Treadmill Exercise Stress Test Research Articles

Impact of Percutaneous Coronary Intervention on Exercise-Induced Repolarization Changes in Patients With Stable Coronary Artery Disease

Recent reports suggest T peak to T end (Tpe) interval and Tpe/QT ratio as valuable indicators of increased arrhythmogenic risk in patients with coronary artery disease (CAD). We aimed to examine the exercise-induced changes in these indexes in patients with stable CAD, before and after percutaneous coronary intervention (PCI). Forty patients were consecutively included in the interventional group (n = 20), with significant lesions (≥75% luminal narrowing) suitable for PCI and in the control group (n = 20), with no significant coronary artery lesions (<50% luminal narrowing). One day before and 30 days after the coronarography, all patients performed treadmill exercise stress testing, and the electrocardiographic (ECG) indexes of repolarization were assessed during baseline and at peak exercise intensity. In the control group, the QT interval, QTc (QT-corrected) interval, Tpe interval, and Tpe/QT ratio measured at peak exercise significantly decreased from baseline values (p = 0.001, p = 0.004, p <0.001, and p = 0.017, respectively). Conversely, in interventional patients before the PCI, an increase in the Tpe interval and the Tpe/QT ratio was observed at exercise (p = 0.009, and p <0.001, respectively), with only the QT interval exhibiting a significant decrease from baseline (p <0.001). Thirty days after the PCI, all the ECG arrhythmogenic indexes measured at peak exercise significantly decreased from baseline values, thus assuming the same trend as detected in controls. In conclusion, restoration of blood supply normalized exercise-induced repolarization changes, suggesting that revascularization of previously ischemic myocardium lowers the cardiac arrhythmogenic potential in patients with stable CAD.

Impact of statin use on cardiorespiratory fitness in multi-racial men and women: The Henry Ford Exercise Testing (FIT) Project

• The statin use was not associated with lower peak metabolic equivalents of tasks achieved on treadmill exercise stress test.

Prevalence and factors associated with inappropriate use of treadmill exercise stress test for coronary artery disease: a cross-sectional study.

BackgroundIn some countries, the public health system has less availability when compared to the population covered by health insurance. In addition, inappropriate referrals for treadmill exercise stress test increase spending and lead to unnecessary interventions. We aim to determine the prevalence and characteristics of inappropriate referrals for treadmill exercise stress tests in the assessment of coronary artery disease (CAD), considering public and private health systems scenarios.MethodsA cross-sectional design was used to describe the frequency of inappropriate use of exercise testing in the diagnosis of CAD and to determine its predictors. We consecutively enrolled 191 patients from two outpatient facilities in Northeast Brazil. For inclusion, the exercise testing should be referred for the assessment of CAD. We performed logistic regression models to identify independent predictors of inappropriate use.ResultsTreadmill exercise stress tests were rated as inappropriate in 150 (78 %) patients. The majority of patients had low or very low pre-test probability of CAD. Presence of hypertension, diabetes and dyslipidemia were more frequent in the appropriate than inappropriate indications (71 %, 19 % and 29 % versus 43 %, 8 % and 16 %, respectively). Tests performed both at the public and private system showed high prevalence of inappropriate examinations, higher in the latter (57 % versus 87 %, P < 0.001). The private health system was the major independent predictor of inappropriate referral, consistent in all regression models (when adjusting for clinical variables, OR = 4.3; P < 0.001).ConclusionThe vast majority of treadmill exercise stress test referrals in the assessment of CAD were inappropriate. The availability of the method and not the estimate probability of CAD appear to be the underlying condition for a treadmill test referral.

Effects of outpatient followed by home-based telemonitored cardiac rehabilitation in patients with coronary artery disease.

