The prognostic value of exercise capacity: a review of the literature

Assessment of Maximum Heart Rate Prediction Equations in Adults at Low and High Risk of Cardiovascular Disease

PURPOSE

Maximum heart rate (HRmax) is commonly used to estimate exercise intensity. Since direct measurement of HRmax is not always practical, prediction equations were developed. However, most equations have not been properly validated in adults at low and high risk of cardiovascular disease (CVD). We sought to: 1) assess the accuracy of commonly used equations to predict HRmax among adults at low and high CVD risk and, 2) determine if SuperLearner (SL) modeling combining base machine algorithms could improve HRmax prediction.

METHODS

A total of 1208 participants (61.6 ± 7.3 yr; 62.7% male) were included. HRmax was measured during a maximal cardiorespiratory exercise test. Predicted HRmax was estimated using the following published equations: Fox, Åstrand, Tanaka, Gelish and Gulati, and a SL model. Bland-Altman analyses as well as performance indicators such as root mean squared error (RMSE) and Lin's Concordance Correlation Coefficient were performed.

RESULTS

All predicted HRmax-derived equations were positively associated with measured HRmax (women: r = 0.31; men: r = 0.46, P ≤ 0.001) but to a greater extent using a SL model (women: r = 0.47; men: r = 0.59, P ≤ 0.001). Overall, all equations tended to overestimate measured HRmax, with a RMSE which varied between 10.4 and 12.3 bpm. Although the SL model outperformed other equations, with no significant difference between measured and predicted HRmax, RMSE remained high (11.3 bpm). Lack of accuracy was mainly observed among adults with low aerobic fitness and with CVD risk factors, such as obesity, diabetes, and hypertension.

CONCLUSIONS

We showed that commonly used equations and the SL model have insufficient accuracy to predict HRmax among adults. The performance of the prediction equations varied considerably according to the population clinical characteristics such as the presence of CVD risk factors or a low aerobic fitness.

Reproducibility (reliability and agreement) of ventilatory threshold and peak responses during cardiopulmonary exercise test in people with stroke

BACKGROUND

A cardiopulmonary exercise test (CPET) is used to determine the ventilatory thresholds and to directly assess cardiorespiratory capacity. However, its reproducibility should be tested in people with stroke as sequelae imposed by the stroke may induce important variations among and within each subject, affecting the reproducibility of the physiological responses to CPET.

PURPOSE

This cross-sectional repeated measures study design aims to determine the reproducibility of anaerobic threshold (AT), respiratory compensation point (RCP), and maximal cardiorespiratory capacity assessed during a CPET in people with stroke.

METHODS

Twenty-eight subjects with hemiparesis after stroke aging 60 ± 13 years were submitted to two treadmill CPETs with identical protocols.

DATA ANALYSIS

The reproducibility of heart rate (HR) and oxygen consumption (VO2) obtained at AT, RCP, and peak effort was evaluated by systematic error (paired t-test); reliability (ICC and 95% confidence interval); and agreement (typical error and coefficient of variation).

RESULTS

There were no systematic errors for HR and VO2assessed at AT, RCP, and peak effort (p  > 0,05). Reliability was high for these variables during CPET (ICCs > 0.93). Agreement was good for all variables. Typical errors for HR and VO2 assessed at AT, RCP, and peak effort were, respectively, 7, 7, and 8 bpm, and 1.51, 1.44, and 1.57 ml.kg-1.min-1. Coefficients of variation assessed at AT, RCP, and peak effort were, respectively, 5.7, 5.1, and 6.0% for HR and 8.7, 7.3, and 7.5% for VO2.

CONCLUSIONS

HR and VO2 measured at AT, RCP, and peak effort during a treadmill CPET present good reproducibility in people with stroke, showing high reliability and good agreement.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Effects of high-intensity interval robot-assisted gait training on cardiopulmonary function and walking ability in chronic stroke survivors: A multicenter single-blind randomized controlled trial

BACKGROUND

Chronic stroke can impair cardiopulmonary function, mobility, and daily activities. This study assessed the impact of robot-assisted gait training (RAGT) on such impairments.

OBJECTIVE

To investigate the effects of robot-assisted gait training on cardiopulmonary function, walking ability, lower extremity function and strength, activities of daily living (ADLs), and blood test results among individuals with chronic stroke.

METHODS

A multicenter, prospective, single-blinded, randomized controlled trial with 22 chronic stroke participants compared RAGT against a control exercise regimen. RAGT involved three days weekly sessions of high-intensity interval training for 8 weeks (24 sessions) with a Morning Walk® device. The control group also performed home exercises. (24 sessions) Measures included VO2max, Functional Ambulatory Category, 2-minute walk test, 10-meter walk test, Motricity Index-Lower, Korean version of the Fugl-Meyer Assessment Scale, Modified Barthel Index, Berg Balance Scale, muscle strength, InBody body composition, and blood tests (cholesterol, lipid, glucose).

RESULTS

RAGT significantly improved VO2max, gait, balance, and lower limb strength compared with controls, with significant improvements in 2-minute walk test, 10-meter walk test, Motricity Index-Lower, and Fugl-Meyer Assessment outcomes. No changes were seen in muscle mass or blood markers.

CONCLUSION

RAGT enhances cardiopulmonary function and ambulatory capacity in chronic stroke patients, underscoring its potential in stroke rehabilitation.

Utility of Cardiopulmonary Exercise Testing in Chronic Obstructive Pulmonary Disease: A Review

Chronic obstructive pulmonary disease (COPD) is a disease defined by airflow obstruction with a high morbidity and mortality and significant economic burden. Although pulmonary function testing is the cornerstone in diagnosis of COPD, it cannot fully characterize disease severity or cause of dyspnea because of disease heterogeneity and variable related and comorbid conditions affecting cardiac, vascular, and musculoskeletal systems. Cardiopulmonary exercise testing (CPET) is a valuable tool for assessing physical function in a wide range of clinical conditions, including COPD. Familiarity with measurements made during CPET and its potential to aid in clinical decision-making related to COPD can thus be useful to clinicians caring for this population. This review highlights pulmonary and extrapulmonary impairments that can contribute to exercise limitation in COPD. Key elements of CPET are identified with an emphasis on measurements most relevant to COPD. Finally, clinical applications of CPET demonstrated to be of value in the COPD setting are identified. These include quantifying functional capacity, differentiating among potential causes of symptoms and limitation, prognostication and risk assessment for operative procedures, and guiding exercise prescription.

