Residual Diameter Stenosis Research Articles

Comparison of Clinical and Angiographic Outcomes After Saphenous Vein Graft Angioplasty Using Coronary Versus ‘Biliary’ Tubular Slotted Stents

Saphenous vein graft (SVG) angioplasty using 15-mm articulated, tubular slotted stents results in low (0% to 20%) residual diameter stenoses and infrequent (< 5%) major complications. A "biliary" stent design with greater radial compressive strength, enhanced visibility, and more variable sizing (diameter and length) has been approved for noncoronary indications. A comparison of outcomes after coronary versus biliary stent placement in SVG stenoses has not been performed. The purpose of this study was to compare the angiographic and clinical results after SVG angioplasty using these two balloon-expandable, tubular slotted stent designs. During a 3-year period, 231 patients with 305 SVG lesions were treated using Palmaz-Schatz coronary (n = 108) or biliary (n = 123) stents. Cineangiograms were reviewed using qualitative morphological and quantitative angiographic methods. Time-dependent clinical outcome (freedom from death, Q-wave myocardial infarction, or the need for repeat coronary bypass surgery or SVG angioplasty) was assessed using Kaplan-Meier life-table methods. Unstable angina (P < .001) and recent myocardial infarction (P = .001) were present more often in patients undergoing biliary stent versus coronary stent placement. Biliary stent-treated SVG lesions were more frequently de novo (P = .001), ostial in location (P = .002), > or = 10 mm in length (P = .009), thrombus containing (P = .001), and ulcerated (P < .001) than coronary stent-treated SVG lesions. Angiographically, biliary stent-treated lesions had larger reference vessel diameter (3.43 +/- 0.59 mm versus 3.10 +/- 0.64 mm, P < .001), higher balloon-to-artery ratio (1.15 +/- 0.16 mm versus 1.07 +/- 0.19, P = .0001), and lower residual diameter stenosis (6 +/- 17% versus 14 +/- 11% in coronary stent-treated patients; P < .001). Procedural success rates were high (95%), in-hospital major complications were uncommon (< 3%), and follow-up clinical outcomes were favorable (6-month event-free survival approximately 80%) in both groups. Despite frequent short-term ischemic syndromes and unfavorable lesion characteristics, both biliary and coronary cohorts have similarly favorable short-term procedural results and long-term clinical outcomes. The increased strut thickness of the biliary stent confers greater fluoroscopic visibility and radial compressive strength in exchange for decreased stent flexibility and added technical demand in stent deployment. Extreme caution is recommended with biliary stent placement in the treatment of SVG lesions as clinical results are highly operator dependent.

Favourable results of treatment of narrowed saphenous vein grafts with Palmaz-Schatz stent implantation

Although conventional balloon angioplasty of saphenous vein grafts can be performed with an acceptable acute success and complication rate, restenosis remains a major problem. However, this may be overcome by the implantation of Palmaz-Schatz stents. Palmaz-Schatz stent deployment was performed in our institution in 43 patients who were referred for PTCA of stenosed saphenous vein grafts. Thirty-seven were located at the mid-portion of the graft, seven at the ostium and six at the distal anastomosis. Overall, we used 59 standard length (15 mm) Palmaz-Schatz stents and 22 short (7 mm) stents. In 15 lesions (30%) multiple stents were implanted in tandem to treat diffuse disease. Angiographic success was achieved in 47 of the 50 attempted lesions (94%). Major cardiac complications occurred in three patients. Two patients had procedures complicated by the development of a Q wave myocardial infarction, one of whom underwent urgent CABG. One patient died. There was no episode of subacute thrombosis. The angiographic follow-up of 37 lesions (80% of eligible lesions) at a mean time of 5 +/- 2 months (range 1-8) showed a restenosis rate of 11% and residual post-stent diameter stenosis was associated with a significantly higher restenosis rate. However, no restenosis occurred in lesions receiving multiple stents. Clinical follow-up was performed in all patients, and at a mean of 25 months after the procedure, 64% were free from clinical events, including recurrent angina. Palmaz-Schatz stent implantation is an effective and safe procedure to treat narrowed vein grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Randomized trials of directional coronary atherectomy: Implications for clinical practice and future investigation

