Very late stent thrombosis and late target lesion revascularization after sirolimus-eluting stent implantation: five-year outcome of the j-Cypher Registry

Black hole restenosis after drug-eluting stent implantation for in-stent restenosis: potential mechanism and optimal strategy

In-stent restenosis (ISR) has long remained as the major limitation of coronary stenting. The use of drug-eluting stent (DES) reduces the risk of repeat revascularization without an increase of death and myocardial infarction, compared to the standard bare metal stents. DES has also demonstrated markedly to reduce ISR for complex lesions. However, ISR after DES implantation still occurs and optimal treatment for ISR after DES has not been established. Herein, we report 3 cases with black hole restenosis confirmed by intravascular ultrasound at the site of overlapped DES and discuss potential mechanism and optimal strategy for this phenomenon.

Ten-year clinical follow-up after sirolimus-eluting stent implantation

BACKGROUND

Little is known on the "very" long-term incidence of major adverse cardiac events (MACE), target-lesion revascularization (TLR), target-vessel revascularization and stent thrombosis after sirolimus-eluting stent (SES) implantation. We present the first study to provide a 10-year clinical follow-up in an unselected patient population who underwent SES implantation.

METHODS AND RESULTS

We ran a systematic 10-year clinical follow-up in a series of 200 consecutive patients treated with unrestricted SES implantation between April 2002 and April 2003 in two Swiss hospitals. Outcomes and follow-up were obtained in all 200 patients. The cumulative 10-year MACE rate was 47% with all-cause death of 20%, cardiac death of 9%, myocardial infarction of 7%, TLR and target-vessel revascularization of 8% and 11% respectively. Academic Research Consortium-defined "definite and probable" stent thrombosis-rate was 2.5%. TLR risk was maximal between 3 to 6 years. New lesion revascularization increased throughout the study period.

CONCLUSION

Incidence of TLR was maximal 3 to 6 years after SES implantation and decreased thereafter. MACE and non-TLR revascularization rates steadily increased during the complete follow-up underlining the progression of coronary artery disease.

Adherence to dual antiplatelet therapy after coronary stenting: a systematic review

BACKGROUND

Adherence to dual antiplatelet therapy (DAPT) is critical after coronary stenting. Although adherence rates are frequently assessed in clinical trials, adherence rates in the unselected population recommended for treatment but beyond clinical trials are largely unknown. Therefore, we performed a systematic review of published observational studies to describe rates of DAPT adherence, trends in DAPT use over time, and patient-level factors associated with nonadherence.

HYPOTHESIS

DAPT adherence declines with increasing time after drug-eluting stent implantation.

METHODS

PubMed, Cumulative Index to Nursing and Allied Health Literature, Embase, and Web of Knowledge were searched through November 20, 2012 for studies including patients receiving 1 or more drug-eluting stents and reporting the use of aspirin and/or thienopyridines, or assessing factors associated with nonadherence to DAPT after bare metal or drug-eluting stent placement.

RESULTS

We included 34 studies in the description of DAPT adherence and 11 studies in the description of factors associated with nonadherence. Adherence to DAPT and thienopyridines was high at 1 month but declined by 12 months. Aspirin adherence was at least 90% throughout. Factors associated with nonadherence included bleeding, lower education level, immigrant status, and lack of education regarding DAPT.

CONCLUSIONS

DAPT adherence is suboptimal at 12 months, and interventions to increase adherence should focus on reducing bleeding risk and improving communication between patients and physicians.

[Coronary stents: 30 years of medical progress]

The history of interventional cardiology has been marked by several technologic revolutions since the late 1970s. The first key step was the use of inflatable balloon angioplasty as an alternative to CABG surgery for coronary revascularization, followed by intracoronary delivery of bare metal stent (BMS) and drug eluting stents (DES) to drastically reduce intracoronary restenosis observed with BMS. Improved stents platforms and polymers (absorbable or biocompatible) led to a dramatic reduction in the rate of late stent thrombosis. Self-expanding stents are now available to improve stent a position especially in acute myocardial infarction. The emergence of new fully bioabsorbable stents that can be combined with antiproliferative drugs is the ongoing revolution. A new generation of stents is continuously improving and likely to become the ideal stent for coronary revascularization in the near future.

