Four-year clinical follow-up of the rapamycin-eluting stent evaluated at Rotterdam Cardiology Hospital registry

Rapamycin promoted thrombosis and platelet adhesion to endothelial cells by inducing membrane remodeling

BACKGROUND

Recently, evidence indicated that the rapamycin-eluting stent which was used worldwide may contribute to an increased risk for thrombosis. On the contrary, other researchers found it was safe. Thus, it is necessary to clarify the effect of rapamycin on thrombosis and the corresponding mechanisms.

RESULTS

The effects of rapamycin in vivo were evaluated by modified deep vein thrombosis animal model. The platelets were from healthy volunteers and the platelet-endothelium (purchased from ATCC) adhesion in cultured endothelial cells was assessed. Membrane rufflings in endothelial cells were examined by confocal and electron microscope. Thrombus formation increased in rats that were injected with rapamycin. Electron microscope analysis exhibited microvilli on the rapamycin-treated endothelium in rats. Rapamycin enhanced membrane ruffling in human umbilical vein endothelial cells (HUVECs) and adhesion of platelets to HUVECs. The platelet-HUVECs adhesion was attenuated when cells were treated with cytochalacin B. Inhibition of autophagy by 3-methyladenine led to suppression of membrane ruffles in HUVECs and augmentation of platelet-endothelial adhesion.

CONCLUSIONS

In conclusion, we found that endothelial membrane remodeling induced by rapamycin is crucial for the adhesion of platelets to endothelial cells and thereby for thrombosis in vivo, and that the endothelial membrane remodeling is autophagy dependent.

Periadventitial application of rapamycin-loaded nanoparticles produces sustained inhibition of vascular restenosis

Open vascular reconstructions frequently fail due to the development of recurrent disease or intimal hyperplasia (IH). This paper reports a novel drug delivery method using a rapamycin-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs)/pluronic gel system that can be applied periadventitially around the carotid artery immediately following the open surgery. In vitro studies revealed that rapamycin dispersed in pluronic gel was rapidly released over 3 days whereas release of rapamycin from rapamycin-loaded PLGA NPs embedded in pluronic gel was more gradual over 4 weeks. In cultured rat vascular smooth muscle cells (SMCs), rapamycin-loaded NPs produced durable (14 days versus 3 days for free rapamycin) inhibition of phosphorylation of S6 kinase (S6K1), a downstream target in the mTOR pathway. In a rat balloon injury model, periadventitial delivery of rapamycin-loaded NPs produced inhibition of phospho-S6K1 14 days after balloon injury. Immunostaining revealed that rapamycin-loaded NPs reduced SMC proliferation at both 14 and 28 days whereas rapamycin alone suppressed proliferation at day 14 only. Moreover, rapamycin-loaded NPs sustainably suppressed IH for at least 28 days following treatment, whereas rapamycin alone produced suppression on day 14 with rebound of IH by day 28. Since rapamycin, PLGA, and pluronic gel have all been approved by the FDA for other human therapies, this drug delivery method could potentially be translated into human use quickly to prevent failure of open vascular reconstructions.

Impact of renal insufficiency on safety and efficacy of drug-eluting stents compared to bare-metal stents at 6 years

BACKGROUND

There is few information on the long-term efficacy and safety of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) compared to bare metal stents (BMS) in all-comer percutaneous coronary intervention (PCI)-patients complicated by renal insufficiency (RI).

OBJECTIVE

Our aim was to assess the 6-year clinical outcome of PCI-patients with RI treated exclusively with BMS, SES, or PES in our academic hospital.

METHODS

A total of 1382 patients, included in three cohorts of consecutive PCI-patients (BMS = 392; SES = 498; PES = 492), were categorized by creatinine clearance calculated by the Cockroft-Gault formula (normal kidney function ≥ 90; mild RI = 60-89; moderate RI < 60) and systematically followed for the occurrence of major adverse cardiac events (MACE).

RESULTS

Mortality rates were significantly higher for patients with moderate RI compared to mild RI and normal kidney function at 6 years (Kaplan-Meier estimate: moderate RI (34%) vs. mild RI (12%), P < 0.001; moderate RI (34%) vs. normal kidney function (8%), P < 0.001). After multivariate Cox-regression analysis, SES and PES decreased the occurrence of target-vessel revascularization (TVR) and MACE at 6 years in patients with a normal creatinine clearance compared to BMS [adjusted hazard ratio (aHR) = 0.48, 95% CI: 0.28-0.84; aHR = 0.75, 95% CI: 0.57-0.97, respectively] with no significant effect on mortality. Safety- and efficacy end points were comparable for the three stent types in patients with mild- and moderate renal function.