Objectives. This study compared and contrasted the randomized trials of directional atherectomy and coronary angioplasty for de novo native coronary artery lesions.Background. The results of two randomized trials, the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) and the Canadian Coronary Atherectomy Trial (CCAT), comparing initial and intermediate-term outcome of directional coronary atherectomy and conventional coronary angioplasty in de novo native vessels, have been reported. In CAVEAT any coronary artery segment that could be by either technique was included; in CCAT only nonostial proximal left anterior descending coronary artery stenoses were studied.Methods. The primary end point was 6-month angiographic restenosis. Clinical outcome end points at 6 months included death, myocardial infarction, emergency bypass surgery and abrupt closure.Results. Initial angiographic success rates were significantly improved with directional coronary atherectomy compared with conventional angioplasty (89% vs. 80% for CAVEAT; 98% vs. 91% for CCAT). Also, the initial improvement in minimal lumen diameter and final immediate postprocedural residual diameter stenosis were better with atherectomy. In CCAT, there was no difference in initial complications; in CAVEAT, non-Q wave myocardial infarction rates and abrupt closure were increased with atherectomy. Despite improved success rates and better lumen achieved with atherectomy, in CCAT there was no difference in angiographic restenosis (46% for directional atherectomy vs. 43% for angioplasty). In CAVEAT, in a prespecified subset analysis involving the proximal left anterior descending coronary artery, restenosis was both significantly and clinically less for directional atherectomy (51% vs. 63%). For non-left anterior descending coronary artery segments, there was no difference.Conclusions. These studies document the difference between achievement of an excellent initial angiographic result and the longer term issue of clinical restenosis. Widespread use of directional coronary atherectomy to treat lesions that would be well treated by angioplasty in an attempt to decrease restenosis rates substantially does not appear indicated by the data. In individual lesions, directional atherectomy should be selected with the view toward optimizing initial results. Further trials are needed to determine whether more aggressive or better targeted directional coronary atherectomy may improve not only the initial gain but the long-term outcome as well.

Prevention of restenosis after coronary balloon angioplasty: Rationale and design of the fluvastatin angioplasty restenosis (FLARE) trial

Prevention of restenosis after successful percutaneous transluminal coronary balloon angioplasty (PTCA) continues to present the greatest therapeutic challenge in interventional cardiology. Experimental and pathological studies describe restenosis as no more than the biologic healing response to arterial injury. Studies of serial quantitative coronary angiography have demonstrated that this biologic process may be measured as the loss in minimal luminal diameter (MLD) from post-PTCA to follow-up angiography and that it is essentially ubiquitous and normally distributed. Thus, quantitative coronary angiography has become the gold standard for evaluation of the angiographic outcome of clinical trials of new agents and devices aimed at prevention of restenosis. The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors inhibit biosynthesis of mevalonate, a precursor of nonsterol compounds involved in cell proliferation, and thus may control the neointimal response, which forms the kernel of restenosis. Experimental evidence suggests that fluvastatin may exert a greater direct inhibitory effect on proliferating vascular myocytes than other HMG-CoA reductase inhibitors, independent of any lipid-lowering action. The Fluvastatin Angioplasty Restenosis (FLARE) Trial was conceived, in collaboration between the Thoraxcenter, Erasmus University, Rotterdam, The Netherlands, and Sandoz Pharma, to evaluate the ability of fluvastatin 40 mg twice dally to reduce restenosis after successful single-lesion PTCA. Treatment of suitable patients begins 2 weeks before PTCA and continues after successful PTCA (residual diameter stenosis <50%, without major cardiac complications) to follow-up angiography at 26 ± 2 weeks. Restenosis is measured by quantitative coronary angiography at a core laboratory as the loss in MLD from post-PTCA to follow-up angiography. It is calculated (90% power, α = 0.05) that 730 evaluable patients will be needed to test the hypothesis that fluvastatin will reduce the expected post-PTCA loss in MLD by 40%. Serial lipid analysis will be carried out at a central laboratory. Trial evaluation is focused on the primary endpoint (change in MLD) but includes primary clinical end-points (death, myocardial infarction, or the need for coronary artery bypass graft surgery or reintervention up to 40 weeks after PTCA) as well as secondary and tertiary clinical, angiographic, and laboratory endpoints. According to this methodologic approach, the effect of fluvastatin on luminal renarrowing and clinical events after successful PTCA as well as possible associations of lipid parameters with restenosis can be comprehensively investigated.

