Ford Exercise Testing Research Articles

MAXIMAL EXERCISE CAPACITY IS INVERSELY RELATED TO INCIDENT PERIPHERAL ARTERY DISEASE

https://youtu.be/wLtxZn3XafA BACKGROUND Maximal exercise capacity (EC) is a strong, independent predictor of incident coronary and cerebrovascular disease. However, less is known about the relationship between EC and incident peripheral artery disease (PAD). Using data from the Henry Ford Exercise Testing (FIT) Project, we evaluated the relationship between EC and incident PAD. We hypothesized that EC, measured in metabolic equivalents of task (METs), is inversely related to incident PAD. METHODS We assessed 41,268 patients (age = 55±12 yrs, 49% female, and 64% white) who completed a clinically indicated exercise stress test between January 1991 and June 2009 at a Henry Ford Health facility. Patients with established PAD at the time of testing were excluded. METs were estimated from peak treadmill speed and grade and standardized to the equivalent of a 50-year-old male to account for differences in absolute risk for a given MET level by age and sex. METs were categorized as <6, 6-9, 10-11, and >12. ICD9 codes 440.XX and 443.9 were used to identify first incidence of PAD from the test date through June 2010. Multivariable Cox regression was used to relate METs to incident PAD. Patients were censored at the date of death or last clinic visit. RESULTS During a median follow-up of 7.1 years (IQR 4.2-11.1 yrs) there were 2,596 (6%) incident diagnoses of PAD. In the adjusted analysis, each 1 MET increase in maximal EC was associated with a 7% lower risk of PAD (aHR=0.93 [0.91, 0.94]). There was a graded, inverse risk of incident PAD by MET category (see Table). A significant interaction was noted for race (overall p=.04; white [HR=0.93 (0.92, 0.95)] vs black [HR=0.91 (0.88, 0.93)], p=.02; white vs other [HR=0.97 (0.87, 1.07)], p=0.47), but not for sex (p=.79). CONCLUSION In a diverse cohort that completed a clinically indicated exercise stress test, higher EC measured in METs, is independently and inversely associated with a lower risk of incident PAD.

Abstract 12537: Sedentary Behavior is a Stronger Risk Factor Than Diabetes for Incident Peripheral Artery Disease: Data From the Henry Ford Exercise Testing (FIT) Project

Introduction: Age, diabetes (DM) and smoking are risk factors related to developing peripheral artery disease (PAD). Little is known about the strength of the association of sedentary behavior (SB) or fitness relative to traditional risk factors, and the risk of PAD. Hypothesis: SB and fitness are independently related to risk of PAD, but their relative contribution is less than DM and smoking. Methods: We assessed 41,268 patients (pts) (age= 55±12 yr, 51% male, 64% white) from the Henry Ford Exercise Testing (FIT) who completed a clinically ordered exercise stress test between January 1991 and June 2009. Fitness (metabolic equivalents of task, METs) was estimated from peak treadmill speed and grade. Patients were asked about current exercise habits and coded as sedentary if not performing regular aerobic mode exercise. Patient self-report and medical records were used to determine smoking history and DM. Those with established PAD at the time of testing were excluded. ICD9 codes 440.XX and 443.9 identified first incidence of PAD from test date up to June 2010. Using multivariable Cox regression (Wald X 2 , α <0.05) we report on the top 5 predictors of time to incident PAD in ALL pts and stratified by race. Results: During a median follow-up of 7.1 yr (IQR 4.2-11.1 yr) there were 2,596 (6%) incident diagnoses of PAD. Wald X 2 values were rank ordered (Table). SB and fitness were independently related to time to incident PAD. SB ranked the 3 rd strongest variable for both ALL (HR=2.5 [2.2, 2.9]) and WHITE pts (HR=2.5 [2.1, 2.9]). For BLACK pts SB ranked 2 nd (HR=2.7 [2.1, 3.6]), above DM and smoking. Fitness ranked 5 th for ALL and BLACK pts, and 6 th in WHITE pts. Conclusion: In ALL pts, and WHITE and BLACK pts separately, SB was strongly associated with time to incident PAD, and explained more of the variation in incident PAD than DM. In BLACK pts SB was also stronger than smoking. Further research is needed to clarify the role of SB as a potential emerging modifiable risk factor for the development of PAD.

