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

Closure of a Popliteal Arteriovenous Fistula Using an Autologous Vein-Covered Palmaz Stent

Purpose:

To report the use of autologous vein to cover a stainless steel stent designated for repair of a traumatic popliteal arteriovenous (AV) fistula.

Methods and Results:

Autologous cephalic vein was harvested to cover a Palmaz biliary stent selected to close a traumatic popliteal AV fistula that persisted despite reparative attempts with balloon occlusion and coil embolization. The vein-covered stent was delivered percutaneously and deployed, successfully obliterating the vascular communication. Patency of the popliteal artery was documented arteriographically at 5 months, and symptomatic improvement continues at 10 months.

Conclusion:

The simplicity of this percutaneous approach and the use of autologous vein to cover endovascular prostheses create the possibility for evaluating this technique in myriad anatomical situations.

In-stent ulceration: an unusual pathology

In-stent restenosis occurs in 10–60% of cases undergoing interventional therapy. Many mechanisms explain the reason for in-stent restenosis, but restenosis due to an ulcerated plaque is very rare and has not been well reported in the literature. We report an interesting case of 72-year-old man presenting with neurological symptoms secondary to in-stent restenosis of the carotid artery caused by an ulcerated plaque. We also explain the different mechanisms for restenosis along with the treatment options.

Drug-Eluting Stents Versus Bare Metal Stents in Saphenous Vein Graft Intervention

Percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) is associated with higher adverse event rates, lower procedural success, and inferior longterm patency rates compared with native vessel PCI. The ability to comply with dual antiplatelet therapy, and whether the patient will need an interruption in dual antiplatelet therapy, should be considered when deciding whether to implant a drug-eluting stent (DES) or bare metal stent (BMS) in an SVG. DES should be used for SVG PCI because they seem to reduce target vessel revascularization. This article reviews the evolution and contemporary evidence regarding use of DES versus BMS in SVG PCI.

Nanotechnology Applications in Vascular Disease

The confluence of nanotechnology and medicine: Nanomedicine is poised to revolutionize the delivery of health care to individuals and populations in the 21st century. Every medical specialty stands to be impacted as emerging nanotechnologies propel modalities for prevention, screening, diagnosis, and treatment. Medical interventions targeting vascular disease are becoming increasingly important, given current epidemiologic trends in morbidity and mortality due to these diseases. Vascular disease is a term that encompasses a collection of pathologies that affect the vessels (arteries, veins, and lymphatics) or vasculature in the body. The purpose of this article is to highlight current and emerging nanotechnologies aimed at vascular disease. Select, clinically relevant examples are described in the categories of drugs and drug delivery, imaging, sensors, biomaterials, diagnostics, and novel therapeutics. Several promising nanomedicine applications that target vascular disease are currently under various stages of development from bench top research to clinical trials. Given the rate of investment, promising research results and progression of many products to market nanomedicine applications in the prevention, diagnosis, and treatment of vascular disease holds great promise for improving the stand of care.

Short- and long-term outcomes after stent-assisted percutaneous treatment of saphenous vein grafts in the drug-eluting stent era

Percutaneous treatment of saphenous vein graft (SVG) lesions has been associated with higher rates of periprocedural complications and restenosis compared with non-SVG lesions. Whether these outcomes are similar in contemporary clinical practice, particularly when drug-eluting stents are used, is unknown. We evaluated outcomes of 110 consecutive patients who were treated with stent-assisted percutaneous coronary intervention for 145 SVG lesions (drug-eluting stents used in 91.0% of lesions). Embolic protection devices were used in 52.1% of treated grafts. Adverse events were recorded up to 1 year. Major or minor periprocedural myocardial necrosis occurred in 11 patients (10.9%). At 1-year clinical follow-up, we observed 13 myocardial infarctions (13.7%), 8 target lesion revascularizations (8.4%), 18 target vessel revascularizations (19.0%), 2 stent thromboses (2.1%), and 7 deaths (7.4%). The incidence of major adverse cardiac events, defined as death, myocardial infarction, or target vessel revascularization, was 30.5% at 1 year. By multivariable analysis, the presence of thrombus inside the graft before the procedure and the length of the stented segment were independent predictors of major adverse cardiac events at 1 year (hazard ratio for thrombus 4.07, 95% confidence interval 1.90 to 8.68, p = 0.0003; hazard ratio per millimeter of stented length 1.02, 95% confidence interval 1.01 to 1.03, p = 0.025). In conclusion, our data show that patients with SVG lesions remain a high-risk subgroup with worse outcomes after percutaneous coronary intervention compared with native vessel disease even in the era of drug-eluting stents.

Results and predictors of angiographic restenosis and long-term adverse cardiac events after drug-eluting stent implantation for aorto-ostial coronary artery disease

The correlates of angiographic and clinical outcomes after drug-eluting stent (DES) implantation for aorto-ostial lesions remain unknown. This study evaluated long-term results of DES implantation for aorto-ostial lesions and determined risk factors for restenosis and adverse cardiac events. In total, 184 consecutive patients who underwent DES implantation for aorto-ostial lesions were investigated (DES group) compared with 172 consecutive patients treated with bare metal stents before the introduction of DESs (pre-DES group). Major adverse cardiac events (MACEs) were defined as death, Q-wave myocardial infarction, and need for target lesion revascularization. The DES group had significantly higher risk clinical and procedural profiles than the pre-DES group. Procedural success rates were 99.5% in the DES group and 100% in the pre-DES group (p = 1.0). The DES group had a significantly lower incidence of in-segment restenosis (10.5% vs 26.0%, p = 0.001) and target lesion revascularization (4.3% vs 11.6%, p = 0.011). Cumulative MACE rates at 1 year were 6.5% in the DES group and 13.4% in the pre-DES group (p = 0.03). By multivariate analysis, treatment of bypass graft, treatment of in-stent restenosis, and reference vessel diameter were predictors of restenosis, and only reference vessel diameter (hazard ratio 0.20, 95% confidence interval 0.05 to 0.75, p = 0.017) inversely correlated with 1-year MACEs after DES implantation. In conclusion, DES implantation for aorto-ostial lesions is associated with a significant decrease in restenosis and MACEs compared with the pre-DES phase. Treatment of bypass graft and in-stent restenosis and reference vessel size were identified as predictors of restenosis and/or long-term MACEs after DES implantation.

