Sustained efficacy of percutaneous transluminal coronary angioplasty

Non-polymer drug-eluting coronary stents

Cardiovascular complications are leading causes of most fatalities. Coronary artery disease and surgical failures contribute to the death of the majority of patients. Advanced research in the field of medical devices like stents has efficiently resolved these problems. Clinically, drug-eluting stents have proven their efficacy and safety compared to bare metal stents, which have problems of in-stent restenosis. However, drug-loaded stents coated with polymers have shown adverse effects related to the stability and deterioration of the polymer coating over time. This results in late stent thrombosis and immunogenicity. These reasons laid the foundation for the development of non-polymeric drug-eluting stents. This review focuses on non-polymer drug-eluting stents loaded with different drugs like anti-inflammatory agents, anti-thrombotic, anti-platelet agents, immune suppressants and others. Surface modification techniques on stents like crystalline coating; microporous, macroporous, and nanoporous coatings; and chemically modified self-assembled monolayers are described in detail. There is also an update on clinically approved products and those under development.

Therapeutic potential of target of rapamycin inhibitors

Target of rapamycin (TOR) functions within the cell as a transducer of information from various sources, including growth factors, energy sensors, and hypoxia sensors, as well as components of the cell regulating growth and division. Blocking TOR function mimics amino acid, and to some extent, growth factor deprivation and has a cytostatic effect on proliferating cells in vivo. Inhibition of TOR in vivo, utilising its namesake rapamycin, leads to immunosuppression. This property has been exploited successfully with the use of rapamycin and its derivatives as a therapeutic agent in the prevention of organ rejection after transplantation with relatively mild side effects when compared to other immunosuppressive agents. The cytostatic effect of TOR on vascular smooth muscle cell proliferation has also recently been exploited in the therapeutic application of rapamycin to drug eluting stents for angioplasty. These stents significantly reduce the amount of arterial reblockage that results from proliferating vascular smooth muscle cells. In cancer, the effect of blocking TOR function on tumour growth and disease progression is currently of major interest and is the basis for a number of ongoing clinical trials. However, different cell types and tumours respond differently to TOR inhibition, and TOR is clearly not cytostatic for all types of cancer cells in vitro or in vivo. As the molecular details of how TOR functions and the targets of TOR activity are further elucidated, tumour and tissue specific functions are being identified that implicate TOR in angiogenesis, apoptosis, and the reversal of some forms of cellular transformation. This review will describe our current understanding of TOR function, describe the current strategies for employing TOR inhibitors in clinical and preclinical development, and outline future strategies for appropriate targets of TOR inhibitors in the treatment of disease.

Drug-Eluting Stents

Advances in catheter and stent design have made stent implantation the standard coronary angioplasty procedure. Unfortunately, in-stent restenosis continues to plague this procedure, with the optimum binary restenosis rates reaching ~10% to 20%. In the past few years, it has become clear that in-stent restenosis is largely due to the migration and proliferation of vascular smooth muscle cells to form a neointima. To address this issue, stents coated with drug-delivery vehicles have been developed to deliver antiproliferative therapeutics. Two drugs, rapamycin and taxol, have been the lead compounds for testing the idea of a drug-eluting stent. These drugs have been successful largely because of the solid mechanistic understanding of their effects and extensive preclinical examination. The result of these years of work is that the rapamycin-coated stent entered the US market in April of 2003, and the taxol-coated stent appears poised to follow soon.

Physiologic response to gain and loss in coronary minimal luminal diameter in patients treated with coronary angioplasty: prediction of restenosis on the basis of exercise capacity

BACKGROUND

The effect of percutaneous transluminal coronary angioplasty (PTCA) on physiologic measurements has previously been shown, but the relation between physiologic response and degree of change in coronary luminal diameter is not known. We studied the relation between exercise capacity and minimal luminal diameter before and after PTCA. We also explored the usefulness of measurement of attenuation in exercise capacity after PTCA to predict the likelihood of restenosis.