Evolving management of patients treated by drug-eluting stent: prevention of late events

SUMMARY

Drug eluting stents (DES) were introduced in clinical practice to overcome the problem of in-stent restenosis (ISR) that limited the overall efficacy of percutaneous coronary revascularization with bare metal stent (BMS). Long-term outcome data confirm a sustained benefit of DES as compared with BMS. However, this benefit is mainly evident in the first year of follow-up. Indeed, DES-related events may extend over this time, due to late events (late ISR and/or very late stent thrombosis). Prevention of late failure of DES may become a specific therapeutic target.

Comparison of cost-effectiveness of oral rapamycin plus bare-metal stents versus first generation of drug-eluting stents (from the Randomized Oral Rapamycin in Argentina [ORAR] 3 trial)

The aim of this study was to compare 5-year cost-effectiveness and clinical outcomes of patients with oral rapamycin (OR) plus bare-metal stent versus the drug-eluting stent (DES) strategy. During 2006 to 2007, a total of 200 patients were randomized to OR (n = 100) and DES (n = 100). Primary end point was to compare costs of initial procedure and cost-effectiveness of both revascularization strategies. Safety was evaluated by the composite of death, myocardial infarction, and cerebrovascular accident. Efficacy was assessed by target vessel and target lesion revascularizations. The 2 groups had similar baseline demographic, clinical, and angiographic characteristics. In the DES group, paclitaxel-, zotarolimus-, and sirolimus-eluting stents were used. Five-year clinical follow-up was accomplished in 99% patients. The DES group had significantly higher procedural (p <0.001), discharge to first-year (p = 0.02), and 1- to 5-year costs (p <0.001) compared with the OR group. At 5 years, the composite end point of death, myocardial infarction, and cerebrovascular accident (12% in the OR group vs 25% in the DES group, p = 0.01) was significantly less in the OR group. Target vessel revascularization (14.5% in the OR group vs 21% in the DES group, p = 0.16) and target lesion revascularization (10% in the OR group vs 17.6% in the DES group, p = 0.05) were not significantly different. In conclusion, a strategy of OR plus bare-metal stent was cost saving than a first-generation DES.

Impact of angiographic peri-stent contrast staining (PSS) on late adverse events after sirolimus-eluting stent implantation: an observation from the multicenter j-Cypher registry PSS substudy

This study sought to assess clinical significance of angiographic peri-stent contrast staining (PSS) after sirolimus-eluting stent (SES) implantation in a large multicenter study with 5-year follow-up. The j-Cypher PSS substudy is a multicenter study including 5712 patients (7838 lesions) who underwent follow-up angiographic study within 12 months after SES implantation. Late acquired PSS was observed in 184 patients (3.2 %) or 194 lesions (2.5 %). Independent risk factors of PSS were chronic total occlusion and left anterior descending artery lesion, while negative risk factors were in-stent restenosis, diabetes mellitus, ≥70 years of age, and left circumflex coronary artery lesion. Cumulative incidence of definite very late stent thrombosis (VLST) at 4 years after the index follow-up angiography in lesions with PSS was significantly higher than that in lesions without PSS (5.3 versus 0.7 %, P < 0.0001). Late target-lesion revascularization (TLR) was also more frequently observed in the PSS group (13 versus 6.9 %, P = 0.01), while late TLR for restenosis excluding those TLR procedures for VLST tended to be higher in the PSS group (9.9 versus 6.3 %; P = 0.15). PSS found in 2.5 % of lesions within 12 months after SES implantation was associated with higher risk for subsequent VLST.

Minimally invasive direct coronary artery bypass improves late survival compared with drug-eluting stents in isolated proximal left anterior descending artery disease: a 10-year follow-up, single-center, propensity score analysis

OBJECTIVES

Minimally invasive direct coronary artery bypass (MIDCAB) has been proposed to reduce surgical morbidity and improve long-term outcomes compared with stenting in the treatment of isolated proximal left anterior descending artery. However, the survival benefit from MIDCAB still needs to be demonstrated, in particular, because percutaneous coronary intervention with drug-eluting stents (DES-PCI) continues to be considered the initial treatment strategy. We conducted a 10-year follow-up, single-center, propensity score-matched MIDCAB versus DES-PCI comparison.

