Negative Treadmill Exercise Test Research Articles

Utility of routine exercise treadmill testing early after percutaneous coronary intervention

BackgroundThere have been few prospective studies examining the utility of routine exercise treadmill testing (ETT) early after percutaneous coronary intervention (PCI). The objective of this study was to examine the impact of a routine ETT strategy early after PCI on follow-up cardiac events and procedures.MethodsWe examined 136 patients who underwent routine ETT at 6 weeks post-PCI in the ADORE trial. The ETT was classified as positive, indeterminate, or negative. The Duke Treadmill Score (DTS) was calculated for all patients. Follow-up occurred at 9 months.ResultsETT results at 6 weeks were: 32 (23.5%) positive, 24 (17.6%) indeterminate and 80 (58.8%) negative. At 9 months, the composite event rate was 21.9% in those with a positive ETT, 20.8% in those with an indeterminate ETT and 12.5% in those with a negative ETT (p = 0.25 positive vs. negative ETT). The sensitivity of early ETT for predicting clinical events was 41.2%, the specificity was 73.3%, the positive predictive value was 21.9% and the negative predictive value was 87.5%. At 9 months, the cardiac procedure rate was 18.8% in those with a positive test, 13.0% in those with an indeterminate test, and 6.3% in those with a negative test (p = 0.07 positive vs. negative ETT). In a multivariate logistic regression model, coronary stenting during PCI and a ≥ 85% MPHR achieved were found to be inversely associated with clinical events. However, the DTS did not independently predict clinical events.ConclusionAlthough the statistical power of the study was limited by the small number of clinical events (particularly MI and death), the results of this study support the ACC/AHA guidelines that exercise treadmill testing should not be used routinely after PCI.

Usefulness of 64-Slice Multidetector Computed Tomography in Diagnostic Triage of Patients With Chest Pain and Negative or Nondiagnostic Exercise Treadmill Test Result

The usefulness of 64-slice multidetector coronary computed tomography (MDCT) in a diagnostic triage of 100 consecutive patients (age 55.8+/-11.6 years; 57% men) with chest pain suspected to be ischemic in origin and a negative or nondiagnostic exercise treadmill test (ETT) result was examined. None of the patients had previously known coronary artery disease (CAD). MDCT showed obstructive (>or=50%) CAD in 29 patients; 13 of 59 patients (22%) with a negative and 16 of 41 patients (39%) with a nondiagnostic ETT result. High-risk (left main and/or 3-vessel) CAD was present in 3.3% of patients with a negative and 4.9% with a nondiagnostic ETT result. The 29 patients with obstructive CAD on MDCT had a higher mean Agatston calcium score (221+/-402 vs 40+/-77 U, p<0.001). Invasive coronary angiography confirmed MDCT findings in 26 of 29 patients (positive predictive value 90%) and 45 of 54 stenotic segments (83%) in a per-segment analysis. For the 71 patients without obstructive CAD on MDCT, clinically driven invasive angiography detected CAD in 1 of 15 patients (1 false-negative MDCT result) and 2 of another 5 patients who were referred for invasive angiography later during a 12-month follow-up period. In the remaining 51 patients, MDCT findings effectively allowed exclusion of obstructive CAD, and there were no major adverse clinical events during follow-up. In conclusion, in patients with chest pain possibly ischemic in origin, no previously known CAD, and a negative or nondiagnostic ETT result, contrast-enhanced 64-slice MDCT scanning was a useful tool to provide direct noninvasive coronary angiography and rapidly advance diagnostic triage.

Relation between Coronary Flow Reserve using Transesophageal Echocardiography and Duke Treadmill Score in Patients with Microvascular Angina

Purpose:The triad of chest pain, normal coronary arteries and a positive stress test has been called microvascular angina. The link between coronary flow reserve (CFR) and Duke treadmill score (DTS) in patients with microvascular angina remains elusive. Methods:We studied 108 subjects (M:F=48:60, mean age 54±9 yrs) with chest pain and normal coronary angiogram. An exercise treadmill test (ETT) was performed by Bruces protocol and the equation for calculating DTS was DTS=exercise time(5×ST deviation)-(4× exercise angina), with 0=none, 1=nonlimiting, 2=exercise-limiting. The coronary flow velocity at diastole (PDV) using transesophageal echocardiography (TEE) was obtained from the proximal left anterior descending coronary artery and coronary flow reserve (CFR) was calculated as the ratio of hyperemic PDV after the intravenous infusion of dipyridamole (0.56 mg/kg) to baseline PDV. Results:1) CFR was 3.04±0.45 in group with negative ETT and 2.19±0.62 in group with positive ETT (p<0.001). 2) CFR was 1.51±0.31 in high-risk group with a score of <-10, 2.39±0.63 in moderate-risk group with scores from -10 to +4 and 3.04±0.43 in low-risk group with a score of ≥+5 on DTS (p<0.001 versus low-risk, respectively). 3) DTS was significantly related to CFR (r=0.704, p<0.001). Conclusion:The composite DTS is closely related to CFR using TEE and may be a useful tool to assist clinicians in determining the severity of ischemia and evaluating the efficacy of treatment in patients with microvascular angina. (Korean Circulation J 2001; 31(3):297-304)