Prolonged dilation with an autoperfusion balloon catheter for refractory acute occlusion related to percutaneous transluminal coronary angioplasty

Objectives. Efficacy and safety of redilation by an autoperfusion balloon catheter over several hours were investigated in this retrospective and observational study.Background. Acute occlusion, refractory to redilation, is a serious complication of coronary angioplasty.Methods. Of 1,123 patients who underwent angioplasty, 83 had a refractory acute occlusion, Thirty-five patients were treated with extended dilation. Seven had stable, 19 unstable and 6 postinfarction angina and 3 had an acute infarction at the time of angioplasty. The duration of dilation was (mean ± SD) 17 (±6) h.Results. Angiographically successful redilation, with a mean residual percent diameter stenosis of 13,5% (±11.6%), was achieved in 22 (67.7%) of 34 patients. Five patients underwent bypass surgery. Three patients, who were poor surgical candidates, died. There was one new Q wave infarction and one death that occurred during extended dilation; one death and four operations were related to reocclusion immediately (≤30 min) after catheter withdrawal; and one death and one operation were related to in-hospital reocclusion. Overall success, defined as angiographic success and freedom from major events, was obtained in 20 (57%) of 35 patients (95% confidence interval 41% to 73%). Of the variables studied, only multilesion dilation was significantly (p = 0.018) associated with an unfavorable outcome. During a mean follow-up period of 13.8 (±6.1) months, two patients underwent repeat angioplasty, one sustained an infarction and three underwent elective bypass surgery.Conclusions. In approximately half of the patients (20 [57%] of 35), an initial angioplasty failure due to refractory occlusion could be reverted to a successful procedure by prolonged dilation with an autoperfusion balloon catheter.

Detailed angiographic analysis of high-speed mechanical rotational atherectomy in human coronary arteries.

Several types of atherectomy devices have been developed recently for treatment of patients with ischemic heart disease. Mechanical rotational atherectomy (MRA) using a high-speed rotational burr (Rotablator) was performed on 116 lesions in 104 patients. MRA alone was performed in 27 lesions (23%), and conventional balloon angioplasty (PTCA) was performed after MRA in 89 lesions (77%). Diameter stenosis decreased from 70 +/- 13% before MRA to 54 +/- 23% after MRA, and the final diameter stenosis (after MRA alone or with adjunctive PTCA) was 30 +/- 20% (P < .001). Minimal lumen diameter increased from 1.0 +/- 0.5 mm before MRA to 1.4 +/- 0.7 mm after MRA, and the final minimal lumen diameter was 2.3 +/- 0.7 mm (P < .001). MRA resulted in a decrease in diameter stenosis of 20% or more in 44% of lesions, and the final diameter stenosis (after MRA alone or after PTCA) was less than 50% in 75% of lesions. Considering the small diameter of available burrs, the magnitude of lumen enlargement was equal to 91% of the burr diameter, and only 9% of the burr diameter was "lost" due to elastic recoil or spasm. These angiographic results were obtained despite the presence of complex lesion morphology, including the presence of calcification in 17% of lesions and ostial location in 26% of lesions. Significant angiographic complications included abrupt closure (13 lesions, 11.2%), no reflow (8 lesions, 7%), severe coronary vasospasm (16 lesions, 13.8%), and guide wire fracture (3 lesions, 2.7%). There were no coronary artery perforations. Adjunctive therapy, including salvage PTCA, thrombolytic agents, and vasodilators, was successful in treating angiographic complications in 42 of 49 lesions (86%). Clinical complications included Q-wave myocardial infarction (5 patients, 4.8%), non-Q-wave myocardial infarction (3 patients, 2.9%), femoral vascular injury requiring surgery (3 patients, 2.9%) or blood transfusion (8 patients, 7.7%), abrupt closure requiring emergency bypass graft surgery (2 patients, 1.9%), and in-hospital death (1 patient, 1.0%). Angiographic follow-up (mean follow-up interval, 5.0 +/- 2.0 months) was available in 84% of successfully treated patients and revealed a restenosis rate of 51%, defined as a residual diameter stenosis of more than 50%. There was no significant difference in restenosis rates between de novo lesions (50%) and restenosis (54%) lesions. These data suggest that for the treatment of most coronary stenoses, PTCA is required after MRA to achieve satisfactory lumen enlargement or to salvage complications. Angiographic complications appear to be more common after MRA, and salvage PTCA often is required to manage these device-induced complications. The combination of MRA and PTCA does not prevent restenosis.

