Five-Year Follow-Up After Intracoronary Gamma Radiation Therapy for In-Stent Restenosis

Inorganic Nanoparticles as Radiosensitizers for Cancer Treatment

Nanotechnology has expanded what can be achieved in our approach to cancer treatment. The ability to produce and engineer functional nanoparticle formulations to elicit higher incidences of tumor cell radiolysis has resulted in substantial improvements in cancer cell eradication while also permitting multi-modal biomedical functionalities. These radiosensitive nanomaterials utilize material characteristics, such as radio-blocking/absorbing high-Z atomic number elements, to mediate localized effects from therapeutic irradiation. These materials thereby allow subsequent scattered or emitted radiation to produce direct (e.g., damage to genetic materials) or indirect (e.g., protein oxidation, reactive oxygen species formation) damage to tumor cells. Using nanomaterials that activate under certain physiologic conditions, such as the tumor microenvironment, can selectively target tumor cells. These characteristics, combined with biological interactions that can target the tumor environment, allow for localized radio-sensitization while mitigating damage to healthy cells. This review explores the various nanomaterial formulations utilized in cancer radiosensitivity research. Emphasis on inorganic nanomaterials showcases the specific material characteristics that enable higher incidences of radiation while ensuring localized cancer targeting based on tumor microenvironment activation. The aim of this review is to guide future research in cancer radiosensitization using nanomaterial formulations and to detail common approaches to its treatment, as well as their relations to commonly implemented radiotherapy techniques.

Intracoronary Brachytherapy for Restenosis: 20 Years of Follow-Up

BACKGROUND/PURPOSE

Intracoronary brachytherapy (ICB) has mainly been used to treat in-stent restenosis following percutaneous coronary intervention and was virtually abandoned about 20 years ago. However, patients treated with this strategy are still alive and some teams continue to perform this therapy. We aimed to investigate the very long-term clinical outcome of patients treated with ICB.

METHODS/MATERIALS

A total of 173 consecutive patients who had been treated with ICB at a large tertiary referral centre between 1998 and 2003 were included. The primary endpoint of the study was all-cause mortality. The secondary endpoints were as follows: occurrence of major adverse cardiac events (MACE, defined as all-cause death, non-fatal myocardial infarction, or target vessel revascularization), cardiac death, and presence of angina at the end of follow-up.

RESULTS

Patients' mean age at the time of ICB was 64 ± 10 years and 77 % were male. Restenosis (bare metal stent vs. balloon angioplasty) was the only indication for ICB. Unstable angina was present in 34 % of the patients. Follow-up was available for 166 patients. After a mean follow-up of 20 ± 1.3 years, 66 % of the patients had died (including 74 patients (67 %) with cardiac death). Cumulative MACE rate at 20 years was 96 %.

CONCLUSIONS

Very long-term follow-up of patients with in-stent restenosis treated with ICB confirmed a high all-cause mortality rate mainly due to cardiac causes and MACEs.

Coronary intravascular brachytherapy for in-stent restenosis: A review of the contemporary literature

Intracoronary stent restenosis (ISR) is a clinically relevant challenge in the modern era. Heterogeneity in patient- and lesion-specific factors can further compound this clinical challenge. Coronary intravascular brachytherapy (IVBT) was the standard therapeutic approach for ISR prior to the advent of drug-eluting stents (DES). Despite prospective data describing the superiority of DES over IVBT for treating de novo ISR, IVBT remains a treatment option for patients with complex disease. The purpose of this review is to evaluate the historical and contemporary literature surrounding IVBT in order to elucidate its role in modern cardiac care and to describe opportunities for future investigations to improve patient selection. Herein, we provide a review of the contemporary literature describing IVBT as a safe and effective treatment option for patients with recurrent, refractory ISR after multilayer DES and no good surgical or mechanical option. Combination therapy with emerging technologies such as DCBs may further increase efficacy.

Health Care Monitoring and Treatment for Coronary Artery Diseases: Challenges and Issues

In-stent restenosis concerning the coronary artery refers to the blood clotting-caused re-narrowing of the blocked section of the artery, which is opened using a stent. The failure rate for stents is in the range of 10% to 15%, where they do not remain open, thereby leading to about 40% of the patients with stent implantations requiring repeat procedure within one year, despite increased risk factors and the administration of expensive medicines. Hence, today stent restenosis is a significant cause of deaths globally. Monitoring and treatment matter a lot when it comes to early diagnosis and treatment. A review of the present stent monitoring technology as well as the practical treatment for addressing stent restenosis was conducted. The problems and challenges associated with current stent monitoring technology were illustrated, along with its typical applications. Brief suggestions were given and the progress of stent implants was discussed. It was revealed that prime requisites are needed to achieve good quality implanted stent devices in terms of their size, reliability, etc. This review would positively prompt researchers to augment their efforts towards the expansion of healthcare systems. Lastly, the challenges and concerns associated with nurturing a healthcare system were deliberated with meaningful evaluations.

Impact of Intravascular Brachytherapy on Patient-Reported Outcomes in Patients with Coronary Artery Disease

BACKGROUND

Intravascular brachytherapy (VBT) is an established treatment for the management of in-stent restenosis (ISR). However, whether VBT is associated with improved patient reported outcomes unknown.

METHODS

We evaluated 51 consecutive patients undergoing VBT in one or more coronary arteries from January 2018 to September 2019. Data on baseline characteristics, procedural outcomes and adverse events were obtained. All patients completed the Seattle Angina Questionnaire - 7 (SAQ-7) form before and after VBT at 1 month and 6 months.