Utility and safety of immediate exercise testing of low-risk patients admitted to the hospital with acute chest pain

It is common practice to hospitalize patients with chest pain for a period of observation and to perform further diagnostic evaluation such as exercise treadmill testing (ETT) once acute myocardial infarction (AMI) has been excluded. This study evaluates the safety and efficacy of immediate ETT for patients admitted to the hospital with acute chest pain. One hundred and ninety non-consecutive low-risk patients admitted to the hospital from emergency department with acute chest pain underwent ETT using Bruce protocol immediately on admission to the hospital (median time 165+30 min). Fifty-seven (30%) patients had positive exercise electrocardiograms, 44 (77.2%) of whom had significant coronary narrowing by angiography. An uncomplicated anterior non-Q-wave AMI was diagnosed in one patient. One hundred and eleven (58.4%) patients had negative and 22 (11.6%) patients had non-diagnostic exercise electrocardiograms. Of these 133 patients, 86 (64.7%) were discharged immediately after ETT, 19 (14.3%) were discharged within 24 h, and 28 (21%) were discharged after 24 h of observation. There were no complications from ETT. During the 17±6 months follow-up no patients died, and only eight (7.2%) patients with negative ETT experienced a major cardiac event (one AMI and seven angina). In conclusion, our results suggest that immediate ETT of low-risk patients with chest pain who are at sufficient risk to be designated for hospital admission, is effective in further stratifying this group into those who can be safety discharged immediately and those who require hospitalization.

Long-term additive prognostic value of thallium-201 myocardial perfusion imaging over clinical and exercise stress test in low to intermediate risk patients : study in 1137 patients with 6-year follow-up.

The exercise treadmill test (ETT) and Tl201 single proton emission computed tomography (SPECT) are of short- to medium-term prognostic value in coronary heart disease. We assessed the long-term prognostic value of these tests in a large population of patients with low- to intermediate risk of cardiac events. One thousand one hundred thirty-seven patients (857 men, age 55+/-9 years) referred for typical (62.1%) or atypical (22.4%) chest pain, or suspected silent ischemia (15.5%), were followed up for 72+/-18 months. Overall mortality was higher after strongly positive (ST depression >2 mm, or >1 mm for a workload </=75 W) (2. 36%/y) or nondiagnostic ETT (1.63%/y) than after normal (0.85%/y) or positive ETT (1.37%/y) (P=0.002), and after abnormal SPECT than after normal SPECT (1.60%/y versus 0.68%/y, P=0.001). The major cardiac event rate (cardiac death or myocardial infarction [MI]) was 0.88%, 1.59%, 2.10%, and 2.13%/y after negative, positive, strongly positive, and nondiagnostic ETT, respectively (P=0.003), and 0.56%, 1.43%, and 2.05%/y in patients with 0, 1 to 2, and >/=3 abnormal segments on SPECT, respectively (P<0.002). An abnormal SPECT was predictive of MI (P<0.001), whereas ETT was not. In multivariate analysis, SPECT was of incremental prognostic value over clinical and ETT data for predicting overall mortality and major cardiac events. The incremental predictive value of SPECT is maintained over 6 years and is particularly relevant after positive, strongly positive, and nondiagnostic ETT.

Differential coronary microvascular function in patients with left ventricular dysfunction of unknown cause — implication for possible mechanism of myocardial ischemia in early stage of cardiomyopathy