A meta-analysis of randomized controlled trials of intracoronary gamma- and beta-radiation therapy for in-stent restenosis

We assessed the effectiveness of intracoronary brachytherapy and compared treatment effects for the two radiation sources as well as the performance of the procedure in saphenous vein grafts (SVG) and native coronary arteries. Five randomized controlled trials comparing intracoronary brachytherapy with placebo involving a total of 1310 patients were reviewed for a meta-analysis. Risk differences (RD) for major adverse cardiac events (MACE), target vessel revascularization, target lesion revascularization, and angiographic binary restenosis at 6-12 months were computed, and a meta-regression analysis of MACE was performed. For MACE, the RD was 0.19 (95% confidence interval [CI], 0.09%-0.29%; P value, 0.00); there was significant between-study variance of 0.2395. In univariate meta-regression analyses, diabetes was a significant factor for the between-study variance (P value, 0.000). In multivariate meta-regression analyses adjusted for diabetes and lesion length, neither gamma-radiation source nor SVG was a significant factor for the between-study variance (P value, 0.675 and 0.433, respectively); the adjusted between-study variance was 0.000. Intra-coronary brachytherapy is effective compared with placebo at mid-term follow up. Neither procedure in SVG (gamma radiation) nor difference in radiation source (beta or gamma) in native coronary arteries was a significant factor in brachytherapy effectiveness compared to placebo.

Impact of internal mammary artery conduit on long-term outcomes after percutaneous intervention of saphenous vein graft

BACKGROUND

The influence of an internal mammary artery (IMA) graft on long-term outcomes after percutaneous saphenous vein graft (SVG) intervention is currently unknown.

METHODS AND RESULTS

To examine the impact of IMA on outcomes in patients undergoing SVG interventions, we analyzed 2119 patients from the Duke Cardiovascular Disease Database (1986-2003) with prior coronary artery bypass surgery undergoing cardiac catheterization who had at least 1 SVG graft. Patients were categorized into 4 groups: group I, SVG intervention and patent IMA; group II, no SVG intervention and patent IMA; group III, SVG intervention without patent IMA; and group IV, no SVG intervention without patent IMA. At a median follow-up of 4.8 years (interquartile range, 2.1 to 8.8 years), adjusted survival rates in groups I, II, III, and IV were 72.8%, 72.3%, 64.5%, and 58.9%, respectively. Multivariate Cox proportional hazards modeling showed similar survival for groups I and II (P=0.63) and for groups III and IV (P=0.33). The presence of IMA graft was related to lower long-term mortality (adjusted hazard ratio [HR], 0.69; 95% CI, 0.58 to 0.82), whereas SVG intervention was not associated with long-term mortality (adjusted HR, 0.94; 95% CI, 0.81 to 1.10). In contrast, the adjusted event-free rates for nonfatal myocardial infarction were lower in the SVG intervention groups (groups I and III) than in the non-SVG intervention groups (groups II and IV) (HR for SVG intervention versus no SVG intervention, 3.19; 95% CI, 2.18 to 4.66), with the presence of patent IMA conferring no significant benefit on this outcome (HR, 1.37; 95% CI, 0.91 to 2.08).

CONCLUSIONS

In patients undergoing SVG interventions, survival, but not nonfatal myocardial infarction, is favorably influenced by the presence of patent IMA. In contrast, SVG intervention had no measurable survival benefit but was associated with an increased risk of nonfatal myocardial infarction.

Treatment of aortocoronary graft lesions with graft-stents

OBJECTIVE

Previous controlled trials do not indicate a superiority of the polytetrafluoroethylene membrane-covered stent graft compared with a conventional stent with respect to acute results, restenosis, or clinical event rates. We evaluated the outcome of stenting aortocoronary bypass grafts with polytetrafluoroethylene-covered stent.

METHODS

The study included 64 patients who had 73 saphenous graft-stent implants. Clinical follow-up was obtained for a median of 6.2 months (1-9 months) for 54 patients.

RESULTS

The mean age of the grafts was 9.2+/-6 years (2-14 years). Procedural success was achieved in 72 of 73 lesions (98.6%). One patient having an anterior Q-wave myocardial infarction died on the second day of procedure. Four patients (6.2%) sustained distal embolization and no reflow. No reflow was overcome after intracoronary administration of nitroglycerine and verapamil in two cases. At follow-up, stable angina pectoris had developed in 10 patients (18%), unstable angina pectoris in two patients (3.7%), acute myocardial infarction in two patients (3.7%), and cardiac death in one patient (1.8%). A total of 45 patients had a coronary angiogram at 6 months of follow-up or earlier, and restenosis at the target site was detected in eight of 53 lesions (15%).

CONCLUSIONS

Saphenous graft lesions can be managed successfully with polytetrafluoroethylene-covered stents with acceptable long-term clinical outcome. Further and larger studies are needed to compare conventional stents, polytetrafluoroethylene-covered stents, drug eluting stents, and additional benefit of distal protection devices in these subgroups.

In stent restenosis: bane of the stent era

The long term outcome of stent implantation is affected by a process called in stent restenosis (ISR). Multiple contributory factors have been identified, but clear understanding of the overall underlying mechanism remains an enigma. ISR progresses through several different phases and involves numerous cellular and molecular constituents. Platelets and macrophages play a central role via vascular smooth muscle cell migration and proliferation in the intima to produce neointimal hyperplasia, which is pathognomic of ISR. Increased extracellular matrix formation appears to form the bulk of the neointimal hyperplasia tissue. Emerging evidence of the role of inflammatory cytokines and suppressors of cytokine signalling make this an exciting and novel field of antirestenosis research. Activation of Akt pathway triggered by mechanical stretch may also be a contributory factor to ISR formation. Prevention of ISR appears to be a multipronged attack as no therapeutic "magic bullet" exists to block all the processes in one go.

Immediate and one-year outcome of percutaneous intervention of saphenous vein graft disease with paclitaxel-eluting stents

The aim of this study was to evaluate the outcome after paclitaxel-eluting stent implantation in 40 patients with 52 saphenous vein graft lesions. By Kaplan-Meier estimates, the probability of major adverse cardiac event-free survival for 1 year was 92.5%. A paclitaxel-eluting stent for saphenous vein graft disease appears to be feasible and safe, with a low rate of reintervention at 1 year, but late follow-up is needed to confirm these observations.

