Exercise-induced ST-segment depression in patients without restenosis after coronary angioplasty. Relation to preprocedural impaired left ventricular function

QT dispersion plus ST-segment depression: a new predictor of restenosis after successful percutaneous transluminal coronary angioplasty

BACKGROUND

ST-segment depression during exercise testing is frequently observed in the absence of restenosis after percutaneous transluminal coronary angioplasty (PTCA).

HYPOTHESIS

With the goal of improving the prediction of restenosis after PTCA, we evaluated the usefulness of ST-segment depression plus QT dispersion (QTd = QTmax - QTmin) during treadmill stress test.

METHODS AND RESULTS

Fifty-six patients (37 men, 19 women, mean age 51 +/- 14 years) were evaluated with treadmill exercise testing and coronary angiography 7 +/- 5 months after PTCA. Treadmill test was positive in 30 patients and negative in 26 patients. At coronary angiography, restenosis was present in 16 patients with positive exercise electrocardiogram (ECG) and in 6 patients with negative exercise ECG. Fourteen patients with a positive stress test did not have restenosis. There was no difference in QTd values between groups at baseline (p > 0.05). Exercise QTd was 63 +/- 9 ms in patients with positive exercise test, 54 +/- 18 ms in patients with negative exercise test (p = 0.003), 71 +/- 13 ms in patients with restenosis, and 53 +/- 17 ms in patients without restenosis (p = 0.001). ST-segment depression during the stress test determined restenosis with a sensitivity of 80% and a specificity of 58%. Sensitivity and specificity of QTd of > or = 60 ms for prediction of restenosis were 83 and 61%, respectively. When QTd of > or = 60 ms was added to ST-segment depression as a condition for positive test, the sensitivity and specificity increased to 91 and 78%, respectively. QT dispersion plus ST-segment depression had higher sensitivity and specificity than either QTd or ST-segment depression alone (p < 0.05).

CONCLUSION

The addition of QTd to ST-segment depression during exercise test improves the diagnostic value and can be used as a noninvasive tool in the diagnosis of restenosis after PTCA.

Electrocardiographic exercise stress testing: an update beyond the ST segment

Routine exercise testing is frequently ordered to evaluate a patient's cardiovascular performance. The test is more direct and less expensive than imaging technology, and derives valuable information. New variables such as dyspnea and heart rate recovery, as well as integrated scores, provide incremental value to conventional analysis of exercise-induced angina or electrocardiographic changes. Considerations relating to test accuracy in women need to be weighed. This paper seeks to make physicians aware of the current status of the test, and improve their understanding of and ability to integrate new variables and scores to more effectively manage their patients.

Clinical impact of functional testing strategy among stented and non-stented patients: insights from the ROSETTA Registry

The clinical utility of routine functional testing following percutaneous coronary intervention (PCI) among patients with and without coronary stenting is unclear. We established an international registry to evaluate the functional testing strategies following successful PCI. Among patients treated with stents, adverse cardiovascular outcomes were similar between those who underwent routine or clinically-driven functional testing. Conversely, among those who were not treated with stents, the rate of death, myocardial infarction or unstable angina was lower than those who underwent routine functional testing (14.8% vs. 6.6%; P=0.033). Our study suggests that routine functional testing may be beneficial to patients not treated with stents.

BACKGROUND

The role of routine functional testing following successful PCI is unclear. By improving patient outcomes with coronary stenting, the value of such a strategy may diminish.

HYPOTHESIS

To determine the clinical utility of routine functional testing following PCI between patients with and without stenting.

METHODS

The routine versus selective exercise testing after angioplasty (ROSETTA) Registry was established to evaluate the utilization of functional testing following PCI. Use of functional testing, either routine or selective (clinically-driven), was left to the discretion of the attending physician.

RESULTS

Of 791 patients enrolled, 462 (58%) underwent coronary stenting. Stented patients were less likely to suffer from concomitant diseases but had more complex angiographic morphological characteristics. Between the groups of patients with and without stents, there was no difference in the proportion of patients undergoing routine functional testing (24% vs. 36%) or subsequent cardiac procedures (18.4% vs. 16.0%). Among patients with stents, outcomes at 6 months were similar between the groups undergoing routine and selective functional testing, including death (0% vs. 1.7%), myocardial infarction (0.9% vs. 2.0%), unstable angina (9.9% vs. 13.7%), repeat angiography (16.2% vs. 16.9%) and revascularization procedures (11.7% vs. 10.8%). However, among non-stented patients, selective functional testing was associated with a higher occurrence of death, myocardial infarction or unstable angina (14.8% vs. 6.6%; P=0.033). There was also no difference in the rates of repeat coronary angiography or revascularization procedures between these two strategies.

CONCLUSION

Although routine functional testing has little impact on outcomes among patients treated with coronary stents, non-stented patients may derive particular benefit.

A QRS score versus ST-segment changes during exercise testing: which is the most reliable ischaemic marker after myocardial revascularisation?

BACKGROUND

The diagnostic ability of exercise testing based on ST-segment changes is low for the detection of restenosis after percutaneous transluminal coronary angioplasty (PTCA) or ischaemia after bypass surgery (CABG). The aim of this study was to improve the diagnostic accuracy of exercise testing in patients with a history of PTCA or CABG, with the implementation of a QRS score.

METHODS

We studied 128 post-PTCA patients (aged 49 +/- 8 years) and 104 post-CABG patients (aged 54 +/- 8 years), who had either positive exercise tests with or without angina, or negative exercise tests with continuing angina-like symptoms, and underwent cardiac catheterisation.

