CPET and cardioesophagectomy: A single centre 10-year experience

Physical fitness predicts post-esophagectomy complications after chemoradiotherapy: a pilot study

BACKGROUND

Esophagectomy following neoadjuvant chemoradiotherapy or definitive chemoradiotherapy has been shown to yield favorable oncological outcomes in patients with locally advanced esophageal squamous cell carcinoma. However, postoperative complications are frequent and can adversely affect patient survival. This study aimed to identify physical fitness factors across multiple domains associated with major postoperative complications.

METHODS

This study enrolled patients with esophageal squamous cell carcinoma who were treated with neoadjuvant chemoradiotherapy or definitive chemoradiotherapy and underwent esophagectomy between 2020 and 2022. Multivariate logistic regression analysis was conducted to identify the factors associated with major postoperative complications. Additionally, a tree-based learning process was employed to assess all the variables influencing major complications.

RESULTS

A total of 142 esophageal cancer patients who underwent esophagectomy were screened. Of these, 72 eligible patients were included in the study, and 29 (40.2%) experienced major postoperative complications. In the full model, factors such as low body weight, low body mass index, low peak oxygen consumption (V̇O2peak), low V̇O2peak/skeletal muscle mass (SMM), low appendicular skeletal muscle index (ASMI), and low ASMI-V̇O2peak/SMM product (AV̇P) were found to be significantly associated with major postoperative complications. However, in the parsimonious model, only low AV̇P (P < 0.01) was associated with major complications. Additionally, AV̇P, EqO2nadir, and hand grip strength emerged as the key predictors of major post-esophagectomy complications in the tree-based learning analysis, which showed a sensitivity of 0.448, specificity of 0.977, and accuracy of 76.4%, with false negative and false positive rates of 55.2% and 2.3%. AV̇P alone yielded similar results.

CONCLUSIONS

Patients with low AV̇P, high EqO2nadir, and low HGS are at a very high risk of experiencing major postoperative complications, with low AV̇P showing the strongest correlation. Preoperative physical fitness screening can help identify high-risk patients and guide appropriate perioperative management.

The Steep Ramp Test as Precursor to Assess Physical Fitness before Esophagectomy in Cancer Patients

INTRODUCTION

Maximum oxygen uptake (VO2max) is a predictor for postoperative complications after esophagectomy. Cardiopulmonary exercise test (CPET) is the golden standard for measuring VO2max. The alternative steep ramp test (SRT) is less strenuous with several benefits, providing an estimation of VO2max. This study aimed to determine whether SRT is a reliable alternative for CPET to evaluate preoperative fitness.

METHODS

A total of 113 patients were included in this study. The agreement between SRT and CPET was analyzed using a t test, Intraclass correlation coefficient (ICC), and the Bland-Altman analysis. The threshold for adequate preoperative fitness was set at 17.0 mL/kg/min.

RESULTS

The mean difference between CPET and SRT was 2.77 mL/kg/min (95% confidence interval [CI]: 2.14-3.41). The ICC was 0.79 (95% CI: 0.70-0.85). The upper limit of agreement of the Bland-Altman was 9.44. The addition of 9.44 to the CPET threshold gives an SRT threshold of 26.44 mL/kg/min. Thirty-one (27.4%) patients scored higher than the SRT threshold.

CONCLUSION

The SRT VO2max differs from VO2max as measured by CPET. However, the difference was found to be clinically irrelevant for a substantial portion of patients. Hence, SRT is a promising alternative to CPET for determining physical fitness and might render CPET obsolete for fit individuals.

Different measures of ventilatory efficiency in preoperative cardiopulmonary exercise testing are useful for predicting postoperative complications in abdominal cancer surgery

BACKGROUND

Ventilation as a function of elimination of CO2 during incremental exercise (VE/VCO2 slope) has been shown to be a valuable predictor of complications and death after major non-cardiac surgery. VE/VCO2 slope and partial pressure of end-tidal carbon dioxide (PetCO2) are both affected by ventilation/perfusion mismatch, but research on the utility of PetCO2 for risk stratification in major abdominal surgery is limited.

AIM

We aimed to determine the correlation between VE/VCO2 slope and PetCO2 measured during preoperative cardiopulmonary exercise testing (CPET) and its association with major cardiopulmonary complications (MCPCs) or death following oesophageal and other major abdominal cancer surgeries.

METHOD

In a retrospective cohort of 116 patients undergoing preoperative CPET 2008-2023, VE/VCO2 slope and PetCO2 (kPa) were recorded. The main outcome was MCPC during hospitalisation or death ≤90 days of surgery. We determined threshold values for each measure, corresponding to 90% specificity, using receiver operating characteristics analysis.

RESULTS

A strong negative correlation was found between PetCO2 after a 5-minute warm-up and VE/VCO2 slope (Pearson r = -.88). In oesophagus cancer, VE/VCO2 slope >38 and PetCO2 < 4.1 kPa (30.8 mmHg) were both significant thresholds for the main outcome. For other major abdominal surgery patients, threshold analyses were non-significant. The area under the curve to predict outcome was similar using VE/VCO2 slope (0.70, 95% confidence interval 0.51-0.89) as compared to PetCO2 (0.71, 0.53-0-90).