RESULTS

The mean age was 69 ± 9 years and 29 (57%) of patients were males. Procedural success was 94.1%. The mean summary SAQ-7 score improved significantly (53.2 ± 21 vs. 83 ± 19, p < .001) at 30-days. The median Quality of Life (QoL) component of SAQ-7 score was 31.3 (Interquartile Range [IQR]: 18.8, 62.5) and improved to 82.5 (IQR: 62.5, 100), p < .001 at 30 days and 87.5 [IQR: 75, 100), p < .001 at last follow up. Likewise, the median angina frequency component of the SQL-7 score pre-VBT was 55 (IQR: 45, 80) and improved significantly to 90 (IQR: 60, 100) at 30-days, p < .001 and 100 [IQR: 68.8, 100], p = .02 at last follow up. Lastly, the median activity component of the SAQ-7 score improved from 83.3 (IQR: 60-100) to 100 (IQR: 83, 100), p = .01 at 30-days. Thus, results were evident as early as 1 month and sustained at median follow up of 17 months.

CONCLUSION

VBT is associated with improvement in patient reported outcome measures at short term and long term follow up.

Combined Vascular Brachytherapy and Stenting for the Treatment of In-Stent Restenosis

In-stent restenosis (ISR) remains a therapeutic challenge in the current drug-eluting stent (DES) era. Vascular brachytherapy (VBT) is a therapeutic option for ISR, but data about the outcomes of combination therapy with VBT and stenting for ISR lesions are sparse. We retrospectively analyzed patients who presented with ISR at our institution from 2003 through 2017. Three treatment arms were compared: VBT alone, VBT plus bare-metal stent (BMS), and VBT plus DES. Clinical, procedural, and 1-year outcome data were collected. Follow-up was obtained by phone calls and clinic visits. The patient cohort included 461 patients (764 ISR lesions). Of these, 333 patients (533 lesions) were treated with VBT alone, 89 patients (158 lesions) with VBT plus BMS, and 39 patients (73 lesions) with VBT plus DES. There were no significant differences in baseline characteristics among the 3 groups except for more patients with a remote smoking history in the VBT plus BMS (43.8%) and VBT plus DES groups (56.4%), and more patients with history of peripheral vascular disease (39.5%) and congestive heart failure (27%) in the VBT plus DES group. The most common clinical presentation was unstable angina (64.6%). In the VBT plus DES group, 10.3% of patients presented with MI, versus 5.5% in the VBT alone group and 2.2% in the VBT plus BMS group. At 1-year follow-up, the VBT plus DES group had higher rates of target vessel revascularization-major adverse cardiovascular events (38.5%) than the VBT plus BMS (21.3%) and VBT alone (15.6%) groups (p = 0.002). In conclusion, in patients with ISR, combination therapy with VBT and stenting at the same setup is associated with worse outcomes at 12 months and, if possible, should be avoided.

Restenosis of the Coronary Arteries: Past, Present, Future Directions

Restenosis is a pathologic response to vascular injury, characterized by neointimal hyperplasia and progressive narrowing of a stented vessel segment. Although advances in stent design have led to a dramatic reduction in the incidence of restenosis, it continues to represent the most common cause of target lesion failure following percutaneous coronary intervention. Efforts to maximize restenosis prevention, through careful consideration of modifiable risk factors and an individualized approach, are critical, as restenosis, once established, can be particularly difficult to treat. Novel approaches are on the horizon that have the potential to alter the natural history of this stubborn disease.

Vascular brachytherapy versus drug-eluting stents in the treatment of in-stent restenosis: A meta-analysis of long-term outcomes

INTRODUCTION

Clinical trials have shown a short-term benefit of drug-eluting stents (DES) compared to vascular brachytherapy (VBT) for treatment of in-stent restenosis (ISR). The long-term benefits of DES vs. VBT are conflicting in the literature. This study aimed to do a meta-analysis of long-term outcomes of DES compared to VBT for treatment of ISR.

METHODS

PubMed, EMBASE, Cochrane Central and unpublished data were searched for cohort studies and randomized controlled trials (RCTs) that directly compared VBT to DES for the treatment of ISR. We evaluated the following outcomes at 2-5 years of follow-up: target lesion revascularization (TLR), target vessel revascularization (TVR), myocardial infarction (MI), stent thrombosis, cardiovascular (CV) mortality, and overall mortality. Heterogeneity was defined as I(2) values > 25%. Review Manager 5.1 was used for statistical analysis.

RESULTS

We included 1,375 patients from five studies, of which three were RCTs. VBT was used to treat ISR in 685 (49.8%) patients. After a 2-5 year follow-up, no significant differences were found between treatment groups regarding MI (P = 0.49), stent thrombosis (P = 0.86), CV mortality (P = 0.35), and overall mortality (P = 0.71). TLR (OR 2.37; CI 1.55-3.63; P < 0.001) and TVR (OR 2.23; CI 1.01-4.94; P = 0.05) were significantly increased in patients who received VBT.

CONCLUSION

This study suggests that DES are associated with decreased long-term revascularization procedures when compared to VBT for the treatment of ISR. This benefit does not appear to be associated with a significant reduction in mortality or myocardial infarction.

Prospective, randomized, double-blinded trial of bone marrow cell transplantation combined with coronary surgery - perioperative safety study

OBJECTIVES

We present here a sub-study of our prospective, randomized, double-blinded trial of bone marrow mononuclear cell (BMMC) transplantation with coronary artery bypass surgery (CABG) (ClinicalTrials.gov Identifier: NCT00418418), evaluating our secondary end-point concerning hospital stay as well as perioperative morbidity. Injecting a substantial amount of biologically active cells into a diseased myocardium inspires concerns for safety, a concern overlooked in previous trials.