Incidence and predictors of target vessel revascularization and clinical event rates of the sirolimus-eluting coronary stent (results from the prospective multicenter German Cypher Stent Registry)

Randomized trials have demonstrated the ability of drug-eluting stents to decrease the risk of restenosis after coronary stent implantation. However, the incidences of major cardiovascular/cerebral adverse events (MACCEs) and target vessel revascularization (TVR) during follow-up in a routine clinical setting remain to be determined. We analyzed data of the multicenter German Cypher Stent Registry. From April 2002 to March 2003, 1,726 patients at 93 hospitals who received >/=1 sirolimus-eluting coronary stent were included. Median follow-up was 6.7 months. During follow-up, death occurred in 1.2% of patients (20 of 1,726), nonfatal myocardial infarction in 2.5% (43 of 1,706), and nonfatal stroke in 0.5% (7 of 1,469). TVR was performed in 8.6% of patients, with percutaneous coronary intervention in 7.3% and coronary artery bypass grafting in 1.5%. The overall rate of MACCEs or TVR was 10.8% (186 of 1,726). Independent predictors of TVR were the target vessel being a bypass graft (odds ratio [OR] 2.43, 95% confidence interval [CI] 1.41 to 4.18, p = 0.001), management of >1 lesion during the same intervention (OR 1.75, 95% CI 1.04 to 2.96, p = 0.035), 2- or 3-vessel disease (OR 1.69, 95% CI 1.05 to 2.72, p = 0.030), and age (per decade; OR 0.82, 95% CI 0.69 to 0.98, p = 0.025). These data confirm the safety and effectiveness of using the sirolimus-eluting stent in daily clinical practice. The management of bypass grafts and multiple lesions in 1 session and the presence of multivessel disease were predictors of MACCEs or TVR.

Clinical outcomes after sirolimus-eluting stent implantation for de novo saphenous vein graft lesions

The purpose of this study was to evaluate the clinical outcome of patients undergoing sirolimus-eluting stent implantation for de novo lesions within saphenous vein grafts (SVGs). Although the incidence of restenosis following sirolimus-eluting stenting (SES) of native coronary arteries is low, the efficacy of SES to treat de novo lesions within SVGs has not been well studied. A total of 35 patients underwent SES implantation of 39 lesions during 36 procedures. All patients had a minimum follow-up of 6 months following the index procedure. The mean bypass graft age was 10.1 +/- 6.5 years (range, 0-23 years). In-hospital major adverse cardiac events [death, myocardial infarction, thrombosis, or target vessel revascularization (TVR)] occurred in four patients (11%). Clinical follow-up was obtained in 100% of patients (mean follow-up, 7.5 +/- 2.2 months). There was one cardiac death, presumed due to stent thrombosis. TVR occurred in only two patients (6%). Myocardial infarction (MI) occurred in four patients (11%), all attributable to a nontarget vessel. The combined endpoint of death, MI, or TVR occurred in seven patients (20%). Freedom from death, nonfatal MI, thrombosis, or any revascularization was 65%. Early experience indicates sirolimus-eluting stents for de novo saphenous vein graft lesions have a low (6%) rate of clinically driven target vessel revascularization. By 7-month follow-up, event-free survival is limited primarily by disease in nontarget vessels.

Treatment of saphenous vein graft lesions with drug-eluting stents

OBJECTIVES

The purpose of the present report was to evaluate clinical and angiographic outcomes of drug-eluting stent (DES) implantation in saphenous vein graft (SVG) lesions.

BACKGROUND

The safety and efficacy of DES implantation for the treatment SVG lesions remains uncertain.

METHODS

We evaluated in-hospital and six-month outcomes in 61 consecutive patients treated with DES in SVG lesions from March 2002 to March 2004 (DES group), as compared to 89 consecutive patients treated with bare-metal stents (BMS) in the 24 months immediately before the introduction of DES (BMS group). Major adverse cardiac events (MACE) including death, myocardial infarction, target lesion revascularization (TLR), and target vessel revascularization (TVR) were recorded in-hospital and at six-month follow-up.

RESULTS

The rate of in-hospital MACE was similar between the two groups (6.6% vs. 5.6%, p = 1.0). Cumulative MACE at six months was 11.5% in the DES group and 28.1% in the BMS group (p = 0.02). The DES group had a significantly lower incidence of in-segment restenosis (10.0% vs. 26.7%, p = 0.03), TLR (3.3% vs. 19.8%, p = 0.003), and TVR (4.9% vs. 23.1%, p = 0.003). By Cox regression analysis, diabetes (hazard ratio [HR]: 3.03; 95% confidence interval [CI]: 1.33 to 6.90; p = 0.008), usage of BMS (HR: 2.53; 95% CI: 1.07 to 5.97; p = 0.03), and age of SVG (HR: 1.10; 95% CI: 1.02 to 1.19; p = 0.02) were identified as predictors of MACE at six-month follow-up.

CONCLUSIONS

Compared to BMS implantation, DES implantation in SVG lesions appears safe with favorable and improved mid-term outcomes.

Randomized study to compare balloon angioplasty and elective stent implantation in venous bypass grafts: the Venestent study

The aim of the study was to compare acute and long-term angiographic and clinical outcome of balloon angioplasty and elective stenting in de novo lesions in the body of a saphenous vein graft (SVG). A total of 150 patients, with de novo lesions in SVG, were randomly assigned to balloon angioplasty or elective Wiktor I stent implantation. The angiographic restenosis rate at 6-month follow-up was 32.8% in the balloon group and 19.1% in the stent group (P = 0.069). At 1-year follow-up, target vessel revascularization rate was 31.4% vs. 14.5% (P < 0.05), and event-free survival was 60.0% vs. 76.3% (P < 0.05) for the balloon and stent group, respectively. Elective stent implantation in de novo SVG lesions is associated with a significant lower target vessel revascularization rate and a significant higher event-free survival at 1-year follow-up as compared to balloon angioplasty.

A randomized trial of polytetrafluoroethylene-membrane-covered stents compared with conventional stents in aortocoronary saphenous vein grafts

We compared a conventional stent (Jostent Flex, Jomed GmbH, Rangendingen, Germany) with a polytetrafluoroethylene (PTFE)-membrane-covered stent (Jostent Stentgraft) in patients undergoing intervention of a stenosis in an obstructed vein graft. The use of stents improved results of percutaneous revascularization of obstructed vein grafts, but did not demonstrate the reduced elevated restenosis rate. In addition, long-term clinical event rate is still high compared with intervention in native vessels. Observational studies suggested that stents covered with a PTFE membrane might be associated with a low complication and restenosis rate in venous bypass grafts. This prospective multicenter study included a total of 211 patients who were randomly assigned to receive either a Flex stent or Stentgraft. The primary end point was binary restenosis rate at six months by core lab quantitative coronary angiography. Acute success and procedural events were comparable between the two groups. Restenosis rate was not significantly different between the Flex (20%) and the Stentgraft (29%) groups (p = 0.15), although there was a nonsignificant trend toward a higher late occlusion rate in the Stentgraft group (7% vs. 16%, p = 0.069) at follow-up. Likewise, after a mean observation period of 14 months, cumulative event rates (death, myocardial infarction, or target lesion revascularization) were comparable in the two groups (31% vs. 31%, p = 0.93). This controlled trial does not indicate a superiority of the PTFE-membrane-covered Stentgraft compared with a conventional stent with respect to acute results, restenosis, or clinical event rates.