Abstract 12532: Maximal Exercise Capacity is Inversely Related to Incident Peripheral Artery Disease: Data From the Henry Ford Exercise Testing (FIT) Project

Introduction: Maximal exercise capacity (EC) is a strong, independent predictor of incident coronary and cerebrovascular disease. However, less is known about the relationship between EC and incident peripheral artery disease (PAD). Using data from the Henry Ford Exercise Testing (FIT) Project, we evaluated the relationship between EC and incident PAD. Hypothesis: EC, measured in metabolic equivalents of task (METs), is inversely related to incident PAD. Methods: We assessed 41,268 patients (age= 55±12 yrs, 49% female, and 64% white) who completed a clinically indicated exercise stress test between January 1991 and June 2009 at a Henry Ford Health facility. Patients with established PAD at the time of testing were excluded. METs were estimated from peak treadmill speed and grade and standardized to the equivalent of a 50-year-old male to account for differences in absolute risk for a given MET level by age and sex. METs were categorized as <6, 6-9, 10-11, and > 12. ICD9 codes 440.XX and 443.9 were used to identify first incidence of PAD from the test date through June 2010. Multivariable Cox regression was used to relate METs to incident PAD. Patients were censored at the date of death or last clinic visit. Results: During a median follow-up of 7.1 years (IQR 4.2-11.1 yrs) there were 2,596 (6%) incident diagnoses of PAD. In the adjusted analysis, each 1 MET increase in maximal EC was associated with a 7% lower risk of PAD (aHR=0.93 [0.91, 0.94]). There was a graded, inverse risk of incident PAD by MET category (see Table). A significant interaction was noted for race (overall p=.04; white [HR=0.93 (0.92, 0.95)] vs black [HR=0.91 (0.88, 0.93)], p=.02; white vs other [HR=0.97 (0.87, 1.07)], p=0.47), but not for sex (p=.79). Conclusion: In a diverse cohort that completed a clinically indicated exercise stress test, higher EC measured in METs, is independently and inversely associated with a lower risk of incident PAD.

A Non-Exercise Model for Predicting Cardiovascular Risks among Apparently Healthy Male Office Workers-Cross-Sectional Analysis: A Pilot Study.

The health condition of working-age males in Poland remains largely associated with long-lasting sick leaves, one of the main reasons of which being cardiovascular diseases (CVD). The aim of this work was to develop a prediction model for FIT Treadmill Score (“FIT” refers to Henry Ford ExercIse Testing (FIT) Project) that only depends on easily accessible somatic data and smoking without the need to perform the exercise test anymore. The study comprised 146 men with a negative cardiological history, aged 26–60, with desk-jobs. By means of regression analysis it was tested to what degree obesity-related indices as well as smoking cigarettes allow for determining the measure level of mortality risk, without the necessity of performing an exercise test. The following independent variables were entered into the linear regression model: age, BMI, Fat%, waist circumference (WC), waist to height ratio (WHtR) as well as smoking. Statistically significant factors were singled out from among them. The obtained model accounts for a significant part (over 87%) of the variability of the mortality risk measure among the tested population. Based on the value of the standardised regression coefficient β, it can be stated that age is the factor that mostly determines the mortality risk measure, followed by the WHtR and smoking. The simplicity of the worked-out model and, resulting from it, the possibility of its common application should enable better health monitoring of working-age men with regard to cardiovascular disease occurrence and, related to it, mortality risk, thereby improving the quality of public health management.

Prognostic Value of Cardiorespiratory Fitness in Patients with Chronic Kidney Disease: The FIT (Henry Ford Exercise Testing) Project

