Duke Treadmill Score Research Articles

Cleveland Clinic Socre – What is the Role of a Novel Prognostic Treadmil Score to Diagnose Coronary Artery Disease?

Background: Ischemic heart disease is increasing all over the world even in the developing countries like Bangladesh. The incidence rate of coronary artery disease is escalating very rapidly among both male and female population in our country. Though exercise treadmill test (ETT) is a well accepted non-invasive investigation to diagnose Coronary Artery Disease (CAD), it has a high false positive and false negative result if ST segment response alone is calculated for interpretation of the test. Accuracy of different treadmill scores in our population is largely unknown. Clevelan Clinic Score is a prognostic ETT score which is validated for prognostic indication but may have some diagnostic value as well.
 Objective: To know the diagnostic role of Cleveland Clinic Score, currently which has only prognostic implication. Method: A Cross-Sectional study was carried out on patients attending University Cardiac Center in Bangabandhu Sheikh Mujib Medical University (BSMMU) for stable chest pain to find out the accuracy of Cleveland Clinic Scores (CCS) in comparison to other diagnostic treadmill scores namely Duke Treadmill Score (DTS) and Simple Treadmill Score (STS).Total 130 persons including male and female who have undergone ETT were included according to inclusion and exclusion criteria. Coronary angiogram reports were collected after the procedure was performed as per clinical practice. The accuracy of ST segment response & different treadmill scores were calculated and compared with each other.
 Result: ETT scores had better sensitivity and specificity than ST segment response which was affected by workup bias more. CCS, DTS and STS have 83.3% & 60.9%; 71.4% & 71.7%; 64.3% & 78.3% sensitivity & specificity, respectively. Receiver Operator Characteristics (ROC) curve analysis showed all of the three scores have similar area under curve (AUC) that means they have similar accuracy to diagnose CAD. But they have different sensitivity and specificity for different cut off value. Overall analysis showed accuracy of STS (83.9%) is comparable to that of DTS (83.3%), CCS (77%) .
 Conclusion: Among the three treadmill scores Cleveland Clinic Score has comparable predictive accuracy when compared with DTS, STS. Though a prognostic ETT score, CCS may have diagnostic role which need to be validated further.
 University Heart Journal Vol. 14, No. 2, Jul 2018; 62-66

The Duke treadmill score with bicycle ergometer: Exercise capacity is the most important predictor of cardiovascular mortality.

BackgroundThe Duke treadmill score, a widely used treadmill testing tool, is a weighted index combining exercise time or capacity, maximum ST-segment deviation and exercise-induced angina. No previous studies have investigated whether the Duke treadmill score and its individual components based on bicycle exercise testing predict cardiovascular death.DesignTwo populations with a standard bicycle testing were used: 3936 patients referred for exercise testing (2371 men, age 56 ± 13 years) from the Finnish Cardiovascular Study (FINCAVAS) and a population-based sample of 2683 men (age 53 ± 5.1 years) from the Kuopio Ischaemic Heart Disease study (KIHD).MethodsCox regression was applied for risk prediction with cardiovascular mortality as the primary endpoint.ResultsIn FINCAVAS, during a median 6.3-year (interquartile range (IQR) 4.5–8.2) follow-up period, 180 patients (4.6%) experienced cardiovascular mortality. In KIHD, 562 patients (21.0%) died from cardiovascular causes during the median follow-up of 24.1 (IQR 18.0–26.2) years. The Duke treadmill score was associated with cardiovascular mortality in both populations (FINCAVAS, adjusted hazard ratio (HR) 3.15 for highest vs. lowest Duke treadmill score tertile, 95% confidence interval (CI) 1.83–5.42, P < 0.001; KIHD, adjusted HR 1.71, 95% CI 1.34–2.18, P < 0.001). However, after progressive adjustment for the Duke treadmill score components, the score was not associated with cardiovascular mortality in either study population, as exercise capacity in metabolic equivalents of task was the dominant harbinger of poor prognosis.ConclusionsThe Duke treadmill score is associated with cardiovascular mortality among patients who have undergone bicycle exercise testing, but metabolic equivalents of task, a component of the Duke treadmill score, proved to be a superior predictor.

