Search

Background: Balloon angioplasty (PTCA) of occluded coronary arteries is limited by high rates of restenosis and reocclusion. Although stenting improves results in anatomically simple occlusions, its effect on patency and clinical outcome in a broadly selected population with occluded coronary arteries is unknown., Methods and Results: Eighteen centers randomized 410 patients with nonacute native coronary occlusions to PTCA or primary stenting with the heparin-coated Palmaz-Schatz stent. The primary end point, failure of sustained patency, was determined at 6-month angiography. Repeat target-vessel revascularization, adverse cardiovascular events, and angiographic restenosis (>50% diameter stenosis) constituted secondary end points. Sixty percent of patients had occlusions of >6 weeks' duration, baseline flow was TIMI grade 0 in 64%, and median treated segment length was 30.5 mm. With 95.6% angiographic follow-up, primary stenting resulted in a 44% reduction in failed patency (10.9% versus 19.5%, P=0.024) and a 45% reduction in clinically driven target-vessel revascularization at 6 months (15.4% versus 8.4%, P=0.03). The incidence of adverse cardiovascular events was similar for both strategies (PTCA, 23.6%; stent, 23.3%; P=NS). Stenting resulted in a larger mean 6-month minimum lumen dimension (1.48 versus 1.23 mm, P<0.01) and a reduced binary restenosis rate (55% versus 70%, P<0.01)., Conclusions: Primary stenting of broadly selected nonacute coronary occlusions is superior to PTCA alone, improving late patency and reducing restenosis and target-vessel revascularization.

Objective: To examine the procedural and long term success of coronary stenting in patients presenting with unstable angina and the effect of warfarin on the clinical outcome of these high risk patients., Design: A nonrandomized, retrospective analysis of patients presenting with unstable angina., Setting: A tertiary care, Canadian university-affiliated teaching hospital., Patients: Of 1250 patients who underwent percutaneous transluminal coronary angioplasty between January 1994 and June 1995, 365 underwent coronary stenting. The study population consisted of the 156 patients presenting with unstable angina who underwent coronary stenting. Patients with Canadian Cardiovascular Society class IV and postinfarction angina were included., Interventions: Stent delivery by standard techniques to the target lesion was successful in all patients. At discharge, 88 patients were prescribed warfarin, ticlopidine and acetylsalicylic acid (ASA); the remaining 68 patients received only ticlopidine and ASA. Late clinical outcomes were assessed by telephone interview., Results: The overall procedural success rate was 96%. One patient died in hospital (0.6%). Other events were abrupt closure (1.9%), myocardial infarction (1.9%) and urgent bypass surgery (1.9%). During follow-up, target vessel reintervention was needed in 19.6% of patients. Early and late clinical outcomes did not differ significantly between anticoagulated patients and those treated with antiplatelet agents alone, but anticoagulated patients had a significantly longer hospital stay., Conclusions: Coronary stenting in patients with unstable angina was associated with excellent procedural success and favourable late clinical outcomes. Warfarin added no apparent additional clinical benefit to antiplatelet agents in this high risk population.

Background: Percutaneous transluminal coronary angioplasty (PTCA) of totally occluded coronary arteries is performed in a variety of clinical settings and for a variety of indications. Most commonly it is performed for relief of symptoms of myocardial ischemia. Studies have also suggested that PTCA of occluded arteries beyond the acute phase of myocardial infarction may improve left ventricular function even in the absence of objective evidence of ischemia. One of the major limitations of total occlusion PTCA is a high rate of reocclusion, reported to be as high as 40%. Recently, small studies have suggested that stenting may improve the long term outcome after PTCA of total coronary occlusions., Objectives: To determine in a prospective, randomized trial whether long term patency and clinical outcome following successful PTCA of a totally occluded coronary can be improved by the use of of a heparin-coated stent., Patients and Methods: Subjects were randomly assigned to one of two strategies once the guide wire had crossed the occluded segment of the target artery: PTCA alone, or PTCA followed by insertion of Palmaz-Shatz heparin-coated stent(s). Randomization was stratified according to duration of the coronary occlusion: six weeks or less, and more than six weeks. The primary end-point is failure of sustained patency (Thrombolysis in Myocardial Infarction [TIMI] flow grade less than 3) at six months. Secondary end-points are change in minimal luminal diameter, target vessel revascularization at one year, cardiovascular events at one year, and change in global and regional left ventricular function., Baseline Characteristics: All 410 patients have been randomly assigned to the PTCA alone (n = 208) or PTCA plus stent (n = 202) group. Mean age was 58 +/- 11 years and 18% were female. Prior myocardial infarction had been documented in 67% of patients. The duration of occlusion was six weeks or less in 40% and more than six weeks in 60% of patients. In 64% of patients TIMI flow was grade 0 and in 36% it was grade 1. STUDY IMPLICATIONS: The trial will demonstrate whether the use of a heparin-bonded stent can improve long term patency and clinical outcome in patients undergoing clinically indicated PTCA of totally occluded coronary arteries. If a significant reduction in reocclusion and clinical events is demonstrated, the Total Occlusion Study of Canada (TOSCA) would offer a more effective long term revascularization strategy in future trials testing the open artery hypothesis.