Cardiac rehabilitation (CR) has been shown to reduce the cardiovascular mortality of patients with coronary artery disease (CAD) and help people to return to professional work. Unfortunately, limited accessibility and low participation levels present persistent challenges in almost all countries where CR is available. Applying telerehabilitation provides an opportunity to improve the implementation of and adherence to CR, and it seems that the hybrid form of training may be the optimal approach due to its cost-effectiveness and feasibility for patients referred by a social insurance institution. To present the clinical characteristics and evaluate the effects of hybrid: outpatient followed by home-based cardiac telerehabilitation in patients with CAD in terms of exercise tolerance, safety, and adherence to the programme. A total of 125 patients (112 men, 13 women) with CAD, aged 58.3 ± 4.5 years, underwent a five-week training programme (TP) consisting of 19-22 exercise training sessions. The first stage of TP was performed in the ambulatory form of CR in hospital; then, patients continued to be telemonitored TP at home (hybrid model of cardiac rehabilitation - HCR). Before and after completing CR, all patients underwent a symptom-limited treadmill exercise stress test. Adherence was reported by the number of dropouts from the TP. The number of days of absence in the HCR programme was 1.50 ± 4.07 days. There were significant improvements (p < 0.05) in some measured variables after HCR in the exercise test: max. workload: 7.86 ± 2.59 METs vs. 8.88 ± 2.67 METs; heart rate (HR) at rest: 77.59 ± 12.53 bpm vs. 73.01 ± 11.57 bpm; systolic blood pressure at rest: 136.69 ± 17.19 mm Hg vs. 130.92 ± 18.95 mm Hg; double product at rest: 10623.33 ± 2262.97 vs. 9567.50 ± 2116.81; HRR1: 97.46 ± 18.27 bpm vs. 91.07 ± 19.19 bpm; and, NYHA class: 1.18 ± 0.48 vs. 1.12 ± 0.35. In patients with documented CAD, HCR is feasible and safe, and adherence is good. Most patients were on social rehabilitation benefit, had a smoking history, and suffered from hypertension, obesity, or were overweight. A hybrid model of CR improved exercise tolerance.

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

BackgroundThe prognostic significance of modest elevations in exercise systolic blood pressure response has not been extensively examined.Methods and ResultsWe 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).ConclusionsOur results suggest that modest increases in exercise systolic blood pressure response are associated with adverse outcomes.

Assessment of the relationship between nondipping phenomenon and microvolt T-wave alternans.

The aim of this cross-sectional study was to evaluate microvolt T-wave alternans (MTWA) as a marker of myocardial electrical instability in normotensive and hypertensive individuals with either nondipper or dipper-type circadian rhythm of blood pressure. The study group included a total of 181 patients: 118 hypertensive patients and 63 normotensive healthy volunteers [mean age 46 ± 8; 34 men (54%)]. The patients with hypertension were divided into two groups on the basis of their results of 24-h ambulatory blood pressure monitoring: 61 patients with dipper hypertension [mean age 46 ± 6; 32 men (52.5%)] and 57 patients with nondipper hypertension [mean age 48 ± 10; 36 men (63.2%)]. The MTWAs of all patients were analyzed using the time-domain modified moving average method by means of a treadmill exercise stress test. MTWA positivity was statistically significantly different between all groups. Left ventricular mass index, E/E', interventricular septum, posterior wall, 24-h systolic blood pressure and diastolic blood pressure, and night-time systolic blood pressure and diastolic blood pressure were correlated positively with MTWA. Left ventricular mass index and the presence of nondipper hypertension were determined to be independent predictors of MTWA positivity. The blunting of the nocturnal decrease in blood pressure was associated with MTWA positivity in hypertensive patients.

Dipper ve Non-Dipper Hipertansif Hastalarda Kardiyak Otonom Fonksiyonlarda Bozulma ve Kronotropik Yetersizlik

Objective: The aim of the present study was to compare the autonomic nervous system activity indexes obtained from treadmill exercise stress testing in dipper and non-dipper hypertensive patients. Material and Methods: This study included 214 hypertensive patients, under antihypertensive medication. All study participants underwent 24-hour ambulatory blood pressure monitoring (ABPM) and maximal exercise testing. Thereafter patients were divided into two groups: 94 dipper hypertensives and 120 non-dipper hypertensives. Heart-rate (HR) response during exercise was evaluated by the chronotropic index (CI). HR recovery (HRR) was defined as the difference between HR at peak exercise and first minute after the exercise test. Results: Daytime systolic and diastolic BP measurements were similar, however night-time measurements were significantly lower among dippers than non-dippers (night-time systolic BP: 114.1±11.4 vs 126.3±15.0 mmHg, p<0.001; night-time diastolic BP: 72.3±7.3 vs 79.9±9.8 mmHg, p<0.001). Chronotropic index was lower than normal in both groups (0.79±0.1 vs 0.78±0.7 p=NS). Dippers had higher HRR values than non-dippers (31.8±4.6 vs 29.1±4.6 p<0,001). HRR was positively correlated with the percentage decline of systolic and diastolic BP from day to night (r=0.255 p<0.001 and r=0.228 p=0.001, respectively). There were no correlation between CI and percentage of systolic and diastolic BP reduction from day to night (r=0.067 p>0.05 and r=0.16 p>0.05, respectively). Conclusion: Hypertensive patients have abnormal HR response to exercise,. Non-dippers had lower HRR values than dippers. This may due to a relative general decrease of parasympathetic reactivation after exercise that is linked to the failure of nighttime fall of BP.