PurposeWe conducted this study to investigate the association of cardiorespiratory fitness and all-cause mortality among patients with chronic kidney disease. MethodsWe studied a retrospective cohort of patients from the Henry Ford Health System who underwent clinically indicated exercise stress testing with baseline cardiorespiratory fitness and estimated glomerular filtration rate measurement. Cardiorespiratory fitness was expressed as metabolic equivalents of task, and kidney function was categorized into stages according to estimated glomerular filtration rate. Multivariable-adjusted Cox proportional hazard models were used to examine the association between metabolic equivalents of task and all-cause mortality among patients with chronic kidney disease stages 3-5. Discrimination of mortality was assessed using receiver operating characteristic curves, while reclassification was evaluated using net reclassification index (NRI). ResultsAmong 50,121 participants, the mean age was 55 ± 12.6 years; 47.5% were women, 64.5% were white, and 6877 (13.7%) participants had chronic kidney disease stage 3-5. Over a median follow-up of 6.7 years, 6308 participants died (12.6%). Each 1-unit higher metabolic equivalents of task was associated with a significant 15% reduction in all-cause mortality (hazard ratio 0.85; 95% confidence interval [CI], 0.84-0.87). Metabolic equivalents of task improved discriminatory ability of mortality prediction when added to traditional risk factors and estimated glomerular filtration rate (area under the curve 0.7996; 95% CI, 0.789-0.810 vs 0.759; 95% CI, 0.748-0.770, respectively; P < .001). The addition of metabolic equivalents of task to traditional risk factors resulted in significant reclassification (6% for events, 5% for non-events: NRI = 0.13, P < .001). ConclusionsCardiorespiratory fitness improves mortality risk prediction among patients with chronic kidney disease. Cardiorespiratory fitness provides incremental prognostic information when added to traditional risk factors and may help guide treatment options among patients with renal dysfunction.

Fitness and prostate cancer screening, incidence, and mortality: Results from the Henry Ford Exercise Testing (FIT) Project.

The relation between cardiorespiratory fitness (CRF) and prostate cancer is not well established. The objective of this study was to determine whether CRF is associated with prostate cancer screening, incidence, or mortality. The Henry Ford Exercise Testing Project is a retrospective cohort study of men aged 40 to 70 years without cancer who underwent physician-referred exercise stress testing from 1995 to 2009. CRF was quantified in metabolic equivalents of task (METs) (<6 [reference], 6-9, 10-11, and ≥12 METs), estimated from the peak workload achieved during a symptom-limited, maximal exercise stress test. Prostate-specific antigen (PSA) testing, incident prostate cancer, and all-cause mortality were analyzed with multivariable adjusted Poisson regression and Cox proportional hazard models. In total, 22,827 men were included, of whom 739 developed prostate cancer, with a median follow-up of 7.5 years. Men who had high fitness (≥12 METs) had an 28% higher risk of PSA screening (95% CI, 1.2-1.3) compared with those who had low fitness (<6 METs. After adjusting for PSA screening, fitness was associated with higher prostate cancer incidence (men aged <55 years, P = .02; men aged >55 years, P ≤ .01), but not with advanced prostate cancer. Among the men who were diagnosed with prostate cancer, high fitness was associated with a 60% lower risk of all-cause mortality (95% CI, 0.2-0.9). Although men with high fitness are more likely to undergo PSA screening, this does not fully account for the increased incidence of prostate cancer seen among these individuals. However, men with high fitness have a lower risk of death after a prostate cancer diagnosis, suggesting that the cancers identified may be low-risk with little impact on long-term outcomes.

Cardiorespiratory Fitness and Incident Stroke Types: The FIT (Henry Ford ExercIse Testing) Project

ObjectiveTo study the association between cardiorespiratory fitness (CRF) and incident stroke types. Patients and MethodsWe studied a retrospective cohort of patients referred for treadmill stress testing in the Henry Ford Health System (Henry Ford ExercIse Testing Project) without history of stroke. CRF was expressed by metabolic equivalents of task (METs). Using appropriate International Classification of Diseases, Ninth Revision codes, incident stroke was ascertained through linkage with administrative claims files and classified as ischemic, hemorrhagic, and subarachnoid hemorrhage (SAH). Multivariable-adjusted Cox proportional hazards models examined the association between CRF and incident stroke. ResultsAmong 67,550 patients, mean ± SD age was 54±13 years, 46% (n=31,089) were women, and 64% (n=43,274) were white. After a median follow-up of 5.4 (interquartile range 2.7-8.5) years, a total of 7512 incident strokes occurred (6320 ischemic, 2481 hemorrhagic, and 275 SAH). Overall, there was a graded lower incidence of stroke with higher MET categories. Patients with METs of 12 or more had lower risk of overall stroke [0.42 (95% CI, 0.36-0.49)], ischemic stroke [0.69 (95% CI, 0.58-0.82)], and hemorrhagic stroke [0.71 (95% CI, 0.52-0.95)]. ConclusionIn a large ethnically diverse cohort of patients referred for treadmill stress testing, CRF is inversely associated with risk for ischemic and hemorrhagic stroke.