Background: Percutaneous transluminal coronary angioplasty (PTCA) is complicated by restenosis within 6 months in > 40% of patients. Theoretical, animal experimental, and human epidemiological and clinical trial findings have suggested that fish oils (n-3) might reduce restenosis. Low-molecular-weight heparin (LMWH) has reduced cellular proliferation and restenosis in several experimental systems., Methods and Results: We randomized 814 patients to fish oils (5.4 g n-3 fatty acids) or placebo a median of 6 days before PTCA and continued for 18 weeks. At the time of sheath removal, 653 patients with at least one successfully dilated lesion were randomized to LMWH (30 mg SC BID) or control for 6 weeks in a 2 x 2 factorial design. Follow-up with quantitative coronary angiography (QCA; target, 18 weeks) was interpretable on 96% of these patients. Restenosis rates per patient were for n-3, 46.5%; placebo, 44.7%; LMWH, 45.8%; and control, 45.4%. Restenosis rates per lesion were for n-3, 39.7%; placebo, 38.7%; LMWH, 38%; and control, 40.4%. At follow-up QCA, mean minimal lumen diameters were (mm) for n-3, 1.12; placebo, 1.10; LMWH, 1.12; and control, 1.10. Fifteen percent of patients permanently discontinued n-3/placebo before study completion, and 21% of patients discontinued LMWH early. There were no significant differences in the occurrences of ischemic events. Bleeding was more common with LMWH, usually was mild, and led to early discontinuation of study medication in only 0.9% of patients. Gastrointestinal side effects were more common in patients receiving n-3 than placebo., Conclusions: There is no evidence for a clinically important reduction of PTCA restenosis in this trial by either n-3 or LMWH. Evaluation of the results for n-3 in the context of previously published data on the reduction of PTCA restenosis indicates that n-3 is not efficacious and that further trials are unwarranted.

We report on a case of intractable recurrent ventricular fibrillation that responded poorly to antiarrhythmic medication and balloon angioplasty, but resolved instantaneously following intracoronary stenting.

From 1988 to 1992, 4,182 coronary bypass grafting procedures were performed at the University of Ottawa Heart Institute. The left internal thoracic artery (ITA) was used in 2,913 patients, the right ITA in 79, and bilateral ITAs in 61 for a total of 3,053 patients with ITAs. This study assessed patients requiring angioplasty for symptomatic ITA stenosis after operation. A total of 29 patients (0.95%) with a mean age of 55.3 +/- 1.9 years underwent angioplasty for ITA stenosis from 4 days to 34 months after operation (mean, 6.5 +/- 1.6 months). Internal thoracic artery stenosis was identified in 18 patients (62.1%) within 3 months after operation. Angina was present in 26 patients (89.7%), a positive stress test in 8 (27.6%), and myocardial infarction in 1 (3.4%). At angiography, a total of 34 stenotic sites were identified in ITA grafts. Angioplasty was successful (< 50% residual stenosis) in 31 sites (91.2%). Follow-up was available for 28 of 29 patients (96.6%) at 24.6 +/- 2.3 months. Four patients (14.3%) returned with restenosis within 3 months, 2 of whom had successful repeat angioplasty, and 1 required reoperation. Canadian Cardiovascular Society anginal class after angioplasty was less than class II in 84.6% of patients. In conclusion, symptomatic postoperative ITA stenosis is uncommon, occurs most frequently at the site of distal anastomosis, and generally presents within 3 months of operation. It may be safely and effectively treated with angioplasty with a low recurrence rate.