CONCLUSION

Both preoperative VE/VCO2 slope and PetCO2 could identify subjects with a very high risk of complications following oesophageal resection, with similar prognostic utility. PetCO2 can be measured with simpler equipment and could therefore be useful when CPET is not available.

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).

Peak oxygen uptake in combination with ventilatory efficiency improve risk stratification in major abdominal surgery

This pilot study aimed to evaluate if peak VO2 and ventilatory efficiency in combination would improve preoperative risk stratification beyond only relying on peak VO2 . This was a single-center retrospective cohort study including all patients who underwent cardiopulmonary exercise testing (CPET) as part of preoperative risk evaluation before major upper abdominal surgery during years 2008-2021. The primary outcome was any major cardiopulmonary complication during hospitalization. Forty-nine patients had a preoperative CPET before decision to pursue to surgery (cancer in esophagus [n = 18], stomach [6], pancreas [16], or liver [9]). Twenty-five were selected for operation. Patients who suffered any major cardiopulmonary complication had lower ventilatory efficiency (i.e., higher VE/VCO2 slope, 37.3 vs. 29.7, p = 0.031) compared to those without complications. In patients with a low aerobic capacity (i.e., peak VO2  < 20 mL/kg/min) and a VE/VCO2 slope ≥ 39, 80% developed a major cardiopulmonary complication. In this pilot study of patients with preoperative CPET before major upper abdominal surgery, patients who experienced a major cardiopulmonary complication had significantly lower ventilatory efficiency compared to those who did not. A low aerobic capacity in combination with low ventilatory efficiency was associated with a very high risk (80%) of having a major cardiopulmonary complication.

Postoperative hyperlactataemia and preoperative cardiopulmonary exercise testing in an elective noncardiac surgical cohort: a retrospective observational study

Background

Blood lactate concentration in the postoperative period is a marker of physiological stress and a predictor of complications and mortality. Cardiopulmonary exercise testing (CPET) is a common preoperative risk stratification tool. We aimed to investigate the association between preoperative CPET results and postoperative lactate concentration with postoperative mortality after major noncardiac surgery.

Methods

We analysed data from patients undergoing major noncardiac surgery in a tertiary UK centre between 2007 and 2014 who had preoperative CPET and postoperative lactate measurements. Univariate and multivariate analyses were performed to assess the association between lactate concentration, CPET results, or both and mortality.

Results

We analysed data from 1075 patients. A mean lactate concentration >2 mM in the first 12, 24, and 48 h after surgery was associated with odds ratios (ORs) and 95% confidence intervals (CIs) for 30-day mortality of 3.9 (2.1-7.3; P<0.005), 4.5 (2.4-8.4; P<0.005), and 6.1 (3.3-11.5; P<0.005), respectively. The dichotomous CPET variable, ventilatory equivalence for CO2 (V̇E/V̇co2; cut-off 34), was associated with increased risk of 30-day mortality (OR 2.5; 95% CI: 1.3-4.8; P<0.005). In a multivariable model, hyperlactataemia and poor V̇E/V̇co2 retained their significant associations with 30- and 90-day mortality when adjusted for age, BMI, and surgical risk. When looking at the combined effect of the dichotomous hyperlactataemia in the first 24 h (cut-off 2 mM) and preoperative V̇E/V̇co2, the OR for 30-day mortality was 11.53 (95% CI: 4.6-28.8; P≤0.005).

Conclusions

Our study suggests that postoperative hyperlactataemia and preoperative poor V̇E/V̇co2 are independently associated with an increased risk of mortality after major noncardiac surgery.

Does Cardiopulmonary Testing Help Predict Long-Term Survival After Esophagectomy?

Background

Esophagectomy is associated with a high rate of morbidity and mortality. Preoperative cardiopulmonary fitness has been correlated with outcomes of major surgery. Variables derived from cardiopulmonary exercise testing (CPET) have been associated with postoperative outcomes. It is unclear whether preoperative cardiorespiratory fitness of patients undergoing esophagectomy is associated with long-term survival. This study aimed to evaluate whether any of the CPET variables routinely derived from patients with esophageal cancer may aid in predicting long-term survival after esophagectomy.

Methods

Patients undergoing CPET followed by trans-thoracic esophagectomy for esophageal cancer with curative intent between January 2013 and January 2017 from single high-volume center were retrospectively analyzed. The relationship between predictive co-variables, including CPET variables and survival, was studied with a Cox proportional hazard model. Receiver operation curve (ROC) analysis was performed to find cutoff values for CPET variables predictive of 3-year survival.

Results

The study analyzed 313 patients. The ventilatory equivalent for carbon dioxide (VE/VCO₂) at the anerobic threshold was the only CPET variable independently predictive of long-term survival in the multivariable analysis (hazard ratio [HR], 1.049; 95% confidence interval [CI], 1.011–1.088; p = 0.011). Pathologic stages 3 and 4 disease was the other co-variable found to be independently predictive of survival. An ROC analysis of the VE/VCO₂ failed to demonstrate a predictive cutoff value of 3-year survival (area under the curve, 0.564; 95% CI, 0.499–0.629; p = 0.056).

Conclusions

A high VE/VCO₂ before esophagectomy for malignant disease is an independent predictor of long-term survival and may be an important variable for clinicians to consider when counseling patients.

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.