Usefulness of early radionuclide angiography for identifying low-risk patients for late restenosis after percutaneous transluminal coronary angioplasty

[Nuclear cardiology: technical bases and clinical applications]

Although the role of nuclear cardiology is currently well consolidated, the addition of new radiotracers and modern techniques makes it necessary to continuously update the requirements, equipment and clinical applications of these isotopic tests. The characteristics of the radioisotopic drugs and examinations presently used are explained in the first part of this text. In the second, the indications of them in diagnostic and prognostic evaluation of the different coronary diseases are presented.

A new predictor of restenosis after successful percutaneous transluminal coronary angioplasty in patients with multivessel coronary artery disease

With the goal of improving prediction of restenosis after percutaneous transluminal coronary angioplasty (PTCA) for multivessel coronary artery disease (CAD), we evaluated the usefulness of serial exercise treadmill tests. We previously reported that an increase in the deltaST/delta heart rate (HR) index at follow-up over the value obtained several days after PTCA was useful for detecting restenosis following PTCA for 1-vessel CAD. In that report, comparison of the deltaST/deltaHR index was made based on measurements from the lead disclosing the greatest ST displacement before PTCA. This method was not applicable to patients with multivessel CAD. Seventy-eight patients with multivessel CAD before and several days after PTCA and just before follow-up performed exercise treadmill tests. Simple HR-adjusted indexes of ST-segment depression during exercise (deltaST/deltaHR index) and the sum of the deltaST/deltaHR index in leads II, III, aVF, V4, V5, and V6 (sigma deltaST/deltaHR index) were determined. We compared the predictive power of an increase in sigma deltaST/deltaHR index at follow-up with that of a positive exercise treadmill test and a positive thallium scintigram for restenosis. At follow-up, 37 of the 78 patients showed restenosis. The sigma deltaST/deltaHR index had increased in 30 of these 37 patients (81%), and in 12 of the 41 patients (29%) without restenosis. An increase in sigma deltaST/deltaHR index had a significantly higher sensitivity than the other methods and a significantly higher specificity than a positive exercise treadmill test.

Importance of immediate and very early postprocedural angiographic and thallium-201 single photon emission computed tomographic perfusion measurements in predicting late results after coronary intervention

We examined prospectively the hypothesis that the adequacy of initial dilatation may be a major determinant of the late result of coronary angioplasty and that a better assessment of initial dilatation can be made from a combined angiographic and perfusion study than from angiography alone. Angiographic and perfusion (thallium-201 single-photon-emission computed tomography) measurements were made very early (18 to 24 hours) after coronary angioplasty in 59 patients (67 lesions) and also immediately (37 +/- 16 minutes) after the procedures in 19 of them (23 lesions). The early measurements, singly, in combination, and as a restenosis index (restenosis index = thallium-201 ischemic score (units) - minimal luminal area (squared millimeters) were examined as predictors of the late angiographic result. At late angiography (5.5 +/- 2.2 months after angioplasty), residual stenosis was related to the immediate and very early postangioplasty minimal luminal dimension, thallium-201 ischemic score, and restenosis index, and also to day-1 loss and lesion length. The combination of a normal result in the immediate or early thallium-201 perfusion study with a large ( > or = 2 mm) angiographic luminal dimension stratified a group of patients with better long-term results after angioplasty and a lower incidence of late restenosis (p = 0.03). The findings emphasize the importance of the initial procedure as a determinant of the late result of angioplasty.

