 measurements by wearable devices for early identification and screening of cardiac fitness for the general population and those at increased risk of cardiovascular disease. The integration of wearable devices into routine patient evaluation may allow for earlier presentation in the diagnostic workflow. Cardiac fitness can be serially measured using the wearable device, allowing for close monitoring of functional capacity parameters. Devices need to be used with caution, and further studies are warranted.

Utilization of Wearable Pedometer Devices in the Perioperative Period: A Qualitative Systematic Review

Functional capacity assessment is important for perioperative risk stratification; however, there are currently limited options for objective and economical functional capacity evaluation. Pedometer functions are now widely available in mobile devices and offer a nonintrusive and objective approach to measuring patient activity level over time. Therefore, we conducted this systematic review to assess the value of pedometer readings in predicting perioperative outcomes. We systematically searched PubMed, EMBASE (Ovid), Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science Citation Index for studies, which assessed the correlation between perioperative (30 days before to 30 days after surgery) pedometer data and perioperative outcomes. We identified a total of 18 studies for inclusion. Seven of the studies recorded preoperative pedometer data, and 13 studies recorded postoperative pedometer data. Notably, 10 of the studies covered oncologic surgery patients. The included studies consistently reported that preoperative pedometer readings correlated with postoperative complication rates. In addition, in-hospital postoperative pedometer readings correlated with postdischarge complications and readmissions. Perioperative pedometer data demonstrated consistent and biologically plausible association with perioperative outcomes. Further studies are needed to validate the use of pedometer in the perioperative period and to identify the optimal approach for its use to potentially improve patient outcomes.

Smoking Habit and Respiratory Function Predict Patients' Outcome after Surgery for Lung Cancer, Irrespective of Histotype and Disease Stage

BACKGROUND

Growing evidence suggests that sublobar resections offer more favorable outcomes than lobectomy in early-stage lung cancer surgery. However, a percentage of cases that cannot be ignored develops disease recurrence irrespective of the surgery performed with curative intent. The goal of this work is thus to compare different surgical approaches, namely, lobectomy and segmentectomy (typical and atypical) to derive prognostic and predictive markers.

PATIENTS AND METHODS

Here we analyzed a cohort of 153 NSCLC patients in clinical stage TNM I who underwent pulmonary resection surgery with a mediastinal hilar lymphadenectomy from January 2017 to December 2021, with an average follow-up of 25.5 months. Partition analysis was also applied to the dataset to detect outcome predictors.

RESULTS

The results of this work showed similar OS between lobectomy and typical and atypical segmentectomy for patients with stage I NSCLC. In contrast, lobectomy was associated with a significant improvement in DFS compared with typical segmentectomy in stage IA, while in stage IB and overall, the two treatments were similar. Atypical segmentectomy showed the worst performance, especially in 3-year DFS. Quite unexpectedly, outcome predictor ranking analysis suggests a prominent role of smoking habits and respiratory function, irrespective of the tumor histotype and the patient's gender.

CONCLUSIONS

Although the limited follow-up interval cannot allow conclusive remarks about prognosis, the results of this study suggest that both lung volumes and the degree of emphysema-related parenchymal damage are the strongest predictors of poor survival in lung cancer patients. Overall, these data point out that greater attention should be addressed to the therapeutic intervention for co-existing respiratory diseases to obtain optimal control of early lung cancer.

The Role and Effect of Multimodal Prehabilitation Before Major Abdominal Surgery: A Systemic Review and Meta-Analysis

BACKGROUND

For patients undergoing abdominal surgery, multimodal prehabilitation, including nutrition and exercise interventions, aims to optimize their preoperative physical and physiological capacity. This meta-analysis aims to explore the impact of multimodal prehabilitation on surgical and functional outcomes of abdominal surgery.

METHODS

Medline, Embase and CENTRAL were searched for articles about multimodal prehabilitation in major abdominal surgery. Primary outcomes were postoperative complications with a Clavien-Dindo score ≥3, and functional outcomes, measured by the 6-Minute Walking Test (6MWT). Secondary outcome measures included the quality-of-life measures. Pooled risk ratio (RR) and 95% confidence interval (CI) were estimated, with DerSimonian and Laird random effects used to account for heterogeneity.

RESULTS

Twenty-five studies were included, analysing 4,210 patients across 13 trials and 12 observational studies. Patients undergoing prehabilitation had significantly fewer overall complications (RR = 0.879, 95% CI 0.781-0.989, p = 0.034). There were no significant differences in the rates of wound infection, anastomotic leak and duration of hospitalization. The 6MWT improved preoperatively in patients undergoing prehabilitation (SMD = 33.174, 95% CI 12.674-53.673, p = 0.005), but there were no significant differences in the 6MWT at 4 weeks (SMD = 30.342, 95% CI - 2.707-63.391, p = 0.066) and 8 weeks (SMD = 24.563, 95% CI - 6.77-55.900, p = 0.104) postoperatively.

CONCLUSIONS

As preoperative patient optimization shifts towards an interdisciplinary approach, evidence from this meta-analysis shows that multimodal prehabilitation improves the preoperative functional capacity and reduces postoperative complication rates, suggesting its potential in effectively optimizing the abdominal surgery patient. However, there is a large degree of heterogenicity between the prehabilitation interventions between included articles; hence results should be interpreted with caution.

Cardiopulmonary exercise testing in patients with end-stage kidney disease: principles, methodology and clinical applications of the optimal tool for exercise tolerance evaluation

Chronic kidney disease (CKD), especially end-stage kidney disease (ESKD), is associated with an increased risk for cardiovascular events and all-cause mortality. Exercise intolerance as well as reduced cardiovascular reserve is extremely common in patients with CKD. Cardiopulmonary exercise testing (CPET) is a non-invasive, dynamic technique that provides an integrative evaluation of cardiovascular, pulmonary, neuropsychological and metabolic function during maximal or submaximal exercise, allowing the evaluation of functional reserves of these systems. This assessment is based on the principle that system failure typically occurs when the system is under stress and thus CPET is currently considered to be the gold standard for identifying exercise limitation and differentiating its causes. It has been widely used in several medical fields for risk stratification, clinical evaluation and other applications, but its use in everyday practice for CKD patients is scarce. This article describes the basic principles and methodology of CPET and provides an overview of important studies that utilized CPET in patients with ESKD, in an effort to increase awareness of CPET capabilities among practicing nephrologists.