METHODS

Bicycle exercise testing was performed 2 weeks before and 2 and 20 weeks after PTCA in 395 consecutively enrolled patients. Angiograms obtained before and after PTCA and 20 weeks afterward were analyzed by quantitative coronary angiography. Restenosis was defined as both angiographic (>/=50% diameter stenosis at follow-up angiography) and clinical (target-vessel revascularization), after successful PTCA. Exercise capacity was defined as the cumulative work performed divided by body weight (watt x minutes x kilograms(-1)).

RESULTS

Exercise capacity increased 43% (P <.0001) from before PTCA to 2 weeks after PTCA (early increase) and decreased 4% (P =.01) from 2 to 20 weeks after PTCA (late decrease). The gain in minimal luminal diameter (Minimal luminal diameter after - Minimal luminal diameter before) was 0.92 +/- 0.46 mm. The loss in minimal luminal diameter (Minimal luminal diameter after PTCA - Minimal luminal diameter at follow-up examination) was 0.27 +/- 0.42 mm. Exercise capacity and minimal luminal diameter measured before PTCA were positively correlated (coefficient 3.3; R = 0.12; P =.01). Gain in minimal luminal diameter correlated with the early increase in exercise capacity (coefficient -3.8; R = 0.23; P <.0001). Loss in minimal luminal diameter correlated with the late decrease in exercise capacity (coefficient 3.3; R = 0.20; P <.0001). Multivariate logistic regression analysis revealed that the late decrease in exercise capacity was independently predictive of both angiographically (odds ratio 1.13; P <.0001) and clinically (odds ratio 1.12; P <.0001) defined restenosis.

CONCLUSIONS

The results demonstrated a linear relation between the severity of coronary stenosis and exercise capacity measured before PTCA. The degree of coronary luminal enlargement achieved with angioplasty and the luminal reduction that occurred between PTCA and follow-up evaluation correlated with increases and decreases in exercise capacity. Attenuation in exercise capacity was found to be a strong predictor of restenosis.

Effect of percutaneous transluminal coronary angioplasty on exercise in patients with and without previous myocardial infarction

Improvement in exercise capacity is an important clinical effect of percutaneous transluminal coronary angioplasty (PTCA), and was assessed in patients with and without previous myocardial infarction (MI) undergoing PTCA. We prospectively followed patients with exercise testing before and 2 weeks after angioplasty in 415 patients, 170 (41%) of whom had a previous MI. A third exercise test was performed 20 +/- 2 weeks after PTCA in 403 patients. From left ventricular angiography obtained before PTCA, regional dyskinesia was classified into anterior or posterior locations. Both patients with and without previous MI had a significant increase in exercise capacity from before to 2 and 20 weeks after PTCA (previous MI: 31.9% and 29.3%; no MI: 50.7% and 38.2%; p <0.0001 [analysis of variance]). In patients with MI and anterior dyskinesia, in whom lesions on the left anterior descending artery were dilated or posterior dyskinesia in whom lesions on the right coronary artery were dilated, exercise capacity increased significantly from before to 2 and 20 weeks after PTCA (left anterior descending artery: 53.1% and 39.7%, p <0.0001; right coronary artery: 16.9% and 27.6%, p = 0.01 [analysis of variance]). Multivariate regression analysis revealed that male sex, no previous MI, and dilation of left anterior descending artery were significantly associated with increased exercise capacity after angioplasty adjusted for age and smoking habits, whereas left ventricular ejection fraction and end-diastolic pressure were not associated with increased exercise capacity.

Coronary risk factor status after percutaneous transluminal coronary angioplasty

OBJECTIVE

To determine whether patients modify their risk factors after undergoing percutaneous transluminal coronary angioplasty (PTCA).

DESIGN

One-group, pretest-posttest. Pretest data were collected on the day before PTCA, and posttest data were collected at a mean follow-up of 11 months after PTCA. Data were collected from medical records and by patient self-report.

SETTING

University-affiliated, metropolitan public and private hospitals.

PATIENTS

Two hundred nine patients undergoing PTCA.

