Clinical and exercise test predictors of all-cause mortality: results from > 6,000 consecutive referred male patients

Short- and long-term prognostic performance of exercise ECG and myocardial perfusion SPECT

BACKGROUND

Myocardial perfusion SPECT (MPS) and exercise electrocardiography (Ex-ECG) results are of prognostic importance for short-term follow up duration. However, the value of MPS or Ex-ECG findings for long-term risk assessment is less evident as underlying risk factors for ischemic heart disease (IHD) gain in importance.

OBJECTIVES

To assess the short- and long-term prognostic value of MPS and Ex-ECG in relation to known risk factors.

METHODS AND MATERIALS

An observational study of 908 patients (age 63 years, 49% male, 45% prior IHD) referred for MPS and Ex-ECG. Follow-up was divided into two periods (short-term: <5 years and long-term: >5 years). Cardiac events were defined as a composite of acute myocardial infarction, unstable angina, unplanned revascularization and cardiovascular death.

RESULTS

The composite endpoint occurred in 95 patients (short-term follow up) and in 94 patients (long-term follow up). In multivariable models stress testing had a strong predictive value for short-term follow up (HR for MPS = 2.9, CI = 1.9-4.5, p < 0.001 and HR for Ex-ECG = 2.1, CI 1.3-3.3, p = 0.002), but no predictive value for long-term follow up (HR for MPS = 0.9, CI = 0.5-1.5, p = 0.70 and HR for Ex-ECG = 1.0, CI = 0.6-1.6, p = 0.92). Male sex and prior IHD were significant predictors regardless of follow up duration. Age, diabetes and decreased exercise capacity were risk factors for long-term follow up.

CONCLUSIONS

The prognostic value of MPS and Ex-ECG results are strong for short-term follow up but diminish over time and do not contribute significantly in multivariable models after 5 years. Long-term prognosis is primarily governed by underlying risk factors and exercise capacity.

Prognostic Impact of a Routine Six-Month Exercise Stress Test after Complex Left Main Bifurcation Percutaneous Intervention

The prognostic value of exercise stress test after complex left main (LM) coronary artery bifurcation (LM) stenting has been poorly investigated. To partially fill this gap in knowledge, we retrospectively analyzed the procedural and medical data of consecutive patients referred to our center for complex LM bifurcation disease between January 2008 and May 2018 who were treated using either single- or dual-stenting techniques. The prognostic impact of an exercise stress test, performed 6 months after the coronary intervention, was evaluated in 502 patients (316 males, mean age 70.3 ± 12.8 years, mean Syntax score 31.6 ± 6.3). At follow up after a mean of 37.1 ± 10.8 months (range 22.1-47.3 months), the target lesion failure (TLF) rate was 10.1% while stent thrombosis and cardiovascular mortality were 1.2 and 3.6%, respectively. A positive exercise stress test was detected at 6-month follow up in 42 out of 502 patients (8.4%); the incidence of a significant restenosis was 7.6% (n = 38). Patients with a negative exercise stress test at 6-month follow up had higher freedom from TLF and improved survival compared to those with a positive exercise stress test.

Incremental Value of Exercise ECG to Myocardial Perfusion Single-Photon Emission Computed Tomography for Prediction of Cardiac Events

Background Both myocardial perfusion single-photon emission computed tomography (MPS) and exercise ECG (Ex-ECG) carry prognostic information in patients with stable chest pain. However, it is not fully understood if combining the findings of MPS and Ex-ECG improves risk prediction. Current guidelines no longer recommend Ex-ECG for diagnostic evaluation of chronic coronary syndrome, but Ex-ECG could still be of incremental prognostic importance. Methods and Results This study comprised 908 consecutive patients (age 63.3±9.4 years, 49% male) who performed MPS with Ex-ECG. Subjects were followed for 5 years. The end point was a composite of cardiovascular death, acute myocardial infarction, unstable angina, and unplanned percutaneous coronary intervention. National registry data and medical charts were used for end point allocation. Combining the findings of MPS and Ex-ECG resulted in concordant evidence of ischemia in 72 patients or absence of ischemia in 634 patients. Discordant results were found in 202 patients (MPS-/Ex-ECG+, n=126 and MPS+/Ex-ECG-, n=76). During follow-up, 95 events occurred. Annualized event rates significantly increased across groups (MPS-/Ex-ECG- =1.3%, MPS-/Ex-ECG+ =3.0%, MPS+/Ex-ECG- =5.1% and MPS+/Ex-ECG+ =8.0%). In multivariable analyses MPS was the strongest predictor regardless of Ex-ECG findings (MPS+/Ex-ECG-, hazard ratio [HR], 3.0, P=0.001 or MPS+/Ex-ECG+, HR,4.0, P<0.001). However, an abnormal Ex-ECG almost doubled the risk in subjects with normal MPS (MPS-/Ex-ECG+, HR, 1.9, P=0.04). Conclusions In patients with chronic coronary syndrome, combining the results from MPS and Ex-ECG led to improved risk prediction. Even though MPS is the stronger predictor, there is an incremental value of adding data from Ex-ECG to MPS, especially in patients with normal MPS.

Significance of 'recovery ST-segment depression' in exercise stress test

Objective

To study the significance of ST-segment depression during ‘recovery’ compared to that ‘during stress’ and ‘both the phases’ in exercise stress test.

Methods

Patients with positive exercise stress test who underwent coronary angiography (CAG) from 1st January 2017 to 31st December 2018 were studied. Patients were divided into 3 groups- Group A with ST-depression restricted to recovery phase, group B with ST-depression restricted to stress phase and group C with ST-depression seen both during exercise and recovery. All patients underwent CAG. Sensitivity, specificity, and predictive values of each of these groups in diagnosis of significant coronary artery disease (CAD) were analysed and compared.

Results

Total 300 patients were studied. Mean age of the study population was 48.77 ± 7.94 years. 78.3% of patients with positive exercise stress test had significant CAD. 96% of patients in group A had significant CAD, which was higher than in group B (88.9%) & group C (70.1%). The specificity, positive predictive value and negative predictive value of ST-segment depression in group A (96.92%, 96% and 25.2% respectively) were higher than that of ST-depression in group B (89.23%, 88.89% and 24.47% respectively) and group C (13.85%, 70.05% and 7.96% respectively). Sensitivity and accuracy of ST-depression in group A were lower (20.43% and 37% respectively), compared to other 2 groups.

Conclusion

Patient with ST-depression restricted to recovery phase had highest specificity, positive predictive value, and negative predictive value. However, accuracy was highest in group with both stress phase and exercise ST-segment depression.

Unsupervised clustering for phenotypic stratification of clinical, demographic, and stress attributes of cardiac risk in patients with nonischemic exercise stress echocardiography

INTRODUCTION AND AIM

Patients undergoing exercise echocardiography with no evidence of myocardial ischemia are considered a low-risk group; however, this group is likely heterogeneous in terms of short-term adverse events and subsequent cardiac testing. We hypothesized that unsupervised cluster modeling using clinical and stress characteristics can detect heterogeneity in cardiovascular risk and need for subsequent cardiac testing among these patients.

METHODS

We retrospectively studied 445 patients who had exercise echocardiography results negative for myocardial ischemia. All patients were followed for adverse cardiovascular events, subsequent cardiac testing, and nonacute coronary syndrome (ACS) revascularization. The heterogeneity of the study subjects was tested using computational clustering, an exploratory statistical method designed to uncover invisible natural groups within data. Clinical and stress predictors of adverse events were extracted and used to construct 3 unsupervised cluster models: clinical, stress, and combined. The study population was split into training (357 patients) and testing sets (88 patients).

RESULTS

In the training set, the clinical, stress, and combined cluster models yielded 5, 4, and 3 clusters, respectively. Each model had 1 high-risk and 1 low-risk cluster while other clusters were intermediate. The combined model showed a better predictive ability compared to the clinical or stress models alone. The need for future testing mirrored the pattern of adverse cardiovascular events. A risk score derived from the combined cluster model predicted end points with acceptable accuracy. The patterns of risk and the calculated risk scores were preserved in the testing set.