METHODS

We evaluated the immediate perioperative effects of intramyocardial injection of autologous BMMCs combined with CABG. In a randomized double-blinded manner, 39 patients received injections either of BMMCs (n = 20) or of vehicle medium (n = 19). The patients' haemodynamics, arterial blood gases, systemic vein oxygen level, blood glucose, acid-base balance, lactate, haemoglobin, body temperature and diuresis, as well as medications needed, were recorded in the operating theatre and in the intensive care unit (ICU) every 4 h throughout the first postoperative 24 h.

RESULTS

No dissimilarities in these parameters were detectable. In the ICU, the median need for adrenaline was 0.0086 µg/kg/min (first quartile 0.0000, third quartile 0.0204) for controls and 0.0090 µg/kg/min (0.0000, 0.0353) for BMMC patients (P = 0.757); for noradrenaline, 0.0586 µg/kg/min (0.0180, 0.0888) for controls and 0.0279 µg/kg/min (0.0145, 0.0780) for BMMC patients (P = 0.405). The median stay at the ICU was 2 days for both groups (1, 2 for controls; 1, 3 for BMMCs; P = 0.967). Within the first postoperative day, one control patient had an elevated level of creatine kinase-myocardial band fraction mass (CK-MBm) up to >100 µg/l; no BMMC patient showed elevated CK-MBm levels (P = 0.474).

CONCLUSIONS

Both intramyocardial BMMC and placebo injections appear safe during surgery and immediate ICU stay after treatment of heart failure.

Sympathetic renal denervation: hypertension beyond SYMPLICITY

Despite a wide range of drug treatment for hypertension, resistant hypertension rates remain high. The Symplicity™ Renal Denervation System (Medtronic, Santa Rosa, CA), which creates renal nerve denervation, has shown initial success in lowering blood pressure among patients with resistant hypertension. Given the enormous market for this treatment approach, an estimated two dozen other companies are pursuing technologies with alternative approaches. Despite this fact, very little has been published on preclinical and clinical experience with these new devices. The current review summarizes the most prominent technologies in the pipeline and provides insight into the mechanism of action, preclinical, and clinical experience with these new devices.

Treatment of sirolimus-eluting stent restenosis: additional stent, balloon angioplasty, and coronary artery bypass graft

OBJECTIVE

Sirolimus-eluting stent (SES) has shown a significant efficacy in reducing restenosis after percutaneous coronary interventions. However, an increase in total number of SES use along with targeting more complex lesions generated a large number of SES restenosis. This study aimed to investigate the clinical and angiographic outcomes of different revascularization strategies for SES restenosis.

METHODS AND RESULTS

A total of 176 lesions in 149 patients were included in the study. Fifteen patients underwent coronary artery bypass graft surgery (CABG group) and the remaining patients were treated with percutaneous coronary intervention (PCI). Stent reimplantation was performed in 88 patients (Stent group), whereas 46 patients received balloon therapy (Balloon group). Among 176 lesions, major cardiac adverse event (MACE) occurred in 41 lesions (23.3%) during a median follow-up of 310 days (interquartile range: 146-517 days). The Kaplan-Meier method with a log-rank test revealed no significant difference in MACE rates between the three groups (6%, 25%, 26%, p = 0.13; CABG group, Stent group, Balloon group, respectively). However, when the Balloon group and Stent group were combined together as a PCI group, PCI group had a significantly higher rate of MACE compared with the CABG group (p = 0.04). In addition, angiographic restenosis was significantly less prevalent in the CABG group when compared with the other two groups (8%, 57%, 46%, p = 0.006; CABG group, Stent group, Balloon group, respectively).

CONCLUSIONS

CABG surgery for patients with SES restenosis is associated with the better clinical outcomes as well as better angiographic outcomes when compared with that of PCI.

Efficiency and safety of the sirolimus eluting stent in complex coronary artery lesions after cessation of dual antiplatelet therapy: fifteen months clinical outcome of the randomised Stenting Coronary Arteries in Non-stress/benestent Disease (SCANDSTENT) trial

BACKGROUND

The randomised Stenting Coronary Arteries in Non-stress/benestent Disease (SCANDSTENT) trial reported considerably less angiographic restenosis after implantation of sirolimus-eluting stents (SES) vs bare metal stents (BMS) in patients with complex coronary lesions. The purpose of this study was to evaluate the clinical outcome after a majority of the SCANDSTENT patients had stopped the dual antiplatelet therapy.

METHODS AND RESULTS

The SCANDSTENT trial randomly assigned 322 patients with symptomatic complex coronary artery disease (occlusions, bifurcations, ostial or angulated lesions) to receive SES or BMS. At 15 months after stent implantation, when 80% of the patients had stopped taking clopidogrel, six patients in the SES group and 10 in the BMS group had died or suffered a myocardial infarction (non significant [NS]). Compared with BMS, SES reduced the rate of target vessel revascularisation (TVR) from 33.1% to 5.6% (P<0.001) and the frequency of major adverse cardiac events from 35.7% to 8.6% (p<0.001). Definite stent thrombosis was observed in five patients in the BMS group, and two cases of probable and possible stent thrombosis were observed in the SES group (NS). One case of possible SES thrombosis occurred more than one year after stent implantation.

CONCLUSIONS

Compared with BMS, SES markedly reduced the frequency of TVR and MACE within 15 months in SCANDSTENT patients with complex coronary artery lesions without development of delayed restenosis.

Improved perioperative neurological monitoring of coronary artery bypass graft patients reduces the incidence of postoperative delirium: the Haga Brain Care Strategy

OBJECTIVES

Postoperative delirium is a major cause of morbidity and mortality after cardiovascular surgery. Risk factors for postoperative delirium include poor cerebral haemodynamics and perioperative cerebral desaturations. Our aim was to reduce the postoperative delirium rate by using a new prevention strategy called the Haga Brain Care Strategy. This study evaluates the efficacy of the implementation of the Haga Brain Care Strategy to reduce the postoperative delirium rate after elective coronary artery bypass graft (CABG) procedures. The primary endpoint was the postoperative delirium rate, and the secondary endpoint was the length of stay in the intensive care unit.

