Quantitative exercise thallium-201 scintigraphy for predicting angina recurrence after percutaneous transluminal coronary angioplasty

The aim of this prospective study was to determine the value of quantitative exercise thallium-201 scintigraphy for predicting short-term outcome in patients after percutaneous transluminal coronary angioplasty (PTCA). Quantitative exercise thallium-201 scintigraphy was performed 2.2 +/- 1.2 weeks after successful PTCA in 68 asymptomatic patients, 64 (94%) of whom had class III or IV angina before the procedure. Clinical follow-up was obtained in all patients at a mean of 10 +/- 2 months and all were followed for at least 6 months; 45 patients (66%) remained asymptomatic during follow-up and 23 (34%) developed recurrent class III or IV angina at a mean of 2.6 +/- 1.2 months. Multivariate analysis of 22 clinical, angiographic and exercise test variables revealed that thallium-201 redistribution, any thallium scan abnormality, presence of a distal stenosis and treadmill time were the only significant predictors of recurrent angina after PTCA. Using a stepwise discriminant function model, thallium-201 redistribution was the only significant independent predictor. Despite its prognostic value relative to other variables as a predictor, thallium redistribution at 2 weeks after PTCA was only detected in 9 of the 23 patients (39%) who subsequently developed recurrent angina, although only 2 of the 45 patients (9%) who remained asymptomatic during follow-up demonstrated thallium-201 redistribution at the time of early testing. After repeat angiography was performed in 17 of the 23 patients with recurrent angina, 14 (82%) demonstrated restenosis and 3 (18%) had worse narrowing distal to or remote from the site of dilatation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Usefulness of tomographic thallium-201 imaging for detection of restenosis after percutaneous transluminal coronary angioplasty

The role of tomographic thallium-201 exercise and redistribution imaging in the detection of restenosis after percutaneous transluminal coronary angioplasty (PTCA) was evaluated in 116 patients: 61 (53%) with 1- and 55 (47%) with multivessel PTCA, with a total of 185 dilated vessels. Complete revascularization was performed in 89 (77%) and partial revascularization in 27 (23%) of the patients. Restenosis was angiographically demonstrated in 69 (60%) of the patients and 85 (46%) of the vessels 6.4 +/- 3.1 months after PTCA. Disease progression in previously normal vessels was noted in 11 patients. The results were: (1) for detection of restenosis in the group of patients, single-photon emission computed tomographic (SPECT) versus exercise electrocardiographic sensitivity was 93 vs 52% (p less than 0.001), specificity 77 vs 64%, and accuracy 86 vs 57% (p less than 0.001). The results were similar in the complete and partial revascularization groups. (2) SPECT was 86% sensitive, specific and accurate for restenosis detection in specific vessels with comparable results for 1-versus multivessel PTCA and complete versus partial revascularization. Sensitivity, specificity and accuracy were: 89, 95 and 92% for the left anterior descending coronary artery; 88, 79 and 82% for the right coronary artery; and 76, 83 and 85% for the left circumflex coronary artery. Eighty-one percent of the diseased nondilated vessels were correctly identified. (3) Disease progression to greater than 50% stenosis was detected with 91% sensitivity, 84% specificity and 85% accuracy. SPECT thallium-201 imaging is an excellent tool for the detection of restenosis and disease progression after PTCA in the settings of 1- and multivessel angioplasty and complete and partial revascularization.     

Quantitative evaluation of exercise T1-201 myocardial scintigraphy before and after transluminal coronary angioplasty. A preliminary report

Quantitative evaluation of exercise T1-201 myocardial scintigraphy was carried out to determine the effect of transluminal coronary angioplasty (TCA) in 15 patients with critical coronary artery stenoses (greater than or equal to 70%). Thirteen lesions were successfully dilated (reduction in stenosis by more than 30%); two were unsuccessful. Calculated indices from T1-201 myocardial scintigraphy, using a semi-automatic computer image processing system, included washout factor (WF), vitality index (VI) and redistribution factor (RDF). No changes were noted in WF before and after dilatation. The VI increased in successfully dilated patients from 66.3 +/- 8.5% (mean +/- SD) to 77.8 +/- 10.9% (p less than 0.001) in the areas perfused by the vessels containing the lesions. The RDF decreased significantly after dilatation from 4.4 +/- 6.1% to 1.2 +/- 2.8% (p less than 0.05) 1 hour after exercise and from 10.4 +/- 7.5% to 4.1 +/- 4.2% (p less than 0.01) 3-4 hours after exercise. From these results, we conclude that the perfusion of ischemic areas distal to critical coronary artery stenoses improves following successful dilatation. T1-201 myocardial scintigraphy was shown to be very useful in the evaluation of TCA.     

