Conventional Balloon Angioplasty Research Articles

Cutting balloon versus conventional balloon angioplasty for the treatment of in-stent restenosis: Results of the restenosis cutting balloon evaluation trial (RESCUT)

ObjectivesThe aim of this trial was to compare cutting balloon angioplasty (CBA) with conventional balloon angioplasty (i.e., percutaneous transluminal coronary angioplasty [PTCA]) for the treatment of patients with coronary in-stent restenosis (ISR). BackgroundRetrospective studies suggest CBA might be superior to conventional PTCA in the treatment of ISR. MethodsThe Restenosis Cutting Balloon Evaluation Trial (RESCUT) is a multicenter, randomized, prospective European trial including 428 patients with all types of ISR (e.g., focal, multifocal, diffuse, proliferative). ResultsIn both groups, the majority of ISR lesions were shorter than 20 mm. The length of restenotic stents was similar (CBA: 18.6 ± 9.7 mm; PTCA: 18.3 ± 8.7 mm). The number of balloons used to treat ISR was lower in the CBA group: only one balloon was used in 82.3% of CBA cases, compared with 75% of PTCA procedures (p = 0.03). Balloon slippage was less frequent in the CBA group (CBA 6.5%, PTCA 25%; p < 0.01). There was a trend toward a lower need for additional stenting in the CBA group (CBA 3.9%, PTCA 8.0%; p = 0.07). At seven-month angiographic follow-up, the binary restenosis rate was not different between the groups (CBA 29.8%, PTCA 31.4%; p = 0.82), with a similar pattern of recurrent restenosis. Clinical events at seven months were also similar. ConclusionsCutting balloon angioplasty did not reduce recurrent ISR and major adverse cardiac events, as compared with conventional PTCA. However, CBA was associated with some procedural advantages, such as use of fewer balloons, less requirement for additional stenting, and a lower incidence of balloon slippage.

Immediate and 3‐Month Follow‐Up Outcome After Cutting Balloon Angioplasty for Bifurcation Lesions

Balloon angioplasty of a bifurcation lesion is associated with lower rates of success and higher rates of complications than such treatment of lesions of most other morphologies. To date, the best device or procedure for bifurcation lesions has not been determined. The aim of this study was to compare the immediate and 3-month follow-up outcome of cutting balloon angioplasty (CBA) versus conventional balloon angioplasty (PTCA) for the treatment of bifurcation lesions. We treated 87 consecutive bifurcation lesions with CBA (n = 50) or PTCA (n = 37). Paired angiograms were analyzed by quantitative angiography, and angiographic follow-up was achieved for 93% of the lesions. The procedural success was 92% in the CBA group and 76% in the PTCA group (P < 0.05). Major in-hospital complications occurred in two lesions in the CBA group and six in the PTCA group (P = 0.05). The incidence of bail-out stenting in the CBA group was lower than in the conventional PTCA (8% vs 24%, P < 0.05). At the 3-month follow-up, the restenosis rate was 40% in the CBA group versus 67% in the PTCA group (P < 0.05). Clinical events during follow-up did not differ between the two groups. In conclusion, in comparison with PTCA, procedural success was greater and the restenosis rate lower with CBA. The results of this study support the use of the cutting balloon as optimal treatment for bifurcation lesions.

Cutting Balloon Angioplasty versus Conventional Balloon Angioplasty for In-Stent Restenosis Treated by Intracoronary Radiation Therapy

Background: Cutting Balloon angioplasty (CBA) may be a useful treatment modality for in-stent restenosis (ISR) as it maintains a stable position during dilatation and results in potentially less injury than plain old balloon angioplasty (POBA). The purpose of this study was to compare CBA and POBA with intracoronary radiation therapy (IRT) for in-stent restenosis (ISR). Methods: We selected 157 consecutive patients from the WRIST (Wa- shington Radiation for In-stent restenosis Trial) series of gamma radiation trials using both gamma and beta emitters for ISR of native coronaries or saphenous vein grafts, who were treated with CBA or POBA as the only treatment strategy before intracoronary radiation therapy. Patients in the CBA (N=64) and POBA (N=93) groups were matched for baseline demographic and procedural characteristics. Radiation was delivered successfully in all cases. Results: At angiographic follow up, acute gain was higher in the CBA group than the POBA group (1.7±0.7 mm vs. 1.4±0.9 mm, p=0.03). The angiographic restenosis rate (17.1% vs. 23.5%, p=NS) and edge restenosis rate (6.3% vs. 12.2%, p=NS) were not significantly lower in the cutting balloon cohort. At a 6 month clinical follow up, the CBA group showed a statistically decreased rate of clinically driven target vessel revascu- larization compared to the POBA group (5.7% vs.18.3%, p=0.038). Conclusions: Cutting balloon angioplasty is a reasonable treatment strategy for in-stent restenosis prior to intracoronary radiation therapy. (Korean Circulation J

Treating intractable venous stenosis: present and future therapy.