The Marsden Morbidity Index: the derivation and validation of a simple risk index scoring system using cardiopulmonary exercise testing variables to predict morbidity in high-risk patients having major cancer surgery

Background

Morbidity and mortality risk prediction tools are increasingly being used as part of preoperative assessment of patients presenting for major abdominal surgery. Cardiopulmonary exercise testing (CPET) can predict which patients undergoing major abdominal surgery are at risk of complications. The primary objective of this study was to identify preoperative variables including those derived from CPET, which were associated with inpatient morbidity in high-risk patients following major abdominal cancer surgery. The secondary objective was to use these variables to derive and validate a morbidity risk prediction tool.

Methods

We conducted a retrospective cohort analysis of consecutive adult patients who had CPET as part of their preoperative work-up for major abdominal cancer surgery. Morbidity was a composite outcome, defined by the Clavien-Dindo score and/or the postoperative morbidity survey (POMS) score which was assessed on postoperative day 7. A risk prediction tool was devised using variables from the first analysis which was then applied prospectively to a matched cohort of patients.

Results

A total of 1398 patients were included in the first phase of the analysis between June 2010 and May 2017. Of these, 540 patients (38.6%) experienced postoperative morbidity. CPET variables deemed significant (p < 0.01) were anaerobic threshold (AT), maximal oxygen consumption at maximal exercise capacity (VO2 max), and ventilatory equivalent for carbon dioxide at anaerobic threshold (AT VE/VCO2). In addition to the CPET findings and the type of surgery the patient underwent, eight preoperative variables that were associated with postoperative morbidity were identified. These include age, WHO category, body mass index (BMI), prior transient ischaemic attack (TIA) or stroke, chronic renal impairment, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and cancer stage. Both sets of variables were then combined to produce a validated morbidity risk prediction scoring tool called the Marsden Morbidity Index. In the second phase of the analysis, this tool was applied prospectively to 424 patients between June 2017 and December 2018. With an area under the curve (AUC) of 0.79, this new model had a sensitivity of 74.2%, specificity of 78.1%, a positive predictive value (PPV) of 79.7%, and a negative predictive value of (NPV) of 79%.

Conclusion

Our study showed that of the CPET variables, AT, VO2 max, and AT VE/VCO2 were shown to be associated with postoperative surgical morbidity following major abdominal oncological surgery. When combined with a number of preoperative comorbidities commonly associated with increased risk of postoperative morbidity, we created a useful institutional scoring system for predicting which patients will experience adverse events. However, this system needs further validation in other centres performing oncological surgery.

Prehabilitation in high-risk patients scheduled for major abdominal cancer surgery: a feasibility study

Background

Patients presenting for major surgery with low cardiorespiratory fitness (deconditioning) and other modifiable risk factors are at increased risk of postoperative complications. This study investigated the feasibility of delivering prehabilitation in high-risk patients scheduled for major abdominal cancer surgery.

Methods

Eligible patients in this single-center cohort study included patients with poor fitness (objectively assessed by cardiopulmonary exercise testing, CPET) scheduled for elective major abdominal cancer surgery. Patients were recruited to participate in a prehabilitation program that spanned up to 6 weeks pre-operatively and comprised aerobic and resistance exercise training, breathing exercise, and nutritional support. The primary outcome assessed pre-specified feasibility targets: recruitment >70%, retention >85%, and intervention adherence >70%. Secondary outcomes were assessed for improved pre-operative functional status and health-related quality of life and for postoperative complications.

Results

Eighty-two (34%) out of 238 patients screened between April 2018 and December 2019 were eligible for recruitment. Fifty (61%) patients (52% males) with a median age of 71 (IQR, 63–77) years participated in the study. Baseline oxygen consumption the at anaerobic threshold and at peak exercise (mean±SD: 9.8±1.8 and 14.0±2.9 mL/kg/min, respectively) confirmed the deconditioned state of the study cohort. The retention rate within the prehabilitation program was 84%, with 42 participants returning for repeat CPET testing. While >60% of participants preferred to do home-based prehabilitation, adherence to the intervention was low—with only 12 (28%) and 15 (35%) of patients having self-reported compliance >70% with their exercise prescriptions.

Conclusion

Our prehabilitation program in high-risk cancer surgery patients did not achieve pre-specified targets for recruitment, retention, and self-reported program adherence. These findings underpin the importance of implementation research and strategies for the prehabilitation programs in major surgery.

Trial registration

Australian New Zealand Clinical Trials Registry (ACTRN12620000073909) retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-022-00263-2.

Cardiopulmonary exercise testing for cardiovascular risk assessment in patients undergoing gastric and oesophageal cancer surgery: results from a prospective interventional cohort study

Background

Cardiopulmonary exercise testing (CPET) has shown to be useful for preoperative risk stratification in various types of intra-abdominal and thoracic surgery. However, data about the predictive value of CPET for cardiovascular outcome after gastric or oesophageal cancer surgery are inconclusive. The aim of this study was to evaluate the prognostic value of CPET parameters for the prediction of cardiovascular complications in patients with this type of surgery.

Methods

This is a prospective single-centre interventional cohort study including 200 consecutive patients who underwent elective surgery for oesophageal and/or gastric cancer. Symptom-limited CPET was performed preoperatively to evaluate the potential of various test-derived parameters including anaerobic threshold (AT) to predict cardiovascular complications within 30 days after surgery.

Results

200 patients (mean age 68±14.2 years) met inclusion and exclusion criteria: oesophageal surgery 54 pts, gastric surgery 132 pts and combined oesophageal/gastric surgery 14 pts. 41/200 pts (20.5%) experienced cardiovascular complications during and within 30 days after surgery including 4 non-fatal myocardial infarctions (2%), 1 stroke (0.5%); 6 dead from cardiovascular causes (3%) and less serious complications in 30 patients (15%) including angina attacks and antiarrhythmic therapy for ventricular arrhythmias or for atrial fibrillation/flutter. Results from preoperative CPET indicate that an AT level below 11 mL/kg/min was highly predictive for any cardiovascular complication (p=0.02, OR 6.33, 95% CI 1.78 to 22.47). An AT level <9.5 had the best predictive accuracy for major perioperative cardiac complications (sensitivity 93%, specificity 68%, positive predicative value 75%, negative predicative value 98.8%).