METHODS

The Haga Brain Care Strategy consisted of the conventional screening protocol for delirium with the addition of preoperative transcranial Doppler examinations, perioperative cerebral oximetry, modified Rankin score, delirium risk score and (if indicated) duplex examination of the carotid arteries. In case of poor preoperative haemodynamics, the cerebral blood flow was optionally optimized by angioplasty or the patient was operated on under mild hypothermic conditions. Perioperative cerebral desaturations >20% outside the normal range resulted in intervention to restore cerebral oxygenation. Cerebral oximetry was discontinued when patients regained consciousness. Patients undergoing elective CABG procedures in 2010 were compared with patients scheduled for coronary bypass graft procedures in 2009 who had not been exposed to additional Haga Brain Care Strategy assessment.

RESULTS

A total of 233 and 409 patients were included in 2009 and 2010, respectively. The number of patients subjected in 2010 to transcranial Doppler examinations, cerebral oximetry or both (Haga Brain Care Strategy) were 262 (64.1%), 201 (49.1%) and 139 (34.0%), respectively. The overall rate of postoperative delirium decreased from 31 (13.3%) in 2009 to 30 (7.3%) in 2010 (P = 0.019). A binary logistic regression model showed that the Haga Brain Care Strategy was an independent predictor of a reduced risk of developing a postoperative delirium (odd ratio = 0.37, P = 0.021).

CONCLUSIONS

With the implementation of the Haga Brain Care Strategy in 2010, a reduction of the incidence of postoperative delirium in patients undergoing elective CABG procedures was observed. In addition, the length of stay in the intensive care unit showed an overall tendency to decline. The limited number of observations and the current study design do not allow a full evaluation of the Haga Brain Care Strategy but the data support the idea that a sophisticated preoperative assessment of cerebral haemodynamics and perioperative monitoring of cerebral oximetry reduce the incidence of the postoperative delirium in CABG surgery.

Five-year follow-up of the Sirolimus-Eluting Stents vs Vascular Brachytherapy for Bare Metal In-Stent Restenosis (SISR) trial

OBJECTIVES

The aim of this study was to evaluate the 5-year clinical safety and efficacy outcomes of patients treated for in-stent restenosis of bare-metal stents (BMSs).

BACKGROUND

The SISR trial is a prospective, randomized trial that compared the safety and efficacy of sirolimus-eluting stent (SES) vs vascular brachytherapy (VBT) for the treatment of BMS in-stent restenosis.

METHODS

A total of 384 patients with BMS in-stent restenosis were randomized to treatment with SES (n = 259) or VBT (n = 125) and were followed for 5 years.

RESULTS

At 5 years, the rates of target lesion revascularization (TLR) had narrowed and were nonsignificant between the SES and VBT groups, with TLR rates of 24.7% and 31.2% (95% CI -16.3% to 2.8%, P = .179) respectively. Target vessel failure was 33.6% vs 36.8% (95% CI -13.5% to 6.7% P = .568) for SES compared with VBT. The rate of major adverse cardiac event at 5 years was 34.0% vs 36.8% (95% CI -13.1% to7.1%, P = .648) for the SES compared with VBT. There were no differences between SES and VBT in terms of survival free from TLR (72.9% vs 66.4%, log-rank P = .08) or from target vessel failure (64.4% vs 61.3%, log-rank P = .349). There were no significant differences in the rates of definite/probable stent thrombosis (5.9% vs 2.5%, 95% CI -7.9% to 1.3%, P = .182) between the 2 groups.

CONCLUSIONS

At a 5-year follow-up, no differences in safety or efficacy outcomes were observed for treatment of BMS restenosis with SES vs VBT. There were no significant differences in survival free from TLR, target vessel revascularization, or major adverse cardiac events between the 2 groups at 5 years. Sirolimus-eluting stent is a viable treatment option compared with VBT for BMS restenosis.

Angiographic evidence of progressive lumen narrowing over 2 years following drug-eluting stent implantation

BACKGROUND

Questions persist regarding the ability of drug-eluting stents (DES) to inhibit intimal growth in the long-term.

METHODS

We prospectively enrolled 766 lesions treated with DES that underwent angiographic examination at 6 months and 2 years after stenting. Lesions with 6-month restenosis (>50% of visual stenosis) were excluded. The primary end point was quantitative change in minimal lumen diameter (MLD) according to serial angiography of the segment (in-segment), the stented region (in-stent) and both edges. Late loss, defined as MLD change, was categorized as early (between post-procedure and 6 months), delayed (between 6 months and 2 years), or overall (between post-procedure and 2-years).

RESULTS

MLD progressively decreased in both the in-stent and edge regions at both 6 months and 2 years (p<0.001 in all paired analyses). In-segment MLD decreased from a median 2.27 mm (interquartile range; 1.98, 2.62) at post-procedure to 2.18 mm (1.86, 2.47; p < 0.001 with post-procedure) at 6 months, and to 2.02 mm (1.66, 2.37; p<0.001 with 6 months) at 2 years. Late loss was 0.0 6 mm (-0.05, 0.26) in the early phase, 0.09 mm (-0.01, 0.28) in the delayed phase, and 0.20mm (0.03, 0.50) overall. Two-year angiographic restenosis occurred in 54 (7.0%) lesions, and 65 (8.5%) underwent target lesion revascularization over a median follow-up of 52.5 months.