Strategy of diagnostic imaging before and after PTCA

It is now widely accepted that percutaneous transluminal coronary angioplasty (PTCA) is an effective nonsurgical technique for achieving coronary revascularization. Exercise electrocardiography remains the standard procedure for functional evaluation before, early, and late after angioplasty because of its availability, safety, and limited cost. The drawback of exercise testing is its low specificity and the fact that the attainment of diagnostically useful data requires a level of exercise that substantially increases myocardial oxygen demand. Exercise thallium imaging has been shown to be highly predictive of restenosis and adverse events after angioplasty, but it is possible that myocardial perfusion may not return to normal immediately after successful revascularization. Stress echocardiography has many practical advantages over scanning tests, as result of its lower cost, shorter imaging time, and the absence of radiation exposure. Dipyridamole echocardiography testing (DET) is an exercise-independent method of evaluating patients who have to undergo coronary angioplasty. Before PTCA, DET allows the clinician to localize the site and extent of myocardial ischemia anatomically. Early after a successful procedure, DET identifies a group at high risk for the late recurrence of symptoms. Late after PTCA, DET is more accurate than exercise electrocardiography in detecting restenosis or disease progression. In asymptomatic patients with exercise-induced ST depression, DET has the same good diagnostic accuracy as thallium scintigraphy. For these reasons, as well as because of its noninvasive nature and availability, DET should be considered an attractive option for the evaluation of patients after anatomically successful angioplasty.

Usefulness of dobutamine echocardiography for detecting restenosis after percutaneous transluminal coronary angioplasty

To determine the usefulness of dobutamine stress echocardiography for detecting restenosis after percutaneous transluminal coronary angioplasty, the results of coronary arteriography and dobutamine stress echocardiography were compared in 103 patients 6 months after percutaneous transluminal coronary angiography. The dobutamine stress echocardiograms were obtained on the same day as the coronary arteriograms, which were analyzed by both quantitative and visual estimates of luminal narrowing. The angiographic restenosis rate was 44% by quantitative and 31% by visual estimates of stenosis. Dobutamine stress echocardiography was abnormal in 38% of previously dilated regions with restenosis and normal in 79% of previously dilated regions without restenosis by quantitative coronary angiography. Dobutamine stress echocardiography was concordant in 69% of 16 patients with multivessel disease compared with 40% of 41 patients with 1-vessel disease (p < 0.05). By quantitative coronary angiography, 64% of patients with significant disease in the left anterior descending artery were identified by dobutamine stress echocardiography compared to 12 and 24% of patients with disease in the left circumflex and right coronary arteries, respectively (p < 0.009). Concordance was seen in 79% of patients with baseline wall motion abnormalities compared with 54% of patients without baseline wall motion abnormalities. Dobutamine stress echocardiography has a low sensitivity but high specificity for detecting restenosis after coronary angioplasty, which may be explained in part by the high prevalence of 1-vessel disease in this patient population. The variables associated with significantly higher degrees of concordance were the presence of left anterior descending artery disease, multivessel disease, and baseline wall motion abnormalities.

Restenosis after coronary angioplasty

Coronary angioplasty is used to treat coronary disease in many patients. Indications for angioplasty have expanded since it was first performed, mainly as a result of improvement in equipment and techniques. One problem with coronary angioplasty is the phenomenon of renarrowing of the treated coronary lesion, a process called restenosis. The events that constitute restenosis appear to be a universal response to the arterial wall injury of angioplasty. They are currently characterized as follows: platelet adhesion and aggregation on the damaged endothelium and within deep splits into the tunica media; release of platelet-derived growth factors; inflammation of the mechanically injured medial zone; transformation of smooth muscle cells of the tunica media after their activation by several of the growth-promoting substances; migration and proliferation of transformed smooth muscle cells, with secretion of copious amounts of extracellular matrix material; and, finally, termination of the growth process with regrowth of endothelium over the injured area. A decade of research work has helped identify clinical correlates of restenosis after coronary angioplasty procedures. This work is hindered by lack of a uniform angiographic definition of restenosis. In addition, much of the information has come from small studies, with incomplete follow-up and retrospective orientation. Nevertheless, some data are available. Patient-related correlates include male gender, unstable angina, diabetes, and continued smoking after angioplasty. Lesion-related correlates include multilesional and multivessel procedures, higher postangioplasty residual stenosis, proximal vessel location, location in the left anterior descending artery, location in a vein graft, long lesions, and total occlusions. The only consistent procedure-related correlate has been incorrect sizing of the angioplasty balloon to the treated artery. For the purposes of individual patient care, clinical correlates are not helpful. No group of variables has been found to be associated with complete freedom from restenosis, and no group is completely predictive of restenosis. All patients undergoing angioplasty procedures require some follow-up through subsequent months and years. Symptom status and the results of noninvasive studies have been investigated for purposes of follow-up. Symptoms are virtually useless by themselves for predicting restenosis or its absence. When symptom status is combined with exercise thallium 201 scintigraphy performed 4 to 6 months after an angioplasty procedure, the two factors are less than ideal but have a negative predictive value of more than 90%. This means that more than 90% of patients who have neither symptoms nor evidence of ischemia by thallium 201 scintigraphy will not have angiographic restenosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Restenosis after coronary angioplasty