To evaluate whether or not coronary microvascular dysfunction is associated with exercise-induced myocardial ischemia in left ventricular dysfunction of unknown cause, both the treadmill exercise test (TET) and coronary hemodynamics were studied in 20 patients with impaired left ventricular ejection fraction (<50% by radionuclide ventriculogram), normal cardiac size, normal coronary angiogram and no evidence of clinical heart failure. Ten subjects with atypical chest pain were studied as the control. Coronary hemodynamics were studied both at baseline and after dipyridamole infusion (0.56mg/kg, i.v. for 4′). There was no difference in age, gender, blood pressure, baseline great cardiac venous flow (GCVF) and coronary vascular resistance between ten patients with a positive TET and the other ten with a negative TET. At baseline, coronary sinus oxygen concentration was increased and myocardial oxygen consumption reduced in patients with a positive TET compared with those with negative a TET. After dipyridamole infusion, maximum GCVF (102±47 vs. 144±31 ml/min, P=0.027) and coronary flow reserve (2.31±0.49 vs. 3.00±0.61, P=0.012) were significantly reduced and minimum coronary vascular resistance was higher (1.00±0.42 vs. 0.63±0.12 mmHg/ml/min, P=0.016) in patients with a positive TET than in those with a negative TET. At follow-up, 40% of patients with a positive TET and 10% of those with a negative TET developed clinical heart failure with a dilated left ventricle during a period of 45 months. Thus, coronary microvascular function is heterogeneous in patients with left ventricular dysfunction of unknown cause. In some of them, coronary microvascular dysfunction could be related to the presence of exercise-induced myocardial ischemia, suggesting that similar pathophysiology underlies the early stage of dilated cardiomyopathy and syndrome X.

802-1 Clinical Value and Cost of Screening Exercise Treadmill Testing in Asymptomatic Individuals

Exercise treadmill testing (ETT) is frequently performed to screen for coronary artery disease (CAD) in asymptomatic individuals; however, its clinical value is questionable. To evaluate the clinical value of ETT, we examined a cohort of asymptomatic individuals undergoing ETT at the Cleveland Clinic between September 1990 and December 1993. ETT was abnormal if it exhibited any of the following; a 1 mm ST-T elevation or depression, a drop in blood pressure ≥10 mmHg, chest pain or failure to reach a target heart rate. Any CAD was defined by at least 1 coronary segment with ≥50% stenosis. Severe CAD was defined by the following: 1) left main coronary artery with ≥50% stenosis, 2) 3 vessels with ≥70% stenosis or 3) proximal left anterior descending artery and 2 vessels with ≥70% stenosis. During this period, 4335 ETT's were performed in individuals with no cardiac symptoms. The average age was 53, 89% were male and 16% had at least one cardiac risk factor. Fifteen percent exhibited an abnormal ETT. Among those with an abnormal ETT, 14% underwent coronary angiography while among those with a negative ETT, 1% underwent angiography. Coronary angiography identified 56% as having any CAD and 15% as having severe CAD. In this asymptomatic population, 228 ETT's and 7 coronary angiograms were performed in order to identify 1 individual with severe CAD. Using Medicare reimbursement of $70 for ETT and $1500 for angiography, the cost of screening per case of severe CAD identified would be $26,460. Based on previously published data on survival with surgical and medical therapy in patients with severe CAD, we estimate a cost of $120,000 to $180,000 per year of life saved with this screening approach. This low yield suggests that screening asymptomatic individuals with ETT may be costly and of little clinical value compared to other screening approaches.

Safety of immediate treadmill testing in selected emergency department patients with chest pain: A preliminary report

To determine the feasibility and safety of an immediate, symptomlimited, treadmill test on selected emergency department (ED) patients, a convenience sample of 28 patients underwent an exercise treadmill test (ETT) within the first several hours after hospital arrival using the modlified Bruce protocol. Patients were included in the study if they presented with otherwise unexplained chest pain consistent with (but not characteristic for) angina pectoris and had a normal electrocardiogram. A negative ETT was seen in 23 of 28 patients, and five of 28 patients had a positive ETT. No patients had serial enzyme or electrocardiogram evolution suggestive of myocardial ischemia, and all patients with a negative ETT were discharged after a full inpatient evaluation designed to rule out unstable coronary disease. At a mean follow-up period of 6.1 months there has been no cardiac morbidity or mortality in the patients with negative ETTs. It was concluded that early ETTs of selected ED patients with chest pain is safe, and an exercise test administered during the ED visit which is negative can preclude unnecessary hospitalization.

Hyperventilation provocation in patients with chest pain and a negative treadmill exercise test

Seventeen (39%) of 44 patients with chest pain but without significant ST depression on treadmill exercise had their usual chest pain reproduced during or after 3 min of voluntary hyperventilation (VHV) at rest. These patients with hyperventilation positive tests had not only significantly more hyperventilation-related symptoms and respiratory complaints but also shorter breath-holding times, lower mean resting end-tidal pCO 2 and higher mean respiratory rates than those with negative tests and normal controls. Of the psychological variables, only phobic avoidance scores for agoraphobia were higher in patients with positive tests. These findings suggest that in two fifths of patients with exercise tests negative for ischaemia, chest pain is associated with HV, but abnormalities of breath control and relative hypocapnia are present even in the absence of chest pain. It is possible that a chronic abnormality of respiratory control may interact with attitudinal factors in the experience of non-cardiac chest pain.

