Fate of lesion-related side branches after coronary artery stenting.

OBJECTIVES: The aim of this study was to assess the immediate and long-term patency of lesion-associated side branches after coronary artery stenting. BACKGROUND: The possible adverse effects related to implantation of coronary stents are not completely known. An important potential complication of stenting is side branch occlusion due to mechanical obstruction or thrombosis. METHODS: Serial coronary angiography was performed in 153 patients (167 lesions) at baseline, after conventional balloon angioplasty, immediately after Palmaz-Schatz stent placement and at 6 months. The patency of side branches, where present, was analyzed at each of these points. RESULTS: Of 167 lesions stented, 57 stent placements spanned 66 side branches with a diameter > or = 1 mm. Twenty-seven (41%) of these side branches had > or = 50% ostial stenosis before standard balloon angioplasty. Six side branches became occluded after standard balloon angioplasty and remained occluded after stenting. Of the 60 side branches patent after conventional angioplasty, 57 (95%) remained patent immediately after stenting. All three side branches that became occluded after stenting had > or = 50% ostial stenosis at baseline. All 60 side branches, including the 3 initially occluded after stenting, were patent at 6-month follow-up. CONCLUSIONS: These findings demonstrate that 1) acute side branch occlusion due to coronary stenting occurs infrequently; 2) when side branch occlusion occurs, it is associated with intrinsic ostial disease; and 3) the patency of side branch ostia is well maintained at long-term follow-up.

Effect of intracoronary stenting on intimal dissection after balloon angioplasty: results of quantitative and qualitative coronary analysis.

The effect of the Palmaz-Schatz stent on the angiographic appearance and residual luminal stenosis in patients with intimal dissection after balloon angioplasty was evaluated in 84 consecutive patients (90 lesions). Coronary angiography was performed before angioplasty, after conventional angioplasty and after stent implantation. The degree of intimal disruption was assessed as follows: grade 0, no dissection; grade 1, simple dissection (intraluminal linear defect or extraluminal cap extravasation); or grade 2, complex dissection (nonlinear spiral defect or luminal defect with multiple irregular borders). Quantitative coronary analysis of digitized cineangiograms was performed with use of a computerized automatic edge detection algorithm. After balloon angioplasty, 31 (34%) of 90 lesions demonstrated intimal dissection (18 simple, 13 complex). After stent implantation, intimal dissection improved by greater than or equal to 1 grade in 29 (94%) of the 31 lesions with 27 (87%) reduced to grade 0 (that is, no dissection). Dissection grade improved after stenting in 16 (89%) of 18 simple dissections and in all 13 complex dissections. Mean diameter stenosis was 77 +/- 17% before angioplasty, 47 +/- 17% after angioplasty and 14 +/- 10% after stenting (before angioplasty vs. after angioplasty and after angioplasty vs. after stenting, p less than 0.0001). In conclusion, intracoronary stenting is effective in reducing the residual luminal stenosis and in improving the angiographic appearance of intimal dissections after conventional balloon angioplasty.

Long-term angiographic and clinical outcome after implantation of a balloon-expandable stent in the native coronary circulation. Palmaz-Schatz Stent Study Group.

OBJECTIVES: The purpose of this study was to examine the long-term clinical and angiographic outcome after coronary stent implantation. BACKGROUND: Previous reports have shown a discordance between the excellent initial angiographic results and subsequent adverse clinical events after coronary artery stenting. METHODS: Single Palmaz-Schatz stents were electively implanted in the native coronary arteries of 300 consecutive patients. Angiograms were obtained at baseline, after balloon angioplasty, after stent implantation and at 6 months after implantation. Films were analyzed by a panel of angiographers utilizing an automated edge detection program. Clinical events, including death, myocardial infarction, coronary bypass surgery and repeat angioplasty, were recorded for 1 year. RESULTS: Although there were no acute in laboratory vessel closures, stent thrombosis occurred in 14 patients (4.7%) at a mean +/- SD of 5 +/- 3 days after implantation. Two hundred fifty-eight (90%) of 286 eligible patients had follow-up angiography at 6.1 +/- 2.2 months after stent implantation. Minimal lumen diameter increased from 0.80 +/- 0.39 mm at baseline to 1.65 +/- 0.51 mm after angioplasty and further increased to 2.55 +/- 0.49 mm after stent placement (p = 0.0001). At follow-up there was a 0.85-mm late loss in lumen diameter, with a final minimal lumen diameter at 6 months of 1.70 +/- 0.71 mm. Restenosis, defined as > or = 50% diameter stenosis at follow-up, occurred in 14% of patients with previously untreated lesions and in 39% of patients with previous angioplasty (p < 0.001). Clinical events after 1 year for the entire group of 300 patients included death in 0.7%, myocardial infarction in 3.7%, bypass grafting in 8% and repeat angioplasty in 13%. Freedom from any adverse clinical event was 80% for all treated patients and 87% for those with previously untreated lesions. CONCLUSIONS: Elective use of this balloon-expandable stent in the native coronary circulation is associated with a low restenosis rate by quantitative angiography in previously untreated lesions and a favorable clinical outcome with an excellent event-free survival rate at 1 year.