Conclusion

CPET is a useful perioperative risk assessment tool for patients undergoing surgery for oesophageal and gastric cancer, which carries a particularly high risk for cardiovascular complications. An AT <9.5 mL/kg/min turned out to be the most reliable predictor for major cardiovascular complications.

Perioperative Risk Stratification and Modification

This article discusses the important topic of perioperative risk stratification and the interventions that can be used in the perioperative period for risk modification. It begins with a brief overview of the commonly used scoring systems, risk-prediction models, and assessments of functional capacity and discusses some of the evidence behind each. It then moves on to examine how perioperative risk can be modified through the use of shared decision making, management of multimorbidity, and prehabilitation programs, before considering what the future of risk stratification and modification may hold.

Preoperative functional capacity and postoperative outcomes following abdominal and pelvic cancer surgery: a systematic review and meta-analysis

BACKGROUND

There is clinical uncertainty regarding an association between preoperative functional capacity of cancer patients, and postoperative outcomes. The aim of this systematic review and meta-analysis is to investigate whether poor performance on preoperative six-minute walk test (6MWT) or five-times sit to stand test (5STS) is associated with worse postoperative complication rates and prolonged length of hospital stay (LOS) in cancer patients.

METHODS

An electronic search was performed from earliest available record to 26th February 2021 in MEDLINE, Embase and AMED. Studies investigating the association between preoperative physical function (measured using either 6MWT or 5STS) and postoperative outcomes (complications and LOS) in patients with gastrointestinal, abdominal and pelvic cancers were included. Risk of bias was assessed using the Quality in Prognosis Studies (QUIPS) tool. Where possible, summary odds ratios (OR) or mean differences (MD), and 95% confidence intervals (CI) were calculated using random-effect models.

RESULTS

Five studies (379 patients) were included, of which none utilized the 5STS. Overall, studies were rated as having low to moderate risk of bias. Higher preoperative performance on the 6MWT (≥400 m) was associated with low grade postoperative complications (OR = 0.38; 95% CI = 0.15-0.95) but was not associated with a shorter LOS (MD = 3.29; 95%CI = -1.07-7.66).

CONCLUSION

The available evidence suggests that in cancer patients, a higher preoperative functional capacity may be associated with reduced postoperative complications. Conversely, there is no significant association between preoperative function and LOS. Further high-quality studies are needed in this area, including studies involving 5STS.

Practical guide to cardiopulmonary exercise testing in adults

Unexplained exertional dyspnoea or fatigue can arise from a number of underlying disorders and shows only a weak correlation with resting functional or imaging tests. Noninvasive cardiopulmonary exercise testing (CPET) offers a unique, but still under-utilised and unrecognised, opportunity to study cardiopulmonary and metabolic changes simultaneously. CPET can distinguish between a normal and an abnormal exercise response and usually identifies which of multiple pathophysiological conditions alone or in combination is the leading cause of exercise intolerance. Therefore, it improves diagnostic accuracy and patient health care by directing more targeted diagnostics and facilitating treatment decisions. Consequently, CPET should be one of the early tests used to assess exercise intolerance. However, this test requires specific knowledge and there is still a major information gap for those physicians primarily interested in learning how to systematically analyse and interpret CPET findings. This article describes the underlying principles of exercise physiology and provides a practical guide to performing CPET and interpreting the results in adults.

Prehabilitation, enhanced recovery after surgery, or both? A narrative review

This narrative review presents a biological rationale and evidence to describe how the preoperative condition of the patient contributes to postoperative morbidity. Any preoperative condition that prevents a patient from tolerating the physiological stress of surgery (e.g. poor cardiopulmonary reserve, sarcopaenia), impairs the stress response (e.g. malnutrition, frailty), and/or augments the catabolic response to stress (e.g. insulin resistance) is a risk factor for poor surgical outcomes. Prehabilitation interventions that include exercise, nutrition, and psychosocial components can be applied before surgery to strengthen physiological reserve and enhance functional capacity, which, in turn, supports recovery through attaining surgical resilience. Prehabilitation complements Enhanced Recovery After Surgery (ERAS) care to achieve optimal patient outcomes because recovery is not a passive process and it begins preoperatively.

Does the introduction of pre‐operative cardiopulmonary exercise testing in radical cystectomy delay or alter surgical care?

Objectives

To assess if the introduction of routine pre‐operative cardiopulmonary exercise testing (CPET) in radical cystectomy has delayed surgical intervention.

Materials and Methods

A prospective database of patients undergoing radical cystectomy in our local health network was maintained. A retrospective analysis of two years (2018–2020) included 38 patients. Of these, 15 patients had CPET pre‐operatively, and a direct comparison was performed.

Results

The mean time from diagnosis to cystectomy was 95 days in patients who did not have CPET compared to 110 days for those who did (p = 0.32), with comparable rates of neoadjuvant chemotherapy (NAC) (62.5% and 64.29%). Average length of stay was 18.6 days compared with 13.87 (p = 0.16), favouring the CPET group. The CPET group also had a lower readmission rate within 30 days (13.33% compared with 21.05%, p = 0.35). Cause‐specific mortality within 90 days was 10.2% and within the study timeframe was 36.84% (estimated 5‐year mortality rate 43–65%). Within the CPET group, eight had an anaerobic threshold (AT) of <11 ml/kg/min (range 6.3–10.5): Of these, 50% had Clavien‐Dindo complications of grade 2 or higher and the 90‐day mortality rate was 37.5% (cf. 0% in those with AT > 11 ml/kg/min in this series).

Conclusion

CPET is a valuable risk evaluation tool. This study suggested that CPET contributed to a minor non‐significant delay to surgery, however was associated with reduced length of stay and readmission rates, and was a valuable risk evaluation tool. We found that CPET AT <11 ml/kg/min is associated with higher rates of patient morbidity and perioperative mortality.

Cardiopulmonary Exercise Testing and Other Tests of Functional Capacity

Purpose of Review

Assessment of functional capacity is a cornerstone of preoperative risk assessment. While subjective clinician assessment of functional capacity is poorly predictive of postoperative outcomes, other objective functional assessment measures may provide more useful information.

Recent Findings

Cardiopulmonary exercise testing (CPET) is generally accepted as the gold standard for functional capacity assessment. However, CPET is resource-intensive and not universally available. Simpler objective tests of functional capacity such as the Duke Activity Status Index (DASI) and the 6-min walk test (6MWT) are cheap and efficient. In addition, they predict important postoperative outcomes including death, disability, and myocardial infarction.