Randomized evaluation of polytetrafluoroethylene-covered stent in saphenous vein grafts: the Randomized Evaluation of polytetrafluoroethylene COVERed stent in Saphenous vein grafts (RECOVERS) Trial

BACKGROUND

Treatment of lesions located in saphenous vein grafts (SVGs) is associated with increased procedural risk and a high rate of restenosis.

METHODS AND RESULTS

We conducted a randomized, multicenter trial to evaluate the usefulness of a polytetrafluoroethylene (PTFE)-covered stent compared with a bare stainless steel (SS) stent for prevention of restenosis and major adverse cardiac events (MACE) in patients undergoing SVG treatment. The primary end point was angiographic restenosis at 6 months. Secondary end points were 30-day and 6-month MACE rates, defined as the cumulative of death, myocardial infarction (MI), and target lesion revascularization. Between September 1999 and January 2002, 301 patients with SVG lesions were randomized to either the PTFE-covered JoStent coronary stent graft (PTFE group, n=156) or the SS JoFlex stent (control group, n=145). Angiographic and procedural success rates were similar between the 2 groups (97.4% versus 97.9% and 87.3% versus 93.8%, respectively). The incidence of 30-day MACE was higher in the PTFE group (10.9% versus 4.1%, P=0.047) and was mainly attributed to MI (10.3% versus 3.4%, P=0.037). The primary end point, the restenosis rate at 6-month follow-up, was similar between the 2 groups (24.2% versus 24.8%, P=0.237). Although the 6-month non-Q-wave MI rate was higher in the PTFE group (12.8% versus 4.1%, P=0.013), the cumulative MACE rate was not different (23.1% versus 15.9%, P=0.153).

CONCLUSIONS

The study did not demonstrate a difference in restenosis rate and 6-month clinical outcome between the PTFE-covered stent and the SS stent for treatment of SVG lesions. However, a higher incidence of nonfatal myocardial infarctions was found in patients treated with the PTFE-covered stent.

Treatment of in-stent restenosis with excimer laser coronary angioplasty

Diffuse in-stent restenosis remains an important problem in percutaneous transluminal coronary angioplasty (PTCA). In this trial, we studied the early and mid-term outcomes of excimer laser coronary angioplasty (ELCA) on diffuse in-stent restenosis. ELCA was performed in 23 patients (19 males). The mean length of the lesions was 14.3 +/- 3 mm and the mean age was 58 +/- 7 years. The minimal lumen diameter (MLD) was measured by on-line quantitative coronary angiography. Before the procedure, MLD was 0.9 +/- 0.4. The Q/non-Q-wave myocardial infarction (MI), coronary artery bypass graft (CABG), PTCA, and mortality were recorded during the procedure and at 6 months follow up. The fluence of laser emission was 45 mj/m2 and the repetition rate was 25 pulses per second. Adjunctive balloon angioplasty was performed in all of the cases at a mean 7 +/- 2 atm pressure. The procedure was successfully performed in all of the cases. Type-B dissection developed, after ELCA in 1 patient (4%). Perforation, death, cerebrovascular accidents, emergency CABG, PTCA or Q/non-Q wave myocardial infarction were not observed. MLD was 0.9 +/- 0.4 mm before ELCA, 1.8 +/- 0.9 mm (P<0.05) after ELCA, and 3.1 +/- 0.7 mm after PTCA. At 6 months follow up, there were 2 (8.7%) Q-wave myocardial infarctions and 2 (8.7%) recurrent anginal pain cases. Control angiography was obtained in 20 cases (87%). Control angiography was not accepted by 3 patients. Their maximal exercise test was negative. Angiographic restenosis was observed in 6 cases (30%). The rate of target lesion revascularization (TLR) was 5 of 23 (22%) in the patients treated with ELCA. It is concluded, ELCA is a safe and efficient debulking technology for treating diffuse in-stent restenosis.

Directional coronary atherectomy vs. rotational atherectomy for the treatment of in-stent restenosis of native coronary arteries

Management of in-stent restenosis has become a significant challenge in interventional cardiology. Since the mechanism of in-stent restenosis is predominantly intimal hyperplasia, debulking techniques have been used to treat this condition. This study is a nonrandomized comparison of the immediate and long-term results of directional coronary atherectomy (DCA; n = 58) vs. high-speed rotational atherectomy (ROTA; n = 61) for the treatment of in-stent restenosis of native coronary arteries. There were no in-hospital deaths, Q-wave myocardial infarctions, or emergency coronary artery bypass surgery in either group. DCA resulted in a larger postprocedural minimal luminal diameter of (2.57 +/- 0.51 vs. 2.14 +/- 0.37 mm; P < 0.0001) and a larger acute gain (1.83 +/- 0.52 vs. 1.42 +/- 0.48 mm; P < 0.0001). Furthermore, 12-month clinically indicated target lesion revascularization (39% vs. 21%; P = 0.02) and long-term follow-up MACE (44% vs. 28%; P = 0.03) was greater in the ROTA group. The present study suggests that DCA appears to be superior to ROTA for the treatment of in-stent restenosis of native coronary arteries. Compared to ROTA, the debulking effect of DCA leads to a larger postprocedure minimal luminal diameter, and a lower incidence of subsequent target lesion revascularization and MACE.

Diffuse in-stent restenosis

Stent restenosis, especially the diffuse pattern, has developed into a significant clinical and economical problem. It has been estimated that up to 250,000 patients developed in-stent restenosis in 2,000 alone, two thirds of them can be expected to have diffuse in-stent restenosis, which is difficult to treat because of high recurrence rates. None of the conventionally available interventional treatment modalities provides optimal long-term results. Intravascular radiation therapy is currently the only effective percutaneous therapy for combating in-stent restenosis. Late thrombotic complications have largely been eliminated by extended antiplatelet regimens. Geographical miss, a major reason for recurrence of in-stent restenosis after brachytherapy, can be reduced by an improved radiation technique. The first preliminary data on drug-eluting stents, showing only minimal neointimal proliferation at 6-month postimplantation, could represent a major breakthrough in the quest to solve restenosis.

Feasibility of photopheresis to reduce the occurrence of restenosis after percutaneous transluminal coronary angioplasty: a clinical pilot study

BACKGROUND

Photopheresis was evaluated as a means of preventing restenosis on the basis of immune modulation.

METHODS

This was a prospective, randomized, controlled clinical trial analyzing clinical restenosis at 6 months after percutaneous transluminal coronary angioplasty (PTCA). Seventy-eight patients with single-vessel angioplasty were randomly assigned to a control group of 41 patients and a treatment group of 37 patients. At 6 months, there were 72 evaluable patients: 39 control patients and 33 treated. Twenty-nine control patients received balloon PTCA only and 10 patients received stents. Twenty treated patients received PTCA only and 13 patients received stents. Baseline clinical characteristics of both groups were similar. The treatment group received photopheresis for a total of 5 treatments. Primary end points were death from any cause, myocardial infarction, ischemia, and repeat revascularization procedures.