CONCLUSION

Patients with a normal creatinine clearance had significant improvement in TVR and MACE rates after SES- or PES implantation compared to BMS at 6 years. However, there was no superiority of both drug-eluting stents over BMS in safety and efficacy end points for patients with impaired renal function.

The Generations of Drug-Eluting Stents and Outcomes in Women

Drug-eluting stents have become one of the mainstays of percutaneous coronary artery revascularization. Since their introduction, there have been many developments in this technology including the optimization of the stent platform, novel polymer coatings, and antiproliferative drugs. Although cardiovascular disease is the leading cause of death in women, the prevalence of obstructive coronary artery disease is lower, and women comprise a minority of patients included in clinical trials assessing the performance of drug-eluting stents. This article reviews the advances in drug-eluting stent technology and the studies reporting outcomes in women after implantation of these stents.

Comparison of 5-year clinical outcomes between sirolimus-versus paclitaxel-eluting stent: Korean multicenter network analysis of 9000-patient cohort

BACKGROUND

The paclitaxel-eluting stent (PES) and sirolimus-eluting stent (SES) are first-generation drug-eluting stents (DES) that have been the most widely used; however, it is unclear whether there are differences in the long-term safety and efficacy between the 2 stents. The long-term effectiveness of DES in unselected people with diabetes is also currently unclear. Moreover, the possibility of late catch-up is suggested in the DES population.

METHODS AND RESULTS

This study is an 8-center collaborative network analysis of all comers who received SES and PES. All patients who received SES and PES from February 2003 to October 2006 were enrolled. We analyzed 9315 patients (33.3% with diabetes) treated with SES or PES in the major 8 centers representing whole area of Korea. The primary end point was a major adverse cardiac event (MACE) composite of overall death, myocardial infarction, and target lesion revascularization. All analyses were performed using multivariable, adjusted models and propensity score-matching methods. Long-term MACE for 5 years were significantly lower in the SES than the PES group (13.3% versus 15.6%; hazard ratio, 0.82; 95% confidence interval, 0.71 to 0.96; P=0.01), which was mainly driven by the difference of MACE within the first year (hazard ratio, 0.73; 95% CI, 0.59 to 0.90; P=0.003), but the rate of MACE between 1 and 5 years in the landmark analysis was not different between the 2 stents (1.9 versus 2.0%/yr). In the subpopulation of people with diabetes, in contrast to the whole population, PES was comparable to SES in terms of any clinical outcome, both within the first year and from 1 to 5 years (MACE for 5 years, 20.3 versus 17.9%; MACE within the first year, 9.6 versus 8.2%; MACE 1 to 5 years, 2.9 versus 2.6%/yr).

CONCLUSIONS

The PES was inferior to the SES in the clinical follow-up of more than 9000 patients' cohort for 5 years, which was mainly driven by the difference in the first year. In the subpopulation of people with diabetes that showed higher MACE than people without diabetes, however, PES was comparable to SES in any clinical outcome for 5 years. Although these 2 stents are not frequently used as before, the data would be useful to expect the long-term clinical course of the current DES.

Drug-eluting stents in patients at high risk of restenosis: assessment for France

BACKGROUND

In unselected patients, the incidence of restenosis is lower after placement of drug-eluting stents (DES) than bare-metal stents (BMS) without difference in safety at a time horizon of 4 years. However, DES appears less effective in "off label" patients.

OBJECTIVES

The aim of the study was to assess available evidence of DES efficacy and safety by patient category to establish when DES placement may be recommended for reimbursement by the French national health insurance.

METHODS

Based on a systematic review by patient category (January 2002 to August 2009), two health technology assessment (HTA) reports and thirty-eight clinical studies not covered by the HTA reports (eleven meta-analysis including ours, eleven randomized trials and sixteen cohort studies) were selected. After assessment of the methodological quality, the studies mostly comparing DES with BMS were reviewed by a panel of health professionals who defined a priori the most relevant end points of safety and efficacy.

RESULTS

Seven to fourteen patients treated with DES were needed to avoid one target lesion revascularization (TLR) in patients with lesions >15 mm long, vessel diameter <3 mm, or diabetes, and with some complex lesions (total coronary occlusion, BMS in-stent restenosis multivessel disease, unprotected left main stenosis). DES appeared as safe as other alternatives over a follow-up of up to 4 years when dual antiplatelet therapy was continued for at least 1 year, but statistical power remains limited to conclude for some clinical features.

CONCLUSIONS

For reimbursement, DES use should be limited to certain categories of patients. Treatment of particular cases requires a multidisciplinary approach.