Quantification of trans-pulmonary physiology in ‘athlete’ population – a validation study of novel echocardiographic parameter “ePLAR”

Background: The “echocardiographic Pulmonary to Left Atrial Ratio” (ePLAR) is a new non-invasive parameter describing the physiologic relationship between pulmonary arterial pressure and left atrial pressure. It is derived using Doppler echocardiography and calculated from peak tricuspid regurgitation velocity (TR Vmax) divided by the transmitral E wave: medial DTI E’ wave ratio (E/E’). We sought to establish normal ePLAR values for an ‘athlete’ population. Methods: A retrospective analysis of patients undergoing treadmill stress echocardiogram between 2013 and 2014 was conducted. Patients who achieved high workload (greater than 17 METs) on treadmill exercise stress test were identified and the recorded resting TR Vmax, E/E’ ratio and ePLAR values were compared to established population normal ePLAR reference values. Results: The stress echocardiograms of 120 patients (average age 45±13.5 years; 88% male) were evaluated. The mean achieved METs was 18±1.6. The mean TR Vmax was 2.2±0.3 m/s, the mean E/E’ ratio was 7.4±1.9, and the mean ePLAR was 0.32±0.09 m/s. No statistically significant difference was found between age-stratified mean ePLAR values for athletes compared to normal population group. Conclusions: ePLAR is a novel echocardiographic parameter that is easily obtained during routine stress echocardiogram. In this cohort of ‘athlete’ population, their trans-pulmonary physiology as measured by ePLAR did not appear to differ significantly compared to normal population.

Exercise-Induced Repolarization Changes in Patients with Isolated Myocardial Bridging.

BackgroundAlthough myocardial bridging (MB) is defined as an angiographic phenomenon with a benign course, it has also been associated with adverse cardiovascular events. The effects of exercise on myocardial repolarization in patients with MB were tested in this study, with Tp-e and Tp-e/QT repolarization indexes.Material/MethodsA total of 50 patients in whom isolated MB was diagnosed at coronary angiography (CAG) (Group I) and 48 patients with normal CAG results (Group II) were included in this study. The participants underwent treadmill exercise stress testing according to the Bruce protocol. QT dispersion (QTd) was defined as the minimum QT interval subtracted from the maximum. The Tp-e interval was defined as the difference between the QT and the QT peak time period. QTd and Tp-e intervals were calculated for all patients before and after exercise testing and differences between groups were compared.ResultsAt peak exercise, QTd and cQTd showed a significant increase in comparison to baseline values in the group of patients with myocardial bridges. Significant increases were also found with exercise in the Tp-e, cTp-e durations and Tp-e/QT ratio of the MB patient group in comparison to the baseline values. On the other hand, significant differences in QTd, cQTd, Tp-e, cTp-e intervals, and Tp-e/QT ratio during peak exercise in comparison with baseline values were not detected in the control group (p>0.05).ConclusionsSignificant increases in QTd, cQTd, Tp-e and cTp-e intervals and Tp-e/QT ratio were detected in the MB patients during exercise testing.