Detection of coronary restenosis by exercise electrocardiography thallium-201 perfusion imaging and coronary angiography in asymptomatic patients after percutaneous transluminal coronary angioplasty

Noninvasive detection of restenosis in patients remaining asymptomatic after percutaneous transluminal coronary angioplasty (PTCA) remains a major clinical problem. The value of exercise electrocardiography (ECG) and exercise-redistribution thallium-201 single-photon emission computed tomography (SPECT) in detecting restenosis in such patients remains uncertain. Discordances between these tests and coronary angiography is a common situation. We studied 179 consecutive patients remaining asymptomatic after successful PTCA (208 vessels), who underwent 6 +/- 2 months of exercise ECG, SPECT, and coronary angiography. We sought to assess the diagnostic value of the noninvasive tests compared with coronary angiography, and identify the determinants of discordances between the tests. Restenosis (diameter stenosis >50%) was detected in 39% of patients and in 37% of vessels. The overall sensitivity, specificity, and accuracy for exercise ECG and SPECT in detecting restenosis in individual vessels were, respectively, 53% versus 63% (p = 0.06), 59% versus 77% (p = 0.0001), and 57% versus 72% (p = 0. 0001). On multivariate analysis, positive exercise ECG was associated with higher heart rate response (p = 0.02), incomplete revascularization (p = 0.004), and angiographic restenosis (p = 0. 03), whereas positive SPECT was associated with incomplete revascularization (p = 0.02), infarct-related artery PTCA (p = 0.01), and angiographic restenosis (p = 0.0001). Accuracies of the 2 tests were not significantly different in patients with incomplete revascularization or PTCA of an infarct-related vessel. Overall, SPECT is more accurate than exercise ECG in detecting asymptomatic restenosis. Nevertheless, incomplete revascularization and PTCA of an infarct-related artery could cause reversible perfusion defects regardless of restenosis, reducing the diagnostic value of SPECT in such patients.     

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, elertrocardiographic (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. By the 1 year evaluation, only five additional patients became symptomatic and four of those had previously been identified as having a positive thallium study. Nineteen patients continued to have chest pain symptoms with a negative thallium scan. Fifteen of these had repeat catheterization and only one had restenosis.In this clinical study, sequential thallium imaging provided an accurate prediction of which patients would develop restenosis and the time course it would follow. Thallium imaging identified high and low risk patients after angioplasty and was superior to symptoms or ECG changes in the evaluation of patients.     

Incomplete revascularization in multivessel percutaneous transluminal coronary angioplasty: the role for stress thallium-201 imaging

Evaluation of patients with multivessel coronary disease for percutaneous transluminal coronary angioplasty raises the question: Is incomplete revascularization an acceptable procedure in these patients, or does complete revascularization need to be performed, as in coronary artery bypass grafting? To provide an answer the present study utilized exercise thallium imaging as a guide to the performance of angioplasty in 85 patients with multivessel coronary disease. Preangioplasty exercise thallium imaging helped to identify the primary stenosis ("culprit lesion") in 93% of patients. Two weeks to 1 month after dilation of this lesion, repeat thallium imaging identified two patient groups: Group 1, 47 patients with no evidence of ischemia in a second vascular distribution and Group 2, 38 patients with evidence of further angioplasty. In Group 2 47% of patients had angioplasty of a second vessel and 79% required multivessel angioplasty at 1 year follow-up. In contrast, only six Group 1 patients (13%) required angioplasty of a second vessel at 1 year. Thus, incomplete revascularization may be an acceptable approach in many patients with multivessel coronary disease. Stress thallium-201 imaging may be a useful technique in the evaluation and management of these patients.     