Long-term outcome following successful reopening of abrupt closure after coronary angioplasty

Abrupt closure after coronary angioplasty is often successfully treated by repeat dilation. Long-term follow-up, including 6-month repeat catheterization and 12-month clinical evaluation, was obtained in 1,056 patients treated with acute (n = 335) or elective (n = 721) coronary angioplasty to evaluate the long-term impact of successful reopening of abrupt closure. Abrupt closure occurred in 13.5% of patients and was successfully reopened in 58%. Adverse outcomes including restenosis, death, bypass surgery, myocardial infarction and repeat angioplasty were compared between patients with successfully treated abrupt closure and those with successful procedures (residual diameter stenosis ≤ 50%) without abrupt closure. For patients with acute angioplasty, the restenosis rates (>50% diameter stenosis at follow-up) were 64% for those with successfully treated abrupt closure versus 36% for those with successful procedures without abrupt closure (p < 0.01). In addition, subsequent myocardial infarction (12 vs 3%; p = 0.01) and repeat angioplasty (21 vs 10%; p = 0.03) were more frequent in the group with abrupt closure. For patients with elective angioplasty, restenosis was 43% in those with successfully treated abrupt closure versus 45% in those without abrupt closure (p = NS). Subsequent death and myocardial infarction were more frequent in patients with abrupt closure (death: 12 vs 3% [p < 0.01]; myocardial infarction: 13 vs 3% [p < 0.01]). Long-term adverse events are increased in patients with successfully treated abrupt closure compared to those with successful procedures without abrupt closure.

Rotational coronary atherectomy after unsuccessful coronary balloon angioplasty

The clinical and angiographic outcome of patients undergoing rotational coronary atherectomy after unsuccessful balloon angioplasty was evaluated using quantitative angiographic methods to provide insight into this procedure's mechanism of benefit. During the study period, 41 patients (50 lesions) were referred for rotational atherectomy after standard balloon angioplasty was unsuccessful. After rotational atherectomy, percent diameter stenosis was reduced from 72 ± 14% to 41 ± 16% (p < 0.001); adjunct balloon angioplasty was performed in 44 lesions (88%), resulting in a 25 ± 17% final diameter stenosis (p < 0.001). The acute gain in minimal lumen diameter was 1.20 ± 0.59 mm. In lesions needing adjunct balloon dilatation, lesion stretch was 73 ± 27%, and elastic recoil was 22 ± 18%, with no variation by etiology of the initial balloon failure. Overall angiographic success (<50% residual diameter stenosis) was obtained in 49 lesions (98%). Procedural success, defined as <50% residual diameter stenosis and the absence of major in-hospital complications (death, Q-wave myocardial infarction or emergency bypass surgery), was obtained in 37 of 41 procedures (90%); complications developed in 3 patients (7%), including 2 who needed emergency bypass surgery after development of delayed abrupt closure. It is concluded that rotational coronary atherectomy may be used in selected patients when standard balloon angioplasty is unsuccessful. Its mechanism of benefit appears related, at least in part, to changes in plaque compliance resulting from partial atheroma ablation.

Functional health status in male patients without restenosis following successful PTCA.

In a prospective pilot study, subjective and objective parameters of the health status were assessed in 148 male patients (mean age 56 +/- 8.4 years) before and 4 months after successful coronary angioplasty (PTCA). Restenosis was defined as residual diameter stenosis > 50%. Although 96 patients (65%) had not developed restenosis at 4 months' invasive follow-up, subjective assessment of general well-being was unchanged in 26% or worse in 71%; overall anginal status and exercise performance had however improved. Of 71 men younger than 60 years who had no restenosis at follow-up, 4 men retired and 13 remained on medical leave. The striking disparity between subjective and objective parameters was not related to significant differences of age, exercise capacity, and left ventricular ejection fraction, as well as to baseline characteristics (previous myocardial infarction, extent of coronary heart disease, comorbidity) compared with 52 patients with restenosis. Thus, despite documented sustained success after PTCA, the majority of patients failed to resume the status of subjective well-being.