METHODS

A total of 1033 patients (303 MIDCAB and 730 DES-PCI) with isolated proximal left anterior descending disease were included. Propensity score matching was used to compare 303 pairs of MIDCAB and DES-PCI patients.

RESULTS

MIDCAB and DES-PCI presented with comparable 30-day mortality (2 of 303 [0.6%] vs 1 of 303 [0.3%]; P=1.0). At 10 years, DES-PCI was associated with a 2.19-fold increased risk of late death (95% confidence interval, 1.15-4.17), a 2.0-fold increased risk of repeat revascularization (95% confidence interval, 1.20-3.47), and a 2.14-fold increased risk of the composite of death and repeat revascularization (95% confidence interval, 1.41-3.24).

CONCLUSIONS

These findings strongly support a survival benefit from MIDCAB at long-term follow-up compared with DES-PCI in the treatment of isolated left anterior descending disease.

Sirolimus-eluting stent implantation for ostial right coronary artery lesions: five-year outcomes from the j-Cypher registry

Ostial right coronary artery (RCA) lesions are associated with a high restenosis rate after bare-metal stent implantation. However, long-term outcomes after drug-eluting stent (DES) implantation for ostial RCA lesions have not been adequately evaluated. Among 12824 patients enrolled in the j-Cypher registry, 5-year outcomes were compared between 397 patients with ostial RCA lesions, and 3716 patients with non-ostial RCA lesions treated with sirolimus-eluting stents (SES). Through 5-year follow-up, patients with ostial RCA lesions had a significantly higher cumulative incidence of target lesion revascularization (TLR) (28.2 versus 13.7 %, P < 0.0001) than those with non-ostial RCA lesions. After adjusting for confounders, excess TLR risk of the ostial group relative to the non-ostial group was significant for both early TLR within 1-year and late TLR beyond 1-year (HR 2.14 [95 % CI 1.59-2.84], P < 0.0001, and HR 1.58 [95 % CI 1.06-2.26], P = 0.02, respectively). Although the cumulative incidence of death was also significantly higher in the ostial group than in the non-ostial group (25.7 versus 14.4 %, P < 0.0001), the excess risk of the ostial group relative to the non-ostial group was no longer significant after adjusting for confounders (HR 1.25 [95 % CI 0.99-1.57], P = 0.07). SES implantation for ostial RCA lesions was associated with higher risk for TLR as compared with that for non-ostial RCA lesions. Restenosis, both early and late, remains an issue in coronary DES implantation for ostial RCA lesions.

Outcomes in diabetic patients undergoing primary percutaneous coronary intervention for acute anterior myocardial infarction: results from the INFUSE-AMI study

OBJECTIVES

To evaluate the clinical, angiographic, and cardiac magnetic resonance imaging (cMRI) results in patients with and without diabetes mellitus (DM) undergoing primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI).

BACKGROUND

DM has been associated with increased mortality in patients with STEMI, yet the mechanisms underpinning this association have not been completely elucidated.

METHODS

Overall, 451 patients (51 diabetics) from the INFUSE-AMI trial were studied. They presented with an anterior STEMI due to an occluded left anterior descending artery (LAD) and underwent bivalirudin-supported primary PCI with or without intralesion abciximab and with or without thrombus aspiration. Angiographic baseline and post-procedure parameters, cMRI at 30 days, and clinical follow-up at 30 days and at 1 year were compared between diabetic and nondiabetic patients.

RESULTS

Patients with DM had significantly more comorbidities and more extensive LAD disease than nondiabetics. Primary PCI was equally effective in restoring coronary flow in both groups and the infarct size at 30 days was similar (14.3% [7.1, 24.5] vs. 17.3% [8.1, 23.6], respectively, P = 0.55). Diabetic patients had more major cardiovascular and cerebrovascular events at 1 year (16.5% vs. 8.0%, P = 0.04). Stent thrombosis within 30 days after primary PCI was higher in diabetic than in nondiabetic subjects (4.3% vs. 0.8%, P = 0.03).

