Two-Year Outcomes After Sirolimus-Eluting Stent Implantation

Safety and efficacy of the CYPHER Select Sirolimus-eluting stent in the "Real World"--clinical and angiographic results from the China CYPHER Select registry

OBJECTIVE

This post-marketing surveillance registry is aimed at determining the safety and reliability of the CYPHER Select Sirolimus-eluting stent (SES) in routine clinical practice.

BACKGROUND

Little information and angiographic follow-up data in large-scale "real world" registry is available for the CYPHER Select SES, an advanced-generation SES.

METHODS

This was a prospective multicenter (20 centers) registry. 1189 consecutive patients who received at least 1 CYPHER Select SES during daily clinical practice were enrolled. Patients who underwent emergency stenting for acute myocardial infarction were excluded.

RESULTS

The procedure's success rate was 98.3% for CYPHER Select SES implantation, and follow-up rates were 98% with 100% data auditing. Target lesion revascularization (TLR) at 12 months occurred in 60 (5.14%) cases, cardiac death in 13 cases (1.11%), Q wave myocardial infarction (MI) in 5 cases (0.43%), non-Q-MI in 9 cases (0.77%), target vessel revascularization (TVR) in 67 cases (5.74%), and MACE defined as cardiac death, nonfatal MI and TLR in 76 cases (6.51%). MACE-free survival rate at 12 months was 93.7%. Angiographic follow-up at 9 months was performed in 418 (68.3%) lesions treated by CYPHER Select SES. The binary restenosis rate was 4.8% in-stent and 9.6% in-segment. Subgroup analysis showed diabetes, bifurcation lesion and combined use of different stents were independent risk factors of cumulative MACE. In-segment MLD </=2.25 mm at post-procedure and ostial lesion was independent predictors of in-segment restenosis.

CONCLUSIONS

In this registry, the MACE, TLR, angiographic late loss and binary restenosis rates of CYPHER Select SES were similar to those reported in SES randomized trials and "real world" registries. The safety and efficacy of CYPHER Select SES shown in this registry are consistent with those seen in SES studies.

mTOR pathway as a target in tissue hypertrophy

Recent work has shown that the mTOR (mammalian target of rapamycin) pathway is an integral cell growth regulator. The mTOR pathway involves two functional complexes, TORC1 and TORC2, which have been defined by both their association with raptor or rictor, respectively, and their sensitivity to short-term rapamycin inhibition. Loss of tumor suppressors TSC1 or TSC2 leads to aberrant activation of TORC1, which has been implicated in the control of cell size. As a result, both physiologic and pathologic tissue hypertrophy are associated with TORC1 activation. Some clinical examples include skeletal and cardiac muscle hypertrophy, vascular restenosis, and compensatory nephrotic hypertrophy. Clarification of the mTOR pathway may lead to increased understanding of both the etiology and consequences of aberrant cell size regulation. This review covers some of the biochemical regulation of the mTOR pathway that may be important to the regulation of cell size, and it will present several potential clinical applications where the control of cell size may be biologically significant.

The effects of drug-eluting coronary stents

A gyógyszerkibocsátó stentek lényegesen csökkentik a stentimplantáció után kialakuló restenosis gyakoriságát, de a simaizomsejt/neointima-proliferáció gátlására alkalmazott cytostaticumok a stent endotelizációját is gátolják, késleltetik, ezért késői gyulladásos reakció és stentthrombosis is felléphet. A szerző áttekinti a gyógyszerkibocsátó és bevonat nélküli, valamint a forgalomban lévő kétféle gyógyszerkibocsátó stentek összehasonlító vizsgálatainak eredményeit. Megállapítja, hogy mindkét gyógyszerkibocsátó stent közel azonos mértékben gátolja a restenosist. A késői stentthrombosis gyakoribb gyógyszerkibocsátó, mint bevonat nélküli stentek használata után. Különösen akkor lehet ilyen szövődményre számítani, ha nem az előírásokban szereplő indikációs területen és anatómiai helyzetben használnak gyógyszerkibocsátó stenteket. A késői stentthrombosis elkerülése érdekében ragaszkodni kell az előírásos stent alkalmazáshoz, hatékonyabb és tartósabb kettős thrombocytaaggregáció-gátló kezelés, felvilágosító munka szükséges.

Success rate of implantation and mid-term outcomes of the sirolimus-eluting stent

BACKGROUND

The sirolimus-eluting stent (SES) is currently the sole drug-coated stent approved for use in Japan, but there are few reports on its safety and outcomes in Japan.

