The outcome of percutaneous coronary intervention in patients with in-stent restenosis who failed intracoronary radiation therapy

Stent placement for treatment of long-segment (≥40 mm) carotid atherosclerotic stenosis: results and long-term follow-up in a single-center experience

BACKGROUND

Treatment of long segment carotid stenosis (≥40 mm) with carotid artery stenting (CAS) has rarely been reported. In randomized trials, use of longer stents (>40 mm) has been associated with adverse clinical events. Here, we report our preliminary experience on the stent length and outcome in treating long segment carotid arterial stenosis.

METHODS AND RESULTS

Between August 2003 and February 2013, 22 patients with long segment stenosis of the carotid artery were treated by CAS. The mean stent length was 58.5 mm (50-60 mm). The procedures were successful in all patients, and all reported remarkable relief of symptoms immediately after stent placement. Complications included 1 case of cerebral hemorrhage and one death from myocardial infarction at 10 months. The mean follow up was 27.3 months (10-60 months). One follow-up was lost. 2 patients had late stent thrombosis at 22 and 36 months by CTA follow-up. 18 patients had persistent relief, and angiography/CTA showed normal carotid flow.

CONCLUSIONS

Our study showed that stenting for long carotid stenosis (≥40 mm) can be beneficial. Large scale clinical trial is needed to further evaluate its efficacy and safety.

Predictive factors for in-stent restenosis after balloon-mounted stent placement for symptomatic intracranial atherosclerosis

OBJECTIVES

We sought to evaluate whether clinical, lesion-related and procedural factors may predict in-stent restenosis (ISR) after intracranial stenting.

METHODS

Sixty-one Chinese patients with 65 lesions treated with single bare metal balloon-mounted stent for symptomatic intracranial arterial stenosis underwent conventional angiographic follow-up after procedures between March 2004 and July 2009. Clinical, lesion-related and procedural factors were analysed for any predictive power for the ISR using univariate and multivariate analysis. ISR was defined as >50% stenosis within or at the edge of the stent or absolute luminal loss >20%.

RESULTS

ISR was found in 18 patients (18/61, 29.5%) with 20 lesions (20/65, 30.8%) at a median follow-up of 7 months (range, 5-30 months). Univariate analysis revealed that diabetes, Mori classification, lesion length and stent diameter were associated with ISR. In addition, diabetes (hazard ratio (HR), 2.661; 95% confidence interval (CI), 1.044-6.787; P=0.040) and lesion length (HR, 1.206; 95% CI, 1.023-1.421; P=0.026) were detected as two independent predictors for ISR by stepwise multivariate Cox regression analysis.

CONCLUSIONS

ISR after intracranial stenting with bare metal balloon-mounted stents in our series seems to be more frequent than those reported by the majority of the published case series. Diabetes and lesion length are associated with increased risk of ISR.

Opposite effects of vascular irradiation on inflammatory response and apoptosis induction in the vessel wall layers via the peroxynitrite-poly(ADP-ribose) polymerase pathway

PURPOSE

We investigated in a surgical rat model of vascular injury the potential role of the peroxynitrite - poly(ADPribose) polymerase (PARP) pathway in inflammatory response and apoptosis induction after vascular gamma irradiation.

METHODS

Male Sprague-Dawley rats underwent left carotid endarterectomy with removal of intima: control (n = 10) and were irradiated with 15 Gray (n = 13) or 20 Gray (n = 10) postoperatively and compared with sham-operated rats (n = 10). Additional animals were solely irradiated with 15 Gy (n = 10) and with 20 Gy (n = 10) to distinguish between primary effects of vascular injury and secondary effects due to irradiation.