Long-term prognostic value of myocardial perfusion imaging in octogenarians able to undergo treadmill exercise stress testing

BackgroundAlthough the use of myocardial perfusion imaging (MPI) for prognostic purposes in general population is well understood, its role in very elderly patients is not extensively studied. Methods247 octgogenarians (79% male, 56% previous myocardial infarction—MI or revascularization) who underwent treadmill exercise testing (TET) with MPI were studied. TET and MPI-related data were registered per patient and prospective follow-up was performed to document all cause death (ACD), cardiac death (CD), non-fatal MI, and late revascularization (LR). Kaplan-Meier and Cox-regression analysis were used to compute event-free survival and identify significant predictors of these events. ResultsAfter 7.3 years there were 48 deaths, 17 CDs, 8 MIs, and 21 LRs. 69 patients were classified as high and 103 as low risk by SSS with annual cardiac mortality rates of 5% and 0.9%, respectively. Differences between survival curves of SSS-based risk groups were significant for ACD, CD, CD/MI, and CD/MI/LR. Summed stress (SSS) and difference scores were the only significant predictors of all endpoints. LVEF and transient ischemic LV dilatation were significant predictors of CD and CD/MI. LVEF and all MPI variables were associated with the CD, MI, and LR endpoint while only Duke treadmill score and angina severity demonstrated such a relationship among TET variables. ConclusionsIn octogenarians, MPI provides effective long-term risk stratification for both hard (ACD, CD, CD/MI) and soft (CD/MI/LR) endpoints and should be preferred over simple TET.

Use of an Ankle-Foot Orthosis Improves Aerobic Capacity in Subacute Hemiparetic Stroke Patients

ObjectiveTo investigate aerobic capacity with and without an ankle-foot orthosis (AFO) in subacute hemiparetic stroke patients. DesignProspective crossover intervention study. SettingRehabilitation clinic in secondary care. PatientsPatients diagnosed with first-ever cerebral stroke involving the cortical or subcortical area resulting in hemiparesis (n = 15, 8 men and 7 women; average age, 62.1 years). MethodsAll subjects participated in 2 continuous, symptom-limited, low-velocity graded treadmill exercise stress tests under 2 different conditions, namely, with and without an AFO. The rest interval between tests was at least 48 hours. The order of exercise stress tests was randomized. Main Outcome MeasurementsTo assess cardiorespiratory responses, oxygen consumption, heart rate, systolic blood pressure, diastolic blood pressure, rate-pressure product, and respiratory exchange ratio were measured continuously throughout the test, and peak values were obtained. The rating of perceived exertion was recorded immediately after each test. The percentage of the age-predicted maximal heart rate and total exercise duration were also measured. Gait function was assessed by the Six-Minute Walk Test. ResultsUsing an AFO significantly increased peak oxygen consumption and Six-Minute Walk Test results. Peak values of each of heart rate, systolic blood pressure, diastolic blood pressure, rate-pressure product, and respiratory exchange ratio, rating of perceived exertion, percentage of age-predicted maximal heart rate, and total exercise duration were similar regardless of AFO use. ConclusionsUse of an AFO may improve aerobic capacity in subacute hemiparetic stroke patients, and may improve energy efficiency and gait endurance.

Effect of socioeconomic status on cardio-respiratory fitness

Lower socioeconomic status (SES) is associated with reduced cardio-respiratory fitness (CRF) and predicts adverse cardiovascular outcomes. We questioned whether this association remains significant among an apparently healthy population with a presumed higher SES. This cross-sectional study enrolled attendees of a health screening program between September 2002 and November 2010. Linear regression models included the metabolic equivalents achieved during an exercise treadmill stress test as the dependent variable and adjusted for self-reported SES parameters (level of education, occupational status, financial strain and a combined variable), cardiovascular risk factors, as well as to multiple potential confounders. Data on 8471 individuals (5463 men and 3008 women) with a mean (SD) age of 44 (11) years were collected. We found a statistically significant difference in mean exercise capacity between the categories of SES, especially for the level of education and occupation, when adjusted for age, sex, cardiovascular risk factors, SES variables and multiple confounders. Multiple factors affect CRF in apparently healthy screened individuals. When adjusted for those factors, SES correlates with CRF even within a more specific highly educated cohort.