Short-Term Prognosis in Females with No or Insignificant Coronary Disease and a Diagnostic Exercise Test

Short-term prognosis in patients with normal or near normal coronary arteries is expected to be good. However, controversy continues about the meaning of anginal syndromes in the setting of normal or insignificantly diseased epicardial coronary arteries. We were interested in whether electrocardiographic evidence of ischemia during stress could select out a higher risk subgroup with a poorer prognosis in a cohort of women with chest pain and no or insignificant coronary disease. Thus we identified all women without a history of organic heart disease who had a diagnostic exercise treadmill test and coronary angiography performed for evaluation of chest pain during a 6-year period. One hundred twenty-one women with a mean age of 51.4 years had both a cardiac catheterization and a positive or negative exercise treadmill test. Of this group, 64 of 66 women with no (49) or hemodynamically insignificant (15) coronary artery disease (<70% luminal diameter narrowing of a major coronary artery or branch) were followed up a mean of 3 years after coronary angiography and are the subjects of this study. During the follow-up period, six women died, three most likely of cardiac causes. Thirty percent of patients had continued chest pain requiring hospitalization or antianginal medications. The presence of a positive exercise test did not predict death or continued chest pain. Sixty-one percent of patients were alive and well with no or minor chest pain complaints. Ejection fraction was significantly lower in the positive exercise group as compared to the negative exercise group (0.58 +/- 0.1 vs 0.67 +/- 0.096, P = 0.0006) with 36% of the positive group as compared to 9% of the negative group having an abnormally low ejection fraction (P < 0.025). Thus, a positive exercise test is not helpful prognostically in a female population with no or insignificant coronary disease. This group appears overall to have an excellent prognosis with exceptions to be described. A positive exercise test may be secondary to an unsuspected cardiomyopathic process in some patients.

Restenosis after successful percutaneous transluminal coronary angioplasty: The montreal heart institute experience

Repeat coronary angiography was performed within 6 months after successful percutaneous transluminal coronary angioplasty (PTCA) in 178 of our first 181 patients (98%). The remaining 3 patients were symptom free, had negative treadmill exercise test results and were considered not to have had restenosis. A second follow-up angiogram was performed in 107 patients (59%), including all patients with persistent or recurrent anginal symptoms, between 7 and 18 months after PTCA. Fifty-one of the 181 patients (28%) had restenosis on 51 of 205 successfully dilated segments (25%). The stenosis was ≥70% in 49 of these 51 segments; it was 65% and 55%, respectively, in the 2 remaining patients. Restenosis was documented angiographically at a median time of 4.7 ± 4 months. However, 47 patients (92%) had restenosis documented within 6 months, 2 between 7 and 12 months and 2 between 13 and 18 months after PTCA. Stepwise logistic regression analysis selected the following factors as independent predictors of restenosis after PTCA: variant angina, multivessel disease, severity of residual stenosis and less reduction in the diameter of the stenosis on the angiogram immediately after PTCA. Of these 4 factors, the degree of residual stenosis immediately after PTCA was by far the most significant. It is concluded that restenosis occurs in approximately 25% of patients, almost always within the first 6 months, after successful PTCA. The degree of residual stenosis after PTCA is the most important predictor of restenosis. Increased experience and improved instrumentation may eventually lead to less residual stenosis and better late results after PTCA.

Comparison of rest and exercise radionuclide angiocardiography and exercise treadmill testing for diagnosis of anatomically extensive coronary artery disease.

The accuracy of rest and exercise radionuclide angiocardiography (RNA) and exercise treadmill testing (ETT) for diagnosis of three-vessel or left main coronary artery disease (extensive CAD) was determined in 544 patients. ETT and RNA sensitivities were similar (88% vs 92%, NS), but ETT was more specific than RNA (46% vs 34%, p less than 0.01). The prevalence of extensive CAD in patients with a positive treadmill (41%) increased only 3% when the RNA was also positive. However, in the 292 patients with a negative or indeterminate ETT, a positive RNA increased this prevalence from 16% to 23%, while a negative RNA decreased this prevalence to 5%. These results support the initial use of ETT followed by RNA if the treadmill is negative or indeterminate for diagnosis in a population with a high prevalence of extensive CAD. This approach separates patients into subgroups with a high or low probability of extensive CAD.

Myocardial infarction immediately following cardiovascular stress testing

A 45 year old man with recent onset of atypical chest pain, who sustained an acute myocardial infarction within 15 minutes after a negative treadmill exercise test, is decribed. The clinical course was complicated by persistence of chest pain despite afterload reduction and electrocardiographic evidence of inferoapical myocardial infarction. Coronary arteriography three and a half months later revealed minimal obstructive disease.