Efficacy of coronary stenting versus balloon angioplasty in small coronary arteries. Stent Restenosis Study (STRESS) Investigators.

OBJECTIVES: The goal of this study was to compare the efficacy of elective stent implantation and balloon angioplasty for new lesions in small coronary arteries. BACKGROUND: Palmaz-Schatz stents have been designed and approved by the Food and Drug Administration for use in coronary arteries with diameters > or = 3.0 mm. The efficacy of elective stent placement in smaller vessels has not been determined. METHODS: By quantitative coronary angiography, 331 patients in the Stent Restenosis Study (STRESS) I-II were determined to have a reference vessel < 3.0 mm in diameter. Of these, 163 patients were randomly assigned to stenting (mean diameter 2.69 +/- 0.21 mm), and 168 patients were assigned to angioplasty (mean diameter 2.64 +/- 0.24 mm). The primary end point was restenosis, defined as > or = 50% diameter stenosis at 6-month follow-up angiography. Clinical event rates at 1 year were assessed. RESULTS: Baseline clinical and angiographic characteristics were similar in the two groups. Procedural success was achieved in 100% of patients assigned to stenting and in 92% of patients assigned to angioplasty (p < 0.001). Abrupt closure within 30 days occurred in 3.6% of patients in both groups. Compared with angioplasty, stenting conferred a significantly larger postprocedural lumen diameter (2.26 vs. 1.80 mm, p < 0.001) and a larger lumen at 6 months (1.54 vs. 1.27 mm, p < 0.001). Restenosis (> or = 50% diameter stenosis at follow-up) occurred in 34% of patients assigned to stenting and in 55% of patients assigned to angioplasty (p < 0.001). At 1 year, event-free survival was achieved in 78% of the stent group and in 67% of the angioplasty group (p = 0.019). CONCLUSIONS: These findings suggest that elective stent placement provides superior angiographic and clinical outcomes than balloon angioplasty in vessels slightly smaller than 3 mm.

False-positive reversible perfusion defect during dobutamine-thallium imaging in left bundle branch block.

In the presence of pre-existing left bundle branch block (LBBB) exercise stress thallium scans have been associated with false-positive septal and apical perfusion abnormalities. Recent reports have documented a lower incidence of false-positive septal perfusion defects when pharmacologic agents such as dipyridamole or adenosine are utilized in patients with LBBB. Dobutamine, a synthetic catecholamine, is being used with increasing frequency in combination with perfusion agents for the diagnosis of coronary artery disease in patients unable to achieve an adequate exercise workload. Because the positive inotropic and chronotropic actions of doubtamine are similar to the physiologic effects of treadmill exercise, it is conceivable that false-positive perfusion abnormalities will be observed in patients with pre-existing LBBB undergoing dobutamine perfusion imaging. We describe a patient with underlying LBBB who underwent dobutamine thallium imaging which revealed septal and periapical defects. Subsequent coronary angiography showed these abnormalities to be false-positive. It is concluded that septal and periapical perfusion abnormalities during dobutamine thallium imaging may be false-positive and should be interpreted cautiously.

Frequency and outcome of development of coronary artery aneurysm after intracoronary stent placement and angioplasty. STRESS Trial Investigators.

Elective Palmaz-Schatz intracoronary stent implantation does not increase the risk for coronary artery aneurysm formation. Angiographic restenosis and clinical outcome are not affected by the development of a coronary artery aneurysm after percutaneous transluminal coronary artery or stent placement.