Benefits of Prehabilitation before Complex Aortic Surgery

The purpose of this narrative review was to detail and discuss the underlying principles and benefits of preoperative interventions addressing risk factors for perioperative adverse events in open aortic surgery (OAS). The term "complex aortic disease" encompasses juxta/pararenal aortic and thoraco-abdominal aneurysms, chronic aortic dissection and occlusive aorto-iliac pathology. Although endovascular surgery has been increasingly favored, OAS remains a durable option, but by necessity involves extensive surgical approaches and aortic cross-clamping and requires a trained multidisciplinary team. The physiological stress of OAS in a fragile and comorbid patient group mandates thoughtful preoperative risk assessment and the implementation of measures dedicated to improving outcomes. Cardiac and pulmonary complications are one of the most frequent adverse events following major OAS and their incidences are correlated to the patient's functional status and previous comorbidities. Prehabilitation should be considered in patients with risk factors for pulmonary complications including advanced age, previous chronic obstructive pulmonary disease, and congestive heart failure with the aid of pulmonary function tests. It should also be combined with other measures to improve postoperative course and be included in the more general concept of enhanced recovery after surgery (ERAS). Although the current level of evidence regarding the effectiveness of ERAS in the setting of OAS remains low, an increasing body of literature has promoted its implementation in other specialties. Consequently, vascular teams should commit to improving the current evidence through studies to make ERAS the standard of care for OAS.

What are the prognostic implications and factors relating to exercise induced electrocardiographic ST segment changes in the setting of a non-ischemic stress echocardiogram?

BACKGROUND

Electrocardiographic (ECG) changes during stress testing are a common and perplexing finding during non-ischemic stress echocardiography (niSE). Research has provided conflicting results regarding the implications.

METHODS

SE was performed after maximal Bruce protocol treadmill exercise.

RESULTS

3020 consecutive patients, mean age 58 ± 12 years, 36% female, were followed-up for up to 9 years (mean 36 ± 21 months) post niSE. Time to first cardiac event (composite of heart failure admission, worsening New York Heart Association class, worsening ejection fraction, acute coronary syndrome, revascularization, angina or cardiovascular death) was analysed and adjusted using Cox proportional hazards regression. Prognostic significance was found with 1.5 mm of downsloping or horizontal ST depression. Adjusting for baseline differences, increased risk of composite major adverse cardiac events was shown with at least 1.5 mm of exercise induced ST depression (Hazard ratio [HR] of 2.47, 95% Confidence ratio [CI] 1.67-3.72, p < 0.0001). Patients achieving high level exercise capacity (≥13 metabolic equivalents or METs) with ST depression lower risk of cardiac events during follow-up.

CONCLUSION

Patients with ST segment depression but non-ischemic stress imaging have a poorer prognosis compared to patients with niSE with normal stress ECGs. ST depression of 1.5 mm or more was established as a prognostically significance value. High exercise capacity was associated with an improved prognosis, and ECG changes in that setting can be regarded as false positives. All niSE have low risk of a cardiac event in the very short term (<12 months). Overall, ST depression during non-ischaemic stress imaging is not a benign finding.

Screening for occult coronary artery disease in potential kidney transplant recipients: time for reappraisal?

Screening for occult coronary artery disease in potential kidney transplant recipients has become entrenched in current medical practice as the standard of care and is supported by national and international clinical guidelines. However, there is increasing and robust evidence that such an approach is out-dated, scientifically and conceptually flawed, ineffective, potentially directly harmful, discriminates against ethnic minorities and patients from more deprived socioeconomic backgrounds, and unfairly denies many patients access to potentially lifesaving and life-enhancing transplantation. Herein we review the available evidence in the light of recently published randomized controlled trials and major observational studies. We propose ways of moving the field forward to the overall benefit of patients with advanced kidney disease.

Dose-dependent effects of aerobic exercise on clinically relevant biomarkers among healthy women at high genetic risk for breast cancer: A secondary analysis of a randomized controlled study

BACKGROUND

Excess adiposity and dysregulated metabolism are associated with increased cancer risk. Triglycerides, cholesterol, glucose, insulin, HOMA-IR, and VO₂ max are robust clinical-metabolic biomarkers of overall health.

AIMS

Aerobic exercise may improve clinical-metabolic biomarkers and decrease cancer risk. This secondary analysis of the WISER Sister randomized controlled trial investigated dose-dependent effects of aerobic exercise on clinical biomarker levels in women at high genetic risk for breast cancer.

METHODS AND RESULTS

One hundred thirty-nine participants were randomized to: control (<75 min/week), low-dose (150 min/week), and high-dose (300 min/week) aerobic exercise intervention groups. Intervention adherence was assessed via heart monitor. Fasting blood draws, cardio-pulmonary tests, and demographical surveys were taken at baseline and 5 months. Triglyceride, cholesterol, glucose, insulin, and VO₂ max changes were assessed for 80 of the 122 study completers. Ninety-six percent of assayed-completers adhered to >80% of their exercise dose. A significant dose-dependent increase in VO₂ max was observed for the low-dose and high-dose groups compared to control. No intervention effects were observed for plasma biomarkers. Overweight women (BMI > 25) showed a significant decrease in insulin levels and a trend for decreased triglycerides following exercise intervention. Significant increases in VO₂ max were independent of BMI stratification.