CONCLUSIONS

Patients with no evidence of ischemia on exercise stress echocardiography represent a heterogeneous group. Cluster-based modeling using combined clinical and stress characteristics can expose this heterogeneity. The findings can help better risk-stratify this group of patients and aid cost-effective healthcare utilization toward better diagnostics and therapeutics.

Cardiorespiratory Fitness and Coronary Artery Calcification in a Primary Prevention Population

Objective

To elucidate whether cardiorespiratory fitness (CRF) is protective or contributory to coronary artery disease plaque burden.

Patients and Methods

Study participants were working middle-aged men from the Mayo Clinic Executive Health Program who underwent coronary artery calcium (CAC) assessment and exercise treadmill testing for risk stratification. Data from January 1, 1995, through December 31, 2008, were considered. The CAC assessment score was used for lifelong plaque burden analysis; functional aerobic capacity (FAC) from treadmill testing was analyzed as 4 ranked categories of CRF. Known risk factors for cardiovascular disease, including family history, were also considered.

Results

In 2946 male patients in this retrospective, cross-sectional, observational study, known cardiovascular risk factor profiles and risk calculations tended to uniformly improve with increasing CRF, defined by the FAC level. Only the above-average group, or the third of 4 levels, was found consistently lower than other levels of FAC for CAC scores. The above-average group also had statistical significance after controlling for age, body mass index, and family history of coronary artery disease in a U-shaped distribution rather than the expected linear dose-response relationship. Plaque burden was significantly increased in patients with the highest FAC level (P=.005) compared with the above-average group despite the observed maximal risk factor optimization in all known conventional cardiovascular risk factors.

Conclusion

For men, maximal CRF is associated with increased atherosclerosis, established with CAC scores. By comparison, average-to-moderate CRF appears to be cardioprotective regardless of either age or the influence of other contributing, recognized cardiac risk factors.

Effectiveness of cardiogoniometry compared with exercise-ECG test in diagnosing stable coronary artery disease in women

AIMS

To investigate the effectiveness of cardiogoniometry, a novel, non-invasive method, in diagnosing coronary artery disease (CAD) in women and compare it with exercise-ECG test, by using coronary angiography as a reference method.

METHODS

It was a single-centre, case-series study including consecutive female patients with stable angina pectoris (AP) undergoing coronary angiography. Exercise-ECG test, done according to the Bruce protocol, and cardiogoniometry were obtained prior to coronary angiography. Clinically significant CAD has been defined as one or more coronary lesions with >70% stenosis.

RESULTS

Study included 114 consecutive female patients with median age of 64.0 (58.0-71.0) years, out of which 32 (28.1%) had CAD. Cardiogoniometry yielded a total accuracy of 74.6% with a sensitivity of 75.0% (95% CI 56.6-88.5) and specificity of 74.4% (95% CI 63.6-83.4). Exercise-ECG test yielded a total accuracy of 45.1% with a sensitivity of 68.1% (95% CI 42.7-83.6) and specificity 36.6% (95% CI 25.2-50.3). Cardiogoniometry showed higher accuracy than exercise-ECG test ( P < 0.001). Pathological cardiogoniometry was associated with almost nine times higher risk for CAD (OR 8.7, 95%CI 3.4-22.3, P < 0.001), which remained significant after adjustment for age, and hypokinesia.

CONCLUSION

Cardiogoniometry is a non-invasive, easy-to-use and free-of-risk method which showed high effectiveness in diagnosing stable CAD in women and superior to exercise-ECG test. Cardiogoniometry could be introduced as a part of the diagnostic algorithm of screening women for stable CAD and is suitable for use in the primary setting, especially in women unable to undergo stress-testing.

Exercise capacity and mortality - a follow-up study of 3033 subjects referred to clinical exercise testing

BACKGROUND

Exercise stress testing is used as a diagnostic and prognostic tool. We determined the prognostic significance of exercise test findings for cardiovascular (CVD) and all-cause mortality in men and women.

MATERIAL AND METHODS

3033 subjects underwent a symptom-limited bicycle exercise test. Exercise capacity was defined as the mean of last four minutes of exercise workload.

RESULTS

During an average follow-up of 19 years, 186 (11.6%) CVD and 370 (20.6%) all-cause deaths in men and 57 (5.0%) CVD and 155 (12.5%) all-cause deaths in women occurred. Among exercise test variables (workload, ECG, BP, HR), exercise capacity was the strongest predictor of mortality. Low exercise capacity (1st quartile) was associated with a hazard ratio of 4.2 (95% CI: 1.7, 10.8) for CVD and 4.0 (95% CI: 2.5, 6.4) for all-cause mortality compared with high exercise capacity (4th quartile) among men and in women with a 5.4-fold (95% CI: 1.2, 24.0) risk for CVD and 2.3-fold (95% CI: 1.2, 4.3) risk for all-cause mortality, respectively. The relationship between other exercise test variables and mortality was much weaker.

CONCLUSIONS

Among exercise test variables exercise capacity was the strongest predictor of CVD and all-cause mortality in both genders, and especially CVD deaths in women. Key Messages Exercise capacity was the most powerful predictor of CVD and all-cause mortality in both men and women. Low exercise capacity is a strong predictor of CVD death, especially among women.

Prognostic value of the post-training oxygen uptake efficiency slope in patients with coronary artery disease

BACKGROUND

Peak oxygen uptake is an independent predictor of mortality in patients with coronary artery disease (CAD). However, patients with CAD are not always capable of reaching peak effort, and therefore submaximal gas exchange variables such as the oxygen uptake efficiency slope (OUES) have been introduced. Baseline exercise capacity as expressed by OUES provides prognostic information and this parameter responds to training. Therefore, we aimed to assess the prognostic value of post-training OUES in patients with CAD.

METHODS

We included 960 patients with CAD (age 60.6 ± 9.5 years; 853 males) who completed a cardiac rehabilitation program between 2000 and 2011. The OUES was calculated before and after cardiac rehabilitation and information on mortality was obtained. The relationships of post-training OUES with all-cause and cardiovascular (CV) mortality was assessed by Cox proportional hazards regression analyses. Receiver operator characteristic curve analysis was performed in order to obtain the optimal cut-off value.

RESULTS

During 7.37 ± 3.20 years of follow-up (range: 0.45-13.75 years), 108 patients died, among whom 47 died due to CV reasons. The post-training OUES was related to all-cause (hazard ratio: 0.50, p < 0.001) and CV (hazard ratio: 0.40, p < 0.001) mortality. When significant covariates, including baseline OUES, were entered into the Cox regression analysis, post-training OUES remained related to all-cause and CV mortality (hazard ratio: 0.40, p < 0.01 and 0.26, p < 0.01, respectively). In addition, the change in OUES due to exercise training was positively related to mortality (hazard ratio: 0.49, p < 0.01).

CONCLUSION

Post-training OUES has stronger prognostic value compared to baseline OUES. The lack of improvement in exercise capacity expressed by OUES after an exercise training program relates to a worse prognosis and can help distinguish patients with favorable and unfavorable prognoses.

Noninvasive Stress Testing for Coronary Artery Disease

Stress testing remains the cornerstone for noninvasive assessment of patients with possible or known coronary artery disease (CAD). The most important application of stress testing is risk stratification. Most patients who present for evaluation of stable CAD are categorized as low risk by stress testing. These low-risk patients have favorable clinical outcomes and generally do not require coronary angiography. Standard exercise treadmill testing is the initial procedure of choice in patients with a normal or near-normal resting electrocardiogram who are capable of adequate exercise. Stress imaging is recommended for patients with prior revascularization, uninterpretable electrocardiograms, or inability to adequately exercise.