The effect of late percutaneous transluminal coronary angioplasty (PTCA) of an occluded infarct-related artery on left ventricular ejection fraction was studied in patients with a recent, first Q-wave myocardial infarction in a prospective, randomized study. Forty-four patients (31 men and 13 women, mean age 58 +/- 12 years) with an occluded infarct-related coronary artery were randomized to PTCA (n = 25) or no PTCA (n = 19). Patients received acetylsalicylic acid, a beta blocker and an angiotensin-converting enzyme inhibitor unless contraindicated. Left ventricular ejection fraction was determined at baseline and 4 months. Coronary angiography was repeated at 4 months. Baseline ejection fraction measured 20 +/- 12 days after myocardial infarction was 45 +/- 12% in both groups. PTCA was performed 21 +/- 13 days after the event. The primary PTCA success rate was 72%. One patient in each group died before angiographic follow-up, which was completed in 37 of the remaining 42 patients (88%; 21 with and 16 without PTCA). At 4 months, the infarct-related artery was patent in 43% of PTCA patients and in 19% of no PTCA patients (p = NS). Reocclusion occurred in 40% of patients after successful PTCA. Secondary analyses showed that the change in left ventricular ejection fraction was significantly greater in patients with a patent infarct-related artery (+9.4 +/- 6.2%) than in those with an occluded artery (+1.6 +/- 8.8%; p = 0.0096). Baseline ejection fraction also independently predicted improvement in left ventricular ejection fraction (p = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Observational studies have suggested that prolonged balloon inflation during coronary angioplasty is associated with a high clinical success rate. This randomized clinical trial sought to evaluate the impact of primary gradual and prolonged inflations versus standard short dilatations in patients undergoing elective angioplasty., Methods and Results: In phase 1 of the study, patients were randomized to receive two to four standard (1 minute) dilatations or one or two prolonged (15 minutes) dilatations after a perfusion balloon had been placed across a single target lesion. Patients with unsuccessful angiographic appearance after phase 1 dilatations had further dilatations in phase 2. Patients were followed for 6 to 12 months after the procedure. Of 478 patients, 242 received a median of one prolonged dilatation of 15 minutes' duration, and 236 received three dilatations for a median of 1 minute. Patients assigned to prolonged dilatations had a higher success rate (< or = 50% residual visual stenosis) (95% versus 89%; P = .016), less severe residual stenosis by quantitative angiography (median [25th and 75th percentiles], 35% [26%, 42%] versus 38% [30%, 46%]; P = .001), and a lower rate of major dissections (3% versus 9%; P = .003) at the end of phase 1. A total of 114 patients had further dilatations in phase 2-43 in the prolonged arm and 71 in the standard arm. The final procedural success rate was 98% with both primary dilatation strategies, which included additional maneuvers such as prolonged dilatations in the patients randomized to the primary standard dilatation. Overall, 320 of 416 patients (77%) who were discharged after a successful procedure without any in-hospital event (death, myocardial infarction, coronary artery bypass graft surgery, abrupt closure, or repeat angioplasty in target vessel) returned for follow-up angiography. The restenosis rate (> 50% residual visual stenosis) was 44% (95% confidence interval, 37% to 52%) in the prolonged dilatation group and 44% (36% to 52%) in the standard dilatation group. The primary angiographic end point of failure at the end of phase 1, abrupt closure, or restenosis throughout the study period was similar in both groups (prolonged, 51%; standard, 49%; P = .62). The secondary end point of absence of clinical events (death, nonfatal myocardial infarction, coronary artery bypass graft surgery, or repeat angioplasty in target vessel) also was similar (prolonged, 66%; standard, 74%; P = .15)., Conclusions: Primary gradual and prolonged dilatations caused less arterial trauma with a modestly larger arterial lumen compared with standard dilatations. This initial improvement in angiographic appearance did not lead to a significant reduction in restenosis or clinical adverse events during follow-up.