RESULTS

By intention-to-treat analysis, clinical restenosis occurred in 27% of control patients versus 8% of treated patients (P =.040, relative risk = 0.30).

CONCLUSIONS

Photopheresis therapy in patients undergoing balloon PTCA with and without stent deployment has been shown to be effective in reducing restenosis. The use of photopheresis in such patients merits further investigation.

Long-term (> or =8 years) outcome after Palmaz-Schatz stent implantation

The purpose of this single-center study was to evaluate the long-term (> or =8 years) outcome of Palmaz-Schatz intracoronary stenting and to identify independent predictors of outcome. Although short-term results of Palmaz-Schatz intracoronary stenting have been promising, with a reduction in both angiographic restenosis and clinical cardiac events up to 3 years, longer-term follow-up has not been established. We analyzed clinical outcome in 426 consecutive patients at least 8 years after coronary stenting. Demographic, clinical, and procedural predictors of restenosis, survival, and event-free survival, defined as freedom from death, myocardial infarction (MI), and coronary revascularization (target stented site, target vessel, and any revascularization) were analyzed. Before discharge, 28 patients (6.6%) sustained at least 1 major cardiovascular event: 3 deaths (0.7%), 18 MIs (4.2%), and 17 repeat revascularizations. Surviving patients were followed for 8.9 years (interquartile range 8.4 to 9.4). After discharge, 59 patients (13.9%) died, 47 (11.1%) sustained an MI, and 188 (44.4%) underwent coronary revascularization. The 8-year event-free survival (freedom from death, freedom from death/MI/target-stented site revascularization, and freedom from death/MI/any coronary revascularization) was (mean +/- SE) 0.86 +/- 0.01, 0.62 +/- 0.03, and 0.47 +/- 0.02, respectively. Unstable angina, lower left ventricular ejection fraction, and saphenous vein graft stenting were found to be independent predictors of death during follow-up. Hypertension, unstable angina, multivessel disease, and multiple stent implantation were found to be independent predictors of the composite of death/MI/any coronary revascularization during follow-up. This study provided a useful assessment of very long-term outcome in survival, event-free survival, and predictors of major cardiac events 8 to 10 years after Palmaz-Schatz stent implantation.

Short-term outcome of stent implantation in saphenous vein grafts: predictors of distal embolization and restenosis

The present study, which aimed to determine the predictors of distal embolization and restenosis after stenting for vein graft disease, retrospectively analyzed 51 consecutive patients who underwent stent implantation for diseased saphenous vein grafts. Follow-up angiography was performed 6 months after the procedure and the clinical and angiographic variables were analyzed by multivariate logistic regression to determine the predictors of distal embolization and restenosis. Initial clinical success was achieved in 49 patients, 44 of whom underwent follow-up angiography and were enrolled in the retrospective analysis. Distal embolization occurred in 6 grafts (13.6%). Multivariate analysis showed that the lesion length and the total cholesterol level were independent predictors of distal embolization. Angiographic restenosis occurred in 13 (26.5%) of 49 lesions. The minimum luminal diameter and the percent diameter stenosis after stenting were associated with the occurrence of restenosis. Multivariate analysis of lesions located in the graft body identified graft age as an independent predictor of restenosis. Distal embolization can occur after vein graft stenting, especially in patients with hypercholesterolemia and diffuse stenosis. The post-stenting minimum luminal diameter and the percent diameter stenosis are predictors of restenosis. In particular, graft age is associated with the restenosis of graft body lesions.

Risk factors for the development of restenosis following stent implantation of venous bypass grafts

OBJECTIVE

To analyse the variables involved in the high restenosis rate following stent implantation in coronary artery bypass grafts.

DESIGN

A retrospective analysis of a consecutive group of patients attending a tertiary centre.

PATIENTS

The long term angiographic outcome of 219 stent implantations for individual lesions performed in 191 patients was investigated. Multivariate analysis correlated clinical, procedural, and angiographic variables with the incidence of angiographic restenosis, defined as diameter stenosis > 50% at follow up.

RESULTS

Angiographic restenosis was observed in 34% of lesions treated. Multiple logistic regression analysis defined diabetes mellitus (odds ratio 6.91, 95% confidence interval (CI) 2.43 to 9.69), graft recanalisation (2.89, 95% CI 1.18 to 6.63), lesion at the aortic anastomosis (6.98, 95% CI 2.77 to 21.31), lesion at the coronary anastomosis (3.01, 95% CI 1.19 to 7.69), high diameter stenosis after stent placement (7.21, 95% CI 2.66 to 16.81), placement of long stents (2.73, 95% CI 1.09 to 7.39), and implantation of more than one stent (7.31, 95% CI 2.08 to 19.96) as independent predictors of graft in-stent restenosis.

CONCLUSIONS

There appears to be a specific risk factor constellation contributing to the high restenosis rate following stent implantation in venous bypass grafts. Critical consideration of these variables may help identify patients who are poor candidates for stent implantation and who may benefit from a different approach.

Stent placement for non-STRESS/BENESTENT lesions: a critical review

Stenting lesions with favorable characteristics as required for inclusion in the STRESS/BENESTENT trials have yielded superior results to that of PTCA alone. Results for less favorable lesions such as in small vessels, diffuse disease, ostial disease, and saphenous vein grafts are less well established. This review seeks to analyze available data for stent placement in this subset of non-STRESS/BENESTENT lesions.

Long-term clinical results after stent implantation in old obstructed saphenous vein grafts

STUDY OBJECTIVE

To assess the long-term clinical outcome of treating patients with coronary artery disease and obstructed saphenous vein grafts (SVGs) with stents deployed by oversized balloon catheters.

DESIGN

The study included 89 of 92 consecutive patients who had 121 SVG stent implants (average, 1.4 stents per patient). We aimed at achieving a negative stenosis using oversized balloons to achieve a catheter to artery ratio of 1.1:1, and a 100% follow-up at 24+/-14 months (range, 0 to 54 months) was achieved.

PATIENTS

As 3 of 92 patients died during hospital admission, the study follow-up population consisted of 89 of 92 patients (mean age, 67+/-10 years). The age of the SVGs was 10+/-4 years.