Abstract 63: Higher Exercise Capacity Predicts Lower Levels of Inflammation in Both Men and Women with Coronary Artery Disease

Introduction: Metabolic equivalent (METS) estimates the amount of oxygen the body uses during physical activity and reflects cardiorespiratory fitness. Exercise capacity (measured in METS), peripheral white blood cell count (WBC) and microalbuminuria (urine microalbumin/creatinine ratio -MCR) are associated with cardiovascular morbidity and mortality. Monocytes are an initiating event in atherosclerosis and are a measure of inflammation as are WBC and MCR. Hypothesis: Higher exercise capacity is associated with lower levels of inflammation (WBC, monocyte count and MCR) in patients with coronary artery disease (CAD). Methods: 291 subjects with stable CAD underwent graded exercise treadmill stress testing with calculation of METS. WBC, monocyte count and MCR were measured. Multivariate linear regression modeling was employed to identify predictors of inflammation for the total group and then stratified by gender and diabetes status. Results: METS was inversely correlated with and the best predictor of WBC, monocyte count and MCR for the total group and for men and women although age was slightly better than METS for WBC in men (see Table). When stratified by diabetes status, METS was inversely correlated with and the best predictor of monocyte count and MCR in non-diabetics whereas in diabetics, BMI was the best predictor. METS was significantly inversely correlated with WBC in diabetics and non-diabetics although age was slightly better in non-diabetics. Conclusions: Higher exercise capacity may have cardiovascular protective effects in patients with CAD through an anti-inflammatory effect as reflected in the lower levels of peripheral WBC, monocytes and microalbuminuria. Our findings suggest that exercise capacity could be a measure of chronic inflammation in patients with CAD and support the importance of exercise training in improving inflammation. The less pronounced effect of METS on monocyte count and MCR in diabetics could be due to other factors affecting inflammation in diabetics.

Comparison between hybrid and standard centre-based cardiac rehabilitation in female patients after myocardial infarction: a pilot study

Despite the known benefits of cardiac rehabilitation (CR) for patients with stable coronary artery disease, it is neglected, especially in women. Home-based programmes may increase adherence to CR. To compare the effectiveness of centre-based CR with a hybrid model of training, partly out-patient and partly home-based and tele-monitored, in terms of physical capacity and adherence in post-myocardial infarction (MI) women with preserved left ventricular function. 53 post-MI female patients, aged 51.3 ± 7.6 years underwent an eight-week training programme (TP) consisting of 24 interval trainings. The first ten trainings were performed in a hospital, then 33 patients (Gruop A) continued them in the centre, the remaining 20 (Group B) did tele-monitored walking training at home (hybrid model). Before and after completing CR, all patients underwent a symptom-limited treadmill exercise stress test during which the analysis included: workload (METs), duration (min), heart rate (HR, bpm), double product (mm Hg/min) at rest and during effort, and HR recovery in the first minute after test. Adherence was reported as the number of trainings completed and the number of dropouts in two CR models. After CR, only workload (Group A: 6.5 ± 1.1 vs. 7.0 ± 1.4, p < 0.05; Group B: 7.4 ± 1.1 vs. 8.3 ± 1.4, p < 0.01) and duration (Group A: 4.7 ± 1.1 vs. 5.1 ± 1.2, p < 0.01; Group B: 8.1 ± 3.9 vs. 9.3 ± 4.2, p < 0.01) improved significantly in both groups. Comparing CR effects between both groups, no significant differences were observed. All patients completed TP. In post-MI women, a hybrid model of training improved physical capacity and was a similarly effective form of CR as a centre-based approach. A home-based tele-monitored programme facilitated our patients' adherence to CR.

PM031 Carotid intima media thickness is associated with reduced heart rate recovery time in patients with low cardiovascular risk profile

O ST E R A B ST R A C T S Introduction: The chronotropic response to exercise and the heart rate recovery (HRR) following exercise are non-invasive measures of autonomic function, which are easily measured duringmaximal exercise stress testing. Bothmeasures are independent predictors of sudden cardiac death. Abnormal ventricular repolarization, evidenced clinically by corrected QT interval (QTc) prolongation, may represent the mechanism leading to fatal sequelae. Objectives: The current study aimed to delineate relationships between the resting and post-exercise QTc with the HRR and chronotropic response during treadmill exercise stress testing. The study compared these associations in patients with and without diabetes. Methods: Data of 95 patients (34 with diabetes; mean age 61 years) referred for exercise stress testing were analysed retrospectively for QTc interval, chronotropic response and HRR. The QT interval was measured at rest and 30, 120, 210 and 300 s post-exercise, and was rate corrected using the Bazett, Fridericia, Framingham and Hodges formulae. No patients had evidence of cardiac ischaemia. Results: Significant inverse relationships were found between (1) resting Hodges QTc interval and HRR; (2) post-exercise QTc intervals and HRR at 30, 120, 210 and 300 s; and (3) resting and post-exercise QTc intervals and chronotropic index. Multivariate regression analysis using the entire patient group identified an independent association between the Bazett QTc interval 120 s and HRR 120 s (r1⁄4-0.40, p<0.001). Diabetic patients showed significantly lengthened QTc intervals at rest and post-exercise and both attenuated chronotropic response and HRR compared to the control group. The strength of associations between the QTc, HRR and chronotropic response were similar in patients with and without diabetes. Conclusion: The findings suggest abnormal ventricular repolarisation may be a mechanistic link by which blunting of the heart rate recovery and chronotropic response are related to sudden cardiac death. The inclusion of these non-invasive autonomic measures in routine exercise stress testing may provide additional risk stratification. Disclosure of Interest: None Declared