Accuracy of non-invasive stress testing in women and men with angina in the absence of obstructive coronary artery disease

ObjectiveWhile >20% of patients presenting to the cardiac catheterization laboratory with angina have no obstructive coronary artery disease (CAD), a majority (77%) have an occult coronary abnormality (endothelial dysfunction, microvascular dysfunction (MVD), and/or a myocardial bridge (MB)). There are little data regarding the ability of noninvasive stress testing to identify these occult abnormalities in patients with angina in the absence of obstructive CAD. MethodsWe retrospectively evaluated 155 patients (76.7% women) with angina and no obstructive CAD who underwent stress echocardiography and/or electrocardiography before angiography. We evaluated Duke treadmill score, heart rate recovery (HRR), metabolic equivalents, and blood pressure response. During angiography, patients underwent invasive testing for endothelial dysfunction (decrease in epicardial coronary artery diameter >20% after intracoronary acetylcholine), MVD (index of microcirculatory resistance ≥25), and intravascular ultrasound for the presence of an MB. ResultsStress echocardiography and electrocardiography were positive in 58 (43.6%) and 57 (36.7%) patients, respectively. Endothelial dysfunction was present in 96 (64%), MVD in 32 (20.6%), and an MB in 83 (53.9%). On multivariable logistic regression, stress echo was not associated with any abnormality, while stress ECG was associated with endothelial dysfunction. An abnormal HRR was associated with endothelial dysfunction and MVD, but not an MB. ConclusionConventional stress testing is insufficient for identifying occult coronary abnormalities that are frequently present in patients with angina in the absence of obstructive CAD. A normal stress test does not rule out a non-obstructive coronary etiology of angina, nor does it negate the need for comprehensive invasive testing.

Addition of Risk Factors of Coronary Heart Disease in Diagnostic Value of Treadmill Score for Detecting Complexity of Coronary Arterial Lesions

Background: Coronary heart disease (CHD) is still the leading cause of death in the world. There are various risk factors for atherosclerosis leading to CHD. Duke Treadmill Score (DTS) is known to demonstrate prognostic stratification and has a diagnostic value in predicting the number of coronary arteries involved in patient populations with ischemic heart disease. However, DTS does not describe the role of risk factors for coronary heart disease to the complexity of coronary artery lesions. This study aims to add risk factors for coronary heart disease on DTS to detect the complexity of coronary artery lesions with stable angina pectoris.Methods: This study was a cross-sectional study in stable angina pectoris patient who comes to Haji Adam Malik Hospital Medan from January 2017 until February 2018. Patients who have done treadmill test and coronary angiography, and fulfill inclusion and exclusion criteria are included in the study. ECG examination and recording of risk factors for coronary heart disease were done. DTS assessment was performed based on a treadmill test and Syntax score based on coronary angiography results. Diagnostic tests were performed to assess the sensitivity and specificity of the addition of CHD risk factors to detect the complexity of coronary artery lesions.Results: Of the 76 people with stable angina pectoris, 55 people were found with low SYNTAX and 21 people with high Syntax. DTS is divided into 3 groups: mild (&gt; -10), moderate (-10 to - 13.5), and severe (≤-13.6) based on the cut off of the ROC curve. Risk factors for CHD are divided into 3 groups, mild (≤3 CHD risk factors), moderate (4-6 CHD risk factors), and severe (7 CHD risk factors) based on the cut off of the ROC curve, then assessed the relationship with Syntax which has been divided into 2 groups, low Syntax, and high Syntax. Diagnostic test shows the addition of risk factors of CHD to DTS to detect the complexity of coronary artery lesions have greater sensitivity and specificity than DTS without the addition of risk factors of CHD, 95%, and 89%.Conclusion: The addition of risk factors for coronary heart disease on DTS can detect the complexity of coronary artery lesions.