Impact of Sirolimus-Eluting Stent Fracture on 4-Year Clinical Outcomes

Background—

Although stent fracture (SF) after sirolimus-eluting stent (SES) implantation has been recognized as one of the predisposing factors of in-stent restenosis, it remains uncertain whether SF can increase the risk of major adverse cardiac events (MACE), especially beyond 1 year after SES implantation. The aim of this study was to assess the impact of SF relative to non-SF on 4-year clinical outcomes after treatment with SES of comparable unselected lesions.

Methods and Results—

A total of 874 lesions in 793 patients undergoing SES implantation and subsequent angiography 6 to 9 months after index procedure were analyzed. At 6- to 9-month angiographic follow-up, SF was identified in 70 of 874 lesions (8.0%). In-stent late loss was significantly higher in SF lesions versus non-SF lesions (0.42±0.59 mm versus 0.13±0.49 mm, P <0.001), resulting in a significantly higher in-stent restenosis rate (21.4% versus 4.1%, P <0.001). At 4 years, SF versus non-SF was associated with a significantly higher MACE rate (23.2% versus 12.6%, P =0.014), mainly driven by significantly higher target-lesion revascularization (18.8% versus 10.2%, P =0.029) rate. Adverse effects of SF on clinical outcomes occurred mostly within the first year (17.4% versus 6.6%, P =0.001), with similar MACE rate between 1 and 4 years (5.8% versus 5.9%, P =0.611). No significant differences between SF versus non-SF patients were observed in the cumulative frequency of very late stent thrombosis (2.9% versus 1.4%, P =0.281), death (0% versus 2.1%, P =0.252), or myocardial infarction (5.8% versus 2.9%, P =0.165).

Conclusions—

SF of SES was associated with higher MACE rate up to 1 year, mainly driven by higher target-lesion revascularization, whereas no significant association was evident between years 1 and 4.

Late outcomes of drug eluting and bare metal stents in saphenous vein graft percutaneous coronary intervention

AIMS

PCI with drug eluting stents (DES) has been shown to reduce restenosis and major adverse cardiac event (MACE) rates compared to bare metal stents (BMS) in native coronary vessels, although outcomes in saphenous vein graft (SVG) lesions are less clear. We retrospectively studied 388 consecutive patients admitted to our centre for SVG PCI to assess mortality and MACE outcomes (defined as composite endpoint of all-death, stroke, myocardial infarction, stent thrombosis and target lesion (TLR)/vessel (TVR) revascularisation) associated with BMS and DES use.

METHODS AND RESULTS

Two hundred and nineteen (219) patients had BMS and 169 had DES (total 388 patients). Mean follow up was 41.9±23.5 months. No significant differences were observed in mortality (14.2% vs. 11.8%) or MACE (37.6% vs. 35.8%) between the BMS and DES groups at four years follow-up or at other intervening time points studied. Similarly, no differences in TVR/TLR rates were observed over a similar time period (19.8% vs. 21.6%).

CONCLUSIONS

We have observed that DES and BMS use in SVG PCI have comparable mortality and MACE rates, and that in contrast to PCI in native coronary arteries, DES do not reduce revascularisation rates in our study cohort.

Potential difficulty for accurate categorization of drug-eluting stent thrombosis without coronary angiography: unignorable involvement of the cases with new onset acute myocardial infarction occurred in target vessels

Very late stent thrombosis (VLST) is a major unresolved problem of drug-eluting stent (DES) implants. However, its actual incidence with respect to the distribution of DES-target vessel and accuracy of adjudicating stent thrombosis according to the ARC definition has not been yet adequately evaluated. We studied 720 patients who had completed over 1 year from elective DES implantation. In this cohort, we extracted patients who present acute coronary syndrome (ACS) (n = 3, 0.4%). The timing of ACS events was 17, 19, and 24 months after DES implantation. At the time of presentation, VLST was strongly suspected as the initial diagnosis, however, coronary angiography (CAG) confirmed the different culprit lesion from DES and clearly no thrombus within the DES. According to ARC definition, three probable stent thromboses in this cohort before CAG, however, no stent thrombosis was confirmed after the CAG. Thus, no stent thrombosis was confirmed among this study population. In the very late phase after DES implantation, new onset ACS is not at all extraordinary occurrence in the target vessels of previous DES implantation. However, stent thrombosis is often assumed without angiographic confirmation. The clinical possibility that non-stent thrombosis is incidentally diagnosed with stent thrombosis without angiographic confirmation should be considered within the current accepted definition of stent thrombosis.