Cardiorespiratory fitness and incident lung and colorectal cancer in men and women: Results from the Henry Ford Exercise Testing (FIT) cohort.

To the authors' knowledge, the relationship between cardiorespiratory fitness (CRF) and lung and colorectal cancer outcomes is not well established. A retrospective cohort study was performed of 49,143 consecutive patients who underwent clinician-referred exercise stress testing from 1991 through 2009. The patients ranged in age from 40 to 70years, were without cancer, and were treated within the Henry Ford Health System in Detroit, Michigan. CRF, measured in metabolic equivalents of task (METs), was categorized as <6 (reference), 6 to 9, 10 to 11, and ≥12. Incident cancer was obtained through linkage to the cancer registry and all-cause mortality from the National Death Index. Participants had a mean age of 54±8years. Approximately 46% were female, 64% were white, 29% were black, and 1% were Hispanic. The median follow-up was 7.7years. Cox proportional hazard models, adjusted for age, race, sex, body mass index, smoking history, and diabetes, found that those in the highest fitness category (METs ≥12) had a 77% decreased risk of lung cancer (hazard ratio [HR], 0.23; 95% CI, 0.14-0.36) and a 61% decreased risk of incident colorectal cancer (HR, 0.39; 95% CI, 0.23-0.66; with additional adjustment for aspirin and statin use). Among those diagnosed with lung and colorectal cancer, those with high fitness had a decreased risk of subsequent death of 44% and 89%, respectively (HR, 0.56 [95% CI, 0.32-1.00] and HR, 0.11 [95% CI, 0.03-0.37], respectively). In what to the authors' knowledge is the largest study performed to date, higher CRF was associated with a lower risk of incident lung and colorectal cancer in men and women and a lower risk of all-cause mortality among those diagnosed with lung or colorectal cancer.

Higher cardiorespiratory fitness predicts long-term survival in patients with heart failure and preserved ejection fraction: the Henry Ford Exercise Testing (FIT) Project.

IntroductionHigher cardiorespiratory fitness (CRF) is associated with improved exercise capacity and quality of life in heart failure with preserved ejection fraction (HFpEF), but there are no large studies evaluating the association of HFpEF, CRF, and long-term survival. We therefore aimed to determine the association between CRF and all-cause mortality, in patients with HFpEF.Material and methodsIn the Henry Ford Exercise Testing (FIT) Project, 167 patients had baseline HFpEF, defined as a clinical diagnosis of heart failure with ejection fraction ≥ 50% on echocardiogram. The CRF was estimated from the peak workload (in METs) from a clinician-referred treadmill stress test and categorized as poor (1–4 METs), intermediate (5–6 METs), and moderate-high (≥ 7 METs). Additional analyses assessing the effect of HFpEF and CRF on mortality were also conducted, matching HFpEF patients to non-HFpEF patients using propensity scores.ResultsMean age was 64 ±13 years, with 55% women, and 46% Black. Over a median follow-up of 9.7 (5.2–18.9) years, there were 103 deaths. In fully adjusted models, moderate-high CRF was associated with 63% lower mortality risk (HR = 0.37, 95% CI: 0.18–0.73) compared to the poor-CRF group. In the propensity-matched cohort, HFpEF was associated with a HR of 2.3 (95% CI: 1.7–3.2) for mortality compared to non-HFpEF patients, which was attenuated to 1.8 (95% CI: 1.3–2.5) after adjusting for CRF.ConclusionsModerate-high CRF in patients with HFpEF is associated with improved survival, and differences in CRF partly explain the intrinsic risk of HFpEF. Randomized trials of interventions aimed at improving CRF in HFpEF are needed.