Recanalization of Coronary Artery Occlusion in Patients with Acute Myocardial Infarction by Use of Brushing Wire—Case Reports

A new coronary intervention using a brushing wire was performed in 11 patients at emergency. All patients were found to have a total obstruction in a coronary artery or a coronary bypass graft. In all patients, thrombolytic ther apy had been performed, without achieving coronary recanalization. Infarct- related arteries on which this technique was used were the left descending artery in 8 patients, right coronary artery in 2 patients, and a bypass graft in 1 patient. The mean ischemic time was 4.18 ±2.59 hours. Coronary recanalization was obtained in all patients (100%). The residual diameter stenosis was less than 50% in 3 patients, between 50% and 95% in 5 patients, and more than 95% in 3 patients. Preserved left ventricular ejection function was 57.0±12.8%. Ventricular fibrillation occurred in 2 cases owing to thrombolytic therapy. Additional intervention was performed with percuta neous transluminal angioplasty in 3 patients and with coronary artery bypass grafting in 7 patients. One patient underwent CABG following PTCA. Addi tional intervention was not required in 2 patients.

Background and methods for the lovastatin restenosis trial after percutaneous transluminal coronary angioplasty

Restenosis remains a critical limitation of percutaneous transluminal coronary angioplasty (PTCA). Recent experimental and clinical data have suggested that lovastatin, an hydroxymethylglutaryl coenzyme A reductase inhibitor, may reduce the rate of restenosis through reduction of low density-lipoprotein (LDL) cholesterol or possibly by direct effects. Lovastatin may therefore produce favorable alterations in endothelial healing, resulting in a decreased smooth muscle cell proliferative response to injury after angioplasty. Emory University, in conjunction with Merck Research Laboratories, has initiated a 10-center double-blinded, placebo-controlled, randomized trial to assess the effect of both pretreatment and aggressive lipid lowering with lovastatin in reducing the rate of restenosis. Lovastatin achieves approximately 75% of its effect on LDL cholesterol by 1 week. Thus, patients scheduled for PTCA are randomly assigned pretreatment with lovastatin, 40 mg twice daily, or placebo 7 to 10 days before PTCA. Therapy is continued for 6 months, at which time repeat coronary arteriography is performed. A detailed safety algorithm was designed, with patients receiving lovastatin and matching placebo back-titrated on a 1:1 basis for LDL cholesterol <50 mg/dl. The power is a 90%, α = 0.05, 2-tailed test to reduce restenosis from 30 to 15%. The sample size is 360 patients in the 2 arms; allowing for a 10% dropout rate, approximately 400 patients will be randomized. Patients with successful PTCA, <50% residual diameter stenosis and ≥20% diameter stenosis reduction are analyzed for restenosis at 4 to 6 months by quantitative coronary arteriography. All lipid values and quantitative coronary artery measurements are performed by core laboratories unaware of clinical data. All data are handled through the biostatistical coordinating center at Emory. Monthly safety reports are made to a Data and Safety Monitoring Board. The primary end point is recurrence of ≥50% diameter narrowing of an index site, the first nontotally occluded native site successfully dilated. Secondary end points are absolute minimal luminal diameter (in mm), recurrence in non-index lesions, exercise response, thallium scintigraphy and cardiac events. The design of this trial is aimed at providing definitive information on the effects of lovastatin monotherapy in preventing restenosis after coronary angioplasty.

Relationship between the preexistent coronary collateral circulation and successful intracoronary thrombolysis for acute myocardial infarction

The purpose of this study was to evaluate whether the existence of coronary collateral circulation influences recanalization rates of intracoronary thrombolysis. The study population consisted of 85 consecutive patients undergoing intracoronary thrombolysis within 6 hours after the onset of the first acute myocardial infarction, all of whom had a complete occlusion of the infarct-related coronary artery. Intracoronary thrombolysis with high-dose urokinase (960,000 IU) was attempted at a rate of 24,000 IU/min. Of 18 patients (group A) who had good angiographic collateral circulation to the area perfused by the infarct-related coronary artery, the obstructed artery was recanalized to a residual luminal diameter stenosis of ≦90% (successful recanalization) in only five (28%). In contrast, of 67 patients (group B) with poor or no collateral circulation, recanalization was successful in 40 (60%) ( p < 0.05). Antegrade flow of infarct-related arteries was observed following thrombolysis in 12 (67%) of 18 group A patients and in 56 (84%) of 67 group B patients ( p = NS). It was concluded that (1) the presence of collaterals correlates with the presence of high-grade stenosis; (2) the presence of collaterals is inversely related to the efficacy of thrombolytic therapy; and (3) the difference in successful recanalization rates observed between the two groups grabably reflects the impact of underlying stenosis severity on the effectiveness of lytic therapy.