CONCLUSIONS

Patients with DM presenting with STEMI had a higher baseline risk profile than those without DM. Although reperfusion success and infarct size were similar, diabetic patients experienced more death, reinfarction, stent thrombosis, and revascularization than nondiabetics.

Long-term safety of drug-eluting stents

Stent implantation in coronary stenosis has revolutionized the treatment of coronary artery disease. The introduction of antirestenotic drug coatings further improved their efficacy in reducing target vessel revascularizations. With increasing use of drug-eluting stents (DES), stent thrombosis (ST) rose as potentially fatal major complication. Initially, the incidence of ST late after stent implantation seemed to be similar for DES and bare metal stents until several studies proved otherwise in first-generation DES. Since then, the design and components of DES have been changed and new polymers, drugs and different combinations of platelet inhibitors have been introduced to further improve the safety of DES. In this review, the authors focus on the relationship between DES, lesion anatomy, implantation technique and pharmacology to avoid the occurrence of ST. Furthermore, the relationship between dual antiplatelet therapy, bleeding rate and its significant impact on patient outcome is discussed. Finally, some promising future concepts are highlighted.

Percutaneous coronary intervention in patients with previous coronary artery bypass grafting (from the j-Cypher Registry)

A paucity of data is available from large-scale studies evaluating the long-term outcomes of percutaneous coronary intervention in patients who had previously undergone coronary artery bypass grafting (CABG) in the drug-eluting stent era. Of 12,812 patients who had undergone sirolimus-eluting stent implantation in the j-Cypher registry, 919 (7.2%) had a history of CABG and had significantly higher crude 5-year mortality (19.9% vs 14.0%, p <0.001). After adjusting for confounders, the excess risk of death was no longer significant (hazard ratio 0.99, 95% confidence interval 0.83 to 1.18, p = 0.90), and the adjusted risk of target lesion revascularization was significantly higher in patients with previous CABG than in those without (hazard ratio 1.25, 95% confidence interval 1.06 to 1.47, p = 0.01). Of the patients with previous CABG, those who had undergone ≥1 saphenous vein graft intervention had significantly higher adjusted risks of cardiac death (hazard ratio 2.21, 95% confidence interval 1.26 to 3.76, p = 0.01), myocardial infarction (hazard ratio 2.56, 95% confidence interval 1.10 to 5.60, p = 0.03), target lesion revascularization (hazard ratio 2.65, 95% confidence interval 1.82 to 3.81, p <0.001), and definite stent thrombosis (hazard ratio 7.70, 95% confidence interval 1.99 to 29.1, p = 0.004) compared with those who underwent percutaneous coronary intervention only for the native coronary artery. In conclusion, the adjusted mortality was similar between patients with and without previous CABG, despite a significantly different risk of target lesion revascularization. Among the patients with previous CABG, those with saphenous vein graft intervention using a first-generation drug-eluting stent had worse clinical outcomes than those with a native coronary artery target only.

Pathological analyses of very long-term sirolimus-eluting stent implantation in human coronary artery

A 73-year-old man underwent sirolimus-eluting stent (SES) implantation for chest pain on exertion with left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX). The patient died due to non-obstructive mesenteric ischemia after 57 months of SES implantation. An autopsy demonstrated that the lesions of stented site at LAD and LCX were histopathologicaly similar images. In short, only mild neointimal formation with enough patent lumen was observed in all stented sites with no evidence of restenosis. In addition, complete coverage of endothelial cells in the surface of neointima was visible. Furthermore, necrotic core formation with a lot of circumferential cholesterol clefts was evident around the struts. In spite of these findings, observations of neointimal rupture and stent thrombosis were not found in this very late period autopsy study. In this histopathological examination, although neointimal coverage with enough lumen was observed, accumulation of extracellular lipid and cholesterol crystal was shaping necrotizing core, in short neoatherosclerosis. In the future, biocompatible drug-eluting stents which do not induce inflammation to the arterial wall post stenting should be appropriately addressed by the future development of improved coronary stents. <Learning objective: This manuscript contains original materials from pathological analysis of very long-term SES implantation. The current case report is the first one with very long-term course after SES implantation over 4 years and 9 months. In this pathological examination, although neointimal coverage with enough lumen was observed, neoatherosclerotic change around stent struts was evident. We should observe close clinical follow up after SES implantation.>.