Relation of Risk of Atrial Fibrillation With Systolic Blood Pressure Response During Exercise Stress Testing (from the Henry Ford ExercIse Testing Project)

Decreases in systolic blood pressure during exercise may predispose to arrhythmias such as atrial fibrillation (AF) because of underlying abnormal autonomic tone. We examined the association between systolic blood pressure response and incident AF in 57,442 (mean age 54 ± 13 years, 47% women, and 29% black) patients free of baseline AF who underwent exercise treadmill stress testing from the Henry Ford ExercIse Testing project. Exercise systolic blood pressure response was examined as a categorical variable across clinically relevant categories (>20 mm Hg: referent; 1 to 20 mm Hg, and ≤0 mm Hg) and per 1-SD decrease. Cox regression, adjusting for demographics, cardiovascular risk factors, medications, history of coronary heart disease, history of heart failure, and metabolic equivalent of task achieved, was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between systolic blood pressure response and incident AF. Over a median follow-up of 5.0 years, a total of 3,381 cases (5.9%) of AF were identified. An increased risk of AF was observed with decreasing systolic blood pressure response (>20 mm Hg: HR 1.0, referent; 1 to 20 mm Hg: HR 1.09, 95% CI 0.99, 1.20; ≤0 mm Hg: HR 1.22, 95% CI 1.06 to 1.40). Similar results were obtained per 1-SD decrease in systolic blood pressure response (HR 1.08, 95% CI 1.04 to 1.12). The results were consistent when stratified by age, sex, race, hypertension, and coronary heart disease. In conclusion, our results suggest that a decreased systolic blood pressure response during exercise may identify subjects who are at risk for developing AF.

Does Improving Exercise Capacity and Daily Activity Represent the Holistic Perspective of a New COPD Approach?

In COPD patients a reduced daily activity has been well documented, resulting from both respiratory and non-respiratory manifestations of the disease. An evaluation by multisensory armband has confirmed that daily physical activity is mainly associated with dynamic hyperinflation, regardless of COPD severity. This aspect is crucial, since exercise capacity is closely correlated to life expectancy. Notwithstanding the causal key role of lung impairment in the patient's symptoms, some authors have suggested that other factors, such as systemic inflammation and co-morbidities, have an important role, particularly as mortality risk factors. Many studies suggest the efficacy of bronchodilators and rehabilitation in improving exercise capacity, and, speaking in terms of daily life, in increasing the number of days in which patients are able to perform their usual activities. On this evidence, the first aim in the management of COPD should be to improve exercise capacity and daily activity since these outcomes have direct effects on patients' quality of life, co-morbidities (heart and metabolic diseases), and prognosis. Thus, improving physical activity represents a modern approach aimed at dealing with both pulmonary and systemic manifestations of the disease. It is however worth of notice to remember that in patients affected by COPD the relationship between the improvement of "potential" exercise capacity and daily physical activity has been found to be only moderate to weak. Obtaining a significant behavior modification with regard to daily physical activity, together with the optimization of therapy thus represents currently the true challenge.

Noninvasive stress testing for coronary artery disease

Stress testing remains the cornerstone for noninvasive assessment of patients with possible or known coronary artery disease (CAD). The most important application of stress testing is risk stratification. Most patients who present for evaluation of stable CAD are categorized as low risk by stress testing. These low-risk patients have favorable clinical outcomes and generally do not require coronary angiography. Standard exercise treadmill testing is the initial procedure of choice in patients with a normal or near-normal resting electrocardiogram who are capable of adequate exercise. Stress imaging is recommended for patients with prior revascularization, uninterpretable electrocardiograms, or inability to adequately exercise.

Systolic Blood Pressure Response During Exercise Stress Testing: The Henry Ford ExercIse Testing (FIT) Project

Background

The prognostic significance of modest elevations in exercise systolic blood pressure response has not been extensively examined.

Methods and Results

We examined the association between systolic blood pressure response and all-cause death and incident myocardial infarction (MI) in 44 089 (mean age 53±13 years, 45% female, 26% black) patients who underwent exercise treadmill stress testing from the Henry Ford ExercIse Testing (FIT) Project (1991–2010). Exercise systolic blood pressure response was examined as a categorical variable (>20 mm Hg: referent; 1 to 20 mm Hg, and ≤0 mm Hg) and per 1 SD decrease. Cox regression was used to compute hazard ratios (HR) and 95% CI for the association between systolic blood pressure response and all-cause death and incident MI. Over a median follow-up of 10 years, a total of 4782 (11%) deaths occurred and over 5.2 years, a total of 1188 (2.7%) MIs occurred. In a Cox regression analysis adjusted for demographics, physical fitness, and cardiovascular risk factors, an increased risk of death was observed with decreasing systolic blood pressure response (>20 mm Hg: HR=1.0, referent; 1 to 20 mm Hg: HR=1.13, 95% CI=1.05, 1.22; ≤0 mm Hg: HR=1.21, 95% CI=1.09, 1.34). A trend for increased MI risk was observed (>20 mm Hg: HR=1.0, referent; 1 to 20 mm Hg: HR=1.09, 95% CI=0.93, 1.27; ≤0 mm Hg: HR=1.19, 95% CI=0.95, 1.50). Decreases in systolic blood pressure response per 1 SD were associated with an increased risk for all-cause death (HR=1.08, 95% CI=1.05, 1.11) and incident MI (HR=1.09, 95% CI=1.03, 1.16).

Conclusions

Our results suggest that modest increases in exercise systolic blood pressure response are associated with adverse outcomes.

Maximal exercise testing variables and 10-year survival: fitness risk score derivation from the FIT Project

OBJECTIVE

To determine which routinely collected exercise test variables most strongly correlate with survival and to derive a fitness risk score that can be used to predict 10-year survival.

PATIENTS AND METHODS

This was a retrospective cohort study of 58,020 adults aged 18 to 96 years who were free of established heart disease and were referred for an exercise stress test from January 1, 1991, through May 31, 2009. Demographic, clinical, exercise, and mortality data were collected on all patients as part of the Henry Ford ExercIse Testing (FIT) Project. Cox proportional hazards models were used to identify exercise test variables most predictive of survival. A "FIT Treadmill Score" was then derived from the β coefficients of the model with the highest survival discrimination.

RESULTS

The median age of the 58,020 participants was 53 years (interquartile range, 45-62 years), and 28,201 (49%) were female. Over a median of 10 years (interquartile range, 8-14 years), 6456 patients (11%) died. After age and sex, peak metabolic equivalents of task and percentage of maximum predicted heart rate achieved were most highly predictive of survival (P<.001). Subsequent addition of baseline blood pressure and heart rate, change in vital signs, double product, and risk factor data did not further improve survival discrimination. The FIT Treadmill Score, calculated as [percentage of maximum predicted heart rate + 12(metabolic equivalents of task) - 4(age) + 43 if female], ranged from -200 to 200 across the cohort, was near normally distributed, and was found to be highly predictive of 10-year survival (Harrell C statistic, 0.811).

CONCLUSION

The FIT Treadmill Score is easily attainable from any standard exercise test and translates basic treadmill performance measures into a fitness-related mortality risk score. The FIT Treadmill Score should be validated in external populations.

Diagnosis of obstructive coronary artery disease by cardiogoniometry: a field test in a real-life setting

Cardiogoniometry is an electrocardiographic and vectorcardiographic method utilizing computer-assisted analysis of cardiac potentials focusing on T-wave abnormalities resulting from myocardial malperfusion. We describe a case of diagnosis of obstructive coronary artery disease with this method and discuss the possible implications for the clinical setting.

Use of functional aerobic capacity based on stress testing to predict outcomes in normal, overweight, and obese patients

OBJECTIVE

To determine the poorly studied relationship between functional aerobic capacity (FAC) as measured by treadmill stress testing and mortality in normal, overweight, and obese patients.

PATIENTS AND METHODS

Patients were identified retrospectively from the stress testing database at Mayo Clinic in Rochester, Minnesota. We selected 5328 male nonsmokers (mean ± SD age, 51.8±11.5 years) without baseline cardiovascular disease who were referred for treadmill exercise testing between January 1, 1986, and December 31, 1991, and classified them by body mass index (BMI) into normal-weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (≥30 kg/m(2)) categories. Functional aerobic capacity was assessed by maximal exercise test results based on age- and sex-specific metabolic equivalents, and patients were stratified into fitness quintiles. Cox proportional hazards analysis was used to determine the relationship of all-cause mortality to fitness in each BMI category.