RESULTS

After 21 days, neointima formation was significantly suppressed after irradiation (control: 0.07 mm(2) +/- 0.04 mm(2), 15 Gy: 0.003 mm(2) +/- 0.004 mm(2), 20 Gy: 0.001 mm(2) +/- 0.0006 mm(2), P< 0.0001). However, a significant inflammation of the vessel wall with focal wall necrosis was detected (control: 0.2 +/- 0.15, 15 Gy: 0.82 +/- 1.2, 20 Gy: 1.25 +/- 0.86, P= 0.003). Immunohistochemistry showed significant staining for nitrotyrosine, poly(ADP-ribose) and nuclear translocation of apoptosis-inducing factor in the neointima of the control group. In the irradiated groups these stainings were significantly higher in the media and adventitia compared to the non-irradiated groups.

CONCLUSION

Activation of the peroxynitrite-PARP pathway was demonstrated during neointima proliferation in a rat model of surgical vascular injury. Vascular irradiation suppressed neointima formation, but induced significant activation of the peroxynitrite - PARP pathway in the outer vessel wall layers concomitant to inflammation and focal wall necrosis. This may contribute to adverse effects of vascular irradiation such as fibrosis and constrictive remodeling.

Predictors of recurrent in-stent restenosis after beta-radiation: An analysis from the START 40/20 trial

OBJECTIVE

The purpose of this study was to identify potential predictors, including clinical, procedural, angiographic, and intravascular ultrasound (IVUS) parameters, for recurrent in-stent restenosis (ISR) following beta-radiation 90Strontium/Yttrium (90Sr/Y) in a large multicenter trial.

BACKGROUND

Although adjunct brachytherapy reduces recurrent ISR after primary catheter-based intervention, recurrence of stenosis after brachytherapy still occurs.

METHODS

We analyzed 185 IVUS cohort patients in the STent And Restenosis Therapy (START) 40/20 trial where a 40-mm, 90Sr/Y, radioactive source train was exclusively used for treatment of ISR to be treatable with a 20-mm balloon.

RESULTS

Thirty-nine patients underwent target lesion revascularization. Preliminary univariate analysis showed that age, smoking, balloon/artery ratio, geographic miss, minimum lumen diameter, and diameter stenosis at baseline were associated with target lesion revascularization, while none of IVUS variables were (minimum lumen area, minimum stent area, or residual plaque burden). The multivariate logistic regression analysis showed that younger age, lower balloon/artery ratio, and presence of geographic miss were independent predictors of target lesion revascularization.

CONCLUSIONS

Even with adjunct beta-radiation therapy, initial mechanical optimization, such as appropriate balloon sizing and positioning, may be critical for the prevention of recurrent ISR.

Restenosis following implantation of bare metal coronary stents: pathophysiology and pathways involved in the vascular response to injury

This review summarizes the restenotic process that occurs after the implantation of bare metal coronary stents. The pathology of in-stent restenosis is distinct from that seen after balloon angioplasty and is characterized by neointimal proliferation and extracellular matrix deposition. The degree of neointimal proliferation is proportional to the amount of injury, the intensity of the inflammatory infiltrate and the association of stent struts with lipid-filled plaque. In-stent restenosis also appears to be associated with systemic markers of inflammation. Shear stress has an important influence on restenosis as does the presence and adhesiveness of vascular progenitor cells. Clinical predictors (e.g., artery size, stent length, diabetes, and gender) may affect the incidence of restenosis seen after stent placement. A number of catheter-based interventions have been used to treat in-stent restenosis. Although preliminary data suggest that the use of drug-eluting stents may be effective, only intracoronary radiation has shown consistent efficacy in randomized trials.

The impact of lesion length on angiographic restenosis after vertebral artery origin stenting

OBJECTIVE

To evaluate the effect of lesion length on in-stent restenosis (ISR) of vertebral artery (VA) origin stenting.

METHODS

We retrospectively analyzed the medical and radiological records of patients receiving VA origin stenting from March 1999 to June 2005. They were subdivided according to lesion length. ISR was defined as >50% diameter narrowing in stent.