Coronary angioplasty is used to treat coronary atherosclerotic disease in many patients. One problem with coronary angioplasty is the phenomenon of restenosis. Restenosis appears to be a universal response to arterial wall injury. The biological events that underlie restenosis are characterized by: platelet adhesion and aggregation at sites of damaged endothelium, and within dissections into the medial layers, release of platelet derived growth-promoting substances, inflammation of the injured medial zone, transformation, migration, and proliferation of smooth muscle cells of the media following their activation by growth-promoting substances, secretion of copious amounts of extracellular matrix material, and finally, termination of the growth process following regrowth of endothelium over the damaged area. More than a decade of research work has helped identify clinical correlates of restenosis after coronary angioplasty. Patient-related correlates include male gender, unstable angina, diabetes, and continued smoking after angioplasty. Lesion-related correlates include multilesion and multivessel procedures, higher post-angioplasty residual stenosis, proximal vessel location, location in the left anterior descending coronary artery, location in a vein graft, long lesions, and total occlusions. However, for the purposes of individual patient care, clinical correlates are not particularly helpful. No group of variables has predicted complete freedom from restenosis, and conversely no group of variables has reliably indicated its presence. All patients undergoing angioplasty will require some form of follow-up evaluation. Symptom status by itself has not been found to be useful for predicting restenosis. However, when symptom status is combined with exercise thallium-201 scintigraphy, performed 4-6 months after angioplasty, it is less than ideal, but has a negative predictive value of over 90%. This means that over 90% of patients who are asymptomatic and have no evidence of ischemia by thallium-201 scintigraphy, will not have angiographic restenosis. Numerous clinical trials have been performed in order to reduce or prevent restenosis. Almost all have been disappointing, while a few have been encouraging. Studies of antiplatelet agents such as aspirin, dipyridamole (Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, USA), and Ticlopidine (Syntex, Humgcao, Puerto Rico) have not shown efficacy, yet studies of an inhibitor of platelet-derived growth factor have been provocatively encouraging. No reduction in restenosis rates was found with the anticoagulants Coumadin (Du Pont Pharmaceuticals, Wilmington, DE, USA) and Heparin (Wyeth-Ayerst, Philadelphia, PA, USA). Fish oils (omega fatty acids) have been found in several clinical trials to provide modest, but encouraging, reductions in restenosis, but await further confirmation.(ABSTRACT TRUNCATED AT 400 WORDS)

Early decrease in minimal luminal diameter after successful percutaneous transluminal coronary angioplasty predicts late restenosis