Variability of quantitative digital subtraction coronary angiography before and after percutaneous transluminal coronary angioplasty

Quantitative coronary angiography has been proposed as a means of reducing observer variability in the interpretation of coronary angiograms, especially before and after percutaneous transluminal coronary angioplasty (PTCA). Analysis of 13 consecutively acquired biplane digital subtraction angiograms before and after PTCA was undertaken to determine intra- and interobserver variability of absolute lesion diameter, relative videodensitometric cross-sectional area, automated percent diameter stenosis and visual percent diameter stenosis using a new fully automated quantitative computer program. The reliability of single-view measurements was also assessed. Both before and after PTCA, measures of absolute diameter showed less interobserver variability than densitometry, percent automated diameter stenosis and percent visual diameter stenosis measurements (before, r = 0.95, 0.83, 0.86, 0.70; after, 0.95, 0.88, 0.81, 0.62, respectively). Relative videodensitometric cross-sectional area correlated poorly with images from the orthogonal view (r = 0.46). These data suggest that quantitative angiography reduces variability from visual estimates; of all quantitative angiographic measurements, the highest interobserver reproducibility is achieved using absolute lesion diameter both before and after PTCA, probably because no operator interaction is needed to identify a "normal" segment. Unselected, single-view quantitative arteriography is poorly reproducible using videodensitometry. Therefore, automated determination of absolute lesion diameter in at least 2 projections provides the most reproducible evaluation of coronary lesions both before and after PTCA.     

Quantitative angiographic assessment of elastic recoil after percutaneous transluminal coronary angioplasty

Little is known about the elastic behavior of the coronary vessel wall directly after percutaneous transluminal coronary angioplasty (PTCA). Minimal luminal cross-sectional areas of 151 successfully dilated lesions were studied in 136 patients during balloon inflation and directly after withdrawal of the balloon. The circumvent geometric assumptions about the shape of the stenosis after PTCA, a videodensitometric analysis technique was used for the assessment of vascular cross-sectional areas. Elastic recoil was defined as the difference between balloon cross-sectional area of the largest balloon used at the highest pressure and minimal luminal cross-sectional area after PTCA. Mean balloon cross-sectional area was 5.2 +/- 1.6 mm2 with a mean minimal cross-sectional area of 2.8 +/- 1.4 mm2 immediately after inflation. Oversizing of the balloon (balloon artery ratio greater than 1) led to more recoil (0.8 +/- 0.3 vs 0.6 +/- 0.3 mm, p less than 0.001), suggestive of an elastic phenomenon. A difference in recoil of the 3 main coronary branches was observed: left anterior descending artery 2.7 +/- 1.3 mm2, circumflex artery 2.3 +/- 1.2 mm2 and right coronary artery 1.9 +/- 1.5 mm2 (p less than 0.025). The difference was still statistically significant if adjusted for reference area. Thus, nearly 50% of the theoretically achievable cross-sectional area (i.e., balloon cross-sectional area) is lost shortly after balloon deflation.     

Assessment of percutaneous transluminal coronary angioplasty by atrial pacing and thallium-201 myocardial imaging: a case report

Combined atrial pacing and thallium-201 scintigraphy were performed in a man with multiple coronary artery lesions unable to perform exercise stress testing. Severe angina and ischemic ST depression in the inferior and anterior ECG leads occurred at a peak double product of 22,400 beats-mm Hg/min; thallium-201 scintigraphy showed reversible perfusion defects of the inferior, posterior, and septal segments. After angiographically successful angioplasty of a 95% right coronary artery lesion, repeat atrial pacing/thallium-201 scintigraphy (peak double product 27,750 beats-mm Hg/min) produced mild angina no ST depression in the inferior leads, and a normal thallium-201 scan. This case illustrates the value of the atrial pacing/thallium-201 stress test for evaluating the need for, and results of, coronary angioplasty in patients unable to perform exercise stress testing.     