The unrestricted use of sirolimus- and paclitaxel-eluting stents results in better clinical outcomes during 6-year follow-up than bare-metal stents: an analysis of the RESEARCH (Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital) and T-SEARCH (Taxus-Stent Evaluated At Rotterdam Cardiology Hospital) registries

OBJECTIVES

The aim of this study was to assess the 6-year clinical outcome after unrestricted use of sirolimus-eluting stents (SES) or paclitaxel-eluting stents (PES) as compared with bare-metal stents (BMS) in consecutive de novo patients undergoing percutaneous coronary intervention (PCI).

BACKGROUND

SES and PES have been shown to significantly decrease target vessel revascularization (TVR) rates compared with BMS in "real-world" registries. However, possible higher rates of very-late stent thrombosis and a restenosis "catch-up" trend might jeopardize the benefit.

METHODS

Three PCI cohorts, each with exclusive use of 1 stent type (BMS = 450; SES = 508; PES = 576), were systematically followed for the occurrence of major adverse cardiac events (MACE).

RESULTS

Very-late stent thrombosis was more common in SES and PES patients than BMS patients (2.4% vs. 0.9% vs. 0.4%, respectively; p = 0.02); however, there were no significant differences between the stent types for all-cause mortality and all-cause mortality/myocardial infarction at 6-year follow-up. Sixty-nine SES patients (Kaplan-Meier estimate 14%) and 72 PES patients (14%) had a TVR, as compared with 79 BMS patients (18%; log-rank p = 0.02), which maintained significance after adjustment for (potential) confounders. Multivariate analysis showed that DES implantation is associated with lower incidence of TVR and MACE than BMS implantation (hazard ratio: 0.65, 95% confidence interval: 0.49 to 0.86; p = 0.003; hazard ratio: 0.79, 95% confidence interval: 0.65 to 0.97; p = 0.02, respectively). Incidence of MACE was also lower in SES and PES patients (30% and 30%, respectively) than in BMS patients (34%); however, significance was borderline.

CONCLUSIONS

The unrestricted use of both DES resulted in a sustained advantage in decreasing TVR and, to a lesser extent, MACE compared with BMS at 6 years. The SES and PES are equally safe and effective in the treatment of coronary lesions.

Four-year clinical outcome of sirolimus- and paclitaxel-eluting stents compared to bare-metal stents for the percutaneous treatment of stable coronary artery disease

BACKGROUND

There are limited data on the long-term safety and efficacy profile of coronary stent implantation in patients with stable coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI).

OBJECTIVE

We aimed to assess the 4-year clinical outcome in patients who received a bare-metal stent (BMS), sirolimus-eluting stent (SES), or a paclitaxel-eluting stent (PES) for the percutaneous treatment of stable angina in our center during 2000-2005.

METHODS

In the study period, a total of 2,449 consecutive patients (BMS = 1,005; SES = 373; and PES = 1071) underwent a PCI as part of three historical PCI-cohorts for stable angina and were routinely followed for the occurrence of major adverse cardiac events (MACE).

RESULTS

At 4 years follow-up, 264 BMS patients (26.8%) had a MACE, compared to 75 SES patients (20.9%) and 199 PES patients (23.9%). Multivariate analysis showed that SES and PES were superior to BMS with respect to MACE [hazard ratio (HR) = 0.62, 95% confidence interval (CI): 0.47-0.81; HR = 0.67, 95% CI: 0.55-0.82, respectively]. The occurrence of MACE was significantly lower in the SES and PES population, primarily due to less target-vessel revascularization (TVR) procedures (HR = 0.53, 95% CI: 0.37-0.75; HR = 0.71, 95% CI: 0.62-0.81, respectively). The occurrence of early, late, and very late stent thrombosis was equally rare with each stent type. There were no significant differences between SES and PES on death, myocardial infarction, TVR, and MACE.

CONCLUSION

These findings suggest that SES and PES result in decreased TVR procedures and MACE compared to BMS at 4 years follow-up. SES or PES implantation should be the preferred choice over BMS for patients with stable CAD undergoing PCI.

Predicting restenosis of drug-eluting stents placed in real-world clinical practice: derivation and validation of a risk model from the EVENT registry

BACKGROUND

Prediction of restenosis after percutaneous coronary intervention (PCI) remains challenging, and existing risk assessment algorithms were developed before the widespread adoption of drug-eluting stents (DES).