Exercise Capacity and the Obesity Paradox in Heart Failure: The FIT (Henry Ford Exercise Testing) Project

ObjectivesTo assess the influence of exercise capacity and body mass index (BMI) on 10-year mortality in patients with heart failure (HF) and to synthesize these results with those of previous studies. Patients and MethodsThis large biracial sample included 774 men and women (mean age, 60±13 years; 372 [48%] black) with a baseline diagnosis of HF from the Henry Ford Exercise Testing (FIT) Project. All patients completed a symptom-limited maximal treadmill stress test from January 1, 1991, through May 31, 2009. Patients were grouped by World Health Organization BMI categories for Kaplan-Meier survival analyses and stratified by exercise capacity (<4 and ≥4 metabolic equivalents [METs] of task). Associations of BMI and exercise capacity with all-cause mortality were assessed using multivariable-adjusted Cox proportional hazards models. ResultsDuring a mean follow-up of 10.1±4.6 years, 380 patients (49%) died. Kaplan-Meier survival plots revealed a significant positive association between BMI category and survival for exercise capacity less than 4 METs (log-rank, P=.05), but not greater than or equal to 4 METs (P=.76). In the multivariable-adjusted models, exercise capacity (per 1 MET) was inversely associated, but BMI was not associated, with all-cause mortality (hazard ratio, 0.89; 95% CI, 0.85-0.94; P<.001 and hazard ratio, 0.99; 95% CI, 0.97-1.01; P=.16, respectively). ConclusionMaximal exercise capacity modified the relationship between BMI and long-term survival in patients with HF, upholding the presence of an exercise capacity-obesity paradox dichotomy as observed over the short-term in previous studies.

Using machine learning on cardiorespiratory fitness data for predicting hypertension: The Henry Ford ExercIse Testing (FIT) Project.

This study evaluates and compares the performance of different machine learning techniques on predicting the individuals at risk of developing hypertension, and who are likely to benefit most from interventions, using the cardiorespiratory fitness data. The dataset of this study contains information of 23,095 patients who underwent clinician- referred exercise treadmill stress testing at Henry Ford Health Systems between 1991 and 2009 and had a complete 10-year follow-up. The variables of the dataset include information on vital signs, diagnosis and clinical laboratory measurements. Six machine learning techniques were investigated: LogitBoost (LB), Bayesian Network classifier (BN), Locally Weighted Naive Bayes (LWB), Artificial Neural Network (ANN), Support Vector Machine (SVM) and Random Tree Forest (RTF). Using different validation methods, the RTF model has shown the best performance (AUC = 0.93) and outperformed all other machine learning techniques examined in this study. The results have also shown that it is critical to carefully explore and evaluate the performance of the machine learning models using various model evaluation methods as the prediction accuracy can significantly differ.

Prognostic value of exercise capacity among patients with treated depression: The Henry Ford Exercise Testing (FIT) Project.

Exercise capacity is associated with survival in the general population. Whether this applies to patients with treated depression is not clear. High exercise capacity remains associated with lower risk of all-cause mortality (ACM) and nonfatal myocardial infraction (MI) among patients with treated depression. We included 5128 patients on antidepressant medications who completed a clinically indicated exercise stress test between 1991 and 2009. Patients were followed for a median duration of 9.4 years for ACM and 4.5 years for MI. Exercise capacity was estimated in metabolic equivalents of tasks (METs). Cox proportional hazards regression models were used. Patients with treated depression who achieved ≥12 METs (vs those achieving <6 METs) were younger (age 46 ± 9 vs 61 ± 12 years), more often male (60% vs 23%), less often black (10% vs 27%), and less likely to be hypertensive (51% vs 86%), have DM (9% vs 38%), or be obese (11% vs 36%) or dyslipidemic (45% vs 54%). In the fully adjusted Cox proportional hazard regression model, exercise capacity was associated with a lower ACM (HR per 1-MET increase in exercise capacity: 0.82, 95% CI: 0.79-0.85, P < 0.001) and nonfatal MI (HR: 0.92, 95% CI: 0.87-0.97, P = 0.004). Exercise capacity had an inverse association with both ACM and nonfatal MI in patients with treated depression, independent of cardiovascular risk factors. These results highlight the potential impact of assessing exercise capacity to identify risk, as well as promoting an active lifestyle among treated depression patients.