Eighty-eight patients underwent serial coronary arteriography before, immediately after, 24 hours after and 7 +/- 2 months after successful percutaneous transluminal coronary angioplasty (PTCA) of 102 lesions. Severity of coronary obstruction was measured using quantitative digital angiography. Three groups of lesions were defined when comparing angiograms recorded immediately after and 24 hours after PTCA: group I--lesions with either no change or < or = 10% increase in arterial diameter stenosis after PTCA (n = 71); group II--lesions with > 10% increase in diameter stenosis after PTCA (n = 19); and group III--patients with total occlusion (n = 12). There were no significant differences in the severity of stenosis before or immediately after PTCA among the 3 groups of lesions. Twenty-four hours after PTCA the diameter stenosis was 14.2 +/- 6.3% in group I, 34.7 +/- 8.1% in group II and 100 in group III (p < 0.0001). At 7.1 +/- 2 months after PTCA the diameter stenosis was 21.2 +/- 16.8% in group I, 61.3 +/- 1.1% in group II, and 98.5 +/- 1.3% in group III (p < 0.0001). Restenosis (> or = 50% stenosis diameter) at follow-up per lesion was significantly greater in group II than in group I (73.6 vs 9.8%) (p < 0.0001). Thus, early angiographic study after successful PTCA stratifies lesions into angiographic subsets with low (group I) and high (group II) risk of coronary restenosis.

Exercise echocardiography for the evaluation of patients after nonsurgical coronary artery revascularization

OBJECTIVES

The purpose of this study was to demonstrate the accuracy of stress echocardiography for detecting the progression of coronary artery disease after nonsurgical revascularization.

BACKGROUND

The expanding role of nonsurgical coronary revascularization procedures mandates the development of sensitive noninvasive techniques for the detection of recurrent ischemia.

METHODS

Bicycle stress echocardiography was performed in a series of 86 patients 6.5 +/- 1.3 months after a revascularization procedure. Seven patients were excluded from analysis because of poor echocardiographic image quality.

RESULTS

Digital analysis achieved a sensitivity of 83% for the entire group and a specificity of 85% for stress echocardiographic detection of significant coronary artery disease. Sensitivity was greater in patients with (88%) than in those without (75%) prior myocardial infarction, but this difference did not reach statistical significance. Additional analysis using an increase in end-systolic volume index or a decrease in ejection fraction during stress as an additional marker for ischemia tended to enhance sensitivity (90% for the entire group and 93% for the subgroup with prior myocardial infarction).

CONCLUSIONS

Stress echocardiography is a useful and sensitive method for the follow-up of patients undergoing nonsurgical revascularization procedures. The addition of volume determination to routine wall motion analysis may be helpful in patients with prior infarction who have scar tissue that may be difficult to distinguish from an adjacent exercise-induced wall motion abnormality.

The role of scintigraphic techniques in the evaluation of functional results of coronary bypass grafting and percutaneous transluminal coronary angioplasty

Scintigraphic techniques can be used first, to guide appropriate referral for interventional procedures, and second to predict the effect of revascularization on regional perfusion and function prior to the intervention, thereby being able to assess efficacy of revascularization and to assess whether ischemia is the origin of recurrence of symptoms. Of increasing importance is the ability of nuclear techniques to identify those myocardial regions with abnormal function which might benefit from revascularization by showing improvement in regional wall motion. Positron emission tomography is considered to be the gold standard to assess regional myocardial perfusion and metabolism. The introduction of the reinjection technique makes 201Tl-scintigraphy the method of choice to detect jeopardized myocardium and to guide appropriate referral for revascularization procedures in those institutes where PET is not available. Even when the costly PET-instrumentation is available, cost-benefit analysis is indicated to assess the additional value of PET compared with 201Tl reinjection imaging.

Indications for routine heart-catheterization after CABG and PTCA

Routine heart-catheterization after Coronary Artery Bypass Graft surgery (CABG) or Percutaneous Transluminal Coronary Angioplasty (PTCA) has been advocated to determine the change in bypass graft or dilated coronary artery and native coronary artery status, the effective disease remaining after CABG or PTCA and the relation between progression of disease, left ventricular function and symptomatology. Results of angiographic follow-up data after CABG and PTCA are presented and the practical implications are discussed. The reliability of symptoms, invasive and non-invasive test for the detection of ischemia are considered. Finally, recommendations are made for the indication of routine heart-catheterization after CABG and PTCA.