Summary

Simple preoperative tests such as the DASI may be useful for routine preoperative assessment. CPET may be helpful to investigate further patients with functional status limitation, and to guide prehabilitation and perioperative shared decision-making in high-risk patients.

Moderate-intensity exercise training or high-intensity interval training to improve aerobic fitness during exercise prehabilitation in patients planned for elective abdominal cancer surgery?

Low preoperative aerobic fitness is associated with an increased risk of postoperative complications and delayed recovery in patients with abdominal cancer. Surgical prehabilitation aims to increase aerobic fitness preoperatively to improve patient- and treatment-related outcomes. However, an optimal physical exercise training program that is effective within the short time period available for prehabilitation (<6 weeks) has not yet been established. In this comparative review, studies (n = 8) evaluating the effect of short-term (<6 weeks) moderate-intensity exercise training (MIET) or high-intensity interval training (HIIT) on objectively measured aerobic fitness were summarized. The content of exercise interventions was critically appraised regarding the frequency, intensity, time, type, volume, and - monitoring of - progression (FITT-VP) principles. Three out of four studies evaluating HIIT showed statistically significant improvements in oxygen uptake at peak exercise (VO_2peak) by more than 4.9%, the coefficient of variation for VO_2peak. None of the two studies investigating short-term MIET showed statistically significant pre-post changes in VO_2peak. Although short-term HIIT seems to be a promising intervention, concise description of performed exercise based on the FITT-VP principles was rather inconsistent in studies. Hence, interpretation of the results is challenging, and a translation into practical recommendations is premature. More emphasis should be given to individual responses to physical exercise training. Therefore, adequate risk assessment, personalized physical exercise training prescription using the FITT-VP principles, full reporting of physical exercise training adherence, and objective monitoring of training progression and recovery is needed to ensure for a personalized and effective physical exercise training program within a multimodal prehabilitation program.

Evidence of a double anaerobic threshold in healthy subjects

AIMS

The anaerobic threshold (AT) is an important cardiopulmonary exercise test (CPET) parameter both in healthy and in patients. It is normally determined with three approaches: V-slope method, ventilatory equivalent method, and end-tidal method. The finding of different AT values with these methods is only anecdotic. We defined the presence of a double threshold (DT) when a ΔVO2 > 15 mL/min was observed between the V-slope method (met AT) and the other two methods (vent AT). The aim was to identify whether there is a DT in healthy subjects.

METHODS AND RESULTS

We retrospectively analysed 476 healthy subjects who performed CPET in our laboratory between 2009 and 2018. We identified 51 subjects with a DT (11% of cases). Cardiopulmonary exercise test data at rest and during the exercise were not different in subjects with DT compared to those without. Met AT always preceded vent AT. Compared to subjects without DT, those with DT showed at met AT lower carbon dioxide output (VCO2), end-tidal carbon dioxide tension (PetCO2) and respiratory exchange ratio (RER), and higher ventilatory equivalent for carbon dioxide (VE/VCO2). Compared to met AT, vent AT showed a higher oxygen uptake (VO2), VCO2, ventilation, respiratory rate, RER, work rate, and PetCO2 but a lower VE/VCO2 and end-tidal oxygen tension. Finally, subjects with DT showed a higher VO2 increase during the isocapnic buffering period.

CONCLUSION

Double threshold was present in healthy subjects. The presence of DT does not influence peak exercise performance, but it is associated with a delayed before acidosis-induced hyperventilation.

Prediction of Exercise Capacity and Training Prescription from the 6-Minute Walk Test and Rating of Perceived Exertion

Walking tests, such as the 6-min walk test (6MWT), are popular methods of estimating peak oxygen uptake (VO₂peak) in clinical populations. However, the strength of the distance vs. VO₂peak relationship is not strong, and there are no equations for estimating ventilatory threshold (VT), which is important for training prescription and prognosis. Since the 6MWT is often limited by walking mechanics, prediction equations that include simple additional predictors, such as the terminal rating of perceived exertion (RPE), hold the potential for improving the prediction of VO₂max and VT. Therefore, this study was designed to develop equations for predicting VO₂peak and VT from performance during the 6MWT, on the basis of walking performance and terminal RPE. Clinically stable patients in a cardiac rehabilitation program (N = 63) performed the 6MWT according to the American Thoracic Society guidelines. At the end of each walk, the subject provided their terminal RPE on a 6-20 Borg scale. Each patient also performed a maximal incremental treadmill test with respiratory gas exchange to measure VO₂peak and VT. There was a good correlation between VO₂peak and 6MWT distance (r = 0.80) which was improved by adding the terminal RPE in a multiple regression formula (6MWT + RPE, R² = 0.71, standard error of estimate, SEE = 1.3 Metabolic Equivalents (METs). The VT was also well correlated with walking performance, 6MWT distance (r = 0.80), and was improved by the addition of terminal RPE (6MWT + RPE, R² = 0.69, SEE = 0.95 METs). The addition of terminal RPE to 6MWT distance improved the prediction of maximal METs and METs at VT, which may have practical applications for exercise prescription.

Poor anaerobic threshold and VO2 max recorded during cardiopulmonary exercise testing (CPET) prior to cytoreductive surgery in advanced (stage 3/4) ovarian cancer (AOC) is associated with suboptimal cytoreduction but does not preclude maximum effort cytoreduction

This study assessed Cardiopulmonary Exercise Testing (CPET) in predicting oncological outcomes, post-operative recovery and complications in advanced ovarian cancer (AOC) cytoreductive surgery. We reviewed all patients who had CPET prior to AOC cytoreductive surgery with evidence of upper abdominal disease on preoperative imaging at the University Hospitals of Derby and Burton (UHDB) between August 2016 and July 2019. Patients were stratified by AT and maximum VO₂ levels. 43 patients were identified. AT showed no relationship with major complications. 100% of patients in the AT ≥11 group received R0 (n = 21, 91.30%), or R1 (n = 2, 8.70%) cytoreduction, whereas in the AT <11 group, only 75.00% achieved and R0 or R1 resection (p = .02). Surgical complexity was higher in the AT ≥11 group (p = .001) and the VO₂ ≥15 group (p = .0006). No other correlations were seen between AT or VO₂ max and complications or readmissions. No difference in overall survival was seen if R0 resection was achieved.IMPACT STATEMENTWhat is already known on this subject? CPET testing allows pre-operative assessment of functional capacity to generate variables that can be used as a risk-stratification tool for major surgery. Whilst CPET testing has been shown to predict morbidity in non-gynaecological surgery, it remains unproven in cytoreductive surgery for ovarian cancer surgery despite being increasingly utilised.What do the results of study add? Our data suggest that CPET testing does not predict complication rates or survival in AOC. Patients with poor CPET performance are more likely to receive suboptimal cytoreductive outcomes from surgery.What are the implications of these findings for clinical practice and/or further research? CPET results should not be used to discount patients from cytoreductive surgery further research should address the interplay with nutrition, haematological markers, neoadjuvant chemotherapy and CPET performance.