CONCLUSION

Women at high genetic risk for breast cancer should maintain healthy weights and aerobic capacities through aerobic exercise to achieve measurable benefits on overall health. For overweight women, exercise appears to improve subclinical metabolic dysregulation. However, normal weight women were unaffected by aerobic exercise as their biomarker levels may be below the threshold for improvement. VO₂ max increases solely quantified the benefits of exercise in already healthy women at high-risk for breast cancer.

Perioperative myocardial damage and the incidence of type 2 myocardial infarction in patients with intermediate and high cardiovascular risk

OBJECTIVE

Perioperative myocardial infarction is a major cause of morbidity and mortality in patients undergoing surgical operations. We aimed to determine the incidence of perioperative myocardial infarction in patients with intermediate- or high-risk Framingham scores.

METHODS

One hundred and one patients (62 males, 39 females) over 40 years of age (mean age 72±11 years) median 73 (65-81), min- max (46-96), with Framingham risk scores of 10% or higher, and scheduled for surgical interventions in the orthopedics and urology departments of our hospital were included in the study. Patient demographics, comorbidities, blood pressures, and biochemical data were recorded. Troponin values and electrocardiographic findings were obtained during the immediate preoperative period and on postoperative day 2 and then compared. Perioperative myocardial injury and infarction were diagnosed using the third universal definition of myocardial infarction.

RESULTS

In 44 (43%) patients, postoperative troponin values were compared with the preoperative values. In 26 (25%) patients, the changes were consistent with myocardial ischemia or damage. Alterations in troponin values with significant electrocardiogram (ECG) changes were found in 6 patients (6%).

CONCLUSION

The risk of postoperative myocardial damage was high in our patients with intermediate or high-risk Framingham scores. This im-plies that close follow-up of these patients with abnormal ECG and troponin values during the pre- and postoperative period is required.

Divergence in aerobic capacity impacts bile acid metabolism in young women

Liver adaptations may be critical for regular exercise and high aerobic capacity to protect against metabolic disease, but mechanisms remain unknown. Bile acids (BAs) synthesized in the liver are bioactive and can putatively modify energy metabolism. Regular exercise influences BA metabolism in rodents, but effects in humans are unknown. This study tested whether female subjects screened for high aerobic capacity (Hi-Fit, n = 19) [peak oxygen consumption (V̇o2peak) ≥45 mL·kg-1·min-1] have increased hepatic BA synthesis and different circulating BA composition compared with those matched for age and body mass with low aerobic capacity (Lo-Fit, n = 19) (V̇o2peak ≤35 mL·kg-1·min-1). Diet patterns, activity level, stool, and blood were collected at baseline before participants received a 1-wk standardized, eucaloric diet. After the 1-wk standardized diet, stool and blood were again collected and an oral glucose tolerance test (OGTT) was performed to assess insulin sensitivity and postprandial BA response. Contrary to our hypothesis, serum 7α-hydroxy-4-cholesten-3-one (C4), a surrogate of BA synthesis, was not different between groups, whereas Hi-Fit women had lower fecal BA concentrations compared with Lo-Fit women. However, Lo-Fit women had a higher and more sustained rise in circulating conjugated BAs during the OGTT. Hi-Fit women showed a significant post-OGTT elevation of the secondary BA, lithocholic acid (a potent TGR5 agonist), in contrast to Lo-Fit women where no response was observed. A 1-wk control diet eliminated most differences in circulating BA species between groups. Overall, the results emphasize the importance of using a standardized diet when evaluating BAs and indicate that regular exercise and aerobic capacity modulate BA metabolism under postprandial conditions.NEW & NOTEWORTHY Women with contrasting exercise and aerobic capacity levels show clear differences in bile acid (BA) metabolism. Women with low aerobic capacity (Lo-Fit) have increased circulating conjugated BAs post oral glucose tolerance test (OGTT), whereas women with high aerobic capacity (Hi-Fit) display a transient increase. Hi-Fit women show an increase in the secondary BA, lithocholic acid, during the OGTT not seen in Lo-Fit women. Differences in circulating BA species between Hi- and Lo-Fit women possibly contribute to differences in insulin sensitivity and energy regulation via different signaling mechanisms.

[Preoperative cardiovascular risk evaluation before elective noncardiac surgical interventions]

A careful and standardized but nevertheless individually adapted and targeted medical history and physical examination are essential components of a preoperative evaluation. The individual cardiovascular risk profile characterized by noninvasive diagnostics requires a targeted further assessment with noninvasive and invasive diagnostic investigations, which should be targeted to the medical needs of the individual patient. The aim is to assess the individual risk of undesired major adverse cardiac events (MACE). The preoperative examination procedures should be limited to the medically necessary needs in order to be able to optimally utilize the material and personnel resources. This review article presents a practical guide for preoperative cardiovascular risk evaluation in patients scheduled for elective, noncardiac surgery.

Feasibility and safety of high-intensity interval training for the rehabilitation of geriatric inpatients (HIITERGY) a pilot randomized study

BACKGROUND

High-intensity interval training (HIIT) has been shown to be more effective than moderate-intensity continuous training (MICT) for the physical rehabilitation. However, data on its suitability for older hospitalized patients is scarce.

METHODS

Randomized controlled trial in a hospital setting. Inclusion of 100 patients, ≥65 years old, hospitalized for rehabilitation after an acute medical condition, in a two-week rehabilitation program of either four HIIT or three MICT sessions per week. Completion was defined as participation in all but two planned sessions accomplishing ≥50% of each session. We assessed: upper-limb muscle strength (handgrip isometric strength test), lower-limb muscle strength (quadriceps and ankle flexion and extension tests); gait speed and spatio-temporal parameters (instrumented walkway), and exercise capacity (6-min walk test). All adverse events were recorded as safety endpoints.