OUTCOME MEASURES

Patients' smoking and exercise habits were assessed by self-report. Serum cholesterol level and body mass index were determined from entries in medical charts.

RESULTS

All measured risk factors, with the exception of smoking, underwent favorable change (p < 0.001) after PTCA. The number of current smokers, however, increased significantly (p < 0.001), as did the number of cigarettes these patients smoked per day (p < 0.05).

CONCLUSION

Evaluation of the effect of intervention strategies on reducing patients' smoking behavior after PTCA is required.

Percutaneous transluminal coronary angioplasty: clinical and quality of life outcomes one year later

BACKGROUND

The quality of life status of patients prior to and following percutaneous transluminal coronary angioplasty (PTCA) has not been comprehensively investigated.

AIM

This study was carried out to determine the effect that PTCA has on patients' quality of life.

METHODS

Data on 209 patients were collected one day pre-PTCA and at a mean of two and 11 months post-PTCA. Data on symptomatic status, functional capacity, life satisfaction and psychological well-being were analysed quantitatively. Clinical outcomes, patient perception of PTCA and employment status wee analysed by descriptive statistics.

RESULTS

Highly significant improvement in all quality of life measures was found at the early follow-up (p < .001). This improvement was sustained at the late follow-up. At the late follow-up, 58% of patients felt that PTCA had been very beneficial to their health and well-being, and 79% of workers had returned to work. PTCA was primarily successful in 91% of vessels dilated. There were no procedural-related deaths, 12 patients (6%) developed acute occlusion and three patients (1.5%) experienced myocardial infarction (MI). A symptomatic restenosis rate of 16% was found, including 19 patients (9%) requiring repeat PTCA and 14 (7%) undergoing coronary artery bypass grafting (CABG).

CONCLUSION

These findings suggest that, after PTCA, the majority of patients experienced improved quality of life which was sustained one year later.

Long-term follow-up after percutaneous transluminal coronary angioplasty in patients with single-vessel disease

Seven hundred ninety-eight patients with symptomatic single-vessel disease who underwent percutaneous transluminal coronary angioplasty (PTCA) between 1977 and 1985 were reevaluated by questionnaire 78 +/- 23 months after dilatation. Indication for PTCA was stenosis of > or = 70%, anginal symptoms, and objective signs of myocardial ischemia. The immediate success rate was 81.2%, and severe complications occurred in 7.1%, which included two fatal complications (0.3%). Repeat angiograms were performed in 582 of 648 patients who underwent successful dilatation and showed restenosis in 143 cases (24.6%). Within 1 year after the first dilatation, 586 patients had been successfully revascularized by PTCA (i.e., there was no evidence of restenosis or redilatation was successful), and 113 patients had undergone bypass surgery. The remaining 99 patients were treated medically if PTCA was unsuccessful or if restenosis (> or = 70%) that was not amenable to redilatation was present. The 8-year overall survival probability was 91.7%, and cardiac survival was 95.5%. The 8-year event-free survival probability was 52.7% for all patients: 62.5% in patients who had successful PTCA and 14.5% in patients who had unsuccessful PTCA (p = 0.0000). The cardiac survival probabilities of patients with lasting PTCA success at 1 year and of surgically treated patients were significantly better than those of patients who did not have successful revascularization (at 8 years 97.2% and 98.1% vs 88.9%; p < 0.04). Late events (> or = 1 year) occurred more often in patients who did not have successful revascularization compared with patients who had successful PTCA (at 8 years 57.9% were event-free vs 74.4%; p < 0.0001); even fewer late events were observed in surgically treated patients (at 8 years 88.2% were event-free; p < 0.004). Cox's proportional hazards regression analysis revealed left ventricular ejection fraction and revascularization status at 1 year as determinants of overall, cardiac, infarct-free, and event-free survival probabilities. At the time of reevaluation significantly more patients in the successful PTCA subgroup were still free of symptoms or had experienced improvement than patients in the bypass or medical subgroups (86.8% vs 68.9% and 59.5%, respectively; p < 0.0001), and more patients in the successful PTCA subgroup were still working (75.4% vs 53.3% and 56.9%, respectively; p < 0.001). We concluded that patients with single-vessel disease who have undergone successful dilatation have an excellent long-term prognosis with regard to survival, cardiac symptoms, and vocational status.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical results and quality of life after percutaneous transluminal coronary angioplasty: a preliminary report