Detection of restenosis with dobutamine stress test after coronary angioplasty

Dobutamine ECG tests were serially performed before, at 15 days, and at 2 and 6 months after successful coronary angioplasty in 58 patients. The dose of dobutamine was progressively increased from 5 micrograms/kg/min to a maximum of 40 micrograms/kg/min every 5 minutes, with ECG and blood pressure control. Coronary angiography was performed at the end of the study. At 15 days after coronary angioplasty, the dobutamine test was of little value for the diagnosis or prediction of restenosis. At the end of the study, both the presence of angina and the results of the dobutamine test were related to coronary angiography, and their accuracy was calculated for the detection of mild (> or = 50%) and severe (> or = 70%) restenosis or new coronary lesions. The accuracy of angina was 68% for the detection of mild lesions and 70% for that of severe lesions, whereas the accuracy of the dobutamine test was 78% for mild lesions and 80% for severe lesions. It is concluded that the dobutamine stress test is a simple and useful method for the detection of restenosis when it is performed at 2 and 6 months after coronary angioplasty. However, it cannot distinguish between restenosis or new coronary lesions.

Safety and clinical use of exercise testing one to three days after percutaneous transluminal coronary angioplasty

To evaluate both the safety and clinical use of predischarge symptom-limited exercise testing after successful uncomplicated percutaneous transluminal coronary angioplasty (PTCA), 100 patients were randomized to undergo exercise testing (n = 50) or no exercise testing (n = 50). There were no differences in clinical or angiographic characteristics between the groups. Exercise testing was performed 38 +/- 14 hours after PTCA. Patients who exercised achieved 71 +/- 12% of predicted maximal heart rate, with 38% reaching greater than or equal to stage III of the Bruce protocol. No patient in either group developed cardiac complications during 48-hour follow-up. Of the 11 patients with a positive test result, 92% had angiographically incomplete revascularization. Attending physicians (n = 16) were questioned both before and after exercise testing about when, after discharge, they would allow their patient to perform each of 11 specific activities of daily living. Questionnaires were administered to physicians at similar time frames for patients in the no-exercise group. Comparison of the responses between initial and repeat questionnaires showed that patients in the exercise group (with a test result negative for ischemia) were allowed to perform 7 of 11 activities, including return to work, earlier (p less than 0.05) than the no-exercise patients. These data indicate that in this well-defined group of patients, symptom-limited exercise testing early after PTCA appears to be safe, and alters physician management in allowing patients with a negative test result to return to various activities at an earlier date. Such testing may be useful in counseling patients after PTCA.

Single photon emission tomography imaging of myocardial oxidative metabolism with 15-(p-[123I]iodophenyl) pentadecanoic acid in patients with coronary artery disease and aorto-coronary bypass graft surgery

A total of 29 patients with coronary artery disease (CAD) were investigated with 15-(p-[123I] iodophenyl)pentadecanoic acid (123I-IPPA) and sequential single photon emission tomography (SPET). Of these, 19 were studied after aorto-coronary bypass graft surgery. Some 13 patients without evidence of CAD served as a control group. Two SPET studies (early and late) were carried out within 45 min after intravenous administration of 200 MBq 123I-IPPA at peak sub-maximal exercise. Semi-quantification of uptake (related to perfusion) and turnover (linked to metabolism) was obtained by segmental comparison of oblique slices. Taking coronary arteriography as the "gold standard", 123I-IPPA scintigraphy had the following figures of merit for sensitivity and specificity in the diagnosis of CAD: for the left anterior descending artery territory 93% and 95%, for the left circumflex artery region 96% and 92%, and for the right coronary artery territory 77% and 92%, respectively. In all, 90% of the reperfused myocardial segments showed an improvement of uptake. Of these, 61% exhibited increased turnover after revascularization and 39% had pathologic turnover and thus a dissociation of improvement of perfusion and oxidative metabolism after surgery.

Coronary restenosis: what have we learned from angiography?