RESULTS

An intention-to-treat analysis showed a 44% completion rate for the HIIT group (95% CI, 30-59) and 77% for MICT (95% CI, 55-82). A modified intention-to-treat analysis restricted to patients who participated in ≥1 session showed an 88% completion rate in the HIIT group (95%CI, 69-97) and an 80% completion rate in MICT (95%CI, 65-90). The exercises most frequently undertaken were the pedal exerciser (54%) and the NuStep (32%). There were no significant differences in the various measures. No serious adverse events occurred.

CONCLUSION

A HIIT rehabilitation program for this population was feasible, safe and had a high adherence rate.

TRIAL REGISTRATION NUMBER

Clinicatrials.gov ID: NCT02318459. Trial registration date: November 7th, 2014. Retrospectively registered. This study adheres to the CONSORT guidelines.

Cardiorespiratory Fitness and Health Outcomes: A Call to Standardize Fitness Categories

An inverse association between physical activity or fitness status and health outcomes has been reported by several cohort studies. When fitness categories are established in quartiles or quintiles based on the peak exercise capacity achieved, the association is graded. Although significant health benefits of increased cardiorespiratory fitness (CRF) have been uniformly reported, the degree of protection has varied substantially between studies. This variability is likely due to varying methods used to define CRF categories, and not considering age, despite its strong effect on CRF. To ameliorate these methodological discrepancies, we propose standardized guidelines by which age-specific CRF categories should be defined.

Using Metabolic Equivalents in Clinical Practice

Metabolic equivalents, or METs, are routinely employed as a guide to exercise training and activity prescription and to categorize cardiorespiratory fitness (CRF). There are, however, inherent limitations to the concept, as well as common misapplications. CRF and the patient's capacity for physical activity are often overestimated and underestimated, respectively. Moreover, frequently cited fitness thresholds associated with the highest and lowest mortality rates may be misleading, as these are influenced by several factors, including age and gender. The conventional assumption that 1 MET = 3.5 mL O₂/kg/min has been challenged in numerous studies that indicate a significant overestimation of actual resting energy expenditure in some populations, including coronary patients, the morbidly obese, and individuals taking β-blockers. These data have implications for classifying relative energy expenditure at submaximal and peak exercise. Heart rate may be used to approximate activity METs, resulting in a promising new fitness metric termed the "personal activity intelligence" or PAI score. Despite some limitations, the MET concept provides a useful method to quantitate CRF and define a repertoire of physical activities that are likely to be safe and therapeutic. In conclusion, for previously inactive adults, moderate-to-vigorous physical activity, which corresponds to ≥3 METs, may increase MET capacity and decrease the risk of future cardiac events.

Exercise testing in heart failure: a contemporary discussion in an era of novel diagnostic techniques and biomarkers

PURPOSE OF REVIEW

The purpose of this review is to highlight recent advances in the field of exercise testing for patients with heart failure.

RECENT FINDINGS

The importance of assessment of cardiorespiratory fitness (CRF) and exercise testing in heart failure is highlighted in the consensus recommendation of the American Heart Association. Contemporary studies have validated the independent and incremental strength of CRF metrics in patients with heart failure and coronary artery disease. The use of respiratory gas analysis and imaging or hemodynamics during physical exercise is feasible and results in high prognostic utility across the continuum of heart failure. Understanding how CRF metrics complement existing and novel biomarkers and risk scores is an emerging subject of scientific inquiry.

SUMMARY

In the current era of personalized medicine, integrating CRF, imaging and circulating biomarkers will allow us to further develop individualized strategies for improving outcome in patients with heart failure.

Preoperative cardiac evaluation with transthoracic echocardiography before non-cardiac surgery

Transthoracic echocardiography has become increasingly popular in clinical practice. It is used for the functional evaluation of patients with various cardiovascular diseases. Its use has been extended further in routine screening for cardiovascular health and in preoperative risk assessment before non-cardiac surgery because it is non-invasive, easy to perform, reproducible, and cost-effective. When the results of preoperative echocardiography contain abnormalities, the findings must be interpreted to determine clinical relevance. However, when the results of preoperative echocardiography are apparently normal, many physicians and surgeons readily think that the patient will not have any cardiovascular events in the future, or at least in the perioperative period. In this review, we will cover 1) current guidelines for preoperative echocardiographic assessment, 2) specific cardiac conditions for which the non-cardiac surgery should be delayed, 3) commonly encountered echocardiographic findings before non-cardiac surgeries, 4) application of stress echocardiography, and 5) clinical perspectives of focused transthoracic echocardiography before non-cardiac surgery.

Cardiorespiratory Fitness after Transient Ischemic Attack and Minor Ischemic Stroke: Baseline Data of the MoveIT Study

BACKGROUND

Cardiorespiratory fitness (CRF) is reduced in patients with stroke. It is unclear whether it is also reduced in patients with a transient ischemic attack (TIA) or minor stroke. We investigated the CRF in patients with a recent TIA or minor stroke and explored which determinants are associated with a lower fitness.

METHODS

In 113 patients with a recent TIA or minor ischemic stroke (64 (SD = 10) years of age; 49 (IQR 27-86) days post TIA or stroke), the peak oxygen consumption (VO2peak) was determined in a symptom-limited ramp exercise test. Physical activity level, vascular risk factors, history of vascular or pulmonary disease, and stroke characteristics were recorded at inclusion and related to the VO2peak.

RESULTS

Mean VO2peak was 22 mL/kg/min (SD = 6), which is the fifth percentile of age- and sex-related normative values. Increasing age and female sex were associated with a lower VO2peak (B (95% CI): per 10 years -2.57 mL/kg/min (-3.75; -1.40) and female sex -5.84 mL/kg/min (-8.06; -3.62)). Age- and sex-adjusted linear regression analyses showed that a history of cardiovascular disease and pulmonary disease was associated with a lower VO2peak. In addition, a lower level of physical activity, hypertension, smoking, and overweight were associated with a lower VO2peak. History of stroke and stroke characteristics were not related to VO2peak.