Effect of two different pre-operative exercise training regimens before colorectal surgery on functional capacity: A randomised controlled trial

BACKGROUND

Multimodal prehabilitation, including exercise training, nutritional therapy and anxiety reduction, has been shown to attenuate functional decline associated with surgery. Due to the growing interest in functional status as a targeted surgical outcome, a better understanding of the optimal prescription of exercise is critical.

OBJECTIVE

The objective is to compare peri-operative functional trajectory in response to two different exercise training protocols within a 4-week, supervised, multimodal prehabilitation programme.

DESIGN

This was a single blinded, single centre, randomised controlled study. Participants performed four assessments: at baseline, after prehabilitation (just before surgery), and at 1 and 2 months after surgery.

PATIENTS

Adult patients scheduled for elective resection of nonmetastatic colorectal cancer were included provided there were no absolute contraindications to exercise nor poor language comprehension.

INTERVENTION

Patients followed either high-intensity interval training (HIIT), or moderate intensity continuous training (MICT), as part of a 4-week multimodal prehabilitation programme. Both groups followed the same supervised resistance training, nutritional therapy and anxiety reduction interventions. All patients followed standardised peri-operative management.

MAIN OUTCOME MEASURE

Changes in oxygen consumption at anaerobic threshold, measured with sequential cardio-pulmonary exercise testing, were assessed and compared between groups.

RESULTS

Forty two patients were included in the primary analysis (HIIT n = 21 vs. MICT n = 21), with mean ± SD age 64.5 ± 11.2 years and 62% were men. At 2 months after surgery, 13/21 (62%) in HIIT and 11/21 (52%) in MICT attended the study visits. Both protocols significantly enhanced pre-operative functional capacity, with no difference between groups: mean (95% confidence interval) oxygen consumption at anaerobic threshold 1.97 (0.75 to 3.19) ml kg min in HIIT vs. 1.71 (0.56 to 2.85) in MICT, P = 0.753. At 2 months after surgery, the HIIT group showed a higher improvement in physical fitness: 2.36 (0.378 to 4.34) ml kg min, P = 0.021. No adverse events occurred during the intervention.

CONCLUSION

Both MICT and HIIT enhanced pre-operative functional capacity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03361150.

Utilizing Machine Learning Techniques to Predict the Efficacy of Aerobic Exercise Intervention on Young Hypertensive Patients Based on Cardiopulmonary Exercise Testing

Recently, the incidence of hypertension has significantly increased among young adults. While aerobic exercise intervention (AEI) has long been recognized as an effective treatment, individual differences in response to AEI can seriously influence clinicians' decisions. In particular, only a few studies have been conducted to predict the efficacy of AEI on lowering blood pressure (BP) in young hypertensive patients. As such, this paper aims to explore the implications of various cardiopulmonary metabolic indicators in the field by mining patients' cardiopulmonary exercise testing (CPET) data before making treatment plans. CPET data are collected "breath by breath" by using an oxygenation analyzer attached to a mask and then divided into four phases: resting, warm-up, exercise, and recovery. To mitigate the effects of redundant information and noise in the CPET data, a sparse representation classifier based on analytic dictionary learning was designed to accurately predict the individual responsiveness to AEI. Importantly, the experimental results showed that the model presented herein performed better than the baseline method based on BP change and traditional machine learning models. Furthermore, the data from the exercise phase were found to produce the best predictions compared with the data from other phases. This study paves the way towards the customization of personalized aerobic exercise programs for young hypertensive patients.

Assessment of Exercise Intolerance in Patients with Pre-Dialysis CKD with Cardiopulmonary Function Testing: Translation to Everyday Practice

BACKGROUND

Chronic kidney disease (CKD) is often characterized by increased prevalence of cardiovascular risk factors and increased incidence of cardiovascular events and death. Reduced cardiovascular reserve and exercise intolerance are common in patients with CKD and are associated with adverse outcomes.

SUMMARY

The gold standard for identifying exercise limitation is cardiopulmonary exercise testing (CPET). CPET provides an integrative evaluation of cardiovascular, pulmonary, hematopoietic, neuropsychological, and metabolic function during maximal or submaximal exercise. It is useful in clinical setting for differentiation of the causes of exercise intolerance, risk stratification, and assessment of response to relevant treatments. A number of recent studies have used CPET in patients with pre-dialysis CKD, aiming to assess the cardiovascular reserve of these individuals, as well as the effect of interventions such as exercise training programs on their functional capacity. This review provides an in-depth description of CPET methodology and an overview of studies that utilized CPET technology to assess cardiovascular reserve in patients with pre-dialysis CKD. Key Messages: CPET can delineate multisystem changes and offer comprehensive phenotyping of factors determining overall cardiovascular risk. Potential clinical applications of CPET in CKD patients range from objective diagnosis of exercise intolerance to preoperative and long-term risk stratification and providing intermediate endpoints for clinical trials. Future studies should delineate the association of CPET indexes, with cardiovascular and respiratory alterations and hard outcomes in CKD patients, to enhance its diagnostic and prognostic utility in this population.