Coronary restenosis remains a major problem for interventional cardiology not only by virtue of its frequency, but also because of the current inability to prevent it. Symptomatic status and non-invasive evaluation have been used to study restenosis, but both lack specificity and sensitivity, particularly in patients with multivessel disease. Angiography remains the reference standard. Several arbitrary definitions have been used, some related to visual estimates of coronary stenosis and others to quantitative angiographic techniques. In another approach, linear modeling is used to assess minimal luminal diameter of lesions on restudy. Although angiographic studies have been essential in the study of restenosis, questions concerning the underlying mechanism and pathophysiology remain. The development of animal models that closely resemble human restenosis should allow evaluation of pathophysiologic mechanisms and development of new strategies to prevent the problem.

Restenosis after coronary angioplasty: an overview

Despite substantial basic and clinical efforts to address the problem of restenosis after percutaneous coronary intervention, effective preventive therapies have not yet been developed. Nevertheless, the accumulated information has provided much insight into the process of restenosis in addition to allowing standards to be developed for adequate clinical trials. The pathophysiology of restenosis increasingly appears to be distinct from that of primary atherosclerosis. Restenosis involves elastic recoil, incorporation of thrombus into the lesion and fibrocellular proliferation in varying degrees in different patients. Lack of an animal model that satisfactorily mimics restenosis is a major impediment to further understanding of the process. Clinical studies are hampered by difficulties in finding a single unifying definition of restenosis and by variable methods of reporting follow-up. Reporting of clinical outcomes of all patients in angiographic substudies would allow a more satisfactory interpretation of the results of clinical trials. Current noninvasive test results are not accurate enough to substitute for angiographic and clinical outcome data in intervention trials. In the majority of observational studies, only diabetes and unstable angina have emerged as consistently associated with restenosis; whereas most of the standard risk factors for atherosclerosis have a less consistent relation. Disappointingly, the new atherectomy and laser technologies have not affected restenosis rates. The one possible exception is coronary stenting, as a result of the larger luminal diameter achieved by the placement of the stent. In conclusion, although substantial continued effort is necessary to explore the basic aspects of cellular proliferation and mechanical alteration of atherosclerotic vessels, attention to the principles of clinical trials and observation are required to detect the impact of risk factors and interventions on the multifactorial problem of restenosis. Adequate sample sizes, collection of clinical and angiographic outcomes and factorial study designs hold promise for unraveling this important limitation of percutaneous intervention.

EPA in the prevention of restenosis post PTCA

The effect of fish oil on restenosis was evaluated in patients undergoing coronary balloon angioplasty. In addition to routine pharmacotherapy, subjects were given 2.8 g of eicosapentanoic acid (EPA) daily. Treatment was started within twenty-four hours after successful percutaneous transluminal coronary angioplasty (PTCA). After six months of therapy, participants were subjected to coronary arteriography, exercise scintigraphy, exercise electrocardiography, or clinical evaluation. Follow-up evaluation involved 97 coronary lesions in 85 patients. Partial or significant restenosis occurred in 36.5% of patients and 33% of vessels. The presence of severe stenosis before PTCA, dissection, thrombus, multilesion PTCA, and template bleeding time values were not correlated with restenosis. Dilation of the left anterior descending (LAD) and a residual stenosis greater than or equal to 35% were associated with restenosis. Approximately 20% of the patients related difficulty in taking the fish oil. Furthermore, these results show no advantage over expected restenosis rates.

A new manifestation and treatment alternative for heparin-induced thrombosis

We treated a coronary artery bypass patient whose postoperative course was complicated by heparin-induced thrombocytopenia and resultant pulmonary artery and saphenous vein graft thromboses. The pulmonary thromboemboli were found first, and pulmonary blood flow was restored with intravenously administered tissue plasminogen activator (tPA). A short time later, the vein grafts were found to be occluded, and we subsequently performed multivessel percutaneous transluminal coronary angioplasty (PTCA) using tPA as an adjuvant to oral warfarin sodium therapy with excellent results. We conclude that heparin-induced thromboses in the pulmonary arteries are amenable to thrombolytic therapy, including tPA, whereas this regimen appears to have little effect on saphenous vein grafts. We also found that a combination of warfarin and thrombolytic therapy is an alternative regimen for heparin-intolerant patients who require PTCA.