The widespread use of percutaneous angioplasty for venous stenoses has lengthened the functional life span of hemodialysis access, while preserving precious venous capital. A subset of dialysis patients with dysfunctional access sites will harbor stenoses which are intractable, in that they fail to respond to conventional balloon angioplasty or recur in the weeks following angioplasty. This editorial discusses various endovascular approaches to the management of intractable venous stenosis as well as promising future therapies.

Utilization of eptifibatide for treatment of severe dissections as a bail-out procedure

Background: It has been shown in several large trials that the inhibition of glycoprotein (GP) IIb/IIIa receptors of platelets can reduce the rate of ischemic complications following percutaneous transluminal coronary angioplasty (PTCA). We sought to determine the efficacy of eptifibatide in patients with severe dissections or threatened vessel closure after PTCA in small coronary arteries (<2.5 mm). Methods: Eptifibatide was used in 51 patients after conventional balloon angioplasty complicated by severe dissections with or without threatened vessel occlusion. Eptifibatide was administered as a double-bolus of 180 μg/kg bodyweight, followed by a continuous infusion at a dosage of 2.0 μg/kg min over a time period of 20 h. In this situation, the implantation of a coronary stent was avoided if a prompt antegrade flow of contrast dye could be maintained. Results: Using the GP IIb/IIIa antagonist eptifibatide, it was possible to increase or to maintain antegrade blood flow in 28 (55%) patients. In 45% of the patient population, however, repeat PTCA was needed, and in four patients (7.8%) an intracoronary stent had to be implanted. During hospitalization three (6%) patients underwent target lesion revascularization (two Re-PTCAs, one coronary bypass graft operation). There were no myocardial infarctions and there was no intrahospital death. The cumulative event rate including acute and long term events was 25%. Conclusions: The findings of our study indicate that eptifibatide is able to prevent vessel occlusion after PTCA complicated by severe dissections with or without threatened vessel occlusion associated with a low-in-hospital complication rate.

Promising efficacy of primary gradual and prolonged balloon angioplasty in small coronary arteries: a randomized comparison with cutting balloon angioplasty and conventional balloon angioplasty

BackgroundSmall vessel size represents a critical risk factor for an adverse outcome after both conventional balloon angioplasty (POBA) and stenting. Gradual and prolonged balloon angioplasty (GPBA) has been shown to cause less arterial trauma, which results in higher procedural success rates and fewer in-hospital complications than POBA. The aim of this study was to assess the clinical and angiographic benefits of primary GPBA with a perfusion balloon in small coronary arteries, as compared with cutting balloon angioplasty (CBA) and POBA. MethodsA total of 263 patients with symptoms and reference diameters <3.0 mm were randomly assigned to undergo GPBA (n = 85), CBA (n = 88), or POBA (n = 90). The cumulative inflation time must be >10 minutes in GPBA. Crossover to stent was allowed for inadequate results. Follow-up angiography was performed after 6 months. The primary end point was angiographic restenosis at follow-up. ResultsCompared with POBA, GPBA resulted in a lower final residual diameter stenosis (27.3% vs 34.2%, P = .01) and decreased the need for stent placement (8.0% vs 22.2%, P = .031). At follow-up, the restenosis rates were lower with GPBA (31.3%, P = .034) and CBA (32.9%, P = .059) than POBA (50.6%). Target lesion revascularization was less frequently needed with GPBA (20.5%, P = .043) and CBA (20.0%, P = .033) than POBA (37.6%). Additionally, the event-free survival rate was higher with GPBA (77.1%, P = .033) and CBA (76.4%, P = .047) than POBA (58.8%). ConclusionsIn small coronary arteries, both GPBA and CBA resulted in favorable angiographic and clinical outcomes. With a lower restenosis rate and target lesion revascularization rate, GPBA may be a superior strategy for small vessels compared with POBA.

Effectiveness of percutaneous coronary intervention in cardiac allograft vasculopathy

Twenty-five heart transplant recipients underwent 45 coronary interventions at a mean of 7.8 ± 2.2 years from time of transplant. Periprocedural success was high, and there was a trend toward better outcomes in the group that underwent stent deployment compared with conventional balloon angioplasty.