METHODS AND RESULTS

From May 2004 to February 2005, a total of 297 patients with 402 lesions were treated with SES at 6 hospitals in the Kansai district. Follow-up angiography was performed in 82% of the patients and 80% of the lesions at 182+/-35 days after stenting. Coronary stenosis was evaluated using quantitative coronary angiography. Clinical and angiographic data were analyzed. Minimum lesion diameter was 0.75+/-0.52 mm and the reference diameter was 2.81+/-0.47 mm before stenting. The SES successfully dilated 99.5% of the lesions with few major adverse cardiac events. Restenosis occurred in 4.0% and the target lesion revascularization rate was 3.7%. Restenosis correlated with chronic hemodialysis, calcification, occlusion, ostial lesions, lesions kinked>45 degrees, right coronary artery (RCA) lesions and lesions at the ostium of the RCA.

CONCLUSION

SES demonstrated a high rate of successful implantation with few complications, and mid-term outcomes were excellent. Patients with lesions at the ostium of the RCA or under chronic hemodialysis developed restenosis.

Gene therapy for restenosis: biological solution to a biological problem

Coronary artery disease remains a significant health threat afflicting millions of individuals worldwide. Despite the development of a variety of technologies and catheter based interventions, post-procedure restenosis is still a significant concern. Gene therapy has emerged as a promising approach aimed at modification of cellular processes that give rise to restenosis. When juxtaposed alongside the failure of traditional pharmacotherapeutics to eliminate restenosis, gene therapy has engendered great expectations for cubing coronary restenosis. In this review we have discussed an overview of gene therapy approaches that hve been utilized to reduce restenosis in preclinical and clinical studies, current status of anti-restenosis gene therapy and perspectives on its future application. For brevity, we have limited our discussion on anti-restenosis gene therapy to the introduction of a nucleic acid to the cell, tissue, organ or organism in order to give rise to the expression of a protein, the function of which will confer therapeutic effect. For the purpose of this review, we have focused ou discussion on two relevant anti-restenosis strategies, anti-proliferative and pro-endothelialization.

Long-Term Outcome of First-Generation Metallic Coronary Stent Implantation in Patients With Coronary Artery Disease Observational Study Over a Decade

BACKGROUND

In the era of drug-eluting stents, percutaneous coronary intervention (PCI) has been considered an established therapeutic modality for patients with coronary artery disease (CAD). However, little is known about the long-term prognosis.

METHODS AND RESULTS

Using data obtained from a single-center registry for cases of first-generation bare metallic stent (BMS) implantation, a 10-year follow-up study in patients with CAD was performed. Data for 125 serial patients (aged 62+/-9 years, 104 males) in whom a BMS was successfully implanted was analyzed. Cardiac death (n=16 [12.8%]), including sudden cardiac death (n=9 [7.2%]), non-cardiac death (n=17 [13.6%]) and non-fatal acute myocardial infarction (n=16 [12.8%]) were documented. At 10 years, cumulative probabilities of target and non-target lesion revascularization were 20.5% and 41.5%, respectively, and only 39.2% of the patients were free from cardiac events (cardiac death/myocardial infarction/unplanned revascularization). Age and left ventricular ejection fraction (LVEF) were significant predictors of total death, and LVEF and the use of diuretics were predictors of cardiac events.

CONCLUSIONS

Stabilization of the initial stented site was relatively good and the majority of cardiac events might have originated in non-target lesions. Prevention of systemic arteriosclerosis progression is important for patients with CAD, even after successful PCI.

Stent thrombosis with drug-eluting stents: A re-examination of the evidence

The excitement of drug-eluting stents and their promise for reduced restenosis rates have been tempered by recent reports of stent thrombosis. The mechanism of stent thrombosis is multifactorial but appears to be related to delayed endothelialization and healing, late stent malapposition, and antiplatelet resistance. The most important risk factor appears to be the discontinuation of dual antiplatelet therapy. The data from clinical trials suggest that drug-eluting stents are associated with increased incidence of death or myocardial infarction compared with bare metal stents at long-term follow-up, suggesting that the window of thrombotic risk with drug-eluting stents may extend far beyond that for bare metal stents. Measures to possibly decrease the incidence of stent thrombosis include improvements in antiplatelet regimens and newer generation of drug-eluting stents which have biodegradable polymers or are polymer-free. In addition, percutaneous coronary intervention with bare metal stents in patients may be helpful in those known to be intolerant or noncompliant to antiplatelet therapy, have planned procedures or surgeries, or have overwhelming risks which may require discontinuation of dual antiplatelet therapy.