Association of asymmetric dimethylarginine levels with treadmill-stress-test-derived prognosticators

BackgroundAsymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide production. The purpose of this study was to assess the correlation between ADMA and treadmill stress test outcome parameters with known prognostic value, in patients with intermediate risk for coronary artery disease (CAD). MethodsStudy participants were referred for treadmill exercise stress test (EST) due to symptoms of suspected CAD. Participants with prior history of CAD, cerebrovascular events, peripheral artery disease, systemic inflammatory disease or use of anti-inflammatory agents were excluded. ADMA levels were measured before EST. ResultsThe study prospectively enrolled 209 individuals (165 males, aged 58.1±10.9). A significant negative correlation was detected between ADMA and maximal exercise time (r=−0.556, p<0.001), metabolic equivalents (METs) (r=−0.555, p<0.001) and Duke treadmill score (DTS) (r=−0.347, p<0.001). Subjects who exercised to ≥10 METs (n=114) had lower ADMA levels than those who achieved <7 METs (n=30) (0.58±0.06 vs 0.87±0.08μmol/L, p<0.001), and those with DTS<5 (n=63) had higher ADMA (0.75±0.19 vs 0.64±0.15μmol/L, p<0.001) compared to those with DTS ≥5 (n=146). In multivariable analysis, ADMA remained an independent predictor of DTS (R2=0.210; beta=−10.5; 95% confidence interval −14.9 to −6.2; adjusted p<0.001) and METs (R2=0.500; beta −8.5; 95% confidence interval −9.7 to −6.0; adjusted p<0.001) after adjustment for age, BMI, gender, diabetes, smoking status, dyslipidemia, hypertension and family history of premature CAD. ConclusionADMA is correlated to EST parameters with proven prognostic value. This implies that ADMA itself might be a useful prognosticator in patients with suspected CAD.

Silent Myocardial Ischemia in Master Marathon Runners

Background: Silent myocardial ischemia is defined as objective documentation of myocardial ischemia in the absence of angina or anginal equivalents. There are a number of reports of exercise-related sudden deaths and myocardial infarctions in aerobically trained athletes suffering from exercise induced silent myocardial ischemia. The most appropriate and used method to discover silent myocardial ischemia is the exercise stress testing. Case Reports: In this article the authors describe three emblematic cases of silent myocardial ischemia detected in master marathon runners during systematic prepartecipation screening. These marathon runners were asymptomatic but suffering from a severe coronary artery disease that only thanks to exercise treadmill stress test was detected and properly treated. Conclusions: Silent myocardial ischemia is not such a rare event in athletes, indeed quite the opposite. In fact, even though athletes are asymptomatic this does not exclude the possibility that they are suffering from severe coronary artery disease.

An Aneurysm of the Left Main Coronary Artery in a Patient with Metabolic Syndrome