CONCLUSION

Serial angiographic analysis showed that DES lumen diameter progressively narrowed over 2 years post-procedure. However, the incidence of target lesion revascularization was relatively low due to the small amount of late loss in the delayed phase.

Impact of incomplete surgical revascularization on survival

Complete revascularization is considered superior to incomplete revascularization (IR), with better long-term survival and a lower rate of reintervention. However, it has yet to be established whether this difference is due directly to IR as a surgical strategy or whether this approach is merely a marker of more severe coronary disease and more rapid progression. We believe that IR is a prognostic marker for a more complex coronary pathology, and adverse effects are probably due to the preoperative condition of the patient. In fact, although IR may negatively affect long-term outcomes, it may be, when wisely chosen, the ideal treatment strategy in selected high-risk patients. IR can derive from a surgical strategy of target vessel revascularization, where the impact of surgery is minimized to reduce perioperative mortality and morbidity, aiming to achieve the best feasible safe revascularization.

In-stent restenosis in the drug-eluting stent era

The introduction of the drug-eluting stent (DES) proved to be an important step forward in reducing rates of restenosis and target lesion revascularization after percutaneous coronary intervention. However, the rapid implementation of DES in standard practice and expansion of the indications for percutaneous coronary intervention to high-risk patients and complex lesions also introduced a new problem: DES in-stent restenosis (ISR), which occurs in 3% to 20% of patients, depending on patient and lesion characteristics and DES type. The clinical presentation of DES ISR is usually recurrent angina, but some patients present with acute coronary syndrome. Mechanisms of DES ISR can be biological, mechanical, and technical, and its pattern is predominantly focal. Intravascular imaging can assist in defining the mechanism and selecting treatment modalities. Based upon the current available evidence, an algorithm for the treatment approaches to DES restenosis is proposed.

Effect of coronary target lesion revascularization on late cardiac events after insertion of sirolimus-eluting or bare metal stents

Restenosis is associated with acute myocardial infarction (MI) either at presentation or related to complications of target lesion revascularization (TLR). The cumulative late effect of TLR after drug-eluting or bare metal stent placement on cardiac death or MI is uncertain. Of the 1,057 patients with one native coronary lesion randomized to a sirolimus-eluting stent or bare metal stent in the Sirolimus-Eluting Stent in De Novo Native Coronary Lesions (SIRIUS) trial, the 983 who survived free of MI for the first 30 days were evaluated for the primary outcome of cardiac death or MI for 5 years. Patients with events occurring at or after TLR were assigned to TLR group. Cox proportional hazards regression analysis with TLR as a time-dependent variable and adjustment for baseline clinical and demographic covariates was used to assess the independent effect of TLR on the primary outcome. TLR occurred in 160 patients (16.3%) and was an independent predictor of the primary end point (hazard ratio 2.8, 95% confidence interval 1.7 to 4.5). This association was significant for sirolimus-eluting stents and bare metal stents. TLR was also associated with an increased risk of subsequent stent thrombosis and nontarget vessel revascularization. Intracoronary brachytherapy in the TLR group was associated with an increased risk of cardiac death or MI. In conclusion, restenosis requiring TLR was associated with an increased risk of cardiac death or MI occurring at TLR and during the subsequent 5 years.

Late progression after sirolimus-eluting stent implantation for de novo lesions--comparison with bare metal stent implantation

BACKGROUND

In previous studies, the minimal luminal diameter (MLD) of lesions treated with a bare metal stent (BMS) was shown to improve from 6 months to 3 years. However, the long-term response to a sirolimus-eluting stent (SES) implantation remains unclear.

METHODS AND RESULTS

To evaluate 6-month, 12-month and 3-year outcomes, clinical and angiographic follow-up data were analyzed for 367 consecutive patients (506 de novo lesions) who underwent successful SES implantation compared to follow-up data for 617 consecutive patients (802 de novo lesions) who underwent BMS implantation. Clinical follow-up information was obtained for 363 SES-treated patients (98.9%) and 581 BMS-treated patients (94.2%) at 1 year, and 334 SES-treated patients (91.0%) and 566 BMS-treated patients (91.7%) at 3 years. At 3 years, there were no significant differences in the cumulative cardiac death and myocardial infarction. Target lesion revascularization (TLR) rates were significantly higher in BMS-treated patients than in SES-treated patients. In BMS-treated patients, most TLR was performed within 450 days, however, after 450 days, the TLR rate was significantly lower than that for the SES-treated patients. In quantitative coronary angiographic data, among lesions that required no revascularization at the initial 12-month follow up, MLD increased significantly from the 12-month to the 3-year follow-up angiography in BMS-treated lesions. However, MLD decreased significantly in SES-treated lesions.

CONCLUSIONS

From a 12-month follow-up to a 3-year follow-up, stenosis in BMS-treated lesions regressed, but stenosis in SES-treated lesions progressed. And late TLR was more frequently required in the SES-treated patients.

Emerging drugs for coronary restenosis: the role of systemic oral agents the in stent era

Introduction of drug eluting stents (DES) during percutaneous coronary interventions significantly reduces the rate of angiographic restenosis, target lesion and vessel revascularization. In spite of these benefits, other clinical hard end points such as death or myocardial infarction were not reduced and, furthermore, new concerns associated with the presence of late and very late stent thrombosis have been raised. The requirement of long-term dual antiplatelet therapy is another limitation associated with DES. Conversely, in this decade, other options to DES have been simultaneously discussed in observational and randomized studies. Several registries and randomized trials using the systemic approach with anti-inflammatory, immunosuppressive or antiplatelet therapies have been identified and discussed in this manuscript. In spite of all randomized studies with oral therapies in the bare metal stent (BMS) era demonstrating positive reductions in coronary restenosis, this practice has not been introduced clinically. Furthermore, a recent randomized trial comparing oral sirolimus plus BMS versus DES demonstrated that the first approach was cost saving and of comparable efficacy to DES. Conclusive evidence of high incidence of late and very late stent thrombosis with DES, together with clinical limitations for its widespread use, has opened up a large opportunity to search for alternative therapies in coronary restenosis prevention.