CONCLUSION

The majority of patients with a recent TIA or minor ischemic stroke have a poor CRF. Our findings suggest that premorbid cardiovascular and pulmonary disease and vascular risk factors, but not TIA- or stroke-related factors, contribute to a reduced CRF.

Secondary prevention of coronary artery disease in patients undergoing elective surgery for peripheral arterial disease

The purpose of the study was to assess the implementation of secondary prevention guidelines of coronary artery disease (CAD) in patients undergoing peripheral revascularization surgery. The design was a descriptive study of the prevalence of cardiac risk factors and preventive pharmacological therapy in vascular surgical patients set in an academic medical center between July 1996 and February 1999. A total of 237 patients were recruited, 82 (35%) having carotid surgery and 155 (65%) having lower extremity bypass. Data were collected from an existing database of a study examining perioperative cardiac events in vascular surgery patients. The majority of patients were hypertensive and 58% of patients had a blood pressure.140/90 mmHg. Most patients (81%) reported a history of tobacco use and 23% were active smokers. Of the 41% of patients who were diabetic, 46% had a random glucose .140 mg/dl. Half of the patients took aspirin, 35% a lipid-lowering medication, 30% a beta-blocker. Patients with lower extremity disease were less likely than patients with carotid disease to be on aspirin (45% vs. 62%), a lipid-lowering agent (30% vs. 45%), or a beta-blocker (26% vs. 39%) (all p,0.05). Of patients with heart disease, more men than women were on aspirin (62% vs. 45%) (p,0.05). In conclusion, our findings suggest that patients presenting for vascular surgery have a high prevalence of modifiable CAD risk factors that are not being adequately managed. Preoperative examination of vascular patients is an important opportunity to assess and implement neglected secondary prevention measures.

The Preoperative Evaluation of the Patient With Cardiac Risk Factors for Noncardiac Surgery: Which Patients Need Further Cardiac Risk Stratification Tests?

Cardiac risk stratification tests should be pursued only in the subgroup of patients who have a moderate to high incidence of significant coronary artery disease and only in those who will gain long-term benefit from coronary revascularization if they are found to have significant coronary artery disease. Furthermore, car diac risk stratification tests should be pursued only if the perioperative mortality and morbidity from com bined coronary revascularization followed by noncar diac surgery is not significantly higher than proceeding straight to noncardiac surgery alone. Indentification of the subgroup of patients who will need cardiac strati fication tests should be based on integration of the patient's cardiac risk factors and functional capacity with the risk and stress of the particular surgery.

Effects of the glucagon-like peptide-1 receptor agonist liraglutide on systolic function in patients with coronary artery disease and type 2 diabetes: a randomized double-blind placebo-controlled crossover study

BACKGROUND

Patients with type 2 diabetes (T2D) and coronary artery disease (CAD) have increased risk of cardiac dysfunction. The diabetic heart is characterized by increased fatty acid oxidation and reduced glucose uptake resulting in reduced cardiac efficiency. Glucagon-like peptide-1 (GLP-1) has shown to increase myocardial glucose uptake and to improve myocardial function. We examined the effect of the GLP-1 receptor agonist, liraglutide, on the systolic function of the left ventricle (LV) in patients with T2D and stable CAD.

METHODS

In this placebo-controlled crossover study, 41 subjects with T2D and stable CAD were randomized to liraglutide or placebo and underwent dobutamine stress echocardiography (DSE) and exercise tolerance test at beginning and end of each intervention. The primary endpoint was changes in LV ejection fraction. Secondary endpoints were exercise capacity and other measures of systolic function: wall motion score index (WMSI), global longitudinal strain (GLS) and strain rate (GLSR).

RESULTS

Liraglutide, when compared to placebo, did not improve LV ejection fraction at rest (+0.54 %; 95 % CI 2.38-3.45), at low stress (+0.03 %; 95 % CI 3.25-3.32), at peak stress (+1.12 %; 95 % CI 3.45-5.69), or at recovery (+4.06 %; 95 % CI 0.81-8.93). No significant changes in WMSI were observed at any stress levels. GLS and GLSR at rest did not improve. The maximal exercise capacity estimated by metabolic equivalents was not affected by liraglutide.

CONCLUSION

In conclusion, liraglutide did not improve the systolic function of the left ventricle during DSE or the exercise capacity in patients with T2D and stable CAD. Clinical Trial Registration http://www.clinicaltrials.gov (unique identifier: NCT01595789).

Cardiorespiratory Fitness and Risk of Sudden Cardiac Death in Men and Women in the United States: A Prospective Evaluation From the Aerobics Center Longitudinal Study

OBJECTIVES

To examine the relation between cardiorespiratory fitness (CRF) and sudden cardiac death (SCD) in a large US adult population and to study the effects of hypertension, obesity, and health status on the relation of CRF with SCD.

PATIENTS AND METHODS

A total of 55,456 individuals (mean age, 44.2 years; 13,507 women) from the Aerobics Center Longitudinal Study, a prospective observational investigation (from January 2, 1974, through December 31, 2002), were included. Cardiorespiratory fitness was assessed by a maximal treadmill test, and baseline assessment included an extensive set of measurements.

RESULTS

There were 109 SCDs. An inverse risk of SCD was found across incremental CRF levels after adjusting for potential confounders. Participants with moderate and high CRF levels had 44% (hazard ratio, 0.56; 95% CI, 0.35-0.90) and 48% (hazard ratio, 0.52; 95% CI, 0.30-0.92) significantly lower risk of SCD, respectively, than did those with low CRF levels (P<.001). The risk of SCD decreased by 14% (hazard ratio, 0.86; 95% CI, 0.77-0.96) per 1-metabolic equivalent increase in the fully adjusted model. Hypertensive, overweight, or unhealthy individuals with moderate to high CRF levels had lower risks of SCD (ranging from 58% to 72% of lower risk) than did those with the same medical conditions and low CRF levels.

CONCLUSION

The risk of SCD in US men and women could be partially reduced by ensuring moderate to high levels of CRF independently of other risk factors and especially in those who are hypertensive, overweight, or unhealthy.