Interprocedural interval as a predictor of stent restenosis after previous coronary angioplasty. The Palmaz-Schatz Stent Investigators.

Coronary artery stent implantation is used increasingly to treat restenosis after balloon angioplasty. This study demonstrates that a short interprocedural interval, between initial angioplasty and stent implantation, is a significant risk factor for in-stent restenosis.

Comparison of coronary angiographic findings during the first six hours of non-Q-wave and Q-wave myocardial infarction.

The angiographic features of non-Q-wave acute myocardial infarction (AMI) soon after symptom onset have not been previously reported. Accordingly, this study reviewed the coronary angiographic findings of 86 patients with AMI studied within 6 hours of symptom onset: 58 had Q-wave and 28 had non-Q-wave AMI. Patients with Q-wave and non-Q-wave AMI were comparable in terms of clinical characteristics, frequency of 1-vessel disease, and infarct-related artery location. Thrombus was observed in 49 patients (84%) with Q-wave AMI versus 12 (43%) with non-Q-wave AMI (p = 0.0002). Whereas complete occlusion of the infarct-related artery was present in 53 patients (91%) with Q-wave AMI, total coronary occlusion was present in only 11 (39%) with non-Q-wave AMI (p = 0.0001). Collaterals to occluded infarct arteries were seen in 10 patients (19%) with Q-wave AMI versus 5 (45%) with non-Q-wave AMI (p = 0.06). Residual perfusion of the infarct artery by either anterograde or collateral flow was typical of patients with non-Q-wave AMI (22 of 28, 79%) but was uncommon in those with Q-wave AMI (15 of 58, 26%) (p = 0.0001). Thus, coronary angiography performed within 6 hours of symptom onset demonstrates important differences between Q-wave and non-Q-wave AMI. Non-Q-wave AMI is characterized by partial perfusion of the infarct-related artery by either anterograde or collateral flow, and a lower incidence of thrombus than Q-wave AMI.(ABSTRACT TRUNCATED AT 250 WORDS)

One-year follow-up of the Stent Restenosis (STRESS I) Study.

We present the completed 1-year follow-up results of the original Stent Restenosis Study (STRESS I), in which 407 patients with symptomatic ischemic heart disease and new lesions of the native coronary circulation were randomly assigned to treatment with either the Palmaz-Schatz coronary stent or conventional percutaneous transluminal coronary angioplasty (PTCA). The present study compares the safety of elective stenting to balloon angioplasty (PTCA) in terms of freedom from clinical events up to 1 year after treatment. Patients were enrolled and treated from January 1991 through February 1993, and follow-up data were collected and verified until July 1995. Ninety-seven percent of all patients had complete follow-up (deceased or alive with known clinical status) beyond 8 months, and 94% beyond 11 months. Anginal status between 9 to 15 months postprocedure was available for 78% of patients. At 1 year, 154 patients (75%) assigned to stent implantation and 141 (70%) to PTCA were free of all clinical events (death, myocardial infarction, or any revascularization procedure), and 162 stent patients (79%) and 149 PTCA patients (74%) were free from death, myocardial infarction, or target lesion revascularization. Symptom-driven target lesion revascularization occurred in 12% of the stent group versus 17% of the PTCA group. None of these differences in clinical events was statistically significant. Only 2 patients in the stent group and 7 in the PTCA group had a first event after 239 days, and freedom from angina at 1 year was reported in equal frequency in both groups (84%). There appear to be no late adverse effects of stent implantation. However, these results are limited by low statistical power, narrow patient selection, and the anticoagulation regimen used in the early experience with this device.

Balloon optimization versus stent study (BOSS): provisional stenting and early recoil after balloon angioplasty.