Comparative efficiency of exercise stress testing with and without stress-only myocardial perfusion imaging in patients with low-risk chest pain

ObjectivesTo compare major adverse cardiac event (MACE), downstream resource utilization, and direct cost of care for low-risk chest pain patients observed in the clinical decision unit (CDU) with exercise treadmill testing (ETT) and with stress-only myocardial perfusion imaging (sMPI). BackgroundCDUs are poised to increase efficiency and resource utilization. However, the optimal testing strategy that would assure favorable outcomes while decreasing cost is not defined. Methods1016 subjects from 2 locations were propensity score-matched (PSM) by age, gender, pre-test likelihood, Duke treadmill score, and test results. Outcomes were length of stay >24 hours, MACE (acute coronary syndrome, revascularization, cardiac death), downstream resource use (admission for chest pain, repeat testing, angiography), and mean direct cost per patient. ResultsPSM yielded 680 patients (340 matches). 98% of all tests were normal. 96.6% of patients were discharged from the CDU within 24 hours but twice as many exceeded 24 hours in the sMPI group. There were no cardiac deaths. MACE rate was 1.47% at 72 hours and 1% at 1 year. Downstream resource use was 4.82% at 72 hours, and 7.69% at 1 year. The sMPI group was event-free longer than the ETT group reflecting less repeat testing. The mean direct cost was 30% higher for sMPI ($3168.70) vs. ETT ($2226.96). ConclusionLow-risk chest pain patients in the observation unit had low MACE rate, not different for ETT vs. sMPI. The majority of ETT and sMPI tests were normal. The sMPI reduced additional testing, but resulted in greater expense and longer stay.

Comparison of Predicted Significant Coronary Lesion by Duke Treadmill Score among Coronary Heart Disease Risk Factors in Patients with Positive Ischemic Response Treadmill Test

Background: According to Framingham Study, independent risk factors for coronary heart disease (CHD) are diabetes, hypertension, smoking, dyslipidemia, family history of CHD and obesity. Previous study reported cut-off value of Duke Treadmill Score (DTS) &lt; -0.5 represents a significant coronary lesion with positive predictive value 88.4%. Objective: To compare the incidence of predicted significant coronary lesions by DTS among various risk factors for coronary heart disease. Methods: A cross sectional study was done on 292 patients age 18 to 74 years old who had positive exercise testing for CAD screening during period of June 1st 2016 until May 30th 2017. DTS was calculated from treadmill test as: exercise time - (5 x ST deviation in mm) - (4 x exercise angina). A coronary lesion was predicted significant with DTS cut off value &lt; -0.5. Results: Subjects mean age was 57 years old, male were 60.4%. The risk factors for CHD were found sequentially from the most frequent were hypertension 51.9%, smoking 35.3%, diabetes mellitus 23.1%, dyslipidemia 11.9%, obesity 4.2% and family history of CHD 6.3%. It was found that diabetes was significantly different from its effect on DTS value with p value = 0.021, while hypertension, obesity, dyslipidemia and family history CHD had no significant effect. Logistic regression found consistently that diabetes was significant (p=0.019). Conclusion: Predicted significant coronary lesions by DTS developed more frequent in diabetes compared to, hypertension, smoking, dyslipidemia, obesity and family history of coronary heart disease.

Higher event rate in patients with high-risk Duke Treadmill Score despite normal exercise-gated myocardial perfusion imaging.

This prospective study was carried out to find the negative predictive value of various Duke Treadmill Scores (DTSs) in patients with normal myocardial perfusion imaging (MPI). This study was conducted from August 2012 to July 2015, and 603 patients having normal exercise MPIs were included. Patients were followed for 2 years for fatal myocardial infarction (FMI) and nonfatal myocardial infarction (NFMI). Follow-up was not available in 23 patients, leaving a cohort of 583 participants. DTS was low risk (≥5) in 286, intermediate risk (between 4 and − 10) in 211, and high risk (≤−11) in 86 patients. Patients with high- and intermediate-risk DTS were significantly elder than low-risk DTS cohort. Patients with high-risk DTS had significantly higher body mass index with male preponderance compared to other groups. No significant difference was found among three groups regarding modifiable or nonmodifiable risk factors and left ventricular ejection fraction. On follow-up, single FMI was observed in high-risk DTS group (log-rank test value = 5.779, P = 0.056). Five NFMI events were observed in high-risk DTS (94.2% survival; log-rank test value = 19.398, P = 0.0001; significant) as compared to two events each in low- and intermediate-risk DTS (nonsignificant). We conclude that patients with normal exercise MPI and low-to-intermediate risk DTS have significantly low NFMI. High-risk DTS despite normal exercise MPI had high NFMI. Further, validation studies to find the predictive value of symptomatic and asymptomatic ST deviation resulting in high-risk DTS in patients with normal exercise MPI are warranted.