To evaluate the effect of percutaneous transluminal coronary angioplasty (PTCA) on quality of life, data on symptomatic status, functional capacity, life satisfaction, and psychological wellness were collected on 102 patients at 1 day pre-PTCA and 2 months post-PTCA, and on the first 50 of these patients at 10 months post-PTCA. There were highly significant changes (p < 0.001) in all quality of life measures between pre-PTCA and the 1st follow-up measurements. No further significant changes occurred in these measures between the 1st and 2nd follow-up measurements, indicating that the initial improvement in quality of life was sustained over this period. Data on primary success rate, complications, and pre- and post-PTCA risk factor scores are also reported.

Percutaneous transluminal coronary angioplasty of the left coronary artery in patients with chronic occlusion of the right coronary artery: clinical and functional results

The safety and therapeutic benefits of percutaneous transluminal coronary angioplasty of the left anterior descending coronary artery, the left circumflex coronary artery or both were assessed in 61 patients with chronic (greater than 3 months) occlusion of the right coronary artery. Recanalization of the right coronary artery was not performed before dilatation of left coronary artery lesions. All lesions could be dilated without an acute ischemic event in the catheterization laboratory. However, three patients underwent coronary artery bypass surgery within the first 8 days after coronary angioplasty. There were no in-hospital deaths. Of the remaining 58 patients, 51 (88%) had repeat angiography at a mean of 5.2 +/- 2.5 months. Patients were divided into two groups according to the presence (n = 17) or absence (n = 34) of restenosis defined as greater than or equal to 50% diameter stenosis at the dilated site. Baseline characteristics were comparable. The mean value for angina functional class at follow-up was significantly better in the group without than in the group with restenosis (0.4 +/- 0.6 vs 2.1 +/- 1.1, respectively; p less than 0.001). Sixty-five percent of the patients without restenosis were asymptomatic at follow-up. Seventy-five percent of the predicted maximal physical capacity was reached by 76% of the patients without restenosis compared with 33% in the group with restenosis (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement in rest and exercise-induced wall motion abnormalities after coronary angioplasty: an exercise echocardiographic study

Exercise echocardiography was performed in 36 patients to evaluate functional improvement after coronary angioplasty. Thirty-one patients (86%) had provokable ischemia before angioplasty including 22 with an abnormal exercise electrocardiographic test (angina or ST depression), 25 with an abnormal exercise echocardiogram (exercise-induced wall motion abnormalities) and 16 with both tests abnormal. Nineteen patients had no induced ischemia after angioplasty. Seventeen (47%) continued to have ischemia that was limited in 12 to exercise-induced wall motion abnormalities, which were less severe compared with those of preangioplasty studies. Fifteen (65%) of 23 patients had improvement in rest wall motion abnormalities after angioplasty. The rest to immediate postexercise change in global wall motion score was significantly improved after angioplasty. The change in regional wall motion score was significantly improved after angioplasty in patients with single vessel right or left circumflex coronary artery disease and approached significant improvement (p = 0.06) in those with single vessel disease of the left anterior descending coronary artery. Exercise echocardiography improves the sensitivity of functional testing for ischemia, aids in localizing the ischemic zone and documents improvement in regional function after coronary angioplasty.