Efficacy of Prehabilitation Including Exercise on Postoperative Outcomes Following Abdominal Cancer Surgery: A Systematic Review and Meta-Analysis

Objectives: This systematic review set out to identify, evaluate and synthesise the evidence examining the effect of prehabilitation including exercise on postoperative outcomes following abdominal cancer surgery. Methods: Five electronic databases (MEDLINE 1946-2020, EMBASE 1947-2020, CINAHL 1937-2020, PEDro 1999-2020, and Cochrane Central Registry of Controlled Trials 1991-2020) were systematically searched (until August 2020) for randomised controlled trials (RCTs) that investigated the effects of prehabilitation interventions in patients undergoing abdominal cancer surgery. This review included any form of prehabilitation either unimodal or multimodal that included whole body and/or respiratory exercises as a stand-alone intervention or in addition to other prehabilitation interventions (such as nutrition and psychology) compared to standard care. Results: Twenty-two studies were included in the systematic review and 21 studies in the meta-analysis. There was moderate quality of evidence that multimodal prehabilitation improves pre-operative functional capacity as measured by 6 min walk distance (Mean difference [MD] 33.09 metres, 95% CI 17.69-48.50; p = <0.01) but improvement in cardiorespiratory fitness such as preoperative oxygen consumption at peak exercise (VO2 peak; MD 1.74 mL/kg/min, 95% CI -0.03-3.50; p = 0.05) and anaerobic threshold (AT; MD 1.21 mL/kg/min, 95% CI -0.34-2.76; p = 0.13) were not significant. A reduction in hospital length of stay (MD 3.68 days, 95% CI 0.92-6.44; p = 0.009) was observed but no effect was observed for postoperative complications (Odds Ratio [OR] 0.81, 95% CI 0.55-1.18; p = 0.27), pulmonary complications (OR 0.53, 95% CI 0.28-1.01; p = 0.05), hospital re-admission (OR 1.07, 95% CI 0.61-1.90; p = 0.81) or postoperative mortality (OR 0.95, 95% CI 0.43-2.09, p = 0.90). Conclusion: Multimodal prehabilitation improves preoperative functional capacity with reduction in hospital length of stay. This supports the need for ongoing research on innovative cost-effective prehabilitation approaches, research within large multicentre studies to verify this effect and to explore implementation strategies within clinical practise.

Perioperative management and anaesthetic considerations in pelvic exenterations using Delphi methodology: results from the PelvEx Collaborative

BACKGROUND

The multidisciplinary perioperative and anaesthetic management of patients undergoing pelvic exenteration is essential for good surgical outcomes. No clear guidelines have been established, and there is wide variation in clinical practice internationally. This consensus statement consolidates clinical experience and best practice collectively, and systematically addresses key domains in the perioperative and anaesthetic management.

METHODS

The modified Delphi methodology was used to achieve consensus from the PelvEx Collaborative. The process included one round of online questionnaire involving controlled feedback and structured participant response, two rounds of editing, and one round of web-based voting. It was held from December 2019 to February 2020. Consensus was defined as more than 80 per cent agreement, whereas less than 80 per cent agreement indicated low consensus.

RESULTS

The final consensus document contained 47 voted statements, across six key domains of perioperative and anaesthetic management in pelvic exenteration, comprising preoperative assessment and preparation, anaesthetic considerations, perioperative management, anticipating possible massive haemorrhage, stress response and postoperative critical care, and pain management. Consensus recommendations were developed, based on consensus agreement achieved on 34 statements.

CONCLUSION

The perioperative and anaesthetic management of patients undergoing pelvic exenteration is best accomplished by a dedicated multidisciplinary team with relevant domain expertise in the setting of a specialized tertiary unit. This consensus statement has addressed key domains within the framework of current perioperative and anaesthetic management among patients undergoing pelvic exenteration, with an international perspective, to guide clinical practice, and has outlined areas for future clinical research.

Inverse Relationship of Maximal Exercise Capacity to Hospitalization Secondary to Coronavirus Disease 2019

OBJECTIVE

To investigate the relationship between maximal exercise capacity measured before severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and hospitalization due to coronavirus disease 2019 (COVID-19).

METHODS

We identified patients (≥18 years) who completed a clinically indicated exercise stress test between January 1, 2016, and February 29, 2020, and had a test for SARS-CoV-2 (ie, real-time reverse transcriptase polymerase chain reaction test) between February 29, 2020, and May 30, 2020. Maximal exercise capacity was quantified in metabolic equivalents of task (METs). Logistic regression was used to evaluate the likelihood that hospitalization secondary to COVID-19 is related to peak METs, with adjustment for 13 covariates previously identified as associated with higher risk for severe illness from COVID-19.

RESULTS

We identified 246 patients (age, 59±12 years; 42% male; 75% black race) who had an exercise test and tested positive for SARS-CoV-2. Among these, 89 (36%) were hospitalized. Peak METs were significantly lower (P<.001) among patients who were hospitalized (6.7±2.8) compared with those not hospitalized (8.0±2.4). Peak METs were inversely associated with the likelihood of hospitalization in unadjusted (odds ratio, 0.83; 95% CI, 0.74-0.92) and adjusted models (odds ratio, 0.87; 95% CI, 0.76-0.99).

CONCLUSION

Maximal exercise capacity is independently and inversely associated with the likelihood of hospitalization due to COVID-19. These data further support the important relationship between cardiorespiratory fitness and health outcomes. Future studies are needed to determine whether improving maximal exercise capacity is associated with lower risk of complications due to viral infections, such as COVID-19.

Exercise Testing and Training in Adults With Congenital Heart Disease: A Surgical Perspective

In the current era, the majority of children born with congenital heart disease (CHD) will survive well into adulthood because of major advances in surgical techniques, as well as in critical and medical care. However, reoperation and palliative surgical interventions are increasingly common in the adults with CHD. Tools to risk stratify patients effectively and therapies to improve outcomes are required to optimize the management of adult patients with CHD during the preoperative and postoperative periods and beyond. Exercise testing is an invaluable tool to guide risk stratification. In addition, exercise training in patients with CHD may decrease postoperative complications by enhancing physiological reserve and also has an important role in physical rehabilitation. This review aims to provide individualized recommendations on exercise prescription in patients with CHD in the preoperative and postoperative settings. The response to exercise testing and prognostic implications is also discussed.