Comparison of outcomes using the sirolimus-eluting stent in calcified versus non-calcified native coronary lesions in patients on- versus not on-chronic hemodialysis (from the j-Cypher registry)

The impact of lesion calcium on long-term outcomes after drug-eluting stent implantation has not been adequately addressed. In 10,595 patients (16,803 lesions) who were exclusively treated with sirolimus-eluting stents in the j-Cypher registry, 5-year outcomes were compared between patients with ≥1 lesion with moderate or severe calcification (the calcium group) and those with noncalcified lesions only (the noncalcium group). Analyses were stratified by hemodialysis (HD) status (non-HD stratum [calcium n = 3,191, noncalcium n = 6,824] and HD stratum [calcium n = 415, noncalcium n = 165]). Adjusted risk in the calcium group for death and target lesion revascularization was significant in the non-HD stratum (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.18 to 1.52, p <0.0001, and HR 1.2, 95% CI 1.07 to 1.36, p = 0.003) and the HD stratum (HR 1.4, 95% CI 1.06 to 1.86, p = 0.02, and HR 2.25, 95% CI 1.51 to 3.36, p <0.0001). Risk for definite stent thrombosis tended to be higher in the calcium group in the HD stratum (HR 5.05, 95% CI 0.66 to 38.9, p = 0.12) but not in then non-HD stratum (HR 1.16, 95% CI 0.81 to 1.67, p = 0.41). The use of rotational atherectomy in patients with severe calcification did not have a significant impact on the cumulative incidence of target lesion revascularization in the non-HD stratum (17.7% [n = 268] with vs 18.2% [n = 588] without rotational atherectomy, p = 0.68) and the HD stratum (54.7% [n = 115] with vs 51.9% [n = 118] without rotational atherectomy, p = 0.19). In conclusion, regardless of HD status, patients with calcified lesions have increased long-term risk for death and target lesion revascularization after sirolimus-eluting stent implantation.

First report of a novel polymer-free dual-drug eluting stent in de novo coronary artery disease: results of the first in human BICARE trial

BACKGROUND

Persistence of stent polymer coating has been associated with incomplete endothelialization, expansive vessel remodeling, neoatherosclerosis, and delayed healing associated with inflammation that may contribute to late adverse events.

METHODS

The BICARE (Lepu Medical, Beijing, China) stent is a novel polymer-free, nanotechnology-based stent eluting sirolimus and probucol. As a first in human feasibility study, patients with a single de novo native coronary stenosis <30 mm in length and with reference vessel diameter from 2.5 to 4.0 mm underwent revascularization with the BICARE stent. The primary endpoint of target lesion failure (TLF) was assessed at 30 days. Secondary endpoints included in-stent late lumen loss and proportion of uncovered or malapposed stent struts by optical coherence tomography at 4-month angiographic surveillance.

RESULTS

Among 32 consecutive patients (age, 55.7 ± 8.7 years; men, 62.5%; diabetes, 18.8%), the average baseline reference vessel diameter and lesion length were 2.85 ± 0.48 mm and 15.0 ± 5.6 mm, respectively. At 30 days there was no occurrence of TLF. At 4 months (angiographic follow-up, N=32), angiographic in-stent late loss was 0.14 ± 0.19 mm, and the in-stent binary restenosis rate was 3.1%. Complete strut coverage was 98.2% with 0.2% malapposition among 16,751 analyzed struts. At 18 months, TLF occurred in 3 (9.4%) patients related to repeat revascularization with no adverse safety events identified.

CONCLUSIONS

The preliminary feasibility and safety of a polymer-free, dual-drug eluting stent are demonstrated by absence of early adverse safety events and favorable angiographic suppression of neointimal hyperplasia. Stent imaging suggests favorable healing with extensive stent strut coverage and very low malapposition. These findings further inform comparison with biopermanent polymer DES.