Clinical, physiologic, anatomic and procedural factors predictive of restenosis after percutaneous transluminal coronary angioplasty

In a recent prospective double-blind placebo-controlled trial, a combination of aspirin and dipyridamole was not associated with a reduction in the rate of restenosis within the 1st 6 months after coronary angioplasty. The purpose of this study was to determine whether clinical, anatomic or procedural factors were predictive of the observed restenosis rates in that prospective trial. A total of 247 patients and 280 segments underwent follow-up angiography and quantitative coronary angiographic analysis between 4 and 7 months after coronary angioplasty.Two baseline clinical characteristics—angina class and duration of angina in months—were related to the rate of restenosis by univariate analysis. Patient-related stepwise logistic regression analysis identified severity of angina as the only clinical predictor of restenosis.Three univariate baseline anatomic characteristics—percent diameter stenosis before angioplasty, stenosis > 10 mm in length and calcific stenosis—and two early postangioplasty characteristics—residual percent diameter stenosis and residual mean pressure gradient—were predictive of restenosis. Of these, only two—length of stenosis and residual percent diameter stenosis—were independently related to restenosis by multivariate analysis and only the former is identifiable before the procedure.It is concluded that in prospective studies in contrast to retrospective studies, few clinical and anatomic factors appear to be predictive of restenosis after coronary angioplasty.

Frequency of low-grade residual coronary stenosis after thrombolysis during acute myocardial infarction

The clinical, angiographic and demographic characteristics of 42 patients with low-grade (<50%) residual stenosis at the infarct lesion after thrombolysis for acute myocardial infarction (MI) were assessed. The study group (group I) represented 21% of 198 consecutive patients receiving thrombolytic therapy over a 59-month period. Data on the 156 remaining patients were pooled for comparison (group II). Group I patients were predominantly men (86%) who were cigarette smokers (81%). Group II patients were predominantly men (75%, p > 0.10) but were significantly older (52 ± 12 vs 56 ± 10 years, p = 0.02). Prior acute MI or angina was unusual in group I. Sixty percent had no significant (>50%) residual coronary artery disease while 25% had residual single artery disease. Average significant (>50% diameter stenosis) residual vessel disease was 0.6 ± 1.0 for group I and 1.9 ± 0.9 for group II (p < 0.001). In group I, average residual infarct lesion diameter stenosis was 36 ± 7% in the right anterior oblique and 34 ± 8% in the left anterior oblique views. Thirty-nine group I patients were discharged with medical therapy and 100% follow-up was obtained over a mean interval of 18 ± 17 months. Fifteen patients experienced chest pain after acute MI accounting for 17 discrete events. Fifty-nine percent of group I had a benign course on follow-up. Eight events were classified as unstable angina, 4 as acute MI and 5 as atypical angina. Documented coronary vasospasm occurred in 3. The infarct narrowing accounted for 58% of documented ischemia and 41% of symptomatic events. Antiplatelet agents, warfarin and residual lesion morphology did not clearly influence frequency of events, whereas data regarding cigarette smoking were suggestive (p = 0.06). Events clearly associated with the infarct narrowing occurred earlier (4 ± 4 months) than events not related to (23 ± 15 months, p < 0.01). Ischemic events unrelated to the infarct lesion were often related to progressive stenosis or occlusion at the site of previously nonsignificant disease.