RESULTS

There were 322 deaths during 14 years of follow-up. After adjustment for age and exercise confounders, FAC predicted mortality in the 3 BMI groups. Hazard ratios for FAC less than 80% of predicted vs a reference group with normal BMI and fitness (FAC ≥100%) were 1.754 (95% CI, 0.874-3.522), 1.962 (1.356-2.837), and 1.518 (1.056-2.182) for the normal, overweight, and obese groups, respectively. The CIs of the hazard ratios overlapped with no statistically significant differences (P>.05).

CONCLUSION

A significant increase in mortality occurs with FAC below 80% of predicted for overweight and obese subjects and below 70% for normal weight subjects. Our results suggest that clinicians need not adjust the standard for low fitness in obese patients.

Stable angina pectoris: head-to-head comparison of prognostic value of cardiac CT and exercise testing

PURPOSE

To determine and compare the prognostic value of cardiac computed tomographic (CT) angiography, coronary calcium scoring, and exercise electrocardiography (ECG) in patients with chest pain who are suspected of having coronary artery disease (CAD).

MATERIALS AND METHODS

This study complied with the Declaration of Helsinki, and the local ethics committee approved the study. Patients (n = 471) without known CAD underwent exercise ECG and dual-source CT at a rapid assessment outpatient chest pain clinic. Coronary calcification and the presence of 50% or greater coronary stenosis (in one or more vessels) were assessed with CT. Exercise ECG results were classified as normal, ischemic, or nondiagnostic. The primary outcome was a major adverse cardiac event (MACE), defined as cardiac death, nonfatal myocardial infarction, or unstable angina requiring hospitalization and revascularization beyond 6 months. Univariable and multivariable Cox regression analysis was used to determine the prognostic values, while clinical impact was assessed with the net reclassification improvement metric.

RESULTS

Follow-up was completed for 424 (90%) patients; the mean duration of follow-up was 2.6 years. A total of 44 MACEs occurred in 30 patients. Four of the MACEs were cardiac deaths and six were nonfatal myocardial infarctions. The presence of coronary calcification (hazard ratio [HR], 8.22 [95% confidence interval {CI}: 1.96, 34.51]), obstructive CAD (HR, 6.22 [95% CI: 2.77, 13.99]), and nondiagnostic stress test results (HR, 3.00 [95% CI: 1.26, 7.14]) were univariable predictors of MACEs. In the multivariable model, CT angiography findings (HR, 5.0 [95% CI: 1.7, 14.5]) and nondiagnostic exercise ECG results (HR, 2.9 [95% CI: 1.2, 7.0]) remained independent predictors of MACEs. CT angiography findings showed incremental value beyond clinical predictors and stress testing (global χ(2), 37.7 vs 13.7; P < .001), whereas coronary calcium scores did not have further incremental value (global χ(2), 38.2 vs 37.7; P = .40).

CONCLUSION

CT angiography findings are a strong predictor of future adverse events, showing incremental value over clinical predictors, stress testing, and coronary calcium scores.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11110744/-/DC1.

Evidence-based risk assessment and recommendations for physical activity clearance: established cardiovascular disease1This paper is one of a selection of papers published in this Special Issue, entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal’s usual peer review process

Physical activity is an effective lifestyle therapy for patients at risk for, or with, documented cardiovascular disease (CVD). Current screening tools — the Physical Activity Readiness Questionnaire (PAR-Q) and the Physical Activity Readiness Medical Evaluation (PARmed-X) — require updating to align with risk/benefit evidence. We provide evidence-based recommendations to identify individuals with CVD at lower risk, intermediate risk, or higher risk of adverse events when participating in physical activity. Forms of exercise and the settings that will appropriately manage the risks are identified. A computer-assisted search of electronic databases, using search terms for CVD and physical activity risks and benefits, was employed. The Appraisal of Guidelines for Research and Evaluation were applied to assess the evidence and assign a strength of evidence rating. A strength rating for the physical activity participation clearance recommendation was assigned on the basis of the evidence. Recommendations for physical activity clearance were made for specific CVD groups. Evidence indicates that those who are medically stable, who are involved with physical activity, and who have adequate physical ability can participate in physical activity of lower to moderate risk. Patients at higher risk can exercise in medically supervised programs. Systematic evaluation of evidence indicates that clinically stable individuals with CVD may participate in physical activity with little risk of adverse events. Therefore, changes in the PAR-Q should be undertaken and a process of assessment and consultation to replace the PARmed-X should be developed. Patients at lower risk may exercise at low to moderate intensities with minimal supervision. Those at intermediate risk should exercise with guidance from a qualified exercise professional. Patients at higher risk should exercise in medically supervised programs.

The value of treadmill exercise test parameters together in patients with known or suspected peripheral arterial disease

BACKGROUND

Exercise test parameters (exercise ankle brachial index (ABI), walking distance and blood pressure response) separately are associated with long-term outcome in patients with known or suspected peripheral arterial disease (PAD). However, the clinical value of the combination of these parameters together is unknown.

METHODS

2165 patients performed a treadmill exercise test to diagnose or to evaluate their PAD. Resting ABI, exercise ABI, abnormal blood pressure response (hypotensive and hypertensive) and walking distance (impairment <150 m) were measured. The study population was divided into patients with a resting ABI ≥ 0.90 and patients with PAD (resting ABI < 0.90).

RESULTS

The mean follow-up period was 5 years (0.5-14 years). Long-term mortality rate and risks increases when more exercise parameters became abnormal (p-value = 0.001). Patients with a normal resting ABI but with an abnormal exercise test had a higher mortality risk--HR 1.90 (1.32-2.73)--than patients with a normal exercise test. The highest mortality risk and cardiac death was observed in PAD patients with a walking impairment together with an abnormal blood pressure response--HR 3.48 (2.22-5.46).

CONCLUSION

Exercise tests give multiple parameters, which together provide important prognostic information on long-term outcome in both patients with normal resting ABI and PAD.

Physical activity and lung cancer survivorship

A lung cancer diagnosis and associated therapeutic management is associated with unique and varying degrees of adverse physical/functional impairments that dramatically reduce a patient's ability to tolerate exercise. Poor exercise tolerance predisposes to increased susceptibility to other common age-related diseases, poor quality of life (QOL), and likely premature death. Here we review the putative literature investigating the role of exercise as an adjunct therapy across the lung cancer continuum (i.e., diagnosis to palliation). The current evidence suggests that exercise training is a safe and feasible adjunct therapy for operable lung cancer patients both before and after pulmonary resection. Among patients with inoperable disease, feasibility and safety studies of carefully prescribed exercise training are warranted. Preliminary evidence in this area supports that exercise therapy may be an important consideration in multidisciplinary management of patients diagnosed with lung cancer.

Prognosis of asymptomatic coronary artery disease after percutaneous coronary intervention

The appropriate treatment for asymptomatic patients with obstructive coronary stenoses is controversial. The effect of percutaneous coronary intervention (PCI) on the prognosis of such patients is unknown. The present study compared the 1-year outcomes of patients with stable coronary artery disease (CAD) with regard to the presence or absence of symptoms after elective PCI. A total of 1,944 consecutive patients with stable CAD who had undergone elective PCI were studied. They were divided into 2 groups according to symptom status: asymptomatic (n = 1,052) and symptomatic (n = 892). A 1-year follow-up evaluation was conducted by office visit and telephone interview. The end points consisted of all-cause mortality, nonfatal myocardial infarction, and target vessel revascularization. Patients without angina pectoris were older, predominantly men, and more frequently had chronic renal insufficiency, a previous myocardial infarction, a coronary artery bypass graft, and a lower left ventricular ejection fraction. The 1-year mortality rate was greater in the asymptomatic patients (43 [4.1%] vs 16 [1.8%], p = 0.003). The incidence of nonfatal myocardial infarction and target vessel revascularization was similar in the 2 groups (15 [1.5%] vs 12 [1.4%], p = 0.85; and 69 [6.7%] vs 68 [7.7%], p = 0.39, respectively). On multivariate analysis, the absence of symptoms was a strong independent predictor of 1-year mortality (p = 0.017). In conclusion, in patients with stable CAD undergoing elective PCI, the absence of symptoms was associated with an increase in 1-year mortality.