The association of serum long-chainn-3 PUFA and hair mercury with exercise cardiac power in men

Long-chainn-3 PUFA from fish and exercise capacity are associated with CVD risk. Fish, especially large and old predatory fish, may contain Hg, which may attenuate the inverse association of long-chainn-3 PUFA with CVD. However, the associations of long-chainn-3 PUFA or Hg exposure with exercise capacity are not well known. We aimed to evaluate the associations of serum long-chainn-3 PUFA EPA, docosapentaenoic acid (DPA) and DHA and hair Hg with exercise cardiac power (ECP, a ratio of VO2max:maximal systolic blood pressure (SBP) during an exercise test), a measure for exercise capacity. For this, data from the population-based Kuopio Ischaemic Heart Disease Risk Factor Study were analysed cross-sectionally in order to determine the associations between serum long-chainn-3 PUFA, hair Hg and ECP in 1672 men without CVD, aged 42–60 years. After multivariate adjustments, serum total long-chainn-3 PUFA concentration was associated with higher ECP and VO2max(Ptrendacross quartiles=0·04 andPtrend=0·02, respectively), but not with maximal SBP (Ptrend=0·69). Associations were generally similar when EPA, DPA and DHA were evaluated individually. Hair Hg was not associated with ECP, VO2maxor maximal SBP. However, the associations of total long-chainn-3 PUFA (Pinteraction=0·03) and EPA (Pinteraction=0·02) with higher VO2maxwere stronger among men with lower hair Hg. Higher serum long-chainn-3 PUFA concentration, mainly a marker for fish consumption in this study population, was associated with higher ECP and VO2maxin middle-aged men from eastern Finland.

Enhanced Recovery After Surgery (ERAS) for gastrointestinal surgery, part 2: consensus statement for anaesthesia practice

Background

The present interdisciplinary consensus review proposes clinical considerations and recommendations for anaesthetic practice in patients undergoing gastrointestinal surgery with an Enhanced Recovery after Surgery (ERAS) programme.

Methods

Studies were selected with particular attention being paid to meta‐analyses, randomized controlled trials and large prospective cohort studies. For each item of the perioperative treatment pathway, available English‐language literature was examined and reviewed. The group reached a consensus recommendation after critical appraisal of the literature.

Results

This consensus statement demonstrates that anaesthesiologists control several preoperative, intraoperative and postoperative ERAS elements. Further research is needed to verify the strength of these recommendations.

Conclusions

Based on the evidence available for each element of perioperative care pathways, the Enhanced Recovery After Surgery (ERAS ^®) Society presents a comprehensive consensus review, clinical considerations and recommendations for anaesthesia care in patients undergoing gastrointestinal surgery within an ERAS programme. This unified protocol facilitates involvement of anaesthesiologists in the implementation of the ERAS programmes and allows for comparison between centres and it eventually might facilitate the design of multi‐institutional prospective and adequately powered randomized trials.

Anesthesia for colorectal surgery

Anesthesiologists play a pivotal role in facilitating recovery of patients undergoing colorectal surgery, as many Enhanced Recovery After Surgery (ERAS) elements are under their direct control. Successful implementation of ERAS programs requires that anesthesiologists become more involved in perioperative care and more aware of the impact of anesthetic techniques on surgical outcomes and recovery. Key to achieving success is strict adherence to the principle of aggregation of marginal gains. This article reviews anesthetic and analgesic care of patients undergoing elective colorectal surgery in the context of an ERAS program, and also discusses anesthesia considerations for emergency colorectal surgery.

Effect of baseline exercise capacity on outcomes in patients with stable coronary heart disease (a post hoc analysis of the clinical outcomes utilizing revascularization and aggressive drug evaluation trial)

The impact of baseline exercise capacity on clinical outcomes in patients with stable ischemic heart disease randomized to an initial strategy of optimal medical therapy (OMT) with or without percutaneous coronary intervention (PCI) in the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial has not been studied. A post hoc analysis was performed in 1,052 patients of COURAGE (PCI + OMT: n = 527, OMT: n = 525) who underwent exercise treadmill testing at baseline. Patients were categorized into 2 exercise capacity groups based on metabolic equivalents (METs) achieved during baseline exercise treadmill testing (<7 METs: n = 464, ≥7 METs: n = 588) and were followed for a median of 4.6 years. The primary composite end point of death or myocardial infarction was similar in the PCI + OMT group and the OMT group for patients with exercise capacity <7 METs (19.1% vs 16.1%, p = 0.31) and ≥7 METs (13.3% vs 10.3%, p = 0.27). After adjusting for baseline covariates, the hazard ratio (99% confidence interval) for the primary end point for the PCI + OMT group versus the OMT group was 1.42 (0.90 to 2.23, p = 0.05) and for the exercise capacity subgroups of ≥7 METs and <7 METs was 0.75 (0.46 to 1.22, p = 0.13). There was no statistically significant interaction between the original treatment arm allocation (PCI + OMT vs OMT) and baseline exercise capacity. In conclusion, there was no difference in the long-term clinical outcomes in patients with exercise capacity <7 METs compared with ≥7 METs, irrespective of whether they were assigned to initial PCI. Patients with exercise capacity <7 METs did not derive a proportionately greater clinical benefit from PCI + OMT compared with those patients who received OMT alone.

Cardiovascular risk stratification in diabetic patients following stress single-photon emission-computed tomography myocardial perfusion imaging: the impact of achieved exercise level

BACKGROUND

Previous studies have demonstrated that diabetic patients undergoing exercise stress single-photon emission-computed tomography (SPECT) myocardial perfusion imaging (MPI) have significantly lower cardiac events when compared to the diabetic patients undergoing pharmacologic stress SPECT MPI across all perfusion categories. However, there are limited data on the level of exercise achieved during exercise SPECT MPI among diabetic patients and its impact on cardiovascular outcomes.