Retrieval of vein graft suture fragments with directional coronary atherectomy: A note of caution

Purpose: The purpose of this study was to evaluate the outcomes of our 6-year experience with directional atherectomy used for treatment of stenoses in infrainguinal vein grafts.Methods: From March 1988 to April 1994, 52 directional atherectomy procedures were undertaken in 42 patients to treat 67 stenoses in 44 vein grafts. Follow-up consisted of periodic physical examinations and graft surveillance: ankle/brachial indexes, pulse volume recordings, and color-flow duplex ultrasonography. Follow-up angiography (n=18) was performed for recurrent symptoms, reproducible drop in ankle/brachial index of greater than 0.15, a twofold to threefold focal increase in peak systolic velocity, or incidentally during evaluation of the opposite leg.Results: Forty-nine of 52 (94%) procedures were technically successful. In two the residual diameter stenosis was greater than 30%, and in one atherectomy could not be performed. Complications were minor in six (11%) and major in three (6%): two acute graft occlusions and one delayed pseudoaneurysm at the atherectomy site. There were no deaths at 30 days. With a mean follow-up of 21±18 months, 36 of 44 grafts (82%) remained patent without restenosis; 6 other were patent but considered “failed” −5 (11%) with restenosis, 1 with a pseudoaneurysm; and 2 grafts (5%) occluded. Clinically 33 of 44 extremities (75%) were asymptomatic during follow-up. Claudication improved in five, recurred in three, and was unchanged in one. There was one below-knee amputation. Life-table analysis including all 52 procedures reveals cumulative primary atherectomy patency rates for the 44 grafts of 82%, 78%, and 78%, respectively, at 1,2, and 3 years after atherectomy, and 86%, 83%, and 83% for the 67 individual stenoses treated.Conclusions: Directional atherectomy of vein graft stenoses has high technical and clinical success rates, acceptably low morbidity rates, and offers better sustained patency rates than balloon angioplasty. Its long-term patency rate seems to approach that of surgical vein patch angioplasty.

Comparison of dissection rates and angiographic results following directional coronary atherectomy and coronary angioplasty

Directional coronary atherectomy is a new percutaneous transluminal technique for treating occlusive coronary artery disease. In this study, angiographic results (i.e., residual stenosis and angiographic evidence of postprocedure dissection) after directional coronary atherectomy and balloon angioplasty were compared. The atherectomy group consisted of 91 lesions in 83 consecutive patients who underwent either left anterior descending artery or right coronary artery atherectomy. The angioplasty group consisted of 91 lesions in 84 patients that were matched with the atherectomy lesions with respect to vessel and whether the lesion was a restenosis lesion. The mean preprocedure diameter stenosis was 76% in both groups as measured quantitatively with electronic calipers. After the procedure, the mean residual diameter stenosis of the atherectomy lesions was 13 ± 17%, whereas for the angioplasty lesions it was 31 ± 18% (p < 0.001). Success rates in both groups were similar (94.5 and 93.4%, respectively). The incidence of postprocedure dissection was 11% in the atherectomy group and 37% in the angioplasty group (p < 0.0001). Directional coronary atherectomy results in significantly improved postprocedure angiographic appearances due to significantly less severe residual stenosis and lower incidence of dissection.

Reocclusion three months after successful thrombolytic treatment of acute myocardial infarction with anisoylated plasminogen streptokinase activating complex

Thirty consecutive patients with acute myocardial infarction (AMI) were treated with anisoylated plasminogen streptokinase activating complex (APSAC) within 4 hours after onset of symptoms. After 1.5 and 48 hours, patency of the infarct-related vessel and the quantitative degree of residual diameter stenosis were studied by selective coronary angiography. Ventriculograms were made to determine the global left ventricular ejection fraction. Patients showing patency at 48 hours were reevaluated anglographically after 3 months. At 1.5 and 48 hours after APSAC administration patent vessels were demonstrated in 6S and 69% of patients, respectively. Mean residual stenosis decreased significantly from 56 ± 11% at 1.5 hours to 46 ± 13% at 48 hours (p <0.01). Patients not responding to thrombolytic therapy showed significant deterioration of the left ventricular function during the first 48 hours after AMI. Side effects were minor and mainly associated with invasive procedures. Despite adequate oral anticoagulation, angiographically documented Roccusion at 3 months amounted to 28%. Reocclusion, however, was neither associated with clinically documented reinfarction, nor with a decrease in the left ventricular ejection fraction. Our study shows that APSAC is an effective thrombolytic agent in AMI but that late Roccusion may occur. Oral anticoagulants appear to be less effective in the prevention of reocclusion in the treatment regimen after thrombolysis.