Hemoglobin levels predict exercise performance, ST-segment depression, and outcome in patients referred for routine exercise treadmill testing

BACKGROUND

While the role of hemoglobin in heart failure and renal disease has been investigated, little is known about its effect on clinical exercise test performance and mortality in patients referred for routine exercise treadmill testing (ETT).

HYPOTHESIS

Patients with low hemoglobin will have poor exercise capacity and would be at increased risk of mortality and cardiovascular (CV) events.

METHODS

Clinical variables, laboratory values, and exercise treadmill data were obtained for 1,799 patients referred for routine ETT from 1997 to 2004. All-cause mortality was obtained from the United States Social Security death index and autopsy reports or clinical notes were used to determine CV events and mortality. P values < 0.05 were considered significant.

RESULTS

Our population had a mean age of 58 +/- 12 years, 16% had diabetes, 53% had hypertension, 35% had hypercholesterolemia, and 67% had a history of smoking. During follow-up, 10.3% of patients died, 3.9% of patients died of CV causes, and 11.6% had cardiovascular events. Anemic patients (hemoglobin [Hgb] < 13 g/dL) achieved lower metabolic equivalents (METs) than nonanemic patients and had more ST-segment depression (15.5% versus 8.6%, p < 0.004). Proportional hazard analysis demonstrated that hemoglobin was significantly associated with all-cause mortality (p < 0.0007), CV mortality (p < 0.009), and CV events (p < 0.01). Kaplan-Meier survival analysis demonstrated that anemic patients had significantly higher mortality and CV events.

CONCLUSION

Hemoglobin is significantly associated with exercise performance, ST-segment depression during ETT, mortality, and cardiovascular events. The incorporation of hemoglobin may add diagnostic and prognostic information to ETT.

Maximal exercise electrocardiographic responses and coronary heart disease mortality among men with metabolic syndrome

OBJECTIVE

To examine the association between abnormal exercise electrocardiographic (E-ECG) test results and mortality (all-cause and that resulting from coronary heart disease [CHD] or cardiovascular disease [CVD]) in a large population of asymptomatic men with metabolic syndrome (MetS).

PATIENTS AND METHODS

A total of 9191 men (mean age, 46.9 years) met the criteria of having MetS. All completed a maximal E-ECG treadmill test (May 14, 1979, through April 9, 2001) and were without a previous CVD event or diabetes at baseline. Main outcomes were all-cause mortality, mortality due to CHD, and mortality due to CVD. Cox regression analysis was used to quantify the mortality risk according to E-ECG responses.

RESULTS

During a follow-up of 14 years, 633 deaths (242 CVD and 150 CHD) were identified. Mortality rates and hazard ratios (HRs) across E-ECG responses were the following: for all-cause mortality: HR, 1.36; 95% confidence interval (CI), 1.09-1.70 for equivocal responses and HR, 1.41; 95% CI, 1.12-1.77 for abnormal responses (P(trend)<.001); for mortality due to CVD: HR, 1.29; 95% CI, 0.88-1.88 for equivocal responses and HR, 2.04; 95% CI, 1.46-2.84 for abnormal responses (P(trend)<.001); and for mortality due to CHD: HR, 1.62; 95% CI, 1.02-2.56 for equivocal responses and HR, 2.45; 95% CI, 1.62-3.69 for abnormal responses (P(trend)<.001). A positive gradient for CHD, CVD, and all-cause mortality rates across E-ECG categories within 3, 4, or 5 MetS components was observed (P<.001 for all).

CONCLUSION

Among men with MetS, an abnormal E-ECG response was associated with higher risk of all-cause, CVD, and CHD mortality. These findings underscore the importance of E-ECG tests to identify men with MetS who are at risk of dying.

Reducing psychosocial stress: a novel mechanism of improving survival from exercise training

BACKGROUND

Exercise training reduces mortality in patients with coronary artery disease. Behavioral characteristics, including depression, hostility, and overall psychosocial stress, have been shown to be independent risk factors for recurrent myocardial infarction and death in these patients. Exercise training can reduce these high-risk behaviors, but it remains uncertain as to what extent the health benefits of exercise training can be attributed to improving these behaviors.

METHODS

We evaluated the impact of exercise training during cardiac rehabilitation on mortality in 53 patients with coronary artery disease with high levels of psychosocial stress and in 469 patients with coronary artery disease with low levels of psychosocial stress and compared them with 27 control patients with high psychosocial stress who did not undergo formal cardiac rehabilitation and exercise training.

RESULTS

Mortality was approximately 4-fold greater in patients with high psychosocial stress than in those with low psychosocial stress (22% vs 5%; P = .003). Exercise training decreased the prevalence of psychosocial stress from 10% to 4% (P<.0001) and similarly improved peak oxygen uptake in patients with high and low psychosocial stress. Mortality in patients who improved exercise capacity by>or=10% (high exercise change) was 60% lower than in patients who had<10% improvement in exercise capacity (low exercise change) (P=.009). Mortality was lower in patients with high psychosocial stress with high exercise change compared with patients with high psychosocial stress with low exercise change (0% vs 19%; P=.009). In contrast, there was no significant improvement in mortality in patients with high versus low exercise change with low psychosocial stress (4% vs 8%; P=.14).

CONCLUSION

Psychosocial stress is an independent risk factor for mortality in patients with coronary artery disease, and exercise training can effectively reduce its prevalence. Exercise training reduces mortality in patients with coronary artery disease, and this effect seems to be mediated in part because of the salutary effects of exercise on psychosocial stress.

Prognostic value of hypotensive blood pressure response during single-stage exercise test on long-term outcome in patients with known or suspected peripheral arterial disease

OBJECTIVE

A decline in systolic blood pressure during exercise is thought to be a sign of severe coronary artery disease. However, no studies have yet examined this effect in patients with known or suspected peripheral arterial disease. Therefore, we investigated the prognostic value of hypotensive blood pressure response after single-stage exercise test on long-term mortality, major adverse cerebrovascular and cardiac events (MACCE) and the effects of statin, beta-blocker and aspirin use in patients with known or suspected peripheral arterial disease.

METHODS

A total of 2022 patients were enrolled in an observational study with a mean follow-up of 5 years. Hypotensive blood pressure response, 4.6% of the total population, was defined as a drop in exercise systolic blood pressure below resting systolic blood pressure.

RESULTS

Our study showed that hypotensive blood pressure response was associated with an increased risk of all-cause mortality [hazard ratio (HR): 1.74, 95% confidence interval (CI): 1.10-2.73] and MACCE (HR: 1.85, 95% CI: 1.14-3.00), independent of other clinical variables. Additionally, after adjustments for clinical risk factors and propensity score, baseline statin use was associated with a reduced risk of all-cause mortality (HR: 0.60, 95% CI: 0.44-0.80). Besides, statin and aspirin use were both also associated with a reduced risk of MACCE (HR: 0.65, 95% CI: 0.47-0.89 and HR: 0.69, 95% CI: 0.53-0.88, respectively).

CONCLUSION

Hypotensive blood pressure response after single-stage treadmill exercise tests in patients with known or suspected peripheral arterial disease was associated with a higher risk for all-cause long-term mortality and MACCE, which might be reduced by statin and aspirin use.

Prognostic value of exercise stress test and dobutamine stress echo in patients with known coronary artery disease

BACKGROUND

The aim of this study was to compare the feasibility of dobutamine stress echocardiography (DSE) and exercise stress test (EST) between patients in different age groups and to evaluate their proportional prognostic value in a population with established coronary artery disease (CAD).

METHODS

The study sample included 323 subjects, subdivided in group 1 (G1), comprising 246 patients aged <75 years, and group 2 (G2), with 77 subjects aged >or=75 years. DSE and EST were performed before enrollment in a cardiac rehabilitation program; for prognostic assessment, end points were all-cause mortality and hard cardiac events (cardiac death or nonfatal myocardial infarction).