Acute and long-term outcomes of cutting balloon angioplasty followed by gamma brachytherapy for in-stent restenosis

In-stent restenosis lesions were divided into 2 groups according to the use of cutting balloon (n = 76) or conventional balloon angioplasty (n = 407) before γ-brachytherapy. Cutting balloon angioplasty, compared with conventional balloon angioplasty, in patients undergoing γ-brachytherapy for in-stent restenosis is associated with less requirement for new stents (11% vs 22%, p = 0.02) but similar target vessel revascularization (35.1% vs 29.8%, p = 0.4) at follow-up.

Comparison of rotational atherectomy with conventional balloon angioplasty in the prevention of restenosis of small coronary arteries: results of the dilatation vs. ablation revascularization trial targeting restenosis (DART)

Comparison of rotational atherectomy with conventional balloon angioplasty in the prevention of restenosis of small coronary arteries: results of the dilatation vs. ablation revascularization trial targeting restenosis (DART)

A randomized comparison ofrepeat stenting with balloon angioplasty in patients with in-stent restenosis

ObjectivesThis randomized trial compared repeat stenting with balloon angioplasty (BA) in patients with in-stent restenosis (ISR). BackgroundStent restenosis constitutes a therapeutic challenge. Repeat coronary interventions are currently used in this setting, but the recurrence risk remains high. MethodsWe randomly assigned 450 patients with ISR to elective stent implantation (224 patients) or conventional BA (226 patients). Primary end point was recurrent restenosis rate at six months. Secondary end points included minimal lumen diameter (MLD), prespecified subgroup analyses, and a composite of major adverse events. ResultsProcedural success was similar in both groups, but in-hospital complications were more frequent in the balloon group. After the procedure MLD was larger in the stent group (2.77 ± 0.4 vs. 2.25 ± 0.5 mm, p < 0.001). At follow-up, MLD was larger after stenting when the in-lesion site was considered (1.69 ± 0.8 vs. 1.54 ± 0.7 mm, p = 0.046). However, the binary restenosis rate (38% stent group, 39% balloon group) was similar with the two strategies. One-year event-free survival (follow-up 100%) was also similar in both groups (77% stent vs. 71% balloon, p = 0.19). Nevertheless, in the prespecified subgroup of patients with large vessels (≥3 mm) the restenosis rate (27% vs. 49%, p = 0.007) and the event-free survival (84% vs. 62%, p = 0.002) were better after repeat stenting. ConclusionsIn patients with ISR, repeat coronary stenting provided better initial angiographic results but failed to improve restenosis rate and clinical outcome when compared with BA. However, in patients with large vessels coronary stenting improved the long-term clinical and angiographic outcome.

Acute and long-term outcomes of rotational atherectomy in small (< 3.0 mm) coronary arteries.

Conventional balloon angioplasty (BA) of small coronary arteries (SCA) is followed by a high rate of restenosis. Rotational atherectomy may be effective as an alternate treatment of stenoses unsuitable for other devices. The purpose of this study was to assess the efficacy of RA in the treatment of SCA. A retrospective analysis was performed of 226 lesions in 159 consecutive patients who underwent RA of SCA (mean diameter = 2.36 +/- 0.49 mm). One hundred forty-eight lesions (65.5%) were type B2 or C of AHA/ACC criteria. Follow-up angiography was performed at 3 and 6 months after the procedure. Procedural success was achieved in 96.9% of patients. The mean burr-to-artery ratio was 0.74 +/- 0.17. Adjunctive BA and stent implantation were needed in 94.2% and 22.6% of lesions, respectively. Minimal lumen diameter (MLD) increased from 0.66 +/- 0.35 mm to 1.97 +/- 0.58 mm (P < 0.01). Angiographic complications consisted of acute reclosure (3.5%), no reflow/slow flow (12.4%), and coronary artery perforation (1.8%). No death, Q-wave myocardial infarction (MI), or coronary artery bypass graft (CABG) occurred during the initial hospitalization. Restenosis rates at 3 and 6 months were 40.6% and 44.2%, respectively, and target lesion revascularization (TLR) rates were 28.5% and 33.0%, respectively. Restenosis and TLR rates during follow-up were comparable among patients who underwent RA + adjunctive BA versus patients who underwent RA + stenting. Long-term clinical follow-up was complete in 143 patients over a mean period of 348 +/- 166 days. The survival free from cardiac death, MI, CABG or repeated BA was 59.6% at 1 year. In conclusion, RA of SCA has relatively high restenosis rates, but may be appropriate for more complex, calcified lesions unsuitable for other devices.