Comparison of machine learning techniques to predict all-cause mortality using fitness data: the Henry ford exercIse testing (FIT) project

BackgroundPrior studies have demonstrated that cardiorespiratory fitness (CRF) is a strong marker of cardiovascular health. Machine learning (ML) can enhance the prediction of outcomes through classification techniques that classify the data into predetermined categories. The aim of this study is to present an evaluation and comparison of how machine learning techniques can be applied on medical records of cardiorespiratory fitness and how the various techniques differ in terms of capabilities of predicting medical outcomes (e.g. mortality).MethodsWe use data of 34,212 patients free of known coronary artery disease or heart failure who underwent clinician-referred exercise treadmill stress testing at Henry Ford Health Systems Between 1991 and 2009 and had a complete 10-year follow-up. Seven machine learning classification techniques were evaluated: Decision Tree (DT), Support Vector Machine (SVM), Artificial Neural Networks (ANN), Naïve Bayesian Classifier (BC), Bayesian Network (BN), K-Nearest Neighbor (KNN) and Random Forest (RF). In order to handle the imbalanced dataset used, the Synthetic Minority Over-Sampling Technique (SMOTE) is used.ResultsTwo set of experiments have been conducted with and without the SMOTE sampling technique. On average over different evaluation metrics, SVM Classifier has shown the lowest performance while other models like BN, BC and DT performed better. The RF classifier has shown the best performance (AUC = 0.97) among all models trained using the SMOTE sampling.ConclusionsThe results show that various ML techniques can significantly vary in terms of its performance for the different evaluation metrics. It is also not necessarily that the more complex the ML model, the more prediction accuracy can be achieved. The prediction performance of all models trained with SMOTE is much better than the performance of models trained without SMOTE. The study shows the potential of machine learning methods for predicting all-cause mortality using cardiorespiratory fitness data.

Prognostic value of exercise capacity among men undergoing pharmacologic treatment for erectile dysfunction: The FIT Project.

Vascular erectile dysfunction (ED) has been identified as a potentially useful risk factor for predicting future cardiovascular events, particularly in younger men. Because these men typically score more favorably on traditional cardiovascular disease risk assessment tools, there exists a gap in knowledge for how to most appropriately identify those men who would benefit from more aggressive treatments. To date, no studies have examined the impact of fitness on cardiovascular outcomes in men with ED. This study sought to examine the prognostic impact of maximal exercise capacity on cardiovascular-related outcomes in men ages 40 to 60 years being treated for ED. We hypothesized that there would be an independent association between higher baseline fitness level and lower cardiovascular events. We analyzed 1152 men with pharmacy claims file-confirmed active pharmacologic treatment for ED from the Henry Ford Exercise Testing (FIT) Project (1991-2009). All patients were free of coronary heart disease and heart failure, and underwent clinician-referred exercise stress testing, with fitness measured in metabolic equivalents of task (METs). Multivariable Cox proportional hazard models adjusted for traditional cardiovascular risk factors were used to study the association between fitness and all-cause mortality, major adverse cardiovascular events (MACE) (defined as myocardial infarction or revascularization), and incident type 2 diabetes mellitus. The mean age of the population was 53 years, with 39% African Americans. In multivariable analysis, each 1 MET of fitness was associated with a 16% lower risk of death (hazard ratio [HR]: 0.84, 95% confidence interval [CI]: 0.76-0.94, P = 0.002), and a nonsignificant reduction in MACE (HR: 0.89, 95% CI: 0.79-1.003, P = 0.048), and incident diabetes (HR: 0.92, 95% CI: 0.85-1.01, P = 0.129). Higher baseline fitness is associated with improved cardiovascular prognosis in a population of middle-aged men treated for ED.

Predicting diabetes mellitus using SMOTE and ensemble machine learning approach: The Henry Ford ExercIse Testing (FIT) project.

Machine learning is becoming a popular and important approach in the field of medical research. In this study, we investigate the relative performance of various machine learning methods such as Decision Tree, Naïve Bayes, Logistic Regression, Logistic Model Tree and Random Forests for predicting incident diabetes using medical records of cardiorespiratory fitness. In addition, we apply different techniques to uncover potential predictors of diabetes. This FIT project study used data of 32,555 patients who are free of any known coronary artery disease or heart failure who underwent clinician-referred exercise treadmill stress testing at Henry Ford Health Systems between 1991 and 2009 and had a complete 5-year follow-up. At the completion of the fifth year, 5,099 of those patients have developed diabetes. The dataset contained 62 attributes classified into four categories: demographic characteristics, disease history, medication use history, and stress test vital signs. We developed an Ensembling-based predictive model using 13 attributes that were selected based on their clinical importance, Multiple Linear Regression, and Information Gain Ranking methods. The negative effect of the imbalance class of the constructed model was handled by Synthetic Minority Oversampling Technique (SMOTE). The overall performance of the predictive model classifier was improved by the Ensemble machine learning approach using the Vote method with three Decision Trees (Naïve Bayes Tree, Random Forest, and Logistic Model Tree) and achieved high accuracy of prediction (AUC = 0.92). The study shows the potential of ensembling and SMOTE approaches for predicting incident diabetes using cardiorespiratory fitness data.