Blood velocity measurements during selective coronary angiography before and after percutaneous transluminal coronary angioplasty

The velocity of blood flowing down a coronary artery may provide an index of myocardial perfusion, independent of the need for measuring the amount of myocardium supplied by a vessel. The velocity of the leading edge of contrast material was therefore measured before and after percutaneous transluminal coronary angioplasty in 15 patients utilizing digitized images from routine coronary angiography. The velocity (mean +/- SD) before percutaneous transluminal coronary angioplasty in the 15 patients was 11.9 +/- 6.0 cm/s, increasing to 21.7 +/- 8.7 cm/s after (P less than 0.01). There was a correlation between the percent change in velocity and the change in percent stenosis before and after percutaneous transluminal coronary angioplasty (r = 0.65; P less than 0.001). The mean absolute interobserver and intraobserver variabilities for the velocity measurements were 2.1 and 1.8 cm/s, respectively. Measurement of coronary flow velocity from data obtained at the time of routine coronary angiography is an easily performed reproducible technique, which may be used to assess the results of an intervention such as percutaneous transluminal coronary angioplasty.     

Sequential multivessel coronary angioplasty assessed by thallium-201 tomography

In 11 patients with multivessel coronary artery disease, SPECT thallium-201 imaging was performed prior to and within 3 days after each of two sequential percutaneous transluminal coronary angioplasties on separate days designed to achieve total revascularization. Thallium-201 SPECT was analyzed quantitatively, and an ischemic score for the vascular bed(s) supplied by the dilated vessel(s) was derived. For the vessels dilated during the first procedure the mean diameter stenosis was 80 +/- 8%, reduced to 27 +/- 9%. For the second procedure mean stenosis was reduced from 67 +/- 10% to 26 +/- 6%. For the two procedures, the mean thallium scores decreased from 298 +/- 225 to 115 +/- 130 (P less than .001) and from 135 +/- 129 to 46 +/- 60 (P less than .001), respectively. Of 10 patients with abnormal thallium-201 SPECT prior to angioplasty, nine improved after the first procedure, and seven improved further following the second procedure. Thus, utilizing staged angioplasty with a strategy of dilating the most severe lesion first, thallium-201 SPECT documented progressive improvement in myocardial perfusion.     

Long-term prognostic value of Duke treadmill score and exercise thallium-201 imaging performed one to three years after percutaneous transluminal coronary angioplasty

The value of exercise nuclear perfusion imaging performed beyond the 6-month restenosis window for percutaneous transluminal coronary angioplasty (PTCA) has not been explored. This study evaluates the long-term prognostic value of exercise thallium (Tl)-201 imaging after PTCA. We studied the late outcome of a series of 211 patients with tomographic Tl-201 exercise studies performed between 1 to 3 years after PTCA. Follow-up was 96% complete at a median duration of 7.3 years. Most (73%) had 1- or 2-vessel coronary artery disease and normal left ventricular function and 193 (91%) had successful PTCA. Two thirds of the patients were symptomatic at the time of testing. The mean Duke score was 5+/-6 and 125 (60%) patients had a low-risk Duke score. Mean summed stress score was 50+/-9 and mean summed reversibility score was 3+/-4. The 5-year overall survival was 95%, yielding a low annual mortality rate of 1%/year. The summed stress score exhibited a significant association (p = 0.047) with the end point of cardiac death or myocardial infarction. The Duke score was predictive of the combination end point of hard and soft cardiac events (p = 0.002). This study demonstrates that exercise Tl-201 perfusion imaging performed 1 to 3 years after PTCA was predictive of cardiac events.     

冠状动脉微血管病变铊-201负荷心肌洗脱率的变化

目的 :观察冠状动脉 (冠脉 )无明显狭窄 (<5 0 % )而冠脉血流储备异常患者的铊 2 0 1(2 0 1T1)负荷心肌洗脱率。方法 :随机测定 2 3例冠脉造影示冠脉正常或狭窄 <5 0 %患者不同冠脉的血流储备值 ,并根据冠脉血流储备 (CFR)分为 2组 :A组为CFR≥ 2 .5 (正常对照组 ) ,包括 34支冠脉 ;B组为CFR <2 .5 (冠脉微循环异常组 ) ,包括 16支冠脉。 2 3例受试者分别行2 0 1Tl潘生丁负荷心肌显像检查 ,处理出靶心图后 ,计算两组局部室壁洗脱率。洗脱率 =(负荷态放射性计数 -延迟态放射性计数 ) /负荷态放射性计数× 10 0 %。另根据心电图正常与否将上述患者分为两组 :组Ⅰ 12例 ,心电图完全正常 ;组Ⅱ 11例 ,平时心电图存在非特异性ST T改变 [成组导联的T低平或倒置和 (或 )ST压低≥ 0 .5mV]。比较两组的室壁洗脱率。结果 :A组的室壁洗脱率高于B组[(4 8.91± 7.75 ) %∶(36 .11± 6 .80 ) % ,P <0 .0 1];心电图有ST T改变的 11例受试者的相应 13段室壁洗脱率下降 ,为 (39.2 5± 7.86 ) % ,低于心电图完全正常的 12例受试者的 36段室壁洗脱率 [(4 9.5 6± 7.31) % ,P <0 .0 1]。结论 :CFR下降及心电图异常患者其心肌洗脱率相应下降     