OP-465 - Association between Epicardial Adipose Tissue and Duke Treadmill Score

Background and Aim: Duke treadmill score (DTS) is well known as a prognostic score in patients with suspected coronary artery disease (CAD) and proved to be a stronger predictor than ST-segment depression alone. Epicardial adipose tissue (EAT) has anatomical and functional contiguity with myocardium and coronary arteries. Increased EAT is strongly associated with CAD. The aim of this study was to evaluate association between epicardial adipose tissue and Duke treadmill score.

ADAPTATION OF ELECTRONIC SYSTEM FOR ISCHEMIC HEART DISEASE PREDICTION AS A STEP TO COMMON INFORMATION SPACE IN CARDIOLOGIC HEALTHCARE

Electronic version of a patient’s individual card protocol forming “Analytic system for monitoring and predicting various clinical variants of ischemic heart disease (CHD DM2)” database № BGU 00314 is combined with the computer system № DGU 01035 to assess yearly risk of adverse events by diagnostic coefficients; up-to-date prognostic signs, such as pre-test probability, Duke treadmill score and ventricular ejection fraction participating in the formation of prognostic conclusion were added. The database is a complex of program products intended for automation of dynamic management processes for both inpatients and outpatients with various clinical IHD forms and concurrent type 2 diabetes mellitus based on assessment of the disease course dynamics, completeness of prescriptions and patient’s compliance. The proposed model is of high clinical practical significance since it can be transformed into electronic medical history or used as a database in chronic IHD registry to improve medical care quality.

Increased myocardial energy expenditure in cardiac syndrome X: More work, more pain

The aim of this study was to assess the myocardial energy expenditure (MEE) in patients with cardiac syndrome X (CSX) and to examine its association with exercise electrocardiogram (ECG) parameters. A total of 99 patients who underwent coronary angiography and who were diagnosed as having normal coronary arteries were included. The patients were divided into 2 groups based on symptoms and exercise ECG parameters: 56 CSX patients and 43 control patients with a negative stress test. MEE was calculated using transthoracic echocardiography-derived parameters: circumferential end-systolic stress, left ventricular ejection time, and stroke volume. In patients with CSX, the MEE at rest was 28% higher in than the control group (89.2±36.3 vs. 69.8±17.2 cal/minute). Correlation analysis revealed a moderately negative correlation between MEE and the Duke treadmill score (DTS) (ß:-0.456; p<0.001). Receiver operating characteristic analysis with a cut-off value of 74.6 cal/minute for MEE had a sensitivity of 78.1% and a specificity of 75.3% for the prediction of CSX (area under the curve: 0.872; p<0.001). An extra 1 calorie spent per minute at rest increased the likelihood of CSX by about 86% (odds ratio: 1.863). This study demonstrated that MEE was greater in CSX patients compared with a control group. Increased MEE was determined to be an independent predictor of CSX. DTS was inversely correlated with MEE. Increased MEE may have a crucial role in CSX pathophysiology.