Long-term efficacy of percutaneous transluminal angioplasty on incidence of myocardial infarction, relief of symptoms and survival

This study was conducted to determine the long-term effects of percutaneous transluminal coronary angioplasty (PTCA) on the incidence of myocardial infarction, survival, and relief of symptoms. A total of 124 patients were included in the study and were followed for 16 to 25 months. The success rate of PTCA was 91.2% and 160 stenoses were dilated. Fifty-nine patients had multivessel disease (MVD) and 54 had single-vessel disease (SVD). There was no difference in survival when patients with SVD were compared with those with MVD. The cardiac survival rate for both groups was greater than 98%. Nine patients had myocardial infarction in the area of the dilated artery: 3 patients (5.5%) with SVD and 6 patients (10.1%) with MVD. Ninety-six patients (84.9%) remained free of symptoms: 46 patients (85.2%) with SVD and 50 patients (84.7%) with MVD. These data demonstrate the long-term efficacy of PTCA in patients with SVD and MVD with regard to control of symptom of angina, improved survival, and prevention of myocardial infarction.

The clinical efficacy and scintigraphic evaluation of post-coronary bypass patients undergoing percutaneous transluminal coronary angioplasty for recurrent angina pectoris

The efficacy of percutaneous transluminal angioplasty in improving recurrent anginal symptoms and myocardial perfusion after coronary artery bypass graft surgery was assessed prospectively in 55 patients, of whom 50 had an initial angiographic and clinical success. Although 80% of those successfully dilated were initially free of angina at 23 +/- 11 months of follow-up, one half of these patients had recurrent angina. Although only 48% of the patient cohort had complete relief of angina, 94% had less angina than before dilatation and 86% were able to decrease antianginal medications. Fifteen patients with persistent or recurrent angina had from one to five repeat dilatations. After angioplasty, lung thallium uptake, the extent of abnormal scan segments, and the magnitude of redistribution in dilated lesions were significantly reduced (n = 24 patients). Redistribution defects were seen in 38% of patients on postangioplasty scans. All were associated with subsequent angina. Of various clinical, angiographic, exercise, and thallium-201 scan variables, only the presence of delayed redistribution was an independent predictor of recurrent angina. Restenosis was the most common underlying cause for this exercise-induced perfusion defect. Thus percutaneous coronary angioplasty performed as primary therapy for recurrent angina after bypass surgery is moderately successful in long-term follow-up for the amelioration of symptoms and enhancement of regional myocardial perfusion.

Exercise testing: uses and limitations considering recent studies

Accurate use and interpretation of exercise test results depend on an understanding of physiologic principles, meticulous attention to proper methodology, and realization of the appropriate applications and limitations of testing. Understanding the relationship between myocardial and ventilatory oxygen consumption and exercise test variables will aid in the diagnosis and prognostic evaluation. Use of proper methodology in preparing the patient, performing the examination, and interpreting the results is critical to obtaining the maximum information with maximum safety for each individual patient. Improvements in methodology including the use of the Borg scale to estimate individual effort, abandonment of the predicted maximum heart rate, and the increased use of ventilatory oxygen uptake measurements should be applied. Exercise capacity should not be reported in total time but rather as the VO2 or MET equivalent of the workload achieved. This permits the comparison of the results of many different exercise testing protocols. The most useful exercise ECG variable for the diagnosis of coronary artery disease remains the ST segment shift. Unfortunately, it is not as helpful in localizing myocardial ischemia. Diagnostic accuracy can be improved by adjusting ST depressions for exercise-induced heart rate increase. Accuracy can be further increased by combining ECG, clinical, and radionuclide variables in probabilistic formulas that retain the independent diagnostic information from each variable and accurately predict disease probability. To avoid errors in clinical decision making, care must be used to insure that the mathematical formula used was derived from a population of patients that is similar to those being tested. The clinical applications for exercise testing include diagnosis of patients with chest pain syndromes, determination of disease severity, and prognosis in patients with known coronary artery disease, evaluation of arrhythmias, screening of asymptomatic patients, and evaluation of medical, surgical, and angioplastic therapy for coronary disease. In spite of studies involving thousands of patients, controversy exists regarding the diagnostic power of exercise testing. The large differences in reported accuracies are largely due to methodologic problems that have been encountered by various investigators. Clinicians should be made aware of these problems when reading the literature on ECG and radionuclide exercise testing. Such awareness will help them understand the limitations of these noninvasive procedures.(ABSTRACT TRUNCATED AT 400 WORDS)