Expandable Bioresorbable Endovascular Stent. I. Fabrication and Properties

A bioresorbable, expandable poly(L-lactic acid) stent has been designed, based on a linear, continuous coil array principle, by which multiple furled lobes convert to a single lobe upon balloon expansion, without heating. Stent strength and compliance are sufficient to permit deployment by a conventional balloon angioplasty catheter. Several multiple lobe configurations were investigated, with expansion ratios ranging from 1.4 to 1.9 and expanded diameters ranging from 2.3 to 4.7 mm. Compression resistance of the expanded stent is dependent on fiber coil density and fiber ply. A range sufficient for endovascular service was obtained, with less than 4% elastic recoil in six day saline incubation studies. Surface plasma treatment with di(ethylene glycol) vinyl ether significantly reduced platelet adhesion in a 1 h porcine arteriovenous shunt model. Patency was maintained in one week implant studies in the porcine common femoral artery. However, a strong inflammatory response, and significant reduction of the vascular lumen were observed following two weeks implantation. The design principles and fabrication techniques for this bioresorbable stent are sufficiently versatile that a broad range of applications can be addressed. Much work remains to be done, including long-term evaluation of the inflammatory response, and of polymer degradation. The results of this study demonstrate the feasibility of expandable biodegradable stent design and deployment by conventional means.

Comparison of In-Hospital and One-Year outcomes in patients with left ventricular ejection fractions ≤40%, 41% to 49%, and ≥50% having percutaneous coronary revascularization

Outcome studies of percutaneous coronary intervention (PCI) with conventional balloon angioplasty have established increased in-hospital and 1-year mortality in patients with left ventricular (LV) dysfunction compared with others. It is unclear whether recent PCI practice innovations, including stents and adjunctive pharmacotherapy, have made PCI safer and more effective in patients with LV dysfunction. We evaluated the influence of LV ejection fraction (EF) indexes on in-hospital and 1-year outcomes in 1,458 patients within the National Heart, Lung, and Blood Institute-sponsored Dynamic Registry. Patients (n = 300) with acute myocardial infarction were excluded. The remaining 1,158 patients were subdivided into 3 categories: group 1, EF ≤40% (n = 166); group 2, EF 41% to 49% (n = 126); and group 3, EF ≥50% (n = 866). We determined the frequency of individual and composite adverse events (death/myocardial infarction [MI]/coronary artery bypass grafting) at discharge and 1 year. In the Dynamic Registry patients, mean EF in the 3 groups was 32%, 45%, and 62% and in-hospital mortality was 3.0%, 1.6%, and 0.1%, respectively (p <0.001). The composite end point of death/MI was also significant, but other in-hospital adverse events did not differ between groups. The respective mortality rates were 11.0%, 4.5%, and 1.9% (p <0.001) after 1 year. The composite end points of death/MI and death/MI/coronary artery bypass grafting also occurred more frequently in group 1 patients. Thus, significant LV dysfunction was still associated with increased in-hospital and 1-year mortality in patients having contemporary PCI.

Comparison of rotational atherectomy with conventional balloon angioplasty in the prevention of restenosis of small coronary arteries: Results of the Dilatation vs Ablation Revascularization Trial Targeting Restenosis (DART)

BackgroundThe optimum treatment of obstructive coronary disease in small (<3.0 mm diameter) arteries remains unknown. Rotational atherectomy is an approved treatment that might reduce the vascular injury during percutaneous coronary intervention compared with angioplasty. We report on a multicenter, randomized, blinded end point trial comparing rotational atherectomy with balloon angioplasty in the prevention of restenosis of obstructed small coronary arteries. MethodsA total of 446 patients with myocardial ischemia associated with an angiographic stenosis in a native coronary artery 2 to 3 mm in diameter and ≤20 mm in length without severe calcification were randomly assigned to receive rotational atherectomy (n = 227) or balloon angioplasty (n = 219). The primary end point was target vessel failure at 12 months (defined as the composite of death, Q-wave myocardial infarction, and clinically driven repeat revascularization of the target vessel). ResultsThe mean reference vessel diameter was 2.46 ± 0.40 mm, the mean lesion length was 9.97 ± 5.59 mm, and the prevalence of diabetes mellitus was 32%. Acute procedural success (91.6% for rotational atherectomy, 94.1% for balloon angioplasty, P = .36) and target vessel failure at 12 months were not significantly different (30.5% vs 31.2%, P = .98). At 8 months, there were no significant differences in minimum lumen diameter (1.28 ± 0.63 mm vs 1.19 ± 0.54 mm, P = .26), percent diameter stenosis (28% ± 12% vs 29% ± 15%, P = .59), binary restenosis rate (50.5% vs 50.5%, P = 1.0), or late loss index (0.57 vs 0.62, P = .7). No Q-wave myocardial infarctions occurred in either arm of the study, and non–Q-wave myocardial infarctions (defined as creatine kinase level >2 times normal with an elevated creatine kinase-myocardial band isoenzyme level) occurred in 2.2% and 1.4% of the patients in the rotational atherectomy and balloon angioplasty groups, respectively (P = .72). ConclusionRotational atherectomy was found to be safe in the treatment of obstructed small arteries, but lower rates of target vessel failure were not achieved compared with balloon angioplasty. Because the acute gain and loss index ratios of the 2 treatments were similar, there was no evident beneficial antirestenosis mechanism seen for rotational atherectomy.