Tanısal Egzersiz Elektrokardiyografi Testi Yapılan Hastalarda Serum Tiyol Disulfid Dengesi ve Endokan Düzeyleri

Introduction: Inflammation and oxidative stress are associated with increased risk of cardiovascular diseases. Parameters derived from exercise electrocardiography (ECG) test, such as Duke treadmill score and heart rate recovery (HRR), have prognostic importance and can be used to predict cardiovascular risk. Endocan and thiol/disulfide homeostasis are emerging biomarkers that reflect the inflammatory and oxidative status. The aim of this study was to investigate serum thiol/disulfide homeostasis and endocan levels in an exercise ECG testing patient cohort and to evaluate the association of these markers with Duke treadmill score and HRR. Patients and Methods: Patients who underwent diagnostic exercise ECG test were divided into two groups according to Duke treadmill score and HRR. Serum endocan levels and thiol/disulfide homeostasis were compared between high and low/intermediate Duke treadmill score groups and blunted and normal HRR groups. Results: Serum endocan levels were similar between the groups according to Duke treadmill score and HRR. Thiol/disulfide ratio was significantly lower in patients with blunted HRR than in those with normal HRR. Serum native thiol levels, total thiol levels, and total thiol/disulfide ratio were significantly elevated in patients with a high Duke treadmill score than in those with low/intermediate Duke treadmill score. Native thiol levels and total thiol levels were significantly correlated with Duke treadmill score. Multivariate regression analysis revealed that hypertension and diabetes were independent predictors of blunted HRR, whereas hypertension and low endocan levels were those of low/intermediate Duke treadmill score. Conclusion: Serum thiol levels are correlated with Duke treadmill score, and low endocan levels are associated with low/intermediate Duke treadmill score.

Prognostic value of electrocardiogram exercise testing for risk stratification in asymptomatic coronary artery disease.

Several variables of electrocardiogram exercise testing (EET) predict cardiovascular events in the general population and in patients with coronary artery disease (CAD). However, most of the studies have not included patients with asymptomatic CAD. The aim of this study was to evaluate the prognostic value of EET in asymptomatic CAD patients. We carried out a retrospective single-center analysis including all patients with asymptomatic CAD documented by angiography who underwent EET from January 2010 to December 2013. A number of EET variables and three exercise scores [Duke Treadmill Score (DTS), Morise score, and FIT score] were analyzed. The primary endpoint was the combined incidence of myocardial infarction (MI), myocardial revascularization, and death from any cause during follow-up. A total of 306 patients were included (mean age was 65±10 years, 61% had previous MI, and the median exercise capacity was 9.4±2.7 metabolic equivalent of task). The primary endpoint occurred in 15.7% of patients during 3.3 years of follow-up. The DTS and FIT were independent predictors of the primary endpoint unlike the Morise score (DTS: hazard ratio=0.91, 95% confidence interval: 0.85-0.99, P=0.018; FIT score: 0.99, 0.98-0.996, P=0.001; Morise score: 0.97, 0.93-1.02, P=0.20). The DTS was independent predictor of MI or revascularization, whereas FIT predicted death from any cause. Excluding patients with early revascularization, DTS had no predictive power at the composite endpoint. In our population with asymptomatic CAD, FIT and DTS had significant value for risk prediction and consequently the EET can be a valid tool in the clinical follow-up of this population.

Duke Treadmill Score Predicts Coronary Artery Disease Status Among Asian Women Patients

Duke Treadmill Score Predicts Coronary Artery Disease Status Among Asian Women Patients

958The Duke treadmill score in assessing the prognosis of patients tested with bicycle ergometer

958The Duke treadmill score in assessing the prognosis of patients tested with bicycle ergometer

A new scoring system for evaluating coronary artery disease by using blood pressure variability.

The aim of this study was to develop a new scoring system using ambulatory blood pressure monitoring (ABPM) to assist in the evaluation of coronary artery disease (CAD). One hundred twenty-five subjects (53.1 ± 9.6 years of age) were included. Pearson's tests were first performed to identify the parameters that correlated with Duke Treadmill Score (DTS). Blood test parameters and blood pressure variability (BPV) measures that were extracted from the ABPM were included. Next, a multiple linear regression analysis was performed to train a new scoring system in the 84 patients from the 125 patients. Then, a correlation analysis was conducted to validate the correlation between the new scoring system and DTS in the remaining 41 subjects. A further correlation analysis was used to verify the clinical value of the new scoring system using ultrasonic cardiogram (UCG) and brachial-ankle pulse wave velocity (baPWV). Our new scoring system, which had a 24.096 - 0.083 × residual standard deviation of night systolic blood pressure (SBP) - 0.130 × age - 0.206 × average real variability of night SBP, was correlated with DTS (r = 0.312, P = 0.047). Moreover, our new scoring system was also correlated with various markers of cardiac function (r = -0.290, P = 0.001; r = -0.262, P = 0.004; r = -0.303, P = 0.001; r = -0.306, P = 0.001, respectively) measured by UCG and with baPWV (r = 0.529, P = 0.001). Furthermore, the r-values for the BPV Score versus the markers were closer to -1 than the corresponding r-values for the Duke Score vs the same parameters. And the differences in r-values between Duke Score and BPV Score were statistically significant (P = 0.022). In conclusion, the new scoring system based on ABPM has potential as a non-invasive tool for evaluating CAD.