RESULTS

Eighty symptomatic patients (64 male, mean age 72 years) with 90 lesions treated with balloon expandable tubular coronary stents were enrolled. There were 34 patients with 38 short lesions (length<or=5 mm, group 1), 37 patients with 42 medium lesions (length>5 mm, <10 mm, group 2) and 9 patients with 10 long lesions (length>or=10 mm, group 3). Eighty seven bare-metal stents and 3 drug-eluting stents were implanted. Repeat angiography was done in 40 lesions (44%) at 11.7+/-9.6 months. The ISR rate in group 1, 2, 3 is 21%, 29%, and 50% (p=0.486). Multivariable Cox regression analysis showed lesion length was the only significant independent predictor of ISR (hazard ratio: 1.19, p=0.039).

CONCLUSION

ISR of VA origin stenting is common. Lesion length is an important predictor of ISR in VA origin stenting.

Brachytherapy for restenosis after stenting for coronary artery disease: its role in the drug-eluting stent era

PURPOSE OF REVIEW

Recent years have brought remarkable changes to the field of interventional cardiology. The need for repeat intervention due to restenosis, the most vexing long-term failure of percutaneous coronary intervention, has been significantly reduced owing to the introduction of two major advances, the vascular brachytherapy (VBT) and the drug-eluting stents (DES).

RECENT FINDINGS

Vascular brachytherapy has demonstrated its efficacy in limiting recurrence of existing in-stent restenosis. The past 2 years have sealed its reputation, with a variety of studies demonstrating its superiority over conventional therapy in challenging patient subsets with high risk for restenosis recurrence. Moreover, the long-term follow-up confirmed durability of this therapy, and the failures of VBT were characterized as easy to treat. Conversely, DES have shown spectacular efficacy at primarily preventing the first restenosis episode following the initial stent placement. Consequently, the role of VBT may be minimized, as the overall need for repeat revascularization is diminished as a result of the wide acceptance of DES. Furthermore, if the capacity of DES to treat in-stent restenosis is confirmed in randomized trials, they may eventually supersede VBT as the therapy of choice for in-stent restenosis.

SUMMARY

At present, VBT is the proven and durable therapeutic choice for patients with complex, diffuse in-stent restenosis who would otherwise have a very poor prognosis for long-term event-free survival. DES have emerged as remarkably effective in minimizing the first restenosis occurrence; they also represent a promising and competitive alternative to VBT for the treatment of in-stent restenosis.

Drug-eluting stents for the treatment of in-stent restenosis

Treatment of in-stent restenosis (ISR) remains problematic despite the widespread application of drug-eluting stents (DES). Challenging lesion cohorts such as diffuse ISR and restenosis after failed intracoronary radiation therapy (IRT) maybe best treated with DES. The overall benefit of DES appears inferior to their utility in treating de novo coronary lesions. Randomised trials comparing DES and IRT will soon be available to determine the optimal therapy for ISR. The challenge to treat ISR in the DES era is the next frontier of interventional cardiology.

Late thrombosis following treatment of in-stent restenosis with drug-eluting stents after discontinuation of antiplatelet therapy

Drug-eluting stent usage has become commonplace for the percutaneous treatment of de novo coronary lesions, but the safety and efficacy profile for their evolving usage in restenotic lesions is largely unknown. We report three cases of angiographically confirmed drug-eluting stent thrombosis following treatment of restenotic lesions that occurred late (193, 237, and 535 days) and shortly after interruption of antiplatelet therapy. All three patients suffered ST elevation myocardial infarction, and there was one death. Further studies are necessary to better define the associated risk and ideal duration of antiplatelet therapy necessary in this cohort of patients with restenotic lesions.

Two-year outcomes of repeated brachytherapy in patients with restenosis after intracoronary radiation therapy

This study compared the 2-year outcomes of repeat brachytherapy (n = 10) and conventional percutaneous intervention (n = 14) in patients with restenosis after intracoronary brachytherapy with a rhenium-188-filled balloon system. The short-term target lesion revascularization rate was significantly lower in the repeat brachytherapy group (0% vs 36%, p = 0.038), and additional target lesion revascularization was required in 2 patients with repeat brachytherapy during 2-year follow-up. There were no vascular complications related to repeat brachytherapy.