RESULTS

During DSE, G2 patients showed worse wall motion score index (WMSI), but the test was stopped for complications in a comparable proportion of cases (54 G1 and 19 G2 patients, P = NS). EST was inconclusive in similarly high proportion of patients in both groups (76% in G1 vs. 84% in G2, P = NS); G2 patients reached a significantly lower total workload (6 +/- 1.6 METs in G1 vs. 5 +/- 1.2 METs in G2, P < 0.001). At multivariate analysis, a lower peak exercise capacity (HR 0.566, CI 0.351-0.914, P = 0.020) was associated with higher mortality, while a high-dose WMSI >2 (HR 5.123, CI 1.559-16.833, P = 0.007), viability (HR 3.354, CI 1.162-9.678, P = 0.025), and nonprescription of beta-blockers (HR 0.328, CI 0.114-0.945, P = 0.039) predicted hard cardiac events.

CONCLUSION

In patients with known CAD, EST and DSE maintain a significant prognostic role in terms of peak exercise capacity for EST and of presence of viability and an extensive wall motion abnormalities at peak DSE.

Long-term mortality with multiple treadmill exercise test abnormalities: comparison between patients with and without cardiovascular disease

BACKGROUND

Poor exercise capacity, abnormal heart rate responses, and electrocardiographic abnormalities during treadmill exercise testing independently predict mortality. The combined relationship of these 3 variables to determine the incremental increase in mortality was compared in groups with and without known cardiovascular disease (CVD).

METHODS

Patients referred for treadmill exercise testing during 1986 to 1991 were included. Exercise capacity <74% (of age- and gender-predicted value), heart rate reserve of <68 beat/min, and horizontal or down-sloping ST depression of > or =1 mm were considered abnormal. Cox proportional hazards regression was used to determine all-cause mortality (average follow-up of 16 years) based on the number of exercise test abnormalities (0, 1, 2, or all 3).

RESULTS

Among 10,897 patients, 20.9% (n = 2,277) had CVD. Poor exercise capacity and limited heart rate reserve were associated with increased risk of mortality (P < .0001) in both groups; however, abnormal exercise electrocardiogram was associated with an increased risk of mortality in the no-CVD group only (P < .0001). A graded increase in mortality was observed with increase in number of abnormal exercise test results in both groups. Patients without CVD having 2 or 3 abnormal exercise test results had a similar age-adjusted risk of long-term mortality as those with CVD but normal exercise test results, with a hazard ratio comparing these groups = 1.01 (95% CI 0.79-1.28).

CONCLUSIONS

The combinatorial approach validates the prognostic significance of multiple exercise test variables. The presence of > or =2 exercise test abnormalities may constitute a "CVD risk equivalent" in patients without CVD.

The Clinical Significance of Aerobic Exercise Testing and Prescription: From Apparently Healthy to Confirmed Cardiovascular Disease

Aerobic exercise testing clearly provides valuable clinical information in apparently healthy adults as well as a number of patient populations. Maximal aerobic capacity, either estimated from workload or measured directly, is perhaps the most frequently analyzed variable ascertained from such testing. This practice is warranted given the consistent prognostic significance of maximal aerobic capacity. Other variables obtained from the aerobic exercise test, such as the heart rate response during exercise and into recovery, the systolic and diastolic blood pressure responses during exercise, oxygen consumption at anaerobic threshold, and the ventilatory response to exercise, also provide important insight into an individual's health and prognosis. Furthermore, the aerobic exercise test is highly valuable in developing an individualized and safe exercise prescription. Aerobic exercise training goals, with respect to frequency, duration, frequency, and mode of exercise, are well established for the apparently healthy population as well as individuals at risk for or diagnosed with cardiovascular disease. Adherence to these physical activity recommendations clearly provides numerous health benefits, perhaps most important of which is a significant decrease in the risk for cardiovascular events and mortality. This review addresses concepts of aerobic exercise testing and training and discusses their clinical implications.

Maximal exercise electrocardiography responses and coronary heart disease mortality among men with diabetes mellitus

BACKGROUND

An abnormal ECG during maximal exercise testing has been shown to be a powerful predictor of future coronary heart disease (CHD) mortality in asymptomatic men. However, little is known about the relationship between exercise ECG responses and CHD risk in men with diabetes mellitus.

METHODS AND RESULTS

We examined the association between exercise ECG responses and mortality in 2854 men with documented diabetes mellitus (mean age 49.5 years) who completed a maximal treadmill exercise test during the period from 1974 to 2001 and who were without a previous cardiovascular disease (CVD) event at baseline. Mortality due to all causes, CHD, and CVD were the main outcome measures across categories of exercise ECG responses, with stratification by cardiorespiratory fitness, quantified as treadmill test duration. During an average follow-up of 16 years, 441 deaths (210 CVD and 133 CHD) were identified. Across normal, equivocal, and abnormal exercise ECG groups, age- and examination year-adjusted CHD mortality rates per 10 000 person-years were 23.0, 48.6, and 69.0, respectively (P(trend)<0.001). After further adjustment for fasting plasma glucose level, smoking, body mass index, hypercholesterolemia, hypertension, family history of CVD or diabetes mellitus, abnormal resting ECG responses, and cardiorespiratory fitness, hazard ratios (95% confidence intervals) were 1.00 (referent), 1.68 (1.01 to 2.77), and 2.21 (1.41 to 3.46; P(trend)<0.001). Similar patterns of associations were noted between exercise ECG testing and both CVD and all-cause mortality risk.

CONCLUSIONS

Among men with diabetes mellitus, equivocal and abnormal exercise ECG responses were associated with higher risk of all-cause, CVD, and CHD mortality.

Prognostication--the lost skill of medicine

Making a prognosis is one of the primary functions of the medical profession. At the end of the nineteenth century prognostication took up approximately ten percent of medical textbooks, by 1970 this had fallen to nearly zero. Given medical technology's awesome ability to prolong the process and suffering of dying today's patients need to know their prognosis in order to make choices about their treatment options. Whilst precise predictions of the future are obviously not possible, relatively simple mathematical modelling techniques can make reasonable estimates of likely outcomes for individual patients. The life expectancy of a patient of any age with any illness can be estimated provided the disease-specific mortality of the illness is known. Decision analysis or logistic regression models can then be used to determine the risks and benefits of various treatment options. A patient's prognosis does not just depend on their age and primary diagnosis, but also on the severity of their illness, their functional capacity both prior to and during the illness and the number of co-morbidities also suffered from. Several predictive instruments have been developed to help simplify the prediction of the outcome of individual patients. There are conflicting reports on how these models compare with doctors' intuition--whatever their strengths and weaknesses it is unlikely that they worsen clinical judgement. Therefore, all doctors should become familiar with them and use them appropriately.

Prognostic evaluation by clinical exercise test scores in patients treated with primary percutaneous coronary intervention or fibrinolysis for acute myocardial infarction (a Danish Trial in Acute Myocardial Infarction-2 Sub-Study)

The prognostic accuracy of exercise testing after myocardial infarction is low, and different models have been proposed to enhance the predictive value for subsequent mortality. This study tested a simple score against 3 established scores. Patients with ST-elevation myocardial infarctions were randomized in the Danish Trial in Acute Myocardial Infarction-2 (DANAMI-2) to either primary percutaneous coronary intervention or fibrinolysis with predischarge exercise testing. Clinical and exercise test data were collected prospectively and were available for 1,115 patients. A simple score was derived, awarding 1 point for history or new signs of heart failure, 1 point for a left ventricular ejection fraction <40%, 1 point for age >65 years in men and age >70 years in women, and 1 point for exercise capacity <5 METs in men and exercise capacity <4 METs in women. This DANAMI score was compared with the Veterans Affairs Medical Center score, the Duke treadmill score, and the Gruppo Italiano per lo Studio Della Sopravvivenza nell'Infarto Miocardico-2 (GISSI-2) score in multivariate Cox models and receiver-operating characteristic plots. All scoring systems were predictive of adverse outcomes. The DANAMI score performed better, with greater chi-square values (142 vs 53 to 88 for the prediction of death). Areas under the receiver-operating characteristic curves were compared and were larger for the DANAMI score (C-statistic 0.79 vs 0.71 to 0.74 for the other tests regarding mortality). The DANAMI score stratified patients into a small high-risk group (8% of the population with 43% mortality in 6 years), an intermediate-risk group (13% with 16% mortality in 6 years), and a low-risk group (79% with 4% mortality in 6 years). In conclusion, a simple exercise test score composed of age, METs, heart failure, and a left ventricular ejection fraction <40% seems to outperform the Duke treadmill score, Veterans Affairs Medical Center score, and GISSI-2 score in risk stratifying patients after myocardial infarction and deserves further evaluation.