"Optimal" percutaneous transluminal coronary angioplasty (PTCA) may have a late restenosis rate similar to stenting. We sought to assess short- and long-term results of a provisional stenting/optimal PTCA approach compared with elective stenting in a prospective, randomized study. A total of 97 patients with discrete, de novo lesions in native coronary arteries > or =3 mm in diameter were randomized 2:1 in PTCA with prolonged perfusion balloon inflation (n = 66) versus elective stenting (n = 31). Recoil after PTCA was assessed by routine delayed angiograms (5 and 20 minutes). Cross over to stent was allowed for an inadequate result; there was no on-line quantitative angiography. An independent core angiographic laboratory assessed all results and evaluated the adequacy of the subjective interpretation. Within the PTCA arm, there were 24 (36%) crossovers to stenting (5 of 24 [21%] due to recoil), whereas 2 stents could not be delivered to the lesion and crossed over to PTCA. As assessed by quantitative angiography, baseline reference vessel diameters were similar between the PTCA and stent groups. The immediate lumen diameter achieved with PTCA was smaller than that achieved with stenting (2.18+/-0.49 vs. 2.44+/-0.38 mm, respectively, p = 0.01). There were no differences in angiographic results between elective and crossover stenting and there were no in-hospital complications in any patient. Target lesion revascularization at 8 months was 19% (n = 6) in the elective stent arm versus 21% (n = 14) in the PTCA arm, p = NS; respective rates in PTCA alone and crossed over-to-stent subsets were 23% (n = 10) versus 17% (n = 4), p = NS. Angiographic restenosis was 47% after elective stenting versus 38% after PTCA (intention to treat), p = NS. By received treatment, it was 41% (11 of 27) in the group treated with the PTCA versus 33% (5 of 15) in the crossover-to-stent arm (p = NS). Thus, provisional stenting can be safely performed in the treatment of discrete, native de novo lesions. Early recoil after PTCA cannot be reliably assessed without quantitative angiography.

Long-term angiographic and clinical outcome after implantation of balloon-expandable stents in aortocoronary saphenous vein grafts.

Balloon angioplasty of aortocoronary saphenous vein graft lesions is associated with high restenosis and clinical event rates. The goal of this multicenter study was to assess long-term angiographic and clinical outcome of patients electively treated with single Palmaz-Schatz stents in aortocoronary saphenous vein grafts. In 198 patients (209 lesions), elective placement of single Palmaz-Schatz stents was attempted. Angiography was performed at baseline, immediately after stent placement, and at 6-month follow-up. Stent placement was successful in 98.5% of patients. One patient (0.5%) had stent thrombosis. Restenosis occurred in 34% (45 of 133) of the restudied lesions. Restenosis was lower in de novo lesions than in restenotic lesions (22% vs 51%, p < 0.001). Ostial lesions had a higher restenosis rate than nonostial lesions (61% vs 28%, p = 0.003). Freedom from death, myocardial infarction, coronary artery bypass surgery, and repeat angioplasty was present in 70% of patients. Eighty-two percent of patients with de novo lesions remained event-free at 1 year, whereas only 55% of patients with prior angioplasty were event-free at 1 year (p < 0.001). The use of the Palmaz-Schatz stent for the treatment of focal, de novo, aortocoronary saphenous vein graft lesions is associated with a high procedural success rate, a low angiographic restenosis rate, and low clinical event rates, including the need for repeat revascularization. The results of this study need validation by a prospective randomized trial comparing stent implantation with angioplasty.

Rheolytic thrombectomy of chronic coronary occlusion.

Percutaneous intervention in patients with intracoronary thrombus continues to pose a significant clinical challenge. In this report, we describe the successful treatment of a 44-year-old patient with an extensive chronic thrombotic occlusion of the right coronary artery using a rheolytic thrombectomy catheter. Despite angiographic documentation of coronary thrombosis 104 days prior to treatment and a voluminous thrombus burden (60 mm in length x 3 mm in diameter), rapid recanalization was accomplished with this device without embolic complications. At 1 year clinical follow-up, the patient has remained symptom free. The design of this novel device and its mechanism of action are described.

A randomized comparison of coronary-stent placement and balloon angioplasty in the treatment of coronary artery disease. Stent Restenosis Study Investigators.