Long-term risk of adverse outcomes and new malignancies in patients treated with oral sirolimus for prevention of restenosis

OBJECTIVES

We sought to investigate the long-term efficacy of oral sirolimus therapy and its impact on the incidence of de novo malignancies in the OSIRIS (Oral Sirolimus to Inhibit Recurrent In-Stent Stenosis) trial population.

BACKGROUND

The OSIRIS trial showed a significant reduction of angiographic restenosis with an oral adjunctive sirolimus treatment for in-stent restenosis. The long-term efficacy of oral sirolimus therapy is unknown.

METHODS

Three hundred patients with in-stent restenosis were randomly assigned to receive placebo, a cumulative loading dose of 8 mg (usual-dose), or 24 mg (high-dose) of sirolimus over 3 days (2 days before and the day of intervention) followed by maintenance therapy of 2 mg/day for 7 days. The primary outcome of this analysis was the incidence of composite of death, myocardial infarction, and target vessel revascularization at 4-year follow-up. Secondary outcome was the incidence of newly diagnosed malignancies.

RESULTS

No significant differences were observed between placebo, usual-, and high-dose sirolimus treatment groups regarding primary outcome (33.3%, 39.4%, and 31.3%, respectively; p = 0.46), death (5.9%, 9.1%, and 11.1%, respectively; p = 0.41), target vessel revascularization (30.4%, 30.3%, and 22.2%, respectively; p = 0.33), and rate of newly diagnosed malignancies (7.8%, 3.0%, and 11.1%, respectively; p = 0.09).

CONCLUSIONS

The benefit in the reduced need for repeat intervention observed at 1 year with high-dose oral sirolimus therapy was attenuated over 4 years. Moreover, this regimen was associated with numerical yet not a significant increase in newly diagnosed malignancies without augmenting the malignancy-induced risk of death. (Oral Sirolimus for In-Stent Restenosis [OSIRUS] trial; NCT00859183).

Decision making after aspirin, clopidogrel and GPIIb/IIIa inhibitor use

The expanding use of antiplatelet agents in patients who undergo coronary bypass grafting raises the problem of balancing the benefit of this treatment and the risk of increased bleeding after surgery. Aspirin and clopidogrel have different mechanisms of actions, but have in common the irreversibility of the inhibition mechanism. Even if platelets half-life is around 10 days, it is not necessary to wait for this period of time. It can be reasonable to discontinue aspirin two to three days and clopidogrel five days before surgery, even if it was recently suggested to reduce the discontinuation interval to two to three days for the clopidogrel as well. GPIIb/IIIa inhibitors have a short acting action. Reasonably, abciximab has to be stopped, when possible, at least 12 hours before surgery, preferably before 24 hours. On the contrary, tirofiban can also be stopped at the moment of skin incision without harmful effects. Very little is known of eptifibatide, but it seems that it is safe to stop it two to four hours before surgery. Patients with acute coronary syndrome do not need to discontinue any antiplatelet treatment.

Passive and active polymer coatings for intracoronary stents: novel devices to promote arterial healing

Coronary stent implantation is the second great advance in the treatment of obstructive coronary artery disease since the introduction of balloon catheter angioplasty. However, in-stent restenosis (ISR) caused by neointimal hyperplasia has been a major limitation of stents, occurring in up to 30% of cases. Advances in coronary stent technology both in terms of stent design and function and especially drug-eluting stents (DES) have significantly improved the safety and efficacy of percutaneous coronary intervention (PCI) with stenting, including marked reduction in ISR. This has led to use of DES for increasingly challenging clinical and lesional subsets, with potential for increased risk of stent-associated complications, especially late stent thrombosis (LST). Because restenosis and stent thrombosis are caused by multiple and often interrelated factors, ideal agents for stent coatings should inhibit thrombus formation, inflammatory reaction, and cellular proliferation, while supporting reendothelialization. To avoid undesirable effects of currently applied (durable) polymers, biocompatible, and bioabsorbable polymers as well as DES delivery systems that minimize polymer burden have been produced and tested. Bioabsorbable stents, both polymeric and metallic, have been developed to decrease potential late complications after stent implantation. Novel strategies to address some of these challenges are in various stages of research and development. In this article we outline developments in the field of passive and active stent coatings and evaluate the ongoing role of such coatings in the contemporary era of DES.

3-year follow-up of the SISR (Sirolimus-Eluting Stents Versus Vascular Brachytherapy for In-Stent Restenosis) trial

OBJECTIVES

The aim of this study was to evaluate long-term outcome of patients treated for in-stent restenosis of bare-metal stents (BMS).

BACKGROUND

Treatment of restenosis of BMS is characterized by high recurrence rates. Vascular brachytherapy (VBT) improved outcome although late catch-up events were documented. Drug-eluting stents tested against VBT in this setting were found superior for at least the first year; superiority at longer follow-up is uncertain.

METHODS

We evaluated 3-year outcome of the multicenter SISR (Sirolimus-Eluting Stents Versus Vascular Brachytherapy for In-Stent Restenosis) trial, which randomized patients with restenosis of BMS to either a sirolimus-eluting stents (SES) or VBT.