METHODS AND RESULTS

We used data from the EVENT registry to develop a risk model for predicting target lesion revascularization (TLR) in 8829 unselected patients undergoing DES implantation between 2004 and 2007. Using a split-sample validation technique, predictors of TLR at 1 year were identified from two thirds of the subjects (derivation cohort) using multiple logistic regression. Integer point values were created for each predictor, and the summed risk score (range, 0 to 10) was applied to the remaining sample (validation cohort). At 1 year, TLR occurred in 4.2% of patients, and after excluding stent thrombosis and early mechanical complications, the incidence of late TLR (more likely representing restenosis-related TLR) was 3.6%. Predictors of TLR were age <60, prior PCI, unprotected left main PCI, saphenous vein graft PCI, minimum stent diameter < or =2.5 mm, and total stent length > or =40 mm. Comparison of observed versus predicted rates of TLR according to risk score demonstrated good model fit in the validation set. There was more than a 3-fold difference in TLR rates between the lowest risk category (score=0; TLR rate, 2.2%) and the highest risk category (score > or =5; TLR rate, 7.5%).

CONCLUSIONS

The overall incidence of TLR remains low among unselected patients receiving DES in routine clinical practice. A simple risk model incorporating 6 readily available clinical and angiographic variables helps identify individuals at extremely low (<2%) and modestly increased (>7%) risk of TLR after DES implantation.

Comparison of long-term outcomes of bare metal or drug-eluting stent implantation in standard versus off-label coronary narrowings

Previous studies have shown impressive short- and medium-term outcomes from drug-eluting stent (DES) implantation in coronary artery disease. We assessed long-term outcomes from DES versus bare metal stent (BMS) implantation in standard and off-label lesions. In 2,345 patients who survived event-free for > or = 30 days after stent implantation for standard (n = 1,540, 66%) or off-label (805, 34%) lesions, we assessed time to occurrence of death, myocardial infarction (MI), death or MI, stent thrombosis, target vessel revascularization (TVR), and major adverse cardiovascular events (defined as composite of all study outcomes). Comparisons were made between standard and off-label lesion subsets and between DES and BMS in lesion subsets. Multivariable differences in outcomes between DES versus BMS were assessed using propensity-adjusted proportional hazards regression. Median follow-up duration was 3.4 years. Stenting of off-label lesions was associated with uniformly worse outcomes than stenting of standard lesions. After adjustment for lesion classification, propensity to receive DES, and baseline differences, DES implantation was associated with statistically significant decreases in death (adjusted hazard ratio 0.71, 95% confidence interval 0.51 to 0.98), TVR (hazard ratio 0.58, 95% confidence interval 0.39 to 0.85 for off-label subset; hazard ratio 0.33, 95% confidence interval 0.24 to 0.46 for standard subset), and major adverse cardiovascular events (hazard ratio 0.51, 95% confidence interval 0.42 to 0.61), without increase in MI, death/MI, or stent thrombosis. Elective TVR occurred in 272 patients and resulted in only 1 early death. In conclusion, compared with BMS, use of DES is associated with clinical benefit in standard and off-label lesions at late follow-up. Decrease in elective TVR does not explain the apparent mortality benefit from DES implantation.

Incidence of stent thrombosis and adverse cardiac events 5 years after sirolimus stent implantation in clinical practice

BACKGROUND

The long-term incidence of stent thrombosis (ST) and complications after sirolimus-eluting stents (SES) implantation is still a matter of debate.

METHOD

We conducted a systematic follow-up on the day of their 5-year SES implantation anniversary, in a series of consecutive real-world patients treated with a SES. The use of SES implantation was not restricted to "on-label" indications, and target lesions included in-stent restenosis, vein graft, left main stem locations, bifurcations, and long lesions. The Academic Research Consortium criteria were used for ST classification.

RESULTS

Three hundred fifty consecutive patients were treated with SES between April and December 2002 in 3 Swiss hospitals. Mean age was 63 +/- 6 years, 78% were men, 20% presented with acute coronary syndrome, and 19% were patients with diabetes. Five-year follow-up was obtained in 98% of eligible patients. Stent thrombosis had occurred in 12 patients (3.6%) [definite 6 (1.8%), probable 1 (0.3%) and possible 5 (1.5%)]. Eighty-one percent of the population was free of complications. Major adverse cardiac events occurred in 74 (21%) patients and were as follows: cardiac death 3%, noncardiac death 4%, myocardial infarction 2%, target lesion revascularization 8%, non-target lesion revascularization target vessel revascularization 3%, coronary artery bypass graft 2%. Non-TVR was performed in 8%.

CONCLUSION

Our data confirm the good long-term outcome of patients treated with SES. The incidence of complications and sub acute thrombosis at 5 years in routine clinical practice reproduces the results of prospective randomized trials.