METHODS

We retrospectively analyzed 14,849 consecutive patients (3,654 diabetics and 11,195 non-diabetics) undergoing exercise stress, combined exercise and pharmacologic stress, and pharmacologic stress SPECT MPI from 1996 to 2005 at a single tertiary care center. Diabetic and non-diabetic patients were categorized into 3 groups based on the metabolic equivalents (METs) achieved: ≥5 METs, <5 METs, and pharmacologic stress groups. All studies were interpreted using the 17-segment ASNC model. The presence, extent, severity of perfusion defects were calculated using the summed stress score (SSS), and patients were classified into normal (SSS < 4), mildly abnormal (SSS 4-8), and moderate-severely abnormal (SSS > 8) categories. Annualized event rates (AER) for the composite end point of non-fatal myocardial infarction and cardiac death were calculated over a mean follow-up period of 2.4 ± 1.4 years with a maximum of 6 years.

RESULTS

In moderate-severe perfusion abnormality (SSS > 8) category, diabetic patients who were able to achieve ≥5 METs had significantly lower AER compared to diabetic patients who were unable to achieve ≥5 METs (3% vs 5.5%, P = .04), and non-diabetic patients unable to achieve ≥5 METs (3% vs 4.8%, P < .001). Diabetic patients who achieved a high workload of ≥10 METs had a very low AER of 0.9%. Diabetic patients, who attempted exercise but were unable to achieve ≥5 METs, still had significantly lower AER than diabetics undergoing pharmacologic stress MPI across all perfusion categories [1.5% vs 3.2%, P = .006 (SSS < 4); 2.5% vs 4.9%, P = .032 (SSS 4-8); 5.5% vs 10.3%, P = .003 (SSS > 8)]. After adjustment for cardiovascular risk factors, the percentage decrease in cardiac event rate for every 1-MET increment in exercise capacity was 10% in the overall cohort, 12% in diabetic group, and 8% in non-diabetic group.

CONCLUSIONS

Despite significant perfusion defects, diabetic patients who achieve ≥5 METs during stress SPECT MPI have significantly reduced risk for future cardiac events. Diabetic patients who achieve ≥10 METs have a very low annualized event rate. These findings support that exercise capacity obtained during SPECT MPI is a surrogate for outcomes among diabetic patients undergoing nuclear stress testing.

Perioperative evaluation and management of cardiac disease in the ambulatory surgery setting

Preoperative cardiac evaluation focuses on risk assessment and reduction. Diagnostic testing and interventions are used only when the risk of adverse outcomes is high and intervention will lower the risk. The evaluation is performed in a stepwise fashion according to guidelines in the literature.

Peri-operative management of older people undergoing surgery

Increasing numbers of older people are undergoing both emergency and elective surgery. However, they remain at increased risk of adverse outcome in comparison with younger patients. This may relate to the association of ageing with physiological deterioration, multi-morbidity and geriatric syndromes such as frailty, all of which are independent predictors of adverse post-operative outcome. Although there is an emerging evidence base for the identification and management of these predictors, this has not yet translated into routine clinical practice. Older patients undergoing surgery often receive sub-optimal care and surgical pathways are not well suited to complex older patients with multi-pathology. Evidence is emerging for alternative models of care that incorporate the evolving evidence base for optimal peri-operative management of the older surgical patient, including risk assessment and optimization. This article aims to provide a practical overview of the literature to all disciplines working in this field.

Lack of exercise is a major cause of chronic diseases

Chronic diseases are major killers in the modern era. Physical inactivity is a primary cause of most chronic diseases. The initial third of the article considers: activity and prevention definitions; historical evidence showing physical inactivity is detrimental to health and normal organ functional capacities; cause versus treatment; physical activity and inactivity mechanisms differ; gene-environment interaction (including aerobic training adaptations, personalized medicine, and co-twin physical activity); and specificity of adaptations to type of training. Next, physical activity/exercise is examined as primary prevention against 35 chronic conditions [accelerated biological aging/premature death, low cardiorespiratory fitness (VO2max), sarcopenia, metabolic syndrome, obesity, insulin resistance, prediabetes, type 2 diabetes, nonalcoholic fatty liver disease, coronary heart disease, peripheral artery disease, hypertension, stroke, congestive heart failure, endothelial dysfunction, arterial dyslipidemia, hemostasis, deep vein thrombosis, cognitive dysfunction, depression and anxiety, osteoporosis, osteoarthritis, balance, bone fracture/falls, rheumatoid arthritis, colon cancer, breast cancer, endometrial cancer, gestational diabetes, pre-eclampsia, polycystic ovary syndrome, erectile dysfunction, pain, diverticulitis, constipation, and gallbladder diseases]. The article ends with consideration of deterioration of risk factors in longer-term sedentary groups; clinical consequences of inactive childhood/adolescence; and public policy. In summary, the body rapidly maladapts to insufficient physical activity, and if continued, results in substantial decreases in both total and quality years of life. Taken together, conclusive evidence exists that physical inactivity is one important cause of most chronic diseases. In addition, physical activity primarily prevents, or delays, chronic diseases, implying that chronic disease need not be an inevitable outcome during life.

A hypothetical protocol for the provisional use of perfusion imaging with exercise stress testing

BACKGROUND

Previous literature suggests that the results of myocardial perfusion imaging (MPI) add little to the prognosis of patients who exercise >10 metabolic equivalents (METS) during stress testing. With this in mind, we attempted to determine if a provisional injection protocol could be developed in which a patient would not receive an injection of radioisotope if adequate exercise was achieved without symptoms and a negative ECG response. This protocol would save a substantial amount of time, radiation exposure, and cost.