Intracoronary stenting has been proposed as an adjunct to balloon angioplasty to improve the immediate and long-term results. However, late luminal narrowing has been reported following the implantation of a variety of stents. One of the studies conducted with the Wiktor stent is a prospective registry designed to evaluate the feasibility, safety and efficacy of elective stent implantation in patients with documented restenosis of a native coronary artery. To identify angiographic variables predicting recurrence of restenosis, the angiograms of the first 91 patients with successful stent implantation and without clinical evidence of (sub)acute thrombotic stent occlusion were analyzed with the Computer Assisted Angiographic Analysis System using automated edge detection. The incidence of restenosis was 44% by patient and 45% by stent according to the 0.72 mm criterion, and 30% by patient and 29% by stent according to the 50% diameter stenosis criterion. The risk for restenosis for several angiographic variables was determined using an univariate analysis and is expressed as odds ratio with corresponding confidence interval. The only statistically significant predictor of restenosis was the relative gain when it exceeded 0.48 using the 0.72 mm criterion (odds ratio 2.7, 95% confidence interval 1.1-6.4). Furthermore, the relation between the relative gain (increase in minimal luminal diameter normalized to vessel size) as angiographic index of vessel wall injury and relative loss (decrease in minimal luminal diameter normalized to vessel size) as index of neointimal thickening was analyzed using a linear regression analysis. When using the categorical approach to address restenosis, there is an increased risk for recurrent restenosis when the relative gain exceeds 0.48. The continuous approach underscores this concept by indicating a weak but positive relation between the relative gain and relative loss.

Intracoronary stenting has been introduced as an adjunct to balloon angioplasty aimed at overcoming its limitations, namely acute vessel closure and late restenosis. This study reports the first experience with the Wiktor stent implanted in the first 50 consecutive patients. All patients had restenosis of a native coronary artery lesion after prior balloon angioplasty. The target coronary artery was the left anterior descending artery in 26 patients, the circumflex artery in 7 patients and the right coronary artery in 17 patients. The implantation success rate was 98% (49 of 50 patients). There were no procedural deaths. Acute or subacute thrombotic stent occlusion occurred in 5 patients (10%). All 5 patients sustained a nonfatal acute myocardial infarction. Four of these patients underwent recanalization by means of balloon angioplasty; the remaining patient was referred for bypass surgery. A major bleeding complication occurred in 11 patients (22%): groin bleeding necessitating blood transfusion in 6, gastrointestinal bleeding in 3 and hematuria in 2. Repeat angiography was performed at a mean of 5.6 +/- 1.1 months in all but 1 patient undergoing implantation. Restenosis, defined by a reduction of greater than or equal to 0.72 mm in the minimal luminal diameter or a change in diameter stenosis from less than to greater than or equal to 50%, occurred in 20 (45%) and 13 (29%) patients, respectively. In this first experience, the easiness and high technical success rate of Wiktor stent implantation are overshadowed by a high incidence of subacute stent occlusion and bleeding complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary angioplasty was used as a human model of transient myocardial ischemia to evaluate the electrocardiographic characteristics and significance of "reciprocal" ST-segment depression and T wave changes. Continuous 12-lead ECGs were recorded before and during coronary angioplasty in 20 patients, 19 of whom had single vessel disease. In 12 of 14 patients, LAD occlusion produced ischemic changes (peaked T and/or ST elevation) in L1, AVL and at least two precordial leads. "Reciprocal" changes (ST depression and/or T inversion) were observed in at least two inferior wall leads. One patient had ST depression in V4-V6 with no change in the inferior leads and in the other the only ECG change was inferior ST depression with partial inversion of the T wave. In four of six patients, RCA occlusion produced ischemic changes in at least two inferior wall leads and "reciprocal" changes in L1, AVL and at least two anterior wall leads. In LAD as well as RCA occlusions "reciprocal" changes were characterized by inversion of the T wave or inversion of its ascending limb with or without ST depression. The magnitude of the ischemic changes tended to be proportional to the magnitude of the "reciprocal" changes. Our data suggest that: (1) "Reciprocal" changes are not a specific indicator of distant myocardial ischemia due to multivessel disease; (2) the magnitude of ischemic changes correlates with the magnitude of "reciprocal" changes; (3) "Reciprocal" changes may be the only manifestation of acute myocardial ischemia; and (4) "Reciprocal" changes may be represented by inversion of the T wave without displacement of the ST-segment.