Increased frequency of restenosis in patients continuing to smoke cigarettes after percutaneous transluminal coronary angioplasty

The influence of continued cigarette smoking on restenosis after percutaneous transluminal coronary angioplasty (PTCA) was retrospectively determined through a study of 160 patients with primary success who underwent follow-up angiography after a mean of 7 ± 7 months. The average number of narrowings at risk for restenosis was 1.7/patient in the 84 patients who continued to smoke (group 1) and 1.9/patient in the 76 patients who stopped smoking at the time of PTCA (group 2) (difference not significant). The 2 patient groups at baseline were similar with respect to gender, frequency of diabetes mellitus, number of pack/year smoking, angina class and number of diseased coronary arteries. The location of the dilated narrowings, the residual luminal diameter stenosis and the transstenotic gradient after the procedure were similar in both groups. The recurrence of angina ≥ class II was the reason for restudy in 43% and 36% of group 1 and group 2 patients, respectively. Restenosis, defined as the presence of ≥50% narrowing at the site of previous successful dilatation at follow-up angiography, was significantly higher in group 1 compared with group 2 patients (55% vs 38%, p = 0.03). Continued smoking was selected as an independent predictor of restenosis by logistic regression analysis. The incidence of coronary artery disease progression (14% vs 10%) was not significantly different between the 2 groups. In conclusion, continued smoking after successful PTCA is associated with an increased risk of restenosis. The higher restenosis rate in smokers emphasizes the need to strengthen educational programs after PTCA.

Assessment of residual coronary arterial stenosis after thrombolytic therapy during acute myocardial infarction

Maximal myocardial salvage appears to be related to the severity of residual coronary arterial stenosis after thrombolysis. The degree of residual infarct vessel stenosis was assessed in 119 consecutive patients with patent arteries who received streptokinase during acute myocardial infarction. After administration of streptokinase, 99 of 119 patients (83%) had a residual stenosis 70% or more in diameter. Assuming that a residual diameter stenosis of at least 70% is flow limiting, the feasibility for percutaneous transluminal coronary angioplasty (PTCA) was determined by the following criteria: length less than 10 mm, no significant distal narrowing or left main stenosis, and an adequate-sized distal artery. In 81 of 99 patients (82%), arterial anatomy was suitable for PTCA. Thus, after therapy with streptokinase for acute myocardial infarction, most patients have a significant infarct arterial residual stenosis and are candidates for PTCA.

Follow-up after coronary arterial reperfusion with intravenous streptokinase in relation to residual myocardial infarct artery narrowings

Short- and long-term changes in residual stenosis of the myocardial infarct-related coronary arteries in patients with successful reperfusion by intravenous streptokinase have not been determined until now. In 15 patients the residual diameter stenosis decreased significantly from 62 ± 9% after 24 hours to 55 ± 13% in the fourth week (p < 0.005). Quantitative angiographic analyses in 61 patients with patent infarct-related coronary arteries in the fourth week revealed a mean diameter stenosis of 61 ±13%. The patients were followed up 34 ± 10 months. Sixteen had elective coronary artery bypass surgery or percutaneous transluminal coronary angioplasty (PTCA). Eighteen without coronary artery bypass surgery or PTCA had undergone repeat angiography after 26 ± 9 months. Twenty-five (41%) have had a residual diameter stenosis greater than 65% in the fourth week. A stenosis greater than 65% was found in: 4 of 5 patients with late reinfarction; 3 of 7 with 1-vessel coronary artery disease and persistent angina, compared with none of 11 with a stenosis less than 65%; 6 of 7, whose silent reocclusion had been found at long-term follow-up compared with 1 of 9 with a residual stenosis less than 65%. In 8 patients with persistent patency of the infarct artery, the stenosis had decreased significantly from 55 ± 6% to 36 ± 12% (p < 0.005). Correspondingly, there was a significant improvement in the infarct-related left ventricular wall motion disorders. These data indicate that in patients with less severe residual stenosis in the fourth week after successful intravenous strepto-kinase the long-term course is relatively uneventful, whereas reocclusion or reinfarction in the same myocardial territory is frequent in patients with a stenosis greater than 65%. PTCA may be advisable in these latter patients.