Cardiorespiratory Fitness Change and Mortality Risk Among Black and White Patients: Henry Ford Exercise Testing (FIT) Project

BackgroundLittle is known about the relationship of change in cardiorespiratory fitness and mortality risk in Black patients. This study assessed change in cardiorespiratory fitness and its association with all-cause mortality risk in Black and White patients. MethodsThis is a retrospective, longitudinal, observational cohort study of 13,345 patients (age = 55 ± 11 years; 39% women; 26% black) who completed 2 exercise tests, at least 12 months apart at Henry Ford Hospital, Detroit, Mich. All-cause mortality was identified through April 2013. Data were analyzed in 2015-2016 using Cox regression to calculate hazard ratios (HR) for risk of mortality associated with change in sex-specific cardiorespiratory fitness. ResultsMean time between the tests was 3.4 years (interquartile range 1.9-5.6 years). During 9.1 years (interquartile range 6.3-11.6 years) of follow-up, there were 1931 (14%) deaths (16.5% black, 13.7% white). For both races, change in fitness from Low to the Intermediate/High category resulted in a significant reduction of death risk (HR 0.65 [95% confidence interval (CI), 0.49-0.87] for Black; HR 0.41 [95% CI, 0.34-0.51] for White). Each 1-metabolic-equivalent-of-task increase was associated with a reduced mortality risk in black (HR 0.84 [95% CI, 0.81-0.89]) and white (HR 0.87 [95% CI, 0.82-0.86]) patients. There was no interaction by race. ConclusionsAmong black and white patients, change in cardiorespiratory fitness from Low to Intermediate/High fitness was associated with a 35% and 59% lower risk of all-cause mortality, respectively.

Change in Maximal Exercise Capacity Is Associated With Survival in Men and Women

ObjectiveTo describe the relationship between change in maximal exercise capacity (MEC) over time and risk of all-cause mortality separately in men and women. Patients and MethodsConsecutive patients (n=10,854; mean ± SD age, 54±11 years; 43% women; 30% nonwhite) who completed 2 physician-referred exercise tests between January 2, 1991, and May 28, 2009, were identified from the Henry Ford Exercise Testing (FIT) Project. The MEC was quantified in metabolic equivalents of task (METs) calculated from peak workload on a treadmill and adjusted to the equivalent for a 50-year-old man. Multivariable Cox proportional hazards regression was performed to assess risk of all-cause mortality associated with change in MEC based on (1) change from age-/sex-adjusted low fitness (<8 METs) to intermediate or high fitness and (2) an absolute change in METs. ResultsRelative to patients with low fitness at both tests, increasing from low to intermediate or high fitness was associated with lower risk of all-cause mortality (adjusted hazard ratio [aHR] = 0.63 [95% CI, 0.45-0.87] in men and 0.56 [95% CI, 0.34-0.91] in women). Each 1-MET increase in age-/sex-adjusted MEC between baseline and follow-up was associated with an aHR of 0.87 (95% CI, 0.84-0.91) in men and 0.84 (95% CI, 0.79-0.89) in women, with no significant interaction by sex (P=.995). Similar aHRs were observed in a subgroup with intermediate fitness at baseline. ConclusionIn men and women referred for an exercise stress test, change in MEC over time is inversely related to risk of all-cause mortality.