Predicting late restenosis after coronary angioplasty by very early (12 to 24 h) thallium-201 scintigraphy: implications with regard to mechanisms of late coronary restenosis

To examine whether late coronary restenosis may be predicted by abnormalities of myocardial perfusion in the early hours after successful percutaneous transluminal coronary angioplasty and to study in greater detail the mechanisms involved in the development of late coronary restenosis after angioplasty, a prospective study was undertaken in 90 consecutive patients. Thallium-201 scintigrams were recorded at rest and during the stress of atrial pacing, 12 to 24 h after angioplasty, and the results were related to the findings at angiography in 70 patients undergoing late cardiac catheterization. A reversible thallium-201 perfusion defect was found in 39 (38%) of 104 myocardial regions supplied by the dilated coronary vessel and identified a subset of patients at high risk of late (6 to 12 months) angiographic restenosis (sensitivity 77%, specificity 67%). In contrast, late coronary restenosis developed in only 7 (11%) of 65 vessels and in 5 (14%) of 37 patients with a nonischemic thallium-201 scintigram on day 1 (p less than 0.005). Multivariate logistic regression analysis of 14 possible preangioplasty and periangioplasty clinical and angiographic variables selected reversible perfusion defect on the thallium-201 scintigram on day 1 (p = 0.016) and immediate postangioplasty residual coronary narrowing (p = 0.004) as significant independent predictors of late restenosis, with younger patient age as an additional less powerful predictor (p less than 0.05). The findings have important implications regarding the pathogenesis of late coronary restenosis in patients undergoing successful angioplasty and they imply that in the majority of these patients pathophysiologic events in the early minutes and hours after angioplasty may determine the development of late restenosis.

Prognostic significance of silent myocardial ischemia detected by early treadmill exercise after coronary angioplasty

Three hundred ninety patients who had successful coronary angioplasty were studied by treadmill exercise testing to determine the incidence and prognostic importance of silent and symptomatic myocardial ischemia in this patient subset. All patients were followed for an average of 11 months. During exercise, 81 patients (20%) had abnormal exercise-induced ST-segment depression without chest pain (group 1). Twenty patients (5%) had chest pain without ST changes (group 2). Twenty-one patients (5%) had both exercise-induced chest pain and ST-T-segment depression (group 3) and 268 patients (70%) had a normal exercise test with no chest pain (group 4). The groups were similar with respect to age, sex, history of previous myocardial infarct and previous coronary bypass surgery. Group 4 included more patients with complete revascularization. Mutually exclusive cardiac events were defined as cardiac death, nonfatal myocardial infarction, class III angina and additional revascularization (coronary angioplasty, coronary artery bypass surgery). The cardiac event rate in groups 1, 2 and 3 were significantly higher than in group 4 (40, 45 and 43 vs 22%; p = 0.001). There were 4 cardiac deaths and 4 nonfatal myocardial infarctions in group 1 compared to 2 cardiac deaths and 3 nonfatal myocardial infarctions in group 4 (p = 0.03 and 0.05, respectively). The event rates in groups 1, 2 and 3 patients with multivessel disease were significantly greater than in group 4 (44, 60 and 47 vs 22%; p = 0.002). Thus, exercise-induced myocardial ischemic episodes, both symptomatic and silent, early after coronary angioplasty are predictive of an unfavorable prognosis and serious cardiac events, particularly in patients with multivessel disease and incomplete revascularization.