Socio-professional rehabilitation after transluminal coronary angioplasty

Between April 1980 and October 1982, 109 patients underwent attempted transluminal coronary angioplasty (TCA) with a primary success rate of 71,6% (78 patients). Two patients died of complications of TCA and another one died suddenly 3 months after TCA. The socio-professional rehabilitation of the 106 survivors was studied by questionnaire to which 98 subjects (81 men, 17 women; average age 50,2 +/- 9,2 years) replied. Seventy seven patients were working before their coronary disease and 73 (62 men, 11 women; average age 46,4 +/- 9,1 years) replied to the questionnaire (95%). This constituted the study group, the socio-professional outcome or which was compared to that of 37 active patients who underwent single aorto-coronary bypass surgery during the same period. After TCA, 53 patients (73% returned to work, 48 as full time workers, after an average convalescent period of 4 months. Professional rehabilitation depended mainly on the initial result of TCA: 85% after primary success; 40% after failure (p less than 0,001); in the latter case, the rate of return to work improved if the patients had surgery (58%) rather than medical therapy (125%). Similarly, the average age of re-employed patients was lower (46,1 +/- 7,9 years, compared to 49,3 +/- 6,8 years, p less than 0,05). Finally, the patients returning to work usually claimed to be in good or very good health (72% compared to 30% p less than 001). After single aorto-coronary bypass, only 14 patients (38%) returned to work, 8 full-time, after an average 7 months' convalescence. The duration off work before surgery was related to the incidence of re-employment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anaerobic threshold and maximal oxygen uptake in patients with coronary artery disease and stable angina before and after percutaneous transluminal coronary angioplasty

In this study, we investigated the effect of percutaneous transluminal coronary angioplasty (PTCA) on functional exercise capacity, oxygen uptake at anaerobic threshold (VO(2 AT)) and maximal oxygen uptake (VO(2 max)) in patients with coronary artery disease (CAD). Twenty-five patients with CAD and stable angina pectoris underwent spiroergometry before and after PTCA. All patients had reduced functional capacity with Weber class B in 5, class C in 16 and class D in 4 patients with mean VO(2 AT) of 9.4 +/- 1.5 ml.kg(-1).min(-1) and mean VO(2 max) of 13.3 +/- 3.3 ml. kg(-1).min(-1). After PTCA, VO(2 max) (15.8 +/- 3.1 ml.kg(-1). min(-1)) increased significantly (p < 0.001) compared to before PTCA. Subgroup analysis revealed that patients with low functional capacity before PTCA (VO(2 max) <15 ml x kg(-1) x min(-1)) had the most benefit from PTCA with an increase in VO(2 AT) from 8.7 +/- 1.0 to 9.6 +/- 1.4 ml x kg(-1) x min(-1) (p < 0.05) and of VO(2 max) from 11.3 +/- 2.2 to 14.8 +/- 3.5 ml x kg(-1) x min(-1) (p < 0.001) whereas in patients with VO(2 max) >15 ml x kg(-1) x min(-1), VO(2 AT) (p = 0.9) and VO(2 max) (p = 0.2) did not improve significantly. In conclusion, there is reduced functional capacity and VO(2 max) which improved after PTCA in CAD patients. In patients with low VO(2 max) before PTCA, functional capacity, VO(2 AT) and VO(2 max) significantly improved after PTCA, suggesting reversible myocardial impairment induced by intermittent myocardial ischemia. Patients with higher VO(2 max) had no significant benefit from PTCA with respect to functional capacity, VO(2 max) and VO(2 AT).