RESULTS

We implanted 118 Palmaz-Schatz and 3 Gianturco-Roubin stents. Procedural success was achieved in 87 of 92 patients (94.5%; < 50% stenosis, and no death, Q-wave acute myocardial infarction, or coronary artery bypass graft [CABG]). Mean SVG stenosis diameter was reduced from 80+/-13% to -11+/-12% (p<0.001) and mean luminal diameter increased from 0.6+/-0.5 mm to 3.3+/-0.8 mm (p<0.001). At follow-up, angina pectoris had developed in 42 of 89 patients (47%), acute myocardial infarction in 12 of 89 patients (14%), reperformed CABG in 12 of 89 patients (14%), cardiac death in 10 of 89 patients (11%), and unrelated death in 6 of 89 patients (7%). Coronary angiography was performed in 37 of 89 patients (42%), with restenosis in 16 of 37 patients (43%) and disease progression at other sites in 11 of 37 patients (30%). Only 25 of 89 patients (28%) experienced event-free survival at follow-up.

CONCLUSIONS

Despite high procedural success and excellent angiographic results with oversized balloon catheters, the long-term clinical outcome of SVG stent implantation is suboptimal.

Local heparin delivery for prevention of second in-stent restenosis. Acute and long-term results in 47 consecutive cases

BACKGROUND: Heparin has been shown to reduce intimal thickening after arterial wall injury by inhibiting vascular smooth muscle cell proliferation and migration. The authors studied the acute and long-term results after local delivery of heparin after balloon angioplasty for in-stent restenosis. METHODS AND RESULTS: Forty-seven in-stent restenosis cases, 32 of them longer than 1 cm, were enrolled. After angioplasty local heparin delivery was performed using the Dispatch coronary infusion catheter (Scimed Life Systems/Boston Scientific Corp, Natick, MA, USA); the infusion rate was 99.9 ml per hour and a target dosage of 4000 iu heparin per site was intended to be delivered. In nine cases (19.15%) heparin delivery had to be stopped because of ischemia. One patient died six days after intervention. After a follow-up interval of 6-12 months target vessel revascularization rate was 28.26%. CONCLUSIONS: For the protocol used ischemia occurred more often than previously reported. Considering the fact that most patients had diffuse in-stent restenosis, the target revascularization rate at follow-up was acceptable.

Long-term clinical outcome after endoluminal reconstruction of diffusely degenerated saphenous vein grafts with less-shortening wallstents

OBJECTIVES

This study was designed to evaluate the immediate and long-term clinical results of patients undergoing endoluminal reconstruction in diffusely degenerated saphenous vein grafts (SVGs) with elective implantation of one or more less-shortening Wallstents.

BACKGROUND

The optimal treatment strategy for patients with diffusely degenerated SVGs is controversial. Endoluminal reconstruction by stent implantation is one proposed strategy; however, there are few data regarding long-term clinical outcome.

METHODS

Between May 1995 and September 1998, 6,534 consecutive patients underwent angioplasty in our institution, including 440 who were treated for SVG lesions. Of these, 126 (115 men, 11 women, median age 69.5 years, range: 33-86 years) with old SVGs (mean age: 13+/-5 years) diffusely degenerated stenosed or occluded (mean lesion length: 27+/-12 mm) were treated electively with implantation of one or multiple (total 197) less-shortening Wallstents.

RESULTS

Before discharge, 13 patients (10.3%) sustained at least one major cardiovascular event, including 4 deaths (3.2%), 11 myocardial infarctions (MI) (8.7%), and 3 repeat revascularizations (target vessel = 1, nontarget vessel = 2, 2.4%). Surviving patients were followed for 22+/-11 months: 13 patients (11.1%) died, 11 (9.4%) sustained an MI, 37 underwent angioplasty (31.6%), and 4 (3.4%) underwent bypass surgery. The estimated three-year event-free survival rates (freedom from death, and freedom from death/MI/target vessel revascularization) were (mean +/- SE) 81.1+/-7.8% and 43.2+/-18.5%, respectively.

CONCLUSIONS

The long-term clinical outcome of patients undergoing endoluminal reconstruction in diffusely degenerated SVG is relatively poor, mainly because of a high incidence of death or MI and the frequent need for repeat angioplasty. It is unlikely that percutaneous intervention alone will provide a satisfactory or definitive solution for these patients.

Procedural results and intermediate clinical outcomes after multiple saphenous vein graft stenting

OBJECTIVES

We evaluated the early and mid-term (18-month) clinical events in a consecutive series of patients undergoing a nonstaged multiple saphenous vein grafting (SVG) intervention with stents as compared with a single SVG stent procedure.

BACKGROUND

Saphenous vein graft angioplasty has been limited by high rates of distal embolization, myocardial infarction, restenosis and late mortality. It is unknown whether stenting of multiple, different SVGs at the same setting is associated with higher risk.

METHODS

We evaluated in-hospital and mid-term clinical outcomes (death, Q wave myocardial infarction [MI] and repeat revascularization rates up to 18 months) in 70 consecutive patients treated with coronary stents in 2 (93% of patients) or 3 SVGs, as compared with 649 patients undergoing stenting of a single SVG between January 1, 1994 and December 31, 1997.

RESULTS

Overall procedural success was obtained in 97% of patients with 2 or 3 SVGs and 97% of patients with a single SVG (p = 0.94). Procedural complications were also similar (2.8% for multiple SVGs vs. 2.7% for a single SVG, p = 0.94). There was a higher prevalence of periprocedural non-Q wave MI (28% vs. 16%, p = 0.009) in the multiple SVG group. During follow-up (18 months), target lesion revascularization was 11% in multiple SVG and 15% in single SVG interventions (p = 0.19), and repeat revascularization (calculated per treated patient) was also similar for both groups (19% vs. 18%, p = 0.94). There was no difference in death (5.6% vs. 5.3%, p = 0.92) and Q wave MI rate (4.3% vs. 2.9%, p = 0.55) after the multiple SVG intervention. Overall cardiac event-free survival was similar for both groups (62% vs. 60%, p = 0.75). The study was powered to detect a clinically meaningful difference of 10% in mortality; smaller differences could not be evaluated on the basis of this sample size.

CONCLUSIONS

Simultaneous stenting of multiple SVGs in carefully selected patients has similar in-hospital procedural success and major complications rates, as well as mid-term (18-month) clinical outcomes, as compared with single SVG stenting. Thus, multiple SVG interventions using stents may be a viable revascularization strategy for carefully selected patients and suitable lesions in multiple SVG disease.