Cardiorespiratory fitness and incident heart failure: The Henry Ford ExercIse Testing (FIT) Project

Prior studies have demonstrated cardiorespiratory fitness (CRF) to be a strong marker of cardiovascular health. However, there are limited data investigating the association between CRF and risk of progression to heart failure (HF). The purpose of this study was to determine the relationship between CRF and incident HF. We included 66,329 patients (53.8% men, mean age 55 years) free of HF who underwent exercise treadmill stress testing at Henry Ford Health Systems between 1991 and 2009. Incident HF was determined using International Classification of Diseases, Ninth Revision codes from electronic medical records or administrative claim files. Cox proportional hazards models were performed to determine the association between CRF and incident HF. A total of 4,652 patients developed HF after a median follow-up duration of 6.8 (±3) years. Patients with incident HF were older (63 vs 54 years, P<.001) and had higher prevalence of known coronary artery disease (42.3% vs 11%, P<.001). Peak metabolic equivalents (METs) of task were 6.3 (±2.9) and 9.1 (±3) in the HF and non-HF groups, respectively. After adjustment for potential confounders, patients able to achieve ≥12 METs had an 81% lower risk of incident HF compared with those achieving <6 METs (hazard ratio 0.19 [95% CI 0.14-0.29], P for trend < .001). Each 1 MET achieved was associated with a 16% lower risk (hazard ratio 0.84 [95% CI 0.82-0.86], P<.001) of incident HF. Our analysis demonstrates that higher level of fitness is associated with a lower incidence of HF independent of HF risk factors.

Chronotropic Incompetence and Risk of Atrial Fibrillation: The Henry Ford ExercIse Testing (FIT) Project.

To examine the association between chronotropic incompetence and incident atrial fibrillation (AF). Patients with inadequate heart rate response during exercise may have abnormalities in sinus node function or autonomic tone that predispose to the development of AF. We examined the association between heart rate response and incident AF in 57,402 (mean age=54±13 years, 47% female, 64% white) patients free of baseline AF who underwent exercise-treadmill stress testing from the Henry Ford ExercIse Testing (FIT) Project. Age-predicted maximum heart rate (pMHR) values <85% and chronotropic index values <80% were used to define chronotropic incompetence. Cox regression, adjusting for demographics, cardiovascular risk factors, medications, coronary heart disease, heart failure, and metabolic equivalent of task achieved, was used to compute hazard ratios (HR) and 95% confidence intervals (CI) for the association between chronotropic incompetence and incident AF. Over a median follow-up of 5.0 years (25th-75th percentiles=2.6, 7.8), a total of 3,395 (5.9%) participants developed AF. pMHR values <85% were associated with an increased risk for AF development (HR=1.33, 95%CI=1.22, 1.44). Chronotropic index values <80% also were associated with an increased risk of AF (HR=1.28, 95%CI=1.19, 1.38). The associations of pMHR and chronotropic index with AF remained significant with varying cut-off points to define chronotropic incompetence. Our analysis suggests that patients with inadequate heart rate response during exercise have an increased risk for developing AF.

Higher Fitness Is Strongly Protective in Patients with Family History of Heart Disease: The FIT Project

BackgroundCardiorespiratory fitness protects against mortality; however, little is known about the benefits of improved fitness in individuals with a family history of coronary heart disease. We studied the association between cardiorespiratory fitness and risk of incident coronary heart disease and all-cause mortality, hypothesizing an inverse relationship similar to individuals without a family history of coronary heart disease. MethodsWe included 57,999 patients (aged 53 ± 13 years; 49% were female; 29% were black) from the Henry Ford Exercise Testing (FIT) Project. Cardiorespiratory fitness was expressed in metabolic equivalents of task based on exercise stress testing. Family history was determined as self-reported coronary heart disease in a first-degree relative at any age. We used Cox proportional hazards models adjusted for demographics and cardiovascular disease risk factors to examine the association between cardiorespiratory fitness and risk of incident coronary heart disease and mortality over a median (interquartile range) follow-up of 5.5 (5.6) and 10.4 (6.8) years, respectively. ResultsOverall, 51% reported a positive family history. Each 1-unit metabolic equivalent increase was associated with lower incident coronary heart disease and mortality risk regardless of family history status. The hazard ratio and 95% confidence interval for a negative family history and a positive family history were 0.87 (0.84-0.89) and 0.87 (0.85-0.89) for incident coronary heart disease and 0.83 (0.82-0.84) and 0.83 (0.82-0.85) for mortality, respectively. There was no significant interaction between family history and categoric cardiorespiratory fitness, sex, or age (P >.05 for all). ConclusionsHigher cardiorespiratory fitness is strongly protective in all patients regardless of family history status, supporting recommendations for regular exercise in those with a family history.