BACKGROUND: Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes. METHODS: We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later. RESULTS: The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 +/- 0.46 vs. 1.23 +/- 0.48 mm, P < 0.001), and a larger luminal diameter immediately after the procedure (2.49 +/- 0.43 vs. 1.99 +/- 0.47 mm, P < 0.001). At six months, the patients with stented lesions continued to have a larger luminal diameter (1.74 +/- 0.60 vs. 1.56 +/- 0.65 mm, P = 0.007) and a lower rate of restenosis (31.6 percent vs. 42.1 percent, P = 0.046) than those treated with balloon angioplasty. There were no coronary events (death; myocardial infarction; coronary-artery bypass surgery; vessel closure, including stent thrombosis; or repeated angioplasty) in 80.5 percent of the patients in the stent group and 76.2 percent of those in the angioplasty group (P = 0.16). Revascularization of the original target lesion because of recurrent myocardial ischemia was performed less frequently in the stent group than in the angioplasty group (10.2 percent vs. 15.4 percent, P = 0.06). CONCLUSIONS: In selected patients, placement of an intracoronary stent, as compared with balloon angioplasty, results in an improved rate of procedural success, a lower rate of angiographically detected restenosis, a similar rate of clinical events after six months, and a less frequent need for revascularization of the original coronary lesion.

Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators.

BACKGROUND: Treatment of stenosis in saphenous-vein grafts after coronary-artery bypass surgery is a difficult challenge. The purpose of this study was to compare the effects of stent placement with those of balloon angioplasty on clinical and angiographic outcomes in patients with obstructive disease of saphenous-vein grafts. METHODS: A total of 220 patients with new lesions in aortocoronary-venous bypass grafts were randomly assigned to placement of Palmaz-Schatz stents or standard balloon angioplasty. Coronary angiography was performed during the index procedure and six months later. RESULTS: As compared with the patients assigned to angioplasty, those assigned to stenting had a higher rate of procedural efficacy, defined as a reduction in stenosis to less than 50 percent of the vessel diameter without a major cardiac complication (92 percent vs. 69 percent, P<0.001), but they had more frequent hemorrhagic complications (17 percent vs. 5 percent, P<0.01). Patients in the stent group had a larger mean (+/-SD) increase in luminal diameter immediately after the procedure (1.92+/-0.30 mm, as compared with 1.21+/-0.37 mm in the angioplasty group; P<0.001) and a greater mean net gain in luminal diameter at six months (0.85+/-0.96 vs. 0.54+/-0.91 mm, P=0.002). Restenosis occurred in 37 percent of the patients in the stent group and in 46 percent of the patients in the angioplasty group (P=0.24). The outcome in terms of freedom from death, myocardial infarction, repeated bypass surgery, or revascularization of the target lesion was significantly better in the stent group (73 percent vs. 58 percent, P = 0.03). CONCLUSIONS: As compared with balloon angioplasty, stenting of selected venous bypass-graft lesions resulted in superior procedural outcomes, a larger gain in luminal diameter, and a reduction in major cardiac events. However, there was no significant benefit in the rate of angiographic restenosis, which was the primary end point of the study.

Safety of intracoronary administration of c-myc antisense oligomers after percutaneous transluminal coronary angioplasty (PTCA).

We wished to assess the clinical safety and pharmacokinetics of ascending doses of a synthetic oligodeoxynucleotide (LR-3280) administered after coronary angioplasty. Antisense oligodeoxynucleotides designed to hybridize with target messenger ribonucleic acid (mRNA) in a complementary fashion to inhibit the expression of corresponding protein also have the ability to bind to extracellular growth factors. LR-3280 has been shown to reduce c-myc expression, inhibit growth and collagen biosynthesis in human vascular cells, and reduce neointimal formation in animal models of vascular injury. After successful percutaneous transluminal coronary angioplasty (PTCA), 78 patients were randomized to receive either standard care (n = 26) or standard care and escalating doses of LR-3280 (n = 52) (doses from 1 to 24 mg), administered into target vessel through a guiding catheter. Overall safety was evaluated by clinical adverse events, laboratory tests, and electrocardiograms. Patency was evaluated by quantitative coronary angiography. There were no clinically significant differences between treated and control patients. No adverse effects of LR-3280 on the patency of dilated coronary arteries were observed. Pharmacokinetic data revealed that peak plasma concentrations of LR-3280 occurred at 1 minute over the studied dose range and rapidly decreased after approximately1 hour, with little LR-3280 detected in the urine between 0-6 hours and 12-24 hours. The intracoronary administration of LR-3280 is well tolerated at doses up to 24 mg and produces no adverse effects in dilated coronary arteries. These results provide the basis for the evaluation of local delivery of this phosphorothioate oligodeoxynucleotide for the prevention of human vasculoproliferative disease.