The anaerobic threshold: 50+ years of controversy

The anaerobic threshold (AT) remains a widely recognized, and contentious, concept in exercise physiology and medicine. As conceived by Karlman Wasserman, the AT coalesced the increase of blood lactate concentration ([La^- ]), during a progressive exercise test, with an excess pulmonary carbon dioxide output ( V ̇ C O 2 ). Its principal tenets were: limiting oxygen (O₂ ) delivery to exercising muscle→increased glycolysis, La^- and H⁺ production→decreased muscle and blood pH→with increased H⁺ buffered by blood [HCO₃ ^- ]→increased CO₂ release from blood→increased V ̇ C O 2 and pulmonary ventilation. This schema stimulated scientific scrutiny which challenged the fundamental premise that muscle anoxia was requisite for increased muscle and blood [La^- ]. It is now recognized that insufficient O₂ is not the primary basis for lactataemia. Increased production and utilization of La^- represent the response to increased glycolytic flux elicited by increasing work rate, and determine the oxygen uptake ( V ̇ O 2 ) at which La^- accumulates in the arterial blood (the lactate threshold; LT). However, the threshold for a sustained non-oxidative contribution to exercise energetics is the critical power, which occurs at a metabolic rate often far above the LT and separates heavy from very heavy/severe-intensity exercise. Lactate is now appreciated as a crucial energy source, major gluconeogenic precursor and signalling molecule but there is no ipso facto evidence for muscle dysoxia or anoxia. Non-invasive estimation of LT using the gas exchange threshold (non-linear increase of V ̇ C O 2 versus V ̇ O 2 ) remains important in exercise training and in the clinic, but its conceptual basis should now be understood in light of lactate shuttle biology.

"Fit for Surgery? What's New in Preoperative Assessment of the High-Risk Patient Undergoing Pulmonary Resection"

Advances in perioperative assessment and diagnostics, together with developments in anesthetic and surgical techniques, have considerably expanded the pool of patients who may be suitable for pulmonary resection. Thoracic surgical patients frequently are perceived to be at high perioperative risk due to advanced age, level of comorbidity, and the risks associated with pulmonary resection, which predispose them to a significantly increased risk of perioperative complications, increased healthcare resource use, and costs. The definition of what is considered "fit for surgery" in thoracic surgery continually is being challenged. However, no internationally standardized definition of prohibitive risk exists. Perioperative assessment traditionally concentrates on the "three-legged stool" of pulmonary mechanical function, parenchymal function, and cardiopulmonary reserve. However, no single criterion should exclude a patient from surgery, and there are other perioperative factors in addition to the tripartite assessment that need to be considered in order to more accurately assess functional capacity and predict individual perioperative risk. In this review, the authors aim to address some of the more erudite concepts that are important in preoperative risk assessment of the patient at potentially prohibitive risk undergoing pulmonary resection for malignancy.

Cardiopulmonary Exercise Testing in Oesophagogastric Surgery: a Systematic Review

BACKGROUND

Cardiopulmonary exercise testing (CPX) can objectively measure fitness and oxygen uptake at anaerobic threshold. The relationship between fitness and postoperative outcomes after upper gastro-intestinal surgery is unclear. The aim of the present review is to assess the prognostic ability of CPX in predicting postoperative outcome associated with oesophagogastric surgery.

METHODS

Relevant studies were identified through a systematic search of EMBASE, Medline, CINAHL, Cochrane Library, and Web of Science to July 2019. The eligibility criteria for studies included prognostic studies of upper gastro-intestinal surgery among adult populations using a preoperative CPX and measurement of postoperative outcome (mortality or morbidity or length of stay). Risk of bias was assessed using the QUIPS Quality in Prognostic Studies validated tool.

RESULTS

Thirteen papers with a total of 1735 participants were included in data extraction. A total of 7 studies examined the association between CPX variables and postoperative mortality. Patients undergoing gastro-intestinal surgery with lower anaerobic threshold values were found to have an increased risk of postoperative mortality. Similarly, a lower rate of oxygen consumption was found to be associated with higher mortality. There was conflicting evidence regarding the association between CPX variables and postoperative morbidity. The evidence did not demonstrate any association between preoperative CPX variables and hospital length of stay.

CONCLUSION

Studies report an association between CPX variables and postoperative mortality; however, there is conflicting evidence regarding the association between CPX variables and postoperative morbidity.

Cardiopulmonary exercise testing - refining the clinical perspective by combining assessments

INTRODUCTION

Cardiorespiratory fitness (CRF) is now established as a vital sign. Cardiopulmonary exercise testing (CPX) is the gold-standard approach to assessing CRF.

AREAS COVERED

A body of literature spanning several decades clearly supports the clinical utility of CPX in those who are apparently health and at risk for chronic disease as well as numerous patient populations. While CPX, in and of itself, is a valid and reliable clinical assessment, combining findings with other available assessments may provide a more comprehensive perspective that enhances clinical decision making and outcomes. The current review will accomplish the following: (1) define key CPX measures based upon current evidence; and (2) describe the current evidence addressing the relationships between CPX and echocardiography, serum biomarkers, and cardiovascular magnetic resonance.

EXPERT OPINION

Cardiopulmonary exercise testing provides prognostic and diagnostic information in apparently healthy individuals, those at risk for one or more chronic conditions, as well as numerous patient populations. Moreover, if the goal of an intervention is to improve one or more systems integral to the physiologic response to exercise, CPX should be considered as a central assessment to gauge therapeutic efficacy. To further refine the information obtained from CPX, combining other assessments has demonstrated promise.

Preoperative Cardiac Risk Assessment

Major adverse cardiac events are common causes of perioperative mortality and major morbidity. Preventing these complications requires thorough preoperative risk assessment and postoperative monitoring of at-risk patients. Major guidelines recommend assessment based on a validated risk calculator that incorporates patient- and procedure-specific factors. American and European guidelines define when stress testing is needed on the basis of functional capacity assessment. Favoring cost-effectiveness, Canadian guidelines instead recommend obtaining brain natriuretic peptide or N-terminal prohormone of brain natriuretic peptide levels to guide postoperative screening for myocardial injury or infarction. When conditions such as acute coronary syndrome, severe pulmonary hypertension, and decompensated heart failure are identified, nonemergent surgery should be postponed until the condition is appropriately managed. There is an evolving role of biomarkers and myocardial injury after noncardiac surgery to enhance risk stratification, but the effect of interventions guided by these strategies is unclear.

Enhanced recovery after surgery programmes in older patients undergoing hepatopancreatobiliary surgery: what benefits might prehabilitation have?