A 68-year-old woman with prior history of hypertension, type 2 diabetes and dyslipidemia was presented at our hospital because of exertional dyspnea. On admission blood pressure was 145/80 mmHg, with a regular pulse of 78 bpm. Cardiovascular and other system examinations were entirely normal. The electrocardiogram showed sinus rhythm with no significant ST segment changes. The exercise treadmill stress test showed ST depression of 1.5 mm in leads V5-6. Coronary angiography revealed a giant aneurysm of the left main coronary artery with proximal ectasia of left anterior descending and circumflex artery (figure 1); the rest of the coronary tree was free of aneurysm and atherosclerosis. The patient was treated with aspirin, perindopril and atorvastatin. Coronary artery aneurysm is a rare anomaly, which is described as the enlargement of coronary artery diameter to 1.5 times or more than its normal size. The incidence varies between 0.3% and 4.9% in different series. Most of the coronary artery aneurysms develop on the right coronary artery. Left main coronary artery aneurysms are extremely rare, and usually extend into the adjacent left anterior descending and circumflex artery proximal segments. Most of the cases are associated with atherosclerosis and Kawasaki disease. Coronary artery aneurysms should be treated according to existence of concomitant coronary artery disease. Patients with no obstructive coronary artery disease are recommended to be managed medically, while coronary bypasses should be performed when indicated by the severity of stenosis or progressive angina despite medical therapy.

The clinical usefulness of carotid ultrasonography in patients with an inconclusive exercise treadmill stress test result

BackgroundAlthough a treadmill exercise stress testing (EST) is often the first-line screening procedure for subjects with an intermediate probability of coronary artery disease (CAD), one limitation of this test is the high rate of inconclusive tests that result from borderline exercise-induced ST changes. The carotid intima media thickness (CIMT) correlates well with atherosclerosis. The purpose of this study was to evaluate the clinical usefulness of performing CIMT measurements in patients with an inconclusive EST. MethodsSymptomatic patients without history of vascular disease and with inconclusive EST result were included. Inconclusive results were defined as the presence of horizontal or downsloping ST-segment depression between 0.5 and 0.9mm or 1.0 and 1.4mm upsloping ST-segment depression. After inconclusive EST regarding electrocardiographic changes, the measurements of the CIMT and myocardial perfusion imaging study (MPS) were performed in all patients. The CIMT was measured at the posterior wall of the common carotid artery. The diagnosis of CAD was based on the presence of reversible perfusion defects on exercise MPS. ResultsA total of 87 patients (57 men) with a mean age of 58.9±7.2 years were enrolled. The MPS was positive in 18 patients. The CIMT in patients with positive MPS was significantly greater than in patients with negative MPS. The CIMT was 0.82±0.33mm in patients with positive MPS and 0.63±0.21mm in patients with negative MPS (p=0.004). Receiver operating characteristic curve analyses revealed that the greatest specificity was obtained when the cut-off value of CIMT was set at 0.66mm (sensitivity 39%; specificity 72.5%; positive predictive value 27%; negative predictive value 82%). ConclusionIn patients with inconclusive electrocardiographic changes during EST, CIMT was a useful measurement to prevent alternative more expensive and invasive tests. Additionally, mean CIMT is useful for screening patients with an inconclusive EST result to exclude CAD.

The Impact of Race and Higher Socioeconomic Status on Cardiorespiratory Fitness

Previous studies suggest that African Americans (AA) have lower levels of cardiorespiratory fitness (CRF) than their Caucasian (C) counterparts. However, the association between CRF and race/ethnicity in the context of higher socioeconomic status (SES) has not been explored. We evaluated 589 AA (309 men and 203 women) and 33,015 C (19,399 men and 8753 women) enrolled in the Cooper Center Longitudinal Study. Education years and access to a preventive health care examination were used as a proxy for higher SES. Data were collected from a questionnaire, maximal treadmill exercise stress test, and other clinical measures. The outcome variable was CRF, which was stratified into low fit (quintile 1 of CRF) and fit (quintiles 2-5). Multivariable regression was used to compare adjusted mean CRF between groups. P values were adjusted for unbalanced sample size and unequal variance between groups. The mean education years were similar for AA and C men at 16 yr; however, AA women had more years of education than C (15.8 vs 15.2 yr, P = 0.0062). AA men and women had a significantly higher prevalence of being unfit compared with their C counterparts (men 26.7% vs 12.6%, P < 0.0001; women 21.3% vs 8.4%, P < 0.0001). The adjusted mean estimated maximal METs were 10.9 vs 11.7 and 8.8 vs 9.8 for AA and C men and women, respectively. Fully adjusted odds ratios revealed that AA men had more than twice the risk of being unfit compared with C men. A trend persisted for AA women to have a lower MET value than their counterparts. Despite comparable higher SES, lower CRF existed among AA men versus C men. These results suggest that CRF may not be mediated strictly by environmental factors related to SES.