RESULTS

The univariate risk ratio of exercise-induced ST-segment deviation to detect restenosis was 3.05 (p = 0.005) and 0.83 (p = 0.690) in group A and group B patients, respectively. The univariate risk ratios of abnormal QRS score values to detect restenosis were 32.1 (p < 0.001) and 18.8 (p < 0.001) for group A and group B patients, respectively. The univariate risk ratios of the combination of exercise-induced ST-segment changes and of abnormal QRS score values to detect restenosis was 9.43 (p < 0.001) and 3.77 (p < 0.044) for group A and group B patients, respectively. The value of the area under the ROC curves is higher for the QRS score in group A patients, group B patients and for the whole study population.

CONCLUSIONS

QRS score values significantly improve the diagnostic ability of ST-segment change-based exercise testing, for the assessment of restenosis after PTCA or ischaemia after CABG.

Use of routine functional testing after percutaneous transluminal coronary angioplasty: results from the ROSETTA Registry

BACKGROUND

The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for exercise testing suggest that only selected groups of high-risk patients should undergo routine functional testing after percutaneous transluminal coronary angioplasty (PTCA) for the detection of restenosis.

OBJECTIVES

Our purpose was (1) to document the patterns of use of post-PTCA functional testing and (2) to determine whether the choice of functional testing strategy is related to clinical characteristics of patients or whether physicians use a similar strategy for all their patients.

METHODS

The Routine Versus Selective Exercise Treadmill Testing After Angioplasty (ROSETTA) Registry is a prospective study examining the use of functional testing among 788 patients at 13 centers in 5 countries.

RESULTS

During the 6-month period after a successful PTCA, 49% of patients underwent functional testing (range among centers 10%-81%). Among patients who underwent functional testing, 39% had a clinical indication and 61% had functional testing as a routine follow-up. The first functional test was performed a median of 7 weeks after PTCA, with 13% of patients having second tests at a median of 14 weeks and 4% having additional tests at a median of 20 weeks. Univariate and multivariate analyses demonstrated that the chief determinant of the use of routine functional testing was clinical center. Aside from age (P <.0001), no baseline clinical or procedural characteristics were consistently associated with the use of routine functional testing after PTCA.

CONCLUSIONS

Physicians do not appear to be adhering to the ACC/AHA guidelines for exercise testing regarding the routine use of post-PTCA functional testing. None of the clinical characteristics identified by the ACC/AHA guidelines were associated with the routine use of post-PTCA functional testing, and the primary determinant of functional testing was the location of the center at which the patient had the PTCA.

Reliability of the exercise-induced ST-segment changes to detect restenosis three months after coronary angioplasty: significance of the appearance in other leads

BACKGROUND

Exercise-induced ST-segment changes 3 months after angioplasty may sometimes show a false-positive result.

METHODS

We therefore analyzed the ST changes observed during the exercise tests performed before and 3 months after angioplasty in 118 patients with single-vessel coronary artery disease.

RESULTS

Ninety-two (78%) of the 118 patients had ST changes in the same lead before and after angioplasty, whereas the remaining 26 (22%) patients had ST changes in other leads in the postangioplasty test when compared with the preangioplasty exercise test. Restenosis was found in 44 (48%) of the 92 patients with ST changes in the some lead but in only four (15%) of the 26 patients with ST changes in other leads.

CONCLUSIONS

Exercise-induced ST-segment changes are not reliable markers of restenosis 3 months after angioplasty. ST-segment changes observed in other leads after angioplasty compared with the preangioplasty exercise test may show a false-positive result.

Reliability of exercise-induced ST segment changes to detect restenosis 3 months after coronary angioplasty: significance of the appearance in other leads

Exercise-induced ST-segment changes 3 months after angioplasty sometimes may show a false-positive result. We therefore analyzed the ST changes observed during the exercise tests performed before and 3 months after angioplasty in 118 patients with single-vessel coronary artery disease. Ninety-two (78%) of the 118 patients had ST changes in the same lead before and after angioplasty, whereas the remaining 26 (22%) patients had ST changes in other leads in the postangioplasty exercise test when compared with the preangioplasty test. Restenosis was found in 44 (48%) of the 92 patients with ST changes in the same lead but in only 4 (15%) of the 26 patients with ST changes in other leads. We conclude that exercise-induced ST segment changes are not reliable markers of restenosis 3 months after angioplasty. ST segment changes observed in other leads after angioplasty may show a false-positive result when compared with the preangioplasty exercise test.

Diagnostic value of exercise electrocardiography and angina after coronary artery stenting. Benestent Study Group

To determine whether metallic stent implantation within a coronary artery modifies the accuracy of angina or exercise test results in predicting stenosis, we studied 172 patients assigned to stent implantation and 153 patients assigned to balloon angioplasty enrolled in the Benestent trial comparing de novo stenting with conventional balloon angioplasty. Sensitivity and specificity curves were constructed for the prediction of percentage diameter stenosis and minimal lumen diameter. Receiver-operator curves were constructed for comparison of diagnostic accuracy. Identical exercise load and duration were achieved in the two groups, despite a better angiographic result in patients treated with a stent. Similarly, the diagnostic accuracy of clinical symptoms or exercise test results as a function of the angiographic results were similar in patients with and patients without a stent. The intersection points of the sensitivity and specificity curves for recurrent angina or ST-segment depression were 72% to 77%. The corresponding cut-off points for percentage diameter stenosis were, respectively, 52% and 50% for patients with and without a stent (1.35 and 1.50 mm for minimal lumen diameter). We conclude that the presence of an intracoronary stent does not affect the diagnostic accuracy of recurrent angina or exercise-induced ST depression in predicting residual stenosis. We also conclude that exercise tolerance is similar after balloon angioplasty, with or without stenting, despite a better angiographic outcome in the group receiving a stent, suggesting a minimal threshold beyond which the patient is no longer at risk for ischemia during exercise.