Intracoronary brachytherapy with ??-radiation for the treatment of long diffuse in-stent restenosis

OBJECTIVE

To assess the efficacy of intracoronary brachytherapy with beta-radiation (Sr/Y) for the treatment of long diffuse in-stent restenosis (ISR).

METHODS

As recurrent ISR depends on intimal injury after coronary angioplasty, long in-stent restenotic lesions were defined as lesions with a treatment length >26 mm (lesion length >20 mm plus a treatment margin of 3 mm at each end). Seventy-eight patients with long ISR were treated at our institution with beta-brachytherapy after coronary angioplasty. Patients were irradiated with either an approximate dose of 12 Gy at 1 mm vessel wall depth or with 18 Gy at 1 mm vessel wall depth. Clinical follow-up was available for 69 patients and angiographic follow-up for 65 patients. Late lumen loss (LLL), binary restenosis (stenosis >50%), target lesion revascularization (TLR) and major adverse cardiac events (MACE) were assessed for a follow-up time of 6.6+/-2.2 months.

RESULTS

Mean interventional treatment length was 46+/-18 mm. TLR was performed in all 23 patients with binary restenosis (33%). Death of cardiac cause was reported for two patients, one of whom did not undergo TLR. Thus, overall MACE rate was 35%. Recurrent ISR was significantly more frequent in patients with geographic miss. Comparison of the different radiation dose regimens revealed significantly lower LLL in patients irradiated with the higher dose (0.20+/-0.68 mm compared with 0.65+/-0.96 mm, P=0.03).

CONCLUSION

Intracoronary brachytherapy with beta-radiation (Sr/Y) is a safe and effective therapeutic option for the reduction of recurrent ISR in long diffuse lesions. We recommend a high-dose irradiation with 18 Gy at 1 mm vessel wall depth.

Effectiveness of sirolimus-eluting stent implantation for treatment of in-stent restenosis after brachytherapy failure

The impact of the use of sirolimus-eluting stents (SESs) in the treatment of in-stent restenosis in previously irradiated sites has not been adequately evaluated. Fifteen consecutive patients who underwent percutaneous coronary interventions using SESs in lesion sites previously intervened with intracoronary radiation therapy were identified. All stents were implanted successfully, and there were no major in-hospital complications. At 30-day follow-up, there was 1 case of subacute thrombosis that led to target lesion revascularization (TLR). At 6 months, 2 patients underwent TLR because of recurrent angina with angiographic restenosis, and 1 patient underwent target vessel revascularization distally to the SES site; no other major adverse cardiac events occurred at long-term follow-up (mean 17 +/- 8 months).

Repeat intracoronary radiation for recurrent in-stent restenosis in patients who failed intracoronary radiation

BACKGROUND

Intracoronary radiation therapy (IRT) is the only proven treatment for in-stent restenosis (ISR). It is, however, associated with a significant failure rate. The present study evaluated the outcomes of patients who underwent repeat intracoronary radiation for recurrent ISR.

METHODS AND RESULTS

Fifty-one consecutive patients who failed a previous radiation treatment, presented with angina and angiographic evidence of ISR, and were treated with percutaneous coronary intervention (PCI) and repeat radiation to the same segment were studied. Twenty-five patients were treated with gamma radiation in a dose of 15 Gy, and 26 were treated with beta radiation doses of 18.3 to 23 Gy. The mean cumulative dose for this cohort was 39.5+/-11.9 Gy (range, 29 to 75.6 Gy). The outcomes of those patients were compared with outcomes of 299 patients who also failed initial radiation but were treated with repeat conventional PCI to a previously irradiated segment without repeat radiation. At 9 months after treatment, the repeat-IRT group had lower rates of target lesion revascularization (23.5% versus 54.6%; P<0.001) and major adverse cardiac events, including target vessel revascularization (29.4% versus 61.3%; P<0.001). At 9 months, patients with repeat IRT were free of angiographic and clinical events related to the radiation therapy.

CONCLUSIONS

Repeat gamma or beta radiation to treat failed IRT for ISR after conventional PCI is safe and effective at 9 months and should be considered as a therapeutic option for this difficult patient subset.