166Ho-coated balloon for vascular brachytherapy

A simple procedure was developed for coating the surface of a conventional percutaneous transluminal coronary angioplasty balloon angioplasty catheter with 166Ho. The absorbed dose delivered by the surface-coated catheter is twice that of a similar catheter filled with a solution containing the same activity of 166Ho. Leakage tests show that <0.6% of the coated activity is removable from the surface of the catheter. The coated catheter removes the risk of release of the 166Ho into the body as a result of rupture of the balloon, and also reduces the radiation exposure to staff.

Association of an activated clotting time < or =250 seconds with adverse event rates after percutaneous coronary intervention using tirofiban and heparin (a TACTICS-TIMI 18 substudy).

An inverse relation between the degree of heparin anticoagulation and the subsequent risk of postprocedural thrombotic complications was observed in the era of conventional balloon angioplasty,1,2 but the optimal dose of heparin during percutaneous coronary intervention (PCI) using newer interventional equipment and glycoprotein IIb/IIIa receptor inhibition has not been well defined. Increased rates of bleeding were noted in the Evaluation of c7E3 for the Prevention of Ischemic Complications (EPIC) trial in patients treated with abciximab and heparin with a target activated clotting time (ACT) of 300 to 350 seconds.3 Later studies using glycoprotein IIb/IIIa receptor inhibitors4–7 found that bleeding complications during coronary angioplasty and stent implantation could be attenuated with early sheath removal and adjusted low-dose heparin. This evidence led to the recommendation of using a goal ACT of 200 to 250 seconds during interventional procedures when heparin and glycoprotein IIb/IIIa receptor inhibitors are used.8,9 Although they minimize bleeding complications, reduced doses of heparin may be associated with a higher risk of adverse events, and a safe and effective lower boundary to the optimal ACT after the administration of tirofiban has not been well defined.10 We hypothesized that ACTs ≤250 seconds during PCI with tirofiban and heparin anticoagulation would be associated with increased adverse events at 30 days.

Effect of uncoated stenting versus balloon angioplasty alone of long coronary (>20 mm) versus shorter narrowings on One-Year Event-Free survival

Conventional balloon angioplasty of long coronary lesions has been associated with suboptimal angiographic results, increased incidence of acute ischemic complications, and increased incidence of long-term repeat revascularization procedures.1–7 Several randomized trials have demonstrated that stenting is superior to balloon angioplasty in reducing the incidence of repeat revascularization procedures.8,9 However, patients with long coronary lesions have been consistently excluded from randomized trials comparing stenting with balloon angioplasty. The present study evaluates the effect of coronary stenting versus balloon angioplasty at 1 year in patients with short, intermediate, and long coronary lesions.