RESULTS

Target vessel failure (cardiac death, infarction, or target vessel revascularization [TVR]) at 9 months as previously reported was significantly improved with SES. Kaplan-Meier analysis at 3 years documented that survival free from target lesion revascularization (TLR) and TVR continues to be significantly improved with SES: freedom from TLR 81.0% versus 71.6% (log-rank p = 0.018), and TVR 78.2% versus 68.8% (log-rank p = 0.022), SES versus VBT. At 3 years, target vessel failure and major adverse cardiac events (death, infarction, emergency coronary artery bypass grafting, or repeat TLR) remained improved with SES, but did not reach statistical significance. There was no statistically significant difference in definite or probable stent thrombosis (3.5% for SES, 2.4% for VBT; p = 0.758).

CONCLUSIONS

At 3 years of follow-up, after treatment of in-stent restenosis of BMS, patients treated with SES have improved survival free of TLR and TVR compared with patients treated with VBT. Stent thrombosis rates are not different between the 2 groups but are higher than reported in trials of treatment of de novo lesions.

Optimal method of coronary revascularization in patients receiving dialysis: systematic review

BACKGROUND AND OBJECTIVES

Patients receiving dialysis have a high burden of cardiovascular disease. Some receive coronary artery revascularization but the optimal method is controversial.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The authors reviewed any randomized controlled trial or cohort study of 10 or more patients receiving maintenance dialysis which compared coronary artery bypass graft (CABG) to percutaneous intervention (PCI) for revascularization of the coronary arteries. The primary outcomes were short-term (30 d or in-hospital) and long-term (at least 1 year) mortality.

RESULTS

Seventeen studies were found. There were no randomized trials: all were retrospective cohort studies from years 1977 to 2002. There were some baseline differences between the groups receiving CABG compared with those receiving PCI, and most studies did not consider results adjusted for such characteristics. Given the variability among studies and their methodological limitations, few definitive conclusions about the optimal method of revascularization could be drawn. In an exploratory meta-analysis, short-term mortality was higher after CABG compared to PCI. A substantial number of patients died over a subsequent 1 to 5 yr, with no difference in mortality after CABG compared to PCI.

CONCLUSIONS

Although decisions about the optimal method of coronary artery revascularization in dialysis patients are undertaken routinely, it was surprising to see how few data has been published in this regard. Additional research will help inform physician and patient decisions about coronary artery revascularization.

Five-year follow-up after sirolimus-eluting stent implantation results of the SIRIUS (Sirolimus-Eluting Stent in De-Novo Native Coronary Lesions) Trial

OBJECTIVES

The aim of this study was to examine the 5-year clinical safety and efficacy outcomes in patients enrolled in the SIRIUS (Sirolimus-Eluting Stent in De-Novo Native Coronary Lesions) trial.

BACKGROUND

The SIRIUS trial was a double-blinded randomized study that demonstrated that sirolimus-eluting stents (SES) significantly improved angiographic results (at 8 months) and clinical outcomes (at 9 and 12 months) compared with bare-metal stents (BMS).

METHODS

Patients (n = 1,058) with de novo native coronary artery lesions were randomized to either SES (n = 533) or control BMS (n = 525) and were followed for 5 years.

RESULTS

Between 1 and 5 years, additional clinical events were similarly distributed among the sirolimus and control groups. At 5 years, in sirolimus versus control patients, target lesion revascularization was 9.4% versus 24.2% (p < 0.001) and major adverse cardiovascular events and target vessel failure rates were 20.3% versus 33.5% and 22.5% versus 33.5%, respectively (p < 0.0001 for both). There were no significant differences in death, myocardial infarction, and nontarget lesion revascularization. No significant differences were observed in the cumulative incidence of stent thrombosis for sirolimus versus control patients with either protocol-derived (1.0% vs. 0.8%) or Academic Research Consortium definitions (3.9% vs. 4.2%).

CONCLUSIONS

In patients with noncomplex coronary artery disease, clinical outcomes 5 years after implantation of SES continue to demonstrate significant reduction in the need for repeat revascularization, with similar safety (death and myocardial infarction) compared with BMS, without evidence for either disproportionate late restenosis or late stent thrombosis.

Long-term clinical benefit of sirolimus-eluting stents in patients with in-stent restenosis results of the RIBS-II (Restenosis Intra-stent: Balloon angioplasty vs. elective sirolimus-eluting Stenting) study

OBJECTIVES

We sought to assess the long-term effectiveness and safety of sirolimus-eluting stents (SES) in patients with in-stent restenosis (ISR).

BACKGROUND

Treatment of patients with ISR remains a challenge. The long-term outcome of patients with ISR treated with SES remains unknown.

METHODS

The RIBS-II (Restenosis Intra-stent: Balloon angioplasty vs. elective sirolimus-eluting Stenting) study was a randomized trial conducted in 150 patients with ISR (76 SES, 74 balloon angioplasty [BA]). The long-term (>1 year) clinical outcome and pre-specified subgroup analyses were pre-defined secondary study end points.

RESULTS

At 1 year, the event-free survival (death, myocardial infarction, target vessel revascularization [TVR]) was better in the SES group (88% vs. 69%, p < 0.005). Additional long-term (>3 years) clinical follow-up was obtained in 97% of patients (median 3.3 years). After the first year, 3 patients died (1 SES, 2 BA), 5 suffered myocardial infarction (4 SES, 1 BA), and 7 required TVR (4 SES, 3 BA). At last follow-up, definitive/probable/possible stent thrombosis was similar in both groups (2/2/1 SES vs. 1/0/3 BA, p = NS). At 4 years, the event-free survival was 76% in the SES arm and 65% in the BA arm (p = 0.019). On multivariate analysis, SES implantation was an independent predictor of event-free survival. Subgroup analyses were consistent with the main outcome measure.

CONCLUSIONS

In patients with ISR, SES implantation remains effective and safe at very long-term clinical follow-up.