Is late stent thrombosis in drug-eluting stents a real clinical issue? A single-center experience and review of the literature

BACKGROUND

Randomized studies have not found an increased rate of late stent thrombosis (LAST) in drug-eluting stents (DES) compared with bare metal stents (BMS) but those studies were statistically not powered to show such a difference. At the same time there is an increasing number of reports of LAST in DES patients in the current literature.

PATIENTS AND METHODS

We tried to describe the incidence of LAST in an unselected DES and BMS patient population. All patients who underwent stenting in our hospital between October 2003 and March 2006 were included in the study (n=1377). A total of 424 (30.1%) patients were treated with only BMS stents, 520 (37.8%) with paclitaxel-eluting stents (PES), 384 (27.9%) with sirolimus-eluting stents (SES) and 49 (3.6%) with BMS and DES. Long-term follow-up of all patients was used to determine the incidence of LAST as defined by angiographically proven stent thrombosis associated with acute symptoms more than 30 days after stent implantation. Followup was between 1 month and 2 years 7 months (mean 12 months). Patients treated with DES were younger (66+/-11 years) than BMS patients (72+/-10 years; p<0.001) and more often had diabetes (24.2% vs 17.4%; p < 0.001). A previous PCI had been performed in 27.1% of DES patients vs 13.9% of BMS patients (p < 0.001).

RESULTS

There were 9 cases of LAST: 2 with SES (at 6 and 11 months after implantation), 6 with PES (at 6, 9 (2x), 10, 16 and 26 months), and one with BMS (at 22 months). All patients with LAST presented with STEMI and without an angina history that suggested restenosis. Two cases were related to complete cessation of antiplatelet therapy, one because of patient non-compliance (SES), one after aspirin was stopped for orthopedic surgery (BMS). Two cases occurred within 1 month of cessation of clopidogrel therapy and while these patients were on aspirin therapy. Five cases occurred on aspirin monotherapy 2, 3, 4, 10 and 20 months, respectively after planned cessation of clopidogrel. None of the cases occurred under dual antiplatelet therapy. All patients underwent primary PCI; none died.

CONCLUSION

Angiographically proven LAST occurred in our unselected patient population with an incidence of 0.84% in patients treated with DES and 0.21% in BMS patients within a mean follow-up of 12 months (p = 0.36). LAST may indeed occur in clinically stable patients while on aspirin monotherapy. Since LAST led in all patients to STEMI it seems to be a serious clinical issue that prompts further investigation and discussion of length of dual platelet therapy.

Coronary collateral function long after drug-eluting stent implantation

OBJECTIVES

This study was designed to compare coronary collateral function in patients after bare-metal stent (BMS) or drug-eluting stent (DES) implantation.

BACKGROUND

Drug-eluting stents have an inhibitory effect on the production of cytokines, chemotactic proteins, and growth factors, and may therefore negatively affect coronary collateral growth.

METHODS

A total of 120 patients with long-term stable coronary artery disease (CAD) after stent implantation were included. Both the BMS group and the DES group comprised 60 patients matched for in-stent stenosis severity of the vessel undergoing collateral flow index (CFI) measurement at follow-up and for the duration of follow-up. The primary end point of the investigation was invasively determined coronary collateral function 6 months after stent implantation. Collateral function was assessed by simultaneous aortic, coronary wedge, and central venous pressure measurements (yielding CFI) and by intracoronary electrocardiogram during balloon occlusion.

RESULTS

There were no differences between the groups regarding age, gender, body mass index, frequency of cardiovascular risk factors, use of cardiovascular drugs, severity of CAD, or site of coronary artery stenoses. Despite equal in-stent stenosis severity (46 +/- 34% and 45 +/- 36%) and equal follow-up duration (6.2 +/- 10 months and 6.5 +/- 5.4 months), CFI was diminished in the DES versus BMS group (0.154 +/- 0.097 vs. 0.224 +/- 0.142; p = 0.0049), and the rate of collaterals insufficient to prevent ischemia during occlusion (intracoronary electrocardiographic ST-segment elevation > or =0.1 mV) was higher with 50 of 60 patients in the DES group and 33 of 60 patients in the BMS group (p = 0.001).

CONCLUSIONS

Collateral function long after coronary stenting is impaired with DES (sirolimus and paclitaxel) when compared with BMS. Considering the protective nature of collateral vessels, this could lead to more serious cardiac events in the presence of an abrupt coronary occlusion.