In-hospital and long-term results of stent deployment compared with balloon angioplasty for treatment of narrowing at the saphenous vein graft distal anastomosis site

Disease at the distal anastomosis site of saphenous vein grafts (SVGs) has been successfully treated with balloon angioplasty, with a lower restenosis rate than at sites of the aortoostial or proximal portion of the SVG. The role of stents for these lesions has not been well defined. To compare the in-hospital and long-term outcome of patients who underwent treatment at this site by either balloon angioplasty or tubular stent implantation, we studied 182 consecutive patients who underwent balloon angioplasty and 77 patients who underwent stenting between January 1994 and August 1997. Baseline clinical characteristics for both groups were similar. Angiographically, SVG stenoses treated with stents were older, longer in lesion length, and more restenotic. The in-hospital outcome was similar for both groups, with 98% procedural success rates and 1% major ischemic complications. Long-term follow-up was obtained for 93% of the patients, for an average of 17 +/- 14 months. The mortality rates were similar for patients who underwent balloon angioplasty and stenting (11.6% vs 13%, p = NS). The Q-wave myocardial infarction rates were also similar (1% vs 0%, p = NS). There was a trend toward a higher rate of target lesion revascularization in the balloon angioplasty group (25% vs 14%, p = 0.058). We conclude that percutaneous revascularization of the SVG distal anastomosis site by either balloon angioplasty or stenting can be performed with a high rate of procedural success and favorable in-hospital and long-term outcomes. Stent deployment may further improve the long-term outcome of these patients by reducing the need for repeat revascularization.

Stenting for in-stent restenosis: A long-term clinical follow-up

We studied the feasibility, safety, and short- and long-term outcomes of treating coronary in-stent restenosis with primary restenting. Thirty-one patients (32 lesions) were treated. Eleven patients had adjunctive rotational atherectomy. Clinical follow-up was obtained in all 31 patients at a mean of 9.1 +/- 5.5 months by direct phone contact with the patients, medical records, and subsequent hospitalization for recurrent symptoms and/or revascularization. There were no cardiac deaths or myocardial infarctions. In native vessels (26 patients), repeat target lesion revascularization was required in eight patients (31%); two other patients (7.7%) had angina and were treated medically. All vein graft lesions had recurrent restenosis. Significant predictors of recurrent clinical events were lesions in vein grafts, multivessel disease, and use of higher poststent deployment inflation pressures. Primary restenting for in-stent restenosis in native vessels is a safe approach with good short-term outcome. Recurrent restenosis remains a problem, as it does with other devices, particularly in vein graft lesions and in patients with multivessel disease. Restenting for in-stent restenosis should probably be used selectively. Cathet. Cardiovasc. Intervent. 48:143-148, 1999.

Long term outcome after coronary stent implantation: a 10 year single centre experience of 1000 patients

OBJECTIVE

To describe the long term clinical outcome (up to 11 years) after coronary stenting.

DESIGN

A single centre observational study encompassing 1000 consecutive patients with a first stent implantation (1560 stents) between 1986 and 1996, who were followed for at least one year with a median follow up of 29 months (range 12-132 months).

RESULTS

Up to July 1997 the cumulative incidence of the major adverse cardiac events (MACE) of death, non-fatal acute myocardial infarction, coronary artery bypass grafting, and repeat percutaneous transluminal coronary angioplasty was 8.2%, 12.8%, 13.1%, and 22.4%, respectively. Survival at one, three, and five years was 95%, 91%, and 86%, respectively. Comparison of MACE incidence during the "anticoagulant era" and the "ticlopidine era" revealed significantly improved event free survival with ticlopidine (27% v 13%; p < 0.005). Multivariable analyses showed that ejection fraction < 50% (relative risk (RR) 4. 1), multivessel disease (RR 3.0), diabetes (RR 2.9), implantation in saphenous vein graft (RR 2.1), indication for unstable angina (RR 1. 9), and female sex (RR 1.7) were independent predictors of increased mortality after stenting. Independent predictors of any MACE were multivessel stenting (RR 2.0), implantation in saphenous bypass graft (RR 1.6), diabetes (RR 1.5), anticoagulant treatment (versus ticlopidine and aspirin) (RR 1.5), bailout stenting (RR 1.5), multivessel disease (RR 1.4), and multiple stent implantation (RR 1. 5).

CONCLUSIONS

Long term survival and infarct free survival was good, particularly in non-diabetic men with single vessel disease and good ventricular function, who had a single stent implanted in a native coronary artery. A dramatic improvement was observed in event free survival, both early and late, with the replacement of anticoagulation by ticlopidine. This, of course, cannot be separated from improved stent implantation techniques between 1986 and 1995. Ultimately, almost 40% of the patients experienced an adverse cardiac event (mainly repeat intervention) in the long term. New advances in restenosis treatments and in secondary prevention must be directed at this aspect of patient management after stenting.

The influence of abciximab use on clinical outcome after aortocoronary vein graft interventions

OBJECTIVES

The purpose of this study was to evaluate the effect of abciximab use on clinical outcome in aortocoronary vein graft interventions.

BACKGROUND

Although large randomized trials have demonstrated a significant benefit of abciximab use in the setting of percutaneous coronary interventions, there is relatively little data with respect to the use of this agent in percutaneous vein graft interventions.

METHODS

Three hundred and forty-three patients were identified; 210 undergoing vein graft intervention without abciximab and 133 patients with abciximab.

RESULTS

There were differences in baseline clinical and angiographic characteristics between the two groups; advanced age, unstable angina, older vein grafts and thrombus containing lesions were relatively common in both groups. Angiographic and procedural success rates were similar with or without the use of abciximab (89% vs. 92%, p = 0.15, and 85% vs. 91%, p = 0.12, respectively). The in-hospital composite end point of death/Q-wave myocardial infarction (QWMI)/repeat revascularization was similar between the two groups. Utilizing statistical modeling to adjust for baseline differences between the groups, abciximab use did not influence the cumulative long-term composite end point of death/MI/repeat revascularization.

CONCLUSIONS

This study demonstrates that in this relatively high-risk population undergoing aortocoronary vein graft interventions, the administration of abciximab periprocedurally does not appear to reduce major adverse clinical events.

Retrieval and analysis of particulate debris after saphenous vein graft intervention

OBJECTIVES

This study was designed to evaluate the composition and quantity of particulate debris resulting from vein graft intervention.

BACKGROUND

Distal embolization and "no reflow" are frequent and important complications resulting from angioplasty of diseased saphenous vein grafts. Little is known about the composition and quantity of embolic particulate debris associated with vein graft intervention, and no intervention has been shown to protect against its clinical consequences.

METHODS

A catheter system, designed to contain, retrieve and protect against distal embolization of this material, was evaluated during 27 percutaneous interventional saphenous vein graft procedures. Clinical, angiographic and pathologic analyses were performed.

RESULTS

The duration of distal graft occlusion required to allow intervention and subsequent debris removal was 150 +/- 54 s, decreasing as experience was gained. Thrombolysis in Myocardial Infarction trial (TIMI) flow grade increased from 2.6 +/- 0.8 to 3.0 +/- 0.0. Creatine kinase (CK) rose above normal in three patients (11.1%) exceeding 3x normal in one (3.7%) resulting in the diagnosis of non-Q-myocardial infarction. Particulate material was identified following 21 of 23 procedures suitable for analysis. Particle size was 204 +/- 57 microm in the major axis and 83 +/- 22 microm in the minor axis. Particles consisted predominantly of soft acellular atheromatous material, such as that typically found under a fibrous cap. Semiquantitative analysis suggested that the quantity of particulate material was less following stenting than following balloon dilation.