Target lesion revascularization after wingspan: assessment of safety and durability

BACKGROUND AND PURPOSE

In-stent restenosis (ISR) occurs in approximately one-third of patients after the percutaneous transluminal angioplasty and stenting of intracranial atherosclerotic lesions with the Wingspan system. We review our experience with target lesion revascularization (TLR) for ISR after Wingspan treatment.

METHODS

Clinical and angiographic follow-up results were recorded for all patients from 5 participating institutions in our US Wingspan Registry. ISR was defined as >50% stenosis within or immediately adjacent (within 5 mm) to the implanted stent and >20% absolute luminal loss.

RESULTS

To date, 36 patients in the registry have experienced ISR after percutaneous transluminal angioplasty and stenting with Wingspan. Of these patients, 29 (80.6%) have undergone TLR with either angioplasty alone (n=26) or angioplasty with restenting (n=3). Restenting was performed for in-stent dissections that occurred after the initial angioplasty. Of the 29 patients undergoing TLR, 9 required >/=1 interventions for recurrent ISR, for a total of 42 interventions. One major complication, a postprocedural reperfusion hemorrhage, was encountered in the periprocedural period (2.4% per procedure; 3.5% per patient). Angiographic follow-up is available for 22 of 29 patients after TLR. Eleven of 22 (50%) demonstrated recurrent ISR at follow-up angiography. Nine patients have undergone multiple retreatments (2 retreatments, n=6; 3 retreatments, n=2; 4 retreatments, n=1) for recurrent ISR. Nine of 11 recurrent ISR lesions were located within the anterior circulation. The mean age for patients with recurrent anterior circulation ISR was 57.9 years (vs 81 years for posterior circulation ISR).

CONCLUSIONS

TLR can be performed for the treatment of intracranial Wingspan ISR with a relatively high degree of safety. However, the TLR results are not durable in approximately 50% of patients, and multiple revascularization procedures may be required in this subgroup.

Radiation therapy for the treatment of benign vascular, skeletal and soft tissue diseases

The concept of radiation therapy for the treatment of benign diseases refers to the use of moderate to high-energy ionising radiation as part of the treatment of non-malignant, but not necessarily harmless, diseases. The usefulness of radiation therapy, based on the anti-inflammatory properties of ionising radiation, has long been known. Apart from the treatment of intracranial benign tumours, such as meningiomas and neurinomas, the prevention of cardiovascular restenosis or treatment of skeletal degenerative diseases are, without doubt, the main fields of action for radiation therapy in benign conditions. Nonetheless, many other non-cancer entities may benefit from ionising radiation therapy treatment. The purpose of this review is to highlight and update indications for treatment with radiation therapy in benign conditions, focusing on skeletal degenerative processes, vascular conditions and soft tissue diseases.

Retrospective cross-validation of simplified predictive index for renal replacement therapy after cardiac surgery

OBJECTIVES

Acute kidney impairment requiring renal replacement therapy is an infrequent but dangerous complication of cardiac surgery. Its development is associated with high mortality and morbidity. A recently published simple risk stratification engine has been developed and validated in the USA and Canada, but its discriminatory power has never been tested in Europe. We aimed to cross-validate the newly developed risk stratification algorithm in a group of patients operated on in a single centre in Poland.

METHODS

From electronic database we selected 1421 patients fulfilling identical inclusion and exclusion criteria as in derivation cohort in Canada. In each patient eligible for analysis we calculated simplified renal index and assessed its predictive power for the need of renal replacement therapy.

RESULTS

After surgery 33 (2.3%) patients developed acute kidney impairment and subsequently underwent renal replacement therapy. The simplified renal index predicted risk of postoperative renal replacement therapy in our group. Patients with low values of simplified renal index (0-1), medium (2-3) and high values (4 and more) were found to have increasingly higher risk for renal replacement therapy of 1.1% (95% CI: 0.5-2.1%), 3.2% (95% CI: 1.9-5%) and 12.5% (95% CI: 5.2-24.1%), respectively. The area under the ROC curve of simplified renal index as predictor of renal replacement therapy in our centre was 0.73 (95% CI: 0.62-0.81) and did not differ significantly from the values obtained in the original paper.

CONCLUSION

The new risk stratification algorithm is effective in discrimination of patients at high risk for development of acute kidney impairment with the need of renal replacement therapy.

Cost-effectiveness of sirolimus-eluting stents compared with vascular brachytherapy for the treatment of in-stent restenosis

BACKGROUND

Sirolimus-eluting stents (SESs) were recently shown to be superior to vascular brachytherapy for the treatment of restenosis within a bare metal stent. No economic comparison of these alternative strategies has yet been reported.

METHODS

We conducted a prospective health economic study involving all patients randomized to SES (n = 259) or brachytherapy (n = 125) in the SISR trial. Procedural, hospital, and outpatient costs, as well as physician fees, were estimated through 12 months based on measured resource use and itemized hospital bills. Cost-effectiveness was assessed in terms of the cost per repeat revascularization avoided, cost per major adverse cardiac event avoided, and cost per event-free patient.

RESULTS

Although initial device costs were approximately $1100/patient higher in the SES group, this was offset by higher physician fees associated with brachytherapy, such that initial hospitalization costs were similar for the 2 groups. Because SES significantly reduced repeat revascularization procedures and major adverse cardiac event compared with brachytherapy during follow-up, cumulative 12-month costs were significantly lower in the SES group ($16,482 vs $19,435, mean difference -$2953, 95% CI -$5470 to -$792). Sirolimus-eluting stenting was thus both more effective and less expensive than brachytherapy, as confirmed in >98% of bootstrap replications for each of the cost-effectiveness outcomes.

CONCLUSIONS

Compared with vascular brachytherapy, SES is an economically dominant strategy for the treatment of in-stent restenosis.