Due to an aging population and the related growing number of less physically fit patients with multiple comorbidities, adequate perioperative care is a new and rapidly developing clinical science that is becoming increasingly important. This narrative review focuses on enhanced recovery after surgery (ERAS®) programmes and the growing interest in prehabilitation programmes to improve patient- and treatment-related outcomes in older patients undergoing hepatopancreatobiliary (HPB) surgery. Future steps required in the further development of optimal perioperative care in HPB surgery are also discussed. Multidisciplinary preoperative risk assessment in multiple domains should be performed to identify, discuss, and reduce risks for optimal outcomes, or to consider alternative treatment options. Prehabilitation should focus on high-risk patients based on evidence-based cut-off values and should aim for (partly) supervised multimodal prehabilitation tailored to the individual patient's risk factors. The program should be executed in the living context of these high-risk patients to improve the participation rate and adherence, as well as to involve the patient's informal support system. Developing tailored (multimodal) prehabilitation programmes for the right patients, in the right context, and using the right outcome measures is important to demonstrate its potential to further improve patient- and treatment-related outcomes following HPB surgery.

Cardiopulmonary Exercise Testing for Preoperative Evaluation: What Does the Future Hold?

Purpose of Review

Cardiopulmonary exercise testing (CPET) informs the preoperative evaluation process by providing individualised risk profiles; guiding shared decision-making, comorbidity optimisation and preoperative exercise training; and informing perioperative patient management. This review summarises evidence on the role of CPET in preoperative evaluation and explores the role of novel and emerging CPET variables and alternative testing protocols that may improve the precision of preoperative evaluation in the future.

Recent Findings

CPET provides a wealth of physiological data, and to date, much of this is underutilised clinically. For example, impaired chronotropic responses during and after CPET are simple to measure and in recent studies are predictive of both cardiac and noncardiac morbidity following surgery but are rarely reported. Exercise interventions are increasingly being used preoperatively, and endurance time derived from a high intensity constant work rate test should be considered as the most sensitive method of evaluating the response to training. Further research is required to identify the clinically meaningful difference in endurance time. Measuring efficiency may have utility, but this requires exploration in prospective studies.

Summary

Further work is needed to define contemporaneous risk thresholds, to explore the role of other CPET variables in risk prediction, to better characterise CPET’s role in combination with other tools in multifactorial risk stratification and increasingly to evaluate CPET’s utility for preoperative exercise prescription in prehabilitation.

The association between preoperative physical functioning and short-term postoperative outcomes: a cohort study of patients undergoing elective hepatic resection

BACKGROUND

This study evaluated the association between practical performance-based indices of preoperative physical functioning and short-term postoperative outcomes in patients undergoing hepatic resection.

METHOD

Preoperative characteristics and results of practical performance-based tests of physical functioning were analyzed concerning the effect on postoperative outcomes (recovery of physical functioning, non-surgical complications, and length of hospital stay) using univariable and multivariable logistic regression.

RESULTS

Perioperative data of 96 patients showed that besides the conventional risk-factors (American Society of Anesthesiologists grade III and BMI), lower absolute steep ramp test performance (in watts; OR 0.992), and lower perceived level of functional capacity to perform activities of daily living (ADL) on Duke activity status index (in metabolic equivalent of task (MET); OR 0.806) and lower score on the veterans-specific activity questionnaire (in MET, OR 0.875) were associated with delayed recovery of physical functioning. Furthermore, more comorbidities, worse functional mobility, and lower levels of perceived functional capacity to perform ADL were associated with non-surgical complications and length of hospital stay.

CONCLUSION

Adequate preoperative performance and perceived level of functional capacity to perform ADL appear to be of importance to identify individual patients that are at risk of a complicated postoperative course.

Peak oxygen uptake reference values for cycle ergometry for the healthy Dutch population: data from the LowLands Fitness Registry

Peak oxygen uptake (V′_O2peak) is recognised as the best expression of aerobic fitness. Therefore, it is essential that V′_O2peak reference values are accurate for interpreting a cardiopulmonary exercise test (CPET). These values are country specific and influenced by underlying biological ageing processes. They are normally stratified per paediatric and adult population, resulting in a discontinuity at the transition point between prediction equations. There are currently no age-related reference values available for the lifespan of individuals in the Dutch population. The aim of this study is to determine the best-fitting regression model for V′_O2peak in the healthy Dutch paediatric and adult populations in relation to age.

In this retrospective study, CPET cycle ergometry results of 4477 subjects without reported somatic diseases were included (907 females, age 7.9–65.0 years). Generalised additive models were employed to determine the best-fitting regression model. Cross-validation was performed against an independent dataset consisting of 3518 subjects (170 females, age 6.8–59.0 years).

An additive model was the best fitting with the largest predictive accuracy in both the primary (adjusted R²=0.57, standard error of the estimate (see)=556.50 mL·min⁻¹) and cross-validation (adjusted R²=0.57, see=473.15 mL·min⁻¹) dataset.

This study provides a robust additive regression model for V′_O2peak in the Dutch population.

Peak oxygen uptake has a nonlinear dependence on years of age in the paediatric and adult Dutch populationshttp://ow.ly/H3fH30nIjRy

Cardiopulmonary exercise testing (CPET) in the United Kingdom-a national survey of the structure, conduct, interpretation and funding

Background

Cardiopulmonary exercise testing (CPET) is an exercise stress test with concomitant expired gas analysis that provides an objective, non-invasive measure of functional capacity under stress. CPET-derived variables predict postoperative morbidity and mortality after major abdominal and thoracic surgery. Two previous surveys have reported increasing utilisation of CPET preoperatively in England. We aimed to evaluate current CPET practice in the UK, to identify who performs CPET, how it is performed, how the data generated are used and the funding models.

Methods

All anaesthetic departments in trusts with adult elective surgery in the UK were contacted by telephone to obtain contacts for their pre-assessment and CPET service leads. An online survey was sent to all leads between November 2016 and March 2017.

Results

The response rate to the online survey was 73.1% (144/197) with 68.1% (98/144) reporting an established clinical service and 3.5% (5/144) setting up a service. Approximately 30,000 tests are performed a year with 93.0% (80/86) using cycle ergometry. Colorectal surgical patients are the most frequently tested (89.5%, 77/86). The majority of tests are performed and interpreted by anaesthetists. There is variability in the methods of interpretation and reporting of CPET and limited external validation of results.

Conclusions

This survey has identified the continued expansion of perioperative CPET services in the UK which have doubled since 2011. The vast majority of CPET tests are performed and reported by anaesthetists. It has highlighted variation in practice and a lack of standardised reporting implying a need for practice guidelines and standardised training to ensure high-quality data to inform perioperative decision making.