Percutaneous transluminal coronary angioplasty in multivessel coronary disease patients: short- and long-term follow-up in single and multiple dilatations

Transluminal coronary angioplasty was successfully performed in 658 of 752 patients with multivessel disease. An angiographic success was achieved in 1198 of 1358 lesions (88%). One lesion was attempted in 338 patients (45%); 2 in 273 (37%); 3, in 101 (13%); and, 4 or more in 40 cases (5.3%). Significant complications occurred in 39 patients (5.2%): 19 (2.5%) had a transmural infarction; 26 (3.5%) required urgent myocardial revascularization; and 14 (1.9%) died. An apparent lesion recurrence occurred in 233 of 658 (35%) patients with 162 of 171 (95%) having a successful second coronary angioplasty. A second apparent lesion recurrence occurred in 37 of 162 patients (23%) with 24 of 28 (86%) having a successful third coronary angioplasty. Clinical improvement (mean follow-up: 31 +/- 17 months) persisted in 81% of successful patients. The cumulative probability of survival was 91.5% at 72 months. Survival was adversely affected, at 63 months, by the presence of prior bypass surgery (no prior bypass surgery, 94% vs. prior bypass surgery, 86%; p less than 0.05): at 24 months by a low left ventricular ejection fraction (less than or equal to 35%, 82% vs. left ventricular ejection fraction greater than 35%, 95%; p less than 0.01) and, at 57 months, in the multiple dilatation group with prior bypass surgery (no bypass surgery 96% vs. prior bypass surgery 84%; p less than 0.05). Multiple dilatation had a beneficial effect upon survival, at 27 months, in patients with a left ventricular ejection fraction less than or equal to 35% [single dilatation, 74% vs. multiple dilatation, 93%; p less than 0.001], and in patients greater than or equal to 70 years, at 39 months (79% vs. multiple dilatation, 92%; p less than 0.01). These data suggest that coronary angioplasty can be an effective treatment in patients with multivessel coronary disease without the need to dilate all diseased vessels, with good success, acceptable complication rates, and a reasonable expectation of satisfactory long-term clinical improvement.

Long-term clinical and angiographic results following percutaneous transluminal coronary angioplasty

The long-term results of percutaneous transluminal coronary angioplasty were evaluated in our first 42 patients, who had initial successful angioplasty and no restenosis on angiogram performed four months after angioplasty. Evaluation included repeat follow-up angiogram performed approximately two years after angioplasty in 22 of the 42 patients. All 42 patients had single vessel disease with severe angina pectoris refractory to medical treatment before angioplasty; at a mean follow-up of 28 months after angioplasty, 37 (88%) were asymptomatic. No patient died or underwent coronary artery bypass graft surgery during the follow-up period, although three patients (7%) suffered a myocardial infarction due to occlusion of a nondilated artery. In the 22 cases studied at a mean of 28 months after angioplasty, angiogram showed that successful coronary artery dilatation remained in all cases, with no deterioration of a dilated lesion between the four and 28 month angiograms. Progression of atherosclerosis, however, did occur in five of the 22 patients (23%), with development of either stenosis or occlusion of a non-dilated vessel. This study suggests that the development of restonsis between four and 28 months after percutaneous transluminal coronary angioplasty is unlikely. The results suggest an excellent long-term prognosis after angioplasty, in patients who have no evidence of restenosis at four months after an initially successful dilatation.