METHODS

All patients who underwent a stress SPECT MPI over a 6.5-year period from 2004 to 2010 were included. Patients who would have been considered for a standby injection protocol were: exercise stress, age < 65, no known coronary artery disease (CAD), and an interpretable ECG. Patients were retrospectively divided into two groups based on whether they would have received radioisotope or not. Criteria for not injecting included a maximal predicted heart rate ≥ 85%, ≥10 METS of exercise, no symptoms of chest pain or shortness of breath, and no ECG changes (ST depression or arrhythmia). The two groups were then compared based on MPI results and all-cause mortality derived from the Social Security Death Index.

RESULTS

A total of 24,689 patients underwent SPECT MPI during this period, and 5,352 would have been eligible for a provisional injection protocol. There were 3,791 (70.8%), who would have been injected and 1,561 (29.2%), who would not have been. Perfusion results were abnormal in 5.9% of non-injected group compared to 14.4% in those who would have been injected. After a mean follow-up of 60.6 ± 21.4 months, 1.1% had died in the non-injected cohort compared to 2.2% in the injected group.

CONCLUSION

A provisional injection protocol defined as age < 65, normal rest ECG, no history of CAD, and high level exercise with a negative ECG response and no symptoms has a very low 5-year all-cause mortality and low yield of MPI. If adopted it would decrease radiation exposure and save time and health care costs without jeopardizing prognosis.

Value of an exercise workload ≥10 metabolic equivalents for predicting inducible myocardial ischemia

BACKGROUND

We sought to identify extensive ischemia on exercise echocardiography (ExE) relative to workload in patients without known coronary artery disease and to investigate whether ExE is useful in predicting outcomes in those with high exercise capacity (≥10 metabolic equivalents [METs]) plus a maximal test (≥85% of their maximal age-predicted heart rate [MAPHR]).

METHODS AND RESULTS

The analysis was performed on 4269 patients who underwent ExE, of whom 3995 achieved ≥85% of their MAPHR. These patients were divided according to the reached workload (<7, 7-9, or ≥10 METs) and compared for ExE results. Outcomes in the group achieving ≥10 METs plus ≥85% of their MAPHR (n=2221) were specifically assessed. Ischemia was defined as new/worsening wall motion abnormalities with exercise. ExE results were different between groups because the METs were lower. Still, among patients achieving ≥10 METs plus ≥85% of their MAPHR, 9.3% had extensive ischemia and 6% multiterritory disease. During follow-up in this subgroup, 108 patients died and 42 had a major cardiac event. Annualized mortality and major cardiac event rates were 0.84% and 0.32% in patients without ischemia versus 2.26% and 0.84% in those with ischemia, respectively (P<0.001 and P=0.002, respectively). Ischemia was an independent predictor of mortality (hazard ratio, 1.88; 95% confidence interval, 1.23-2.89; P=0.004) and major cardiac event (hazard ratio, 2.39; 95% confidence interval, 1.22-4.71; P=0.01).

CONCLUSIONS

Patients without known coronary artery disease achieving ≥10 METs plus ≥85% of their MAPHR may still have ischemia. However, the low event rates even in those with ischemia limit the usefulness of imaging for assessing outcomes in this group.

Endovascular aneurysm repair: a perioperative perspective

Endovascular aneurysm repair (EVAR), has surpassed open repair as the technique of choice in many centres in response to several large studies which showed significantly improved 30-day mortality. While several multicentre EVAR trials looked at surgical outcomes, very few have specifically investigated the effect of anaesthetic techniques or perioperative care of these patients. The purpose of this review to is to present some of the current evidence for the different aspects of perioperative management of patients undergoing EVAR. This includes surgical considerations, pre-operative assessment, and choice of anaesthetic technique as well as pharmacological protective strategies.

Preoperative assessment and perioperative management of cardiovascular risk

Preoperative cardiovascular evaluation of patients scheduled to undergo surgery requires a multidisciplinary approach involving anesthetists, surgeons, and cardiologists. Within the last 5 to 10 years, there have been considerable scientific advances in this field, and the European Society of Cardiology (ESC) and the American College of Cardiology/American Heart Association(ACC/AHA) have updated their guidelines.(1,11) Greater emphasis now lies on preoperative clinical risk stratification and less on routine cardiac testing. Prophylactic coronary revascularization is now also seen as rarely indicated simply to lower the risk of surgery.(1) This review will give a brief summary of the guidelines and suggests a practical stepwise approach to evaluate the patient preoperatively.

Preoperative muscle weakness as defined by handgrip strength and postoperative outcomes: a systematic review

BACKGROUND

Reduced muscle strength- commonly characterized by decreased handgrip strength compared to population norms- is associated with numerous untoward outcomes. Preoperative handgrip strength is a potentially attractive real-time, non-invasive, cheap and easy-to-perform "bedside" assessment tool. Using systematic review procedure, we investigated whether preoperative handgrip strength was associated with postoperative outcomes in adults undergoing surgery.

METHODS

PRISMA and MOOSE consensus guidelines for reporting systematic reviews were followed. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Clinical Trials (1980-2010) were systematically searched by two independent reviewers. The selection criteria were limited to include studies of preoperative handgrip strength in human adults undergoing non-emergency, cardiac and non-cardiac surgery. Study procedural quality was analysed using the Newcastle-Ottawa Quality Assessment score. The outcomes assessed were postoperative morbidity, mortality and hospital stay.

RESULTS

Nineteen clinical studies (17 prospective; 4 in urgent surgery) comprising 2194 patients were identified between1980-2010. Impaired handgrip strength and postoperative morbidity were defined inconsistently between studies. Only 2 studies explicitly ensured investigators collecting postoperative outcomes data were blinded to preoperative handgrip strength test results. The heterogeneity of study design used and the diversity of surgical procedures precluded formal meta-analysis. Despite the moderate quality of these observational studies, lower handgrip strength was associated with increased morbidity (n = 10 studies), mortality (n = 2/5 studies) and length of hospital stay (n = 3/7 studies).

CONCLUSIONS

Impaired preoperative handgrip strength may be associated with poorer postoperative outcomes, but further work exploring its predictive power is warranted using prospectively acquired, objectively defined measures of postoperative morbidity.