CONCLUSIONS

Particulate matter is commonly present following routine angioplasty and stenting of saphenous vein grafts. Containment, retrieval and analysis of this particulate debris are all feasible. Comparison to prior clinical experience is limited by small sample size. However, to the extent that these particles may contribute to distal embolization, no-reflow and infarction, such a system may contribute to the reduction of complications following vein graft intervention.

An embolization containment device

A coaxial catheter system for containment of distal embolization is described. Utilizing a novel 0.014" hypotube with a distal elastomeric occlusion balloon, the PercuSurge GuardWire functions as a guidewire while trapping distal embolization resulting from more proximal intervention. The particulate debris is evacuated with a single operator exchange aspiration catheter (Export catheter) prior to deflation of the distal occlusion balloon. This animal study confirmed the feasibility of concept. The system was easily delivered through tortuous coronary anatomy. The GuardWire served as an adequate rail for delivery of dilatation balloons and a multitude of stents. There was no evidence of deep wall damage from low-pressure inflation and apposition of the distal occlusion balloon.

[Stent restenosis: therapy concepts and possibilities for prevention]

BACKGROUND

In-stent restenosis has become a significant problem for interventional cardiologists. Due to different pathogenic causes it remains unclear whether a uniform therapeutic regimen is appropriate.

TREATMENT

Redilatation has predominantly been used for the treatment of instent restenosis, however, in long and diffuse restenotic stents, long-term results are reported to be poor. Therefore, tissue-debulking techniques may have beneficial effects in complex cases of in-stent restenosis. The therapeutic benefit of intracoronary radiation, local drug delivery or gene transfer has not been evaluated so far.

PREVENTION

Therefore, prevention of the iatrogenic entity in-stent restenosis has become more important.

Directional coronary atherectomy for the treatment of Palmaz-Schatz in-stent restenosis

Management of in-stent restenosis has become a significant challenge in interventional cardiology. The results of balloon angioplasty have been disappointing due to the high recurrence of restenosis at follow-up. Debulking of the restenotic tissue within the stents using directional coronary atherectomy (DCA) may offer a therapeutic advantage. We report the immediate clinical and angiographic outcomes and long-term clinical follow-up results of 45 patients (46 lesions), mean age 63+/-12 years, 73% men, with a mean reference diameter of 2.9+/-0.6 mm, treated with DCA for symptomatic Palmaz-Schatz in-stent restenosis. DCA was performed successfully in all 46 lesions and resulted in a postprocedural minimal luminal diameter of 2.7+/-0.7 mm and a residual diameter stenosis of 17+/-10%. There were no in-hospital deaths, Q-wave myocardial infarctions, or emergency coronary artery bypass surgeries. Four patients (9%) suffered a non-Q-wave myocardial infarction. Target lesion revascularization was 28.3% at a mean follow-up of 10+/-4.6 months. Kaplan-Meier event-free survival (freedom from death, myocardial infarction, and repeat target lesion revascularization) was 71.2% and 64.7% at 6 and 12 months after DCA, respectively. Thus, DCA is safe and efficacious for the treatment of Palmaz-Schatz in-stent restenosis. It results in a large postprocedural minimal luminal diameter and a low rate of both target lesion revascularization and combined major clinical events at follow-up.

The stent decade: 1987 to 1997. Stanford Stent Summit faculty

In January 1997, experts from the United States, Europe, and Japan gathered at Stanford University to review their collective experience with intracoronary and noncoronary stenting and to identify and prioritize issues requiring further clinical investigation. This report summarizes the discussions that took place during this stent summit. Knowledge of stent-tissue interaction from animal and human pathologic specimens was reviewed in the context of evolving stent designs. The relative merits of coil and slotted tubular stent designs were discussed. Stent deployment routines, including self-expansion, balloon expansion, and high-pressure delivery were debated. The potential for covered stents and coated stents was explored. Problems surrounding the routine deployment of stents were identified: small vessel disease, long lesions, bifurcation stenoses, vein graft disease, ostial disease, left main stenoses, and intrastent restenosis. The value of intravascular ultrasound, as an adjunct to stenting, was explored and debated. An algorithm for "provisional stenting" based on ultrasound criteria was developed. Noncoronary stenting of the aorta, iliacs, and carotids were discussed. Clinical applications that may lead to randomized clinical trials were identified.

Acute directional coronary atherectomy prior to stenting in complex coronary lesions: ADAPTS Study

The purpose of this study was to determine the results of directional coronary atherectomy (DCA) combined with stenting in a high-risk patient population. The use of stenting or DCA alone for aorto-ostial lesions, total chronic occlusions, long lesions, and lesions containing thrombus is associated with lowered success and a relatively high restenosis rate. Between July 1993 and October 1996, we treated 89 lesions with the combined approach of DCA and stenting in 60 consecutive patients. Thirty-one (51.7%) patients were treated because of unstable angina, 11 (18.3%) for post-myocardial infarction (MI) angina, 3 (5.0%) for acute MI, and 15 (25.0%) patients for stable angina. A total of 43 (71.7%) patients had multivessel disease, 19 (31.7%) had undergone previous coronary artery bypass graft (CABG), and 17 (28.3%) patients had undergone multivessel revascularization. The procedure was successful in all patients; and no postprocedural deaths or emergent CABG occurred. Two patients (3.3%) had non-Q-wave MI after the procedure and 1 patient (1.7%) experienced Q-wave MI due to subacute stent closure 7 days after the procedure. During follow-up ranging from 6 months to 3 years, 2 (3.3%) patients died, 2 (3.3%) required CABG surgery, 1 (1.7%) patient had an MI, and 6 patients (10.0%) required target vessel revascularization. By the quantitative coronary angiography, the initial minimal luminal diameter (MLD) averaged 0.91+/-0.45 mm (74.7+/-11.8% stenosis) increasing to 3.80+/-0.44 mm (-6.7+/-12.1%) after the combined approach procedure. Thirty patients (50.0%) met criteria for late (> or =6 months) angiographic follow-up. Late MLD loss averaged 1.13+/-1.07 mm, for a mean net gain of 1.61+/-1.23 mm. Available angiographic follow-up evaluation showed a restenosis rate of 13.3%. A combined approach, defined as the use of both DCA and stenting, is safe and yields a low restenosis rate in high-risk patients who have lesions known to respond less favorably to stenting or DCA alone.