Clinical and Angiographic Factors Affect on In-Stent Restenosis

Background and Objectives:Percutaneous coronary intervention with stent implantation has been shown to reduce the rate of restenosis as compared with conventional balloon angioplasty, but the risk of in-stent restenosis continues to be a significant limitation of this procedure. Of the numerous studies evaluating the predictors of instent restenosis, several have indicated that smaller stent sizes, smaller reference diameters and smaller final stent diameters maybe be associated with an increased risk of restenosis. Subjects and Methods:We studied 164 patients with native coronary artery lesions who were treated with coronary stent and underwent angiographic follow up from April 1999 to Jan 2002. Clinical characteristics, angiographic features, and factors related to stenting procedure were analyzed in order to evaluate the affect of predictors on in-stent restenosis. Results: Angiographic analysis presented in-stent restenosis in 86 patients (52.3%). Between the in-stent restenosis group and the non-restenosis group, there were no differences in baseline characteristics except for smoking. The instent restenosis group had a significantly smaller reference diameter (2.94±0.47 vs. 3.12±0.59 mm, p=0.039), smaller stent diameter (3.05±0.45 vs. 3.21±0.55 mm, p=0.012) and longer stent length (19.98±4.12 vs. 17.89± 4.06 mm, p=0.048) than the non-restenosis group by angiographic analysis (p<0.05). Multivariate analysis revealed that stent length (odds ratio, 1.20) is a predictive factor for in-stent restenosis. In the in-stent restenosis group, the diffuse type, in-stent restenosis group (45.4%) showed more frequent ACC/AHA type C lesions than focal type, in-stent restenosis group (15.2%) (p<0.001). Conclusion:Longer coronary stent length is associated with an increased risk of in-stent restenosis and diffuse type, in-stent restenosis. ACC/AHA class C lesions are associated with an increased risk of diffuse type, in-stent restenosis. (Korean Circulation J 2003;33 (12):1084-1092) KEY WORD:Coronary restenosis;Stents. 논문접수일:2003년 5월 13일 수정논문접수일:2003년 8월 19일 심사완료일:2003년 9월 15일 교신저자:김기식, 700-712 대구광역시 중구 동산동 194 계명대학교 의과대학 내과학교실 전화:(053) 250-7379·전송:(053) 250-7434·E-mail:kks7379@dsmc.or.kr

Do the Benefits of New Technology Outweigh the Costs?

Over the past decade, coronary stenting has been shown to reduce the rates of angiographic and clinical restenosis compared with conventional balloon angioplasty; however, the use of bare-metal stents remains limited by a high incidence of restenosis, leading to frequent repeat revascularization procedures and substantial economic burden. Antiproliferative drug-eluting stents have recently demonstrated dramatic reductions in in-stent restenosis compared with conventional bare-metal stenting; however, the high cost of drug-eluting stents has raised important questions about the clinical and economic benefits of this ‘disruptive technology’.Prospective economic evaluations conducted alongside two randomized clinical trials (SIRolImUS-eluting stent in de novo coronary lesions [SIRIUS] trial and the RAndomized study with the sirolimus-eluting VElocity™ balloon-expandable stent in the treatment of patients with de novo native coronary artery Lesions [RAVEL]) comparing drug-eluting stents with conventional bare-metal stenting, as well as decision-analytic models, have examined the economic merit of using drug-eluting stents.Findings from these studies suggest that although the initial treatment costs with drug-eluting stents are substantially higher, much of the difference in initial costs could be offset by reductions in follow-up costs, mainly due to a reduced requirement for repeat revascularization procedures. Results from these studies show that the cost effectiveness of drug-eluting stents varies considerably with the underlying clinical and angiographic characteristics of the patient population. While drug-eluting stents should be reasonably cost effective for most patients who currently undergo percutaneous coronary intervention (and cost saving for a sizeable minority), for certain subgroups with very low expected clinical restenosis rates (e.g. 5–10%), the routine use of drug-eluting stents may be questioned, at least on economic grounds.In the future, lower incremental costs for drug-eluting stents should render this technology cost saving for a larger subgroup of patients with PCI, and broaden the ideal target population.

Therapeutic potential of active stent coating

Various clinical studies have shown the superiority of stent implantation as compared to conventional balloon angioplasty for the treatment of significant coronary stenosis. However, restenosis remains a major drawback of this interventional technique. Against the background of this serious problem, the concept of stent coating has been developed. In general, coatings can be classified into two types: passive coatings, which only serve as a barrier between the stainless steel, and the tissue and active coatings, which directly interfere with the process of intima proliferation. At this moment, primarily immunosuppressive and cytostatic substances are used as active coatings. Large randomised studies have shown that this novel concept can be successfully implemented into clinical practice. Beside these promising results, studies also revealed potential risks of this new approach. Not only the dosage of the drug but also an optimised kinetic of drug release seem to be essential in preventing restenosis. As with most drugs, the inhibition of neointima proliferation is not restricted to vascular smooth muscle cells but also affects the process of re-endothelialisation, thus we may face a new pitfall of late-stent thrombosis. Although this technique may harbour potential risks, the introduction of stent coating has the potential to dramatically reduce the incidence of restenosis and an exciting chapter in the field of cardiology has been opened.