Objective assessment of coronary angioplasty for multivessel disease: results of exercise stress testing

The efficacy of coronary angioplasty in multivessel coronary artery disease was evaluated in a series of 145 consecutive patients in whom angioplasty had been successful and in whom a follow-up exercise stress test was performed within 2 months. Exercise stress test results of these patients with multivessel disease were compared with those of 177 patients with single vessel disease after successful coronary angioplasty. The postangioplasty exercise test showed ischemia in 13% of patients with single vessel and 29% of those with multivessel disease, although only 7 and 13%, respectively, experienced angina. The mean exercise duration was comparable for patients with multivessel disease (453 +/- 174 s) and single vessel disease (476 +/- 166 s). To assess the impact of the degree of revascularization in patients with multivessel disease on the results of exercise testing, 48 patients with completely revascularized vessels and 97 with incompletely revascularized vessels were evaluated. The mean exercise duration (459 +/- 178 versus 450 +/- 173 s), mean maximal heart rate (132 +/- 31 versus 136 +/- 25 beats/min) and mean systolic blood pressure (174 +/- 25 versus 170 +/- 26 mm Hg) were similar in completely and incompletely revascularized groups. Exercise-induced angina occurred in 13% of both groups. Ischemic ST segments were more common in the incompletely revascularized group (34 versus 19%, p = 0.06). Thus, exercise stress testing provides evidence that successful angioplasty can relieve electrocardiographic manifestations of ischemia as well as anginal symptoms in the majority of patients with either single or multivessel coronary artery disease who are suitable candidates for the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary angioplasty for patients with multivessel coronary artery disease: follow-up clinical status

To determine the value of percutaneous transluminal coronary angioplasty (PTCA) for patients with multivessel coronary artery disease, we reviewed follow-up data of 92 consecutive multivessel disease patients in whom PCTA had been successful and in whom at least 6 months had elapsed. Clinical outcome of multivessel disease patients was compared to that of 189 patients with single-vessel disease who experienced successful PTCA. Eighty percent of multivessel disease patients noted clinical improvement at follow-up. More single-vessel disease patients, however, were free of angina (77% vs 63%, p = 0.02), were not taking long-acting antianginal medicationS (46% vs 27%, p less than 0.001), and had repeat PTCA less often (5% vs 12%, p = 0.05) than multivessel disease patients. The incidence of late clinical events such as myocardial infarction, coronary artery bypass surgery, and death was low in both single- and multivessel disease patients. To determine whether the degree of revascularization achieved accounted for differences between single- and multivessel disease outcome, PTCA for multivessel disease was classified as either complete or incomplete revascularization. Those patients classified as having incomplete revascularization, although they had multivessel coronary artery disease, had only one significant ischemic zone and this was successfully revascularized by PTCA. There was no significant difference in anginal status or incidence of myocardial infarction, coronary artery bypass surgery, or death between the two multivessel disease subgroups. Thus, PTCA is of clinical value for selected patients with multivessel coronary artery disease, even in those who are incompletely revascularized by design.

Sequential thallium-201 myocardial perfusion studies after successful percutaneous transluminal coronary artery angioplasty: delayed resolution of exercise-induced scintigraphic abnormalities

To characterize the sequential changes of myocardial perfusion scintigraphy in patients with coronary artery disease (CAD) after complete revascularization, 43 patients underwent exercise thallium-201 (201Tl) myocardial perfusion scintigraphy before and at 9 +/- 5 days, 3.3 +/- 0.6, and 6.8 +/- 1.2 months after percutaneous transluminal coronary angioplasty (PTCA). Only patients with single-vessel CAD, without previous myocardial infarction, and without evidence of restenosis at 6 to 9 months after PTCA were included. Perfusion scans were analyzed blindly with the use of a new quantitative method to define regional myocardial perfusion in the topographic distribution of each coronary artery, which was shown to be reproducible (r = .94 or higher and SEE of 7% or less, between repeated measures by one and two operators). At 4 to 18 days after PTCA, the mean treadmill walking time increased by 123 +/- 42 sec, mean exercise-induced ST segment depression decreased by 0.6 +/- 0.3 mm, group maximal heart rate increased by 20 +/- 9 beats/min, and group systolic blood pressure at peak exercise increased by 24 +/- 10 mm Hg, compared with pre-PTCA values (p less than .001). However, no group differences were noted in these variables between the three post-PTCA stages. Myocardial perfusion in the distribution of the affected (dilated) coronary artery, on the other hand, improved progressively. In the 45 degree left anterior oblique view for instance, myocardial perfusion increased at 9 days after PTCA (from 68 +/- 24% before PTCA to 91 +/- 9%, p less than .001) and at 3.3 months after PTCA (101 +/- 8%, p less than .05 vs 9 days after PTCA), but no further significant changes were seen at 6.8 months after PTCA (102 +/- 8%). Similar changes were noted in the other two views. No relationship between minor complications during PTCA and delayed improvement on the 201Tl was observed. Myocardial ischemia was diagnosed in 12 of the 43 scans recorded a few days after PTCA, but in none recorded at later stages. We conclude that 201Tl scans after PTCA often show delayed improvement and therefore, an abnormal myocardial perfusion scan soon after PTCA does not necessarily reflect residual coronary stenosis or recurrence.