Fragmented QRS on a 12-lead ECG: a predictor of mortality and cardiac events in patients with coronary artery disease

BACKGROUND

Fragmented QRS (fQRS) on a 12-lead electrocardiogram (ECG) is associated with myocardial scar in patients with coronary artery disease (CAD).

OBJECTIVE

We postulated that fQRS is a predictor of cardiac events and mortality in patients who have known CAD or who are being evaluated for CAD.

METHODS

The cardiac events (myocardial infarction, need for revascularization, or cardiac death) and all-cause mortality were retrospectively reviewed in 998 patients (mean age 65.5 +/- 11.9 years, male 967) who underwent nuclear stress test. The fQRS on a 12-lead ECG included various RSR' patterns (> or =1 R' prime or notching of S wave or R wave) without typical bundle branch block in 2 contiguous leads corresponding to a major coronary artery territory.

RESULTS

All-cause mortality (93 [34.1%] vs 188 [25.9%]) and cardiac event rate (135 [49.5%] vs 200 [27.6%]) were higher in the fQRS group compared with the non-fQRS group during a mean follow-up of 57 +/- 23 months. A Kaplan-Meier survival analysis revealed significantly lower event-free survival for cardiac events (P <.001) and all-cause mortality (P = .02). Multivariate Cox regression analysis revealed that significant fQRS was an independent significant predictor for cardiac events but not for all-cause mortality. The Kaplan-Meier survival analysis showed no significant difference between fQRS and Q waves groups for cardiac events (P = .48) and all-cause mortality (P = .08).

CONCLUSION

The fQRS is an independent predictor of cardiac events in patients with CAD. It is associated with significantly lower event-free survival for a cardiac event on long-term follow-up.

Submaximal effort tolerance as a predictor of all-cause mortality in patients undergoing cardiac rehabilitation

BACKGROUND

Submaximal effort tolerance is routinely available during cardiac rehabilitation, but its prognostic value in relation to underlying referral diagnosis is not known.

HYPOTHESIS

Treadmill effort capacity during submaximal exercise training predicts all-cause mortality after cardiac rehabilitation.

METHODS

We followed 600 consecutive patients (450 men and 150 women, mean age 65 years) who were referred to a 12-week outpatient program of cardiac rehabilitation; 37% had a prior myocardial infarction (MI), 44% had a recent percutaneous intervention (PCI), and 39% had history of coronary artery bypass surgery (CABG).

RESULTS

There were 48 deaths during a mean follow-up period of 1603 +/- 822 days. By multivariate Cox analysis, exit MET activity was the most significant predictor of all-cause mortality. In this model, each 1 MET increase in exit submaximal effort tolerance was associated with a 34% decrease in mortality (hazard ratio [HR] 0.66, 95% confidence interval 0.56-0.77) alone and 28% decrease after adjustment for age (HR = 0.72, confidence interval 0.60-0.85). Enty MET level also had predictive value. Subgroup analysis revealed that the predictive value of exit METs was limited to patients after recent CABG and with MI. None of the variables predicted death after PCI, in whom mortality was significantly lower than in the other groups.

CONCLUSIONS

Submaximal effort tolerance at completion of cardiac rehabilitation, and also at entry, is a strong and age-independent predictor of mortality in patients who have had either recent CABG or MI without intervention, but not in patients after recent PCI.

Exercise capacity and body mass as predictors of mortality among male veterans with type 2 diabetes

OBJECTIVE

To demonstrate the relation of exercise capacity and BMI to mortality in a population of male veterans with type 2 diabetes.

RESEARCH DESIGN AND METHODS

After excluding two underweight patients (BMI <18.5 kg/m2), the study population comprised 831 consecutive patients with type 2 diabetes (mean age 61 +/- 9 years) referred for exercise testing for clinical reasons between 1995 and 2006. Exercise capacity was determined from a maximal exercise test and measured in metabolic equivalents (METs). Patients were classified both according to BMI category (18.5-24.9, 25.0-29.9, and > or =30 kg/m2) and by exercise capacity (<5.0 or > or =5.0 maximal METs). The association among exercise capacity, BMI, other clinical variables, and all-cause mortality was assessed by Cox proportional hazards. Study participants were followed for mortality up to 30 June 2006.

RESULTS

During a mean follow-up of 4.8 +/- 3.0 years, 112 patients died, for an average annual mortality rate of 2.2%. Each 1-MET increase in exercise capacity conferred a 10% survival benefit (hazard ratio 0.90 [95% CI 0.82-0.98]; P = 0.01), but BMI was not significantly associated with mortality. After adjustment for age, ethnicity, examination year, BMI, presence of cardiovascular disease (CVD), and CVD risk factors, diabetic patients achieving <5 maximal METs were 70% more likely to die (1.70 [1.13-2.54]) than those achieving > or =5 maximal METs.

CONCLUSIONS

There was a strong inverse association between exercise capacity and mortality in this cohort of men with documented diabetes, and this relationship was independent of BMI.

Predicting prognosis in stable angina--results from the Euro heart survey of stable angina: prospective observational study

OBJECTIVES

To investigate the prognosis associated with stable angina in a contemporary population as seen in clinical practice, to identify the key prognostic features, and from this to construct a simple score to assist risk prediction.

DESIGN

Prospective observational cohort study.

SETTING

Pan-European survey in 156 outpatient cardiology clinics.

PARTICIPANTS

3031 patients were included on the basis of a new clinical diagnosis by a cardiologist of stable angina with follow-up at one year.

MAIN OUTCOME MEASURE

Death or non-fatal myocardial infarction.

RESULTS

The rate of death and non-fatal myocardial infarction in the first year was 2.3 per 100 patient years; the rate was 3.9 per 100 patient years in the subgroup (n = 994) with angiographic confirmation of coronary disease. The clinical and investigative factors most predictive of adverse outcome were comorbidity, diabetes, shorter duration of symptoms, increasing severity of symptoms, abnormal ventricular function, resting electrocardiogaphic changes, or not having any stress test done. Results of non-invasive stress tests did not significantly predict outcome in the population who had tests done. A score was constructed using the parameters predictive of outcome to estimate the probability of death or myocardial infarction within one year of presentation with stable angina.

CONCLUSIONS

A score based on the presence of simple, objective clinical and investigative variables makes it possible to discriminate effectively between very low risk and very high risk patients and to estimate the probability of death or non-fatal myocardial infarction over one year.

Impaired Coronary Vascular Reactivity and Functional Capacity in Women

OBJECTIVES

We investigated the relationship between coronary vascular reactivity and functional capacity as assessed from the Duke Activity Status Index (DASI) in a cohort of women evaluated for suspected ischemia.

BACKGROUND

Reduced functional capacity and impaired vascular reactivity are associated with poor prognosis, but an association between vascular reactivity and functional capacity is unknown.

METHODS

A total of 190 women enrolled in the National Heart, Lung, and Blood Institute (NHLBI)-sponsored Women's Ischemia Syndrome Evaluation (WISE) study had baseline clinical assessment and coronary artery flow velocity response to adenosine (CFVR(ado)). We compared these results with self-reported DASI metabolic equivalents (METs).

RESULTS

Mean age was 55 +/- 11 years (range 21 to 83 years), and only 18% had coronary stenosis > or =50%. Women with a CFVR(ado) <2.5 (n = 98) had mean DASI of 15.1 +/- 13.6, compared to women (n = 92) with CFVR(ado) > or =2.5, whose mean DASI was 21.0 +/- 15.2 (p = 0.004). This relationship was maintained after adjusting for age and presence of coronary artery disease. CFVR(ado) of > or =2.5 was associated with a DASI of >20 (odds ratio 3.03, 95% confidence interval 1.56 to 5.90, p = 0.001).