Association between fractional flow reserve and Duke treadmill score in patients with single-vessel disease.

Duke treadmill score (DTS) is an index that provides prognostic information calculated at exercise stress test. Fractional flow reserve (FFR) is an invasive method used to evaluate intermediate coronary stenosis. The direct relation of DTS and FFR has not been studied to date. The present study aims to investigate the relationship between the DTS and FFR. The study population consisted of a total of 106 patients with single-vessel disease, as confirmed by coronary angiography performed following EST, and whose FFRs were measured. The patients were separated into three groups according to the DTS values: low risk (DTS ≥ +5), intermediate risk (-10 ≤ DTS ≤ +4), and high risk (DTS ≤ -11). According to the FFR values, the patients were separated into two groups: FFR < 0.80 and FFR ≥ 0.80. Angina symptoms and chronic heart failure were more frequent in the group with FFR < 0.80 than the group with FFR ≥ 0.80; respectively, 95% vs. 69.8%, p = 0.020 and 15% vs. 3.5%, p = 0.045. The mean DTS value was lower in the group with FFR < 0.80 than the group with FFR ≥ 0.80 (1.60 vs. 5.07; p = 0.011). However, there were no statistically significant differences in the DTS risk groups among the FFR groups (p = 0.070). A weak positive correlation was found between the numerical DTS and FFR values (r = 0.139; p = 0.156). When the patients with high-risk were excluded, a statistically significant relationship was determined between the FFR and in the groups with low- and intermediate-risk in terms of the DTS values (p = 0.029). In conclusion, our study results showed an association with FFR and in the groups with low and intermediate risk in terms of the DTS values. DTS levels can be useful to determine patients who require invasive management.

Diagnostic Value of Duke Treadmill Score in Predicting Coronary Lesions Severity in Patients with Suspected Stable Coronary Artery Diseases

Diagnostic Value of Duke Treadmill Score in Predicting Coronary Lesions Severity in Patients with Suspected Stable Coronary Artery Diseases

Value of Duke treadmill score in predicting coronary artery lesion and the need for revascularisation.

Exercise electrocardiography is a long-standing method for the evaluation of coronary artery disease (CAD), and it remains the initial test for most patients who can exercise adequately with a baseline interpretable electrocardiogram. However, there is little information about the relationship between Duke treadmill test score (DTS) and severity of coronary artery lesion, as well as estimating the need for revascularisation. The aim of the study was to ascertain whether the DTS could be an efficient parameter in choosing coronary revascularisation in different DTS groups. Two hundred and fifty-eight (n = 258) patients had positive exercise testing for CAD and underwent coronary angiography. The patients were divided into three groups according to the DTS: low-risk (with a score of ≥ +5), moderate-risk (with scores ranging from -10 to +4), and high-risk (with a score of ≤ -11). Coronary angiography was done by the Judkins technique. A coronary lesion was considered significant when stenosis of the coronary artery was ≥ 70% and stenosis of the trunk was ≥ 50%. The SYNTAX score was determined. The study group included 258 patients with mean age 62.66 ± 9.6 years, and most of them were men (72.8%). Patients with high- and intermediate-risk DTS had the same SYNTAX score (16.35 ± 7.3, 15.09 ± 10.08 and 11.80 ± 9.88, respectively; p = 0.064) compared to low-risk DTS. A negative correlation between DTS and significant coronary artery stenosis (r = -0.181; p = 0.005), SYNTAX score (r = -0.173; p = 0.007), and cardiac revascularisations (r = -0.213; p = 0.001) were found. In multiple linear regressions to predict coronary revascularisation the SYNTAX score (B = 0.018; p = 0.0001), DTS (B = -0.014, p = 0.008) and previous myocardial infarction (B = -0.143; p = 0.047) were significant predictors. The DTS alone is a useful tool in suspecting a significant coronary artery stenosis, but it is not accurate enough for revascularisation. Thus, by adding clinical information, its value may be maximised.