Multilesion coronary angioplasty: clinical and angiographic follow-up

Determination of the restenosis rate after multilesion percutaneous transluminal coronary angioplasty is an important consideration in defining expanded indications for the procedure. Of 209 patients who underwent successful multilesion coronary angioplasty, 55 symptomatic and 74 asymptomatic patients were restudied an average of 7 +/- 4 months after dilation. The restenosis rate was 82% (45 of 55) in the symptomatic patients and 30% (22 of 74) in the asymptomatic patients (p less than 0.001). Only 4% of the asymptomatic patients had restenosis at more than one dilation site. When only patients who developed a restenosis were considered, the restenosis occurred at more than one dilation site in 47% (21 of 45) of the symptomatic group versus 14% (3 of 22) of the asymptomatic group (p less than 0.05). When all recurrent stenoses were examined, the severity of the luminal narrowing was greater than or equal to 70% in 64% (45 of 70) of the stenotic lesions in the symptomatic patients versus 31% (8 of 26) of the stenotic lesions in the asymptomatic patients (p less than 0.05). Proximal left anterior descending coronary artery disease, increased length of the stenotic narrowing, male gender and diabetes were associated with an increased incidence of restenosis by multivariate analysis. Patient-related variables were not predictive of multilesion restenosis. In conclusion, the majority of patients are clinically improved after multilesion coronary angioplasty. Recurrent symptoms after multilesion coronary angioplasty are frequently associated with multilesion restenosis and a more severe degree of restenotic narrowing. Restenosis at more than one dilation site is uncommon in the asymptomatic patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary angioplasty

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Three year anatomic, functional and clinical follow-up after successful percutaneous transluminal coronary angioplasty

Because the long-term anatomic effects of percutaneous transluminal coronary angioplasty are unknown, follow-up evaluations including coronary angiography, treadmill exercise testing and rest and bicycle exercise radionuclide angiography were performed in 46 patients 6.3 +/- 2.0 and 37.6 +/- 3.6 (mean +/- SD) months after they had undergone successful single lesion angioplasty. The severity of the coronary stenosis decreased significantly at each evaluation; the mean diameter stenosis was 66 +/- 13% before angioplasty, 30 +/- 13% immediately after and 26 +/- 16% and 19 +/- 13% at 6 months and 3 years, respectively. Exercise time increased from 9.8 +/- 4.4 minutes before angioplasty to 18.3 +/- 4.5 minutes immediately after the procedure and remained at that level at 6 months (20.3 +/- 4.6 minutes) and 3 years (18.2 +/- 4.5 minutes). Left ventricular ejection fraction during exercise decreased 4 +/- 6% compared with rest before angioplasty, but increased 7 +/- 7% immediately after angioplasty and this increase was maintained at 6 months (+/- 6 +/- 7%) and 3 years (+/- 4 +/- 6%). Before angioplasty, 1 patient was in Canadian Heart Association functional class 0, 15 were in class II, 24 in class III and 6 in class IV. Three years later, 25 were in class 0, 10 in class I, 7 in class II and 4 in class III. These results indicate that the short-term anatomic and functional success of coronary angioplasty is maintained for at least 3 years.