CONCLUSIONS

Women with reduced CFVR(ado) were significantly more likely to have reduced functional capacity. Impairment in coronary vascular function and reduced levels of activity may both play a role in the poorer prognosis observed in the WISE study women; however, the relationship between the two is still unclear.

Can we reliably predict long-term mortality after exercise testing? An external validation

OBJECTIVE

The aim of the study was to derive and externally validate a mortality prediction rule for patients undergoing exercise testing.

BACKGROUND

The prognostic value of exercise testing is increasingly appreciated. However, global prognosis estimates ideally should account for numerous routinely obtained variables, including demographics, risk factors, resting electrocardiogram, and multiple exercise test measures.

METHODS

A prediction rule was derived by parametric hazards modeling on a derivation set of 46047 Cleveland Clinic patients (age 55 +/- 11 years, 67% male) who had no history of heart failure, valve disease, or atrial fibrillation. Twenty-two variables covering demographics, risk factors, exercise hemodynamics, and electrocardiogram findings at rest and during exercise were considered. The resulting model included 16 variables and was tested on 4981 patients (age 50 +/- 12 years, 55% male) who underwent exercise testing at West Virginia University.

RESULTS

In the derivation cohort there were 3173 deaths during a mean of 7 years of follow-up, whereas in the validation cohort there were 180 deaths during a mean of 5 years of follow-up. Comparisons of predicted and observed death rates showed very good agreement among all patients across all spectrums of risk, as well as among prespecified high-risk subgroups. Model discrimination was also good, with c statistic of c = 0.79 in the derivation group and c = 0.81 in the validation cohort.

CONCLUSIONS

We have externally validated a mortality prediction rule for patients undergoing exercise testing and confirmed its accuracy among a wide spectrum of patients.

Exercise Capacity in Adult African-Americans Referred for Exercise Stress Testing

STUDY OBJECTIVES

To determine the factors associated with exercise capacity.

DESIGN

Retrospective evaluation of large stress-testing database.

SETTING

Multispecialty tertiary care center.

PATIENTS

A total of 5,069 consecutive patients who were referred for exercise stress testing.

MEASUREMENTS

We compared levels of fitness in 641 African-Americans (52% male) with 4,428 whites (73% male), and performed univariate and multivariate analyses to determine the predictors of fitness (including race).

RESULTS

Compared with African-American men (mean [+/- SD] age, 60 +/- 11 years), white men (mean age, 63 +/- 11 years) have significantly higher exercise capacity (10.7 +/- 3.5 vs 11.4 +/- 3.4 metabolic equivalents [METs], respectively; p < 0.001). The exercise capacity in African-American and white women was similar (8.5 +/- 2.9 vs 8.7 +/- 3.0 METs, respectively). However, body mass indexes (BMIs) were significantly higher in both African-American men (29.1 +/- 4.3 vs 28.2 +/- 4.3 kg/m(2), respectively; p < 0.001) and women (30.2 +/- 5.7 vs 27.9 +/- 5.5 kg/m(2), respectively; p < 0.0001) compared to their white counterparts, as was the prevalence of obesity (men, 44% vs 33%, respectively; women, 37% vs 27%, respectively; both p < 0.001). Although a model containing age, gender, BMI, and race only accounted for 32% of exercise capacity, all independently (p < 0.0001) predicted higher exercise capacity, as follows: younger age (r(2) = 0.14); male gender (r(2) = 0.12); BMI (r(2) = 0.06); and white race (r(2) = 0.004).

CONCLUSIONS

In an adult population of individuals who were referred for exercise stress testing, African-Americans were more obese and had significantly lower exercise capacity than their white counterparts. Emphasis on weight reduction and increasing physical fitness is particularly needed for the prevention of cardiovascular diseases in African-Americans.

Determining the need for coronary revascularization by an exercise test assessment computer program (ETAP)

The rate at which coronary artery revascularization procedures are performed remains inconsistent, and their risks may be greater and long-term benefits less than imagined by the general public and open to considerable inter-individual variation. However, these risks and benefits can be explicitly estimated for an individual patient from a brief medical history and the results of a standard exercise test by a computer program that uses conventional medical decision making techniques. The program first estimates the prior and post-exercise test probability of coronary artery disease and then employs a decision analysis model to define the risks and benefits associated with different treatment options. These results are provided in a printed report that can become part of the clinical record to be reviewed with the patient. In contrast with traditional clinical intuition, the program consistently and explicitly defines the risks and benefits of coronary artery disease treatments. The program forces physicians and their patients to appraise critically the information and beliefs upon which they base their clinical decisions.

Cholinergic stimulation with pyridostigmine protects against exercise induced myocardial ischaemia

OBJECTIVE

To determine the acute effects of pyridostigmine bromide, a reversible cholinesterase inhibitor, during exercise in patients with coronary artery disease.

DESIGN

Double blind, randomised, placebo controlled, crossover study.

SETTING

Outpatients evaluated in an exercise test laboratory.

PATIENTS

15 patients with exercise induced myocardial ischaemia.

INTERVENTIONS

Maximal cardiopulmonary exercise test on a treadmill according to an individualised ramp protocol on three days. The first day was used for adaptation to the equipment and to determine exercise tolerance and the presence of exercise induced ischaemia. On the other two days, the cardiopulmonary exercise test was performed two hours after oral administration of pyridostigmine (45 mg) or placebo. All patients were taking their usual medication during the experiments.

MAIN OUTCOME MEASURES

Rate-pressure product and oxygen uptake during exercise.

RESULTS

Pyridostigmine inhibited the submaximum chronotropic response (p = 0.001), delaying the onset of myocardial ischaemia, which occurred at a similar rate-pressure product (mean (SE) placebo 20.55 (1.08) mm Hg x beats/min 10(3); pyridostigmine 19.75 (1.28) mm Hg x beats/min 10(3); p = 0.27) but at a higher exercise intensity (oxygen consumption: placebo 18.6 (1.7) ml/kg/min; pyridostigmine 19.6 (1.8) ml/kg/min; p = 0.03). Also, pyridostigmine increased peak oxygen consumption (placebo 23.6 (2) ml/kg/min; pyridostigmine 24.8 (2) ml/kg/min; p = 0.01) and peak oxygen pulse (placebo 12.9 (1) ml/beat; pyridostigmine 13.6 (1) ml/beat; p = 0.02).

CONCLUSIONS

Pyridostigmine improved peak exercise tolerance and inhibited the chronotropic response to submaximum exercise, increasing the intensity at which myocardial ischaemia occurred. These results suggest that pyridostigmine can protect against exercise induced myocardial ischaemia.

Five-year cardiovascular and all-cause mortality, and myocardial infarction in all subjects referred for exercise testing in two Danish counties

OBJECTIVE

To examine the association between exercise test results and the 5-year cardiovascular and all-cause mortality, and myocardial infarction, in patients referred for exercise testing because of known or suspected coronary heart disease.

DESIGN

A study of all patients (N = 2763) who in 1996 had an exercise test in two Danish counties (900000 inhabitants). Data and follow-up were based on medical records and general administrative healthcare and population registries.

RESULTS

Abnormal tests, compared with normal ones, were associated with an increased adjusted cardiovascular mortality ratio of 1.77 (95% confidence interval (CI): 1.19-2.63), all-cause mortality ratio of 1.46 (95% CI: 1.11-1.93), and myocardial infarction ratio of 1.71 (95% CI: 1.28-2.28). Inconclusive tests, compared with normal ones, were associated with an increased adjusted all-cause mortality ratio of 1.52 (95% CI: 1.05-2.20) and myocardial infarction ratio of 1.67 (95% CI: 1.12-2.56). A history of myocardial infarction increased the cardiovascular death ratio by 1.51 (95% CI: 1.05-2.16) and the myocardial infarction ratio by 2.39 (95% CI: 1.84-3.10).

CONCLUSION

Over a 5-year period, the result of the bicycle exercise test was clearly associated with both mortality and risk of myocardial infarction. An inconclusive test may deserve special attention.