The effects of successful PTCA on left ventricular function: assessment by exercise echocardiography

To assess the usefulness of exercise echocardiography in the follow-up of patients after percutaneous transluminal coronary angioplasty (PTCA), we studied 56 patients at rest and immediately following exercise with two-dimensional echocardiography. Sixty-nine of 73 stress/echo studies (94%) were suitable for interpretation. Seventeen patients (group I) with significant coronary artery disease (CAD) were studied before and after PTCA. Sixteen patients with coronary disease not undergoing PTCA (group II) and 23 individuals without significant coronary disease (group III) served as age-matched controls. Left ventricular ejection fraction did not change significantly in group I patients prior to PTCA (56 +/- 7 versus 54 +/- 12, p = ns) or in group II patients (52 +/- 10 versus 56 +/- 15, p = ns), rest versus immediate after exercise measurements. Following angioplasty, left ventricular ejection fraction increased in group I patients from 55 +/- 7 to 65 +/- 8, p less than 0.001 from rest to exercise, and to a similar extent in group III individuals (55 +/- 6 to 66 +/- 8, p less than 0.001). Electrocardiographic (ECG) evidence of ischemia (greater than 1 mm ST segment depression) was found in 13 of 17 group I patients prior to PTCA and in 8 of 16 group II patients (CAD). None of the 25 normal patients and four of the group I patients following PTCA had abnormal ECG changes with exercise. New exercise-induced echocardiographic wall motion abnormalities were found in 12 of 17 group I patients prior to PTCA and in none of the group I patients following PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic value of early exercise stress testing after successful coronary angioplasty: importance of the degree of revascularization

The prognostic value of early exercise testing after successful coronary angioplasty was determined in 196 and 225 consecutive patients with single-vessel and multivessel coronary disease, respectively, who underwent a symptom-limited exercise test within 30 days of the procedure. The incidence of exercise-induced ST segment depression greater than or equal to 1 mm was significantly greater in patients with multivessel versus single-vessel disease (27% versus 14%; p less than 0.005) and in patients with multivessel coronary disease who had incomplete versus complete revascularization (36% versus 10%; p less than 0.001). An abnormal exercise ECG result was associated with a significantly increased risk of cardiac events in patients with multivessel disease but not in patients with single-vessel disease. Exercise-induced angina occurred in a small and similar proportion of patients with single and multivessel coronary disease (8% versus 12%). The presence of exercise-induced angina was associated with a higher incidence of follow-up cardiac events in patients with multivessel disease and incomplete revascularization (52% versus 33%; p less than 0.05). Exercise duration was significantly less in patients with multivessel disease who had a subsequent cardiac event compared with that in patients who did not have such an event (458 +/- 168 versus 519 +/- 156 seconds; p = 0.01). Thus an abnormal exercise ECG finding within 1 month of successful coronary angioplasty is predictive of subsequent cardiac events in patients who have multivessel disease. The prognostic content of the test might be further improved if the test were performed several months after the procedure when the risk of restenosis is greatest.

Stress thallium-201 imaging after coronary angioplasty predicts restenosis and recurrent symptoms

The predictive accuracy of thallium imaging for the diagnosis of restenosis after angioplasty was evaluated in 121 patients who had undergone a successful procedure. Patients were evaluated three times over a 1 year follow-up period for symptoms, electrocardiographic (ECG) changes during exercise and the presence of reversible ischemia on exercise thallium imaging. At initial evaluation (4 to 6 weeks after angioplasty), 104 patients (86%) were asymptomatic. Of the 17 patients with chest pain symptoms, 9 had reversible ischemia on thallium imaging and all had restenosis. Of the 104 asymptomatic patients, 26 (25%) had a positive thallium scan (reversible ischemia) and this sign identified a high risk group. Evidence of restenosis was present by 6 months in 22 (85%) and by 1 year in 25 (96%) of these 26 patients. The largest group of patients manifested symptoms by the second evaluation (between 3 and 6 months after angioplasty). Of 28 patients with symptoms and a positive thallium scan at this evaluation, 26 had restenosis; on initial evaluation, 22 of these 26 patients had no symptoms but had had a positive thallium study. Ten of the 65 patients in the asymptomatic group had a positive thallium scan, but the scans of this group were not as predictive for recurrent symptoms as were those of the same group at initial evaluation. The 74 patients who had a negative thallium scan at 3 to 6 months with or without associated symptoms had a low likelihood of developing restenosis or symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)