A pilot study to assess the utility of five established variables to standardize exercise treadmill test reporting

BackgroundThe prognostic utility of 5 established variables (functional capacity, Duke treadmill score, chronotropic response to exercise, heart rate recovery, and premature ventricular contractions) together after routine exercise treadmill testing (ETT) has not been determined. MethodsWe assessed the combined prognostic ability of 5 established variables for the primary outcome (myocardial infarction [MI], coronary revascularization [CR] or all-cause mortality) and the secondary outcome of unnecessary downstream testing (defined as receipt of further noninvasive imaging without CR, MI, or death) compared with standard methods. Using a retrospective study design, 1857 consecutive patients were enrolled in the year 2014 and followed until December 31, 2015. Optimal discrimination and global fit statistics were assessed from logistic regression models. Classification and regression tree (CART) methodology was used for the final model. ResultsThe mean [SD] age was 56.0 [12.5]years; median comorbidities (2, IQR 2) with 26% having an equivocal report. Compared to other models, a model with age, sex, and the 5 established variables showed an improvement in discrimination for the primary [c-statistic 0.85 versus (0.69–0.79)] and secondary [c-statistic 0.73 versus (0.65–0.71)] outcomes with substantial improvement in global fit. The final, optimal, 10-fold cross-validated CART model had a c-statistic of 0.78. ConclusionsThe utility of the 5-established variables, based on the current study, resides in its ability to decrease unnecessary downstream testing and improve cardiovascular event prognostication. This is accomplished by removing the subjective interpretation of currently used ETT variables that can lead to an equivocal report.

Diagnostic Invasive Coronary Angiography in Patients with Small Myocardial Perfusion Defects with Low Exercise Tolerance

Background: The diagnostic and prognostic value of stress myocardial perfusion scintigraphy is well established in literature. The sensitivity and specificity of the test depends on multiple factors. The workload achieved during treadmill exercise is one of the most important determinants. Hence, we thought to assess the coronary anatomy in a group of patients with low exercise tolerance that showed small perfusion defects on stress MPI studies. Material and methods: We prospectively enrolled 50 patients with mild perfusion defects and a poor exercise tolerance. An invasive coronary angiography was done according to the clinical decision of the treating physician. All patients were subjected to full history and clinical examination. Stress SPECT Tc99m Sestamibi scintigraphy was done on basis of a 2 day stress/rest imaging protocol (Exercise duration, age predicted maximal heart rate (APMHR %), ejection fraction (EF%), transient ischemic dilatation and duke treadmill score(DTS)) were recorded. A coronary stenosis ≥ 75% was considered significant. In the current study, APMHR 0.05 is considered significant. Results: Among the study cohort, a total of 6 patients (12%) had significant CAD. In presence of a small perfusion defect in the setting of low exercise tolerance, significant CAD was observed more frequently in patients with exercise duration ≤ 7 min, APMHR <85%, transient stress induced LV cavity dilatation and moderate/high DTS. The six patients with significant angiographic lesions demonstrated single vessel disease in the whole group. Distribution of the angiographic lesions was as follows: RCA (4 patients) 66.7%, the LAD (one patient) 16.65%, and the LCX (one patient) 16.65%. Conclusion: In the setting of low exercise tolerance, negative MPI/small sized perfusion defect may not exclude significant CAD. Several clinical, stress, and SPECT-MPI findings may help to predict high risk patients. Consideration of these factors may improve the overall assessment of the likelihood of significant CAD in patients undergoing stress SPECT- MPI.