A case report of very late stent thrombosis observed simultaneously in all three vessels 5 years after sirolimus-eluting stent implantation

A 67-year-old man with recent myocardial infarction underwent a total of five sirolimus-eluting stents (SES) implantation for three vessels stage by stage. A follow-up angiography showed no significant restenosis except one in the side branch. Thereafter, he had remained asymptomatic. Sixty-six months later, he had an acute myocardial infarction with cardiogenic shock due to simultaneous 3-vessel very late stent thrombosis (VLST). After successful percutaneous coronary intervention, final angiography revealed serious peri-stent contrast staining along with positive remodeling and grade V stent fracture. This rare case illustrates simultaneous 3-vessel VLST, associating with multiple SES-related problems, under continuation of aspirin and cilostazol.

Long-term incidence and prognostic factors of the progression of new coronary lesions in Japanese coronary artery disease patients after percutaneous coronary intervention

Revascularization of an initially non-target site due to its progression as a new culprit lesion has emerged as a new therapeutic target of coronary artery disease (CAD) in the era of drug-eluting stents. Using the Shinken database, a single-hospital-based cohort, we aimed to clarify the incidence and prognostic factors for progression of previously non-significant coronary portions after prior percutaneous coronary intervention (PCI) in Japanese CAD patients. We selected from the Shinken database a single-hospital-based cohort of Japanese patients (n = 15227) who visited the Cardiovascular Institute between 2004 and 2010 to undergo PCI. This study included 1,214 patients (median follow-up period, 1,032 ± 704 days). Additional clinically driven PCI to treat previously non-significant lesions was performed in 152 patients. The cumulative rate of new-lesion PCI was 9.5 % at 1 year, 14.4 % at 3 years, and 17.6 % at 5 years. There was no difference in background clinical characteristics between patients with and without additional PCI. Prevalence of multi-vessel disease (MVD) (82 vs. 57 %, p < 0.001) and obesity (47 vs. 38 %, p = 0.028) were significantly higher and high-density lipoprotein cholesterol (HDL) level (51 ± 15 vs. 47 ± 12 mg/dl, p < 0.001) was significantly lower in patients with additional PCI than those without. Patients using insulin (6 vs. 3 %, p = 0.035) were more common in patients with additional PCI. Multivariate analysis showed that MVD, lower HDL, and insulin use were independent determinants of progression of new culprit coronary lesions. In conclusion, progression of new coronary lesions was common and new-lesion PCI continued to occur beyond 1 year after PCI without attenuation of their annual incidences up to 5 years. Greater coronary artery disease burden, low HDL, and insulin-dependent DM were independent predictors of progression of new culprit coronary lesions.

Long-term outcomes following off-label use of sirolimus-eluting stent

OBJECTIVE

To clarify the impact of off-label use of drug-eluting stent (DES) on 5-year outcomes.

BACKGROUND

Studies on the outcomes of on- vs. off-label use of DES have been limited by the duration of observation.

METHODS

We analyzed 1937 patients from a multicenter registry that includes 95% of patients with 5-year follow-up data. We defined 10 variables as off-label indications according to the manufacturer's instructions for use, and 1665 of 1937 patients (86.0%) met the criteria for at least 1 off-label indication.

RESULTS

At 5 years, there were no differences in the rates of death, myocardial infarction (MI), and stent thrombosis between off-label and on-label use. The frequency of major adverse cardiac events (MACE), target lesion revascularization (TLR), non-TL but target vessel revascularization (TVR), and target vessel failure were higher in the off-label only during the first year. Among the off-label, having 2 indications was associated with TVR hazard ratio (HR) 1.62; 95% confidence interval (95%CI), 1.09-2.36 and TLR (HR, 1.90; 95%CI, 1.30-2.85). Moreover, having ≥3 off-label indications increased the risk of MACE (HR, 1.70; 95% CI, 1.23-2.40) compared with on-label use. Thrombosis rates increased with the number of off-label indications; it was 0.32% with 1, 0.69% with 2, and 3.54% with ≥3 off-label indications (p<0.001). This trend was also seen with other outcomes, except for non-TL TVR. Patients with ≥3 off-label indications had a remarkably different clinical course.

CONCLUSION

Off-label use did not increase rates of death and MI as compared with on-label use, but the number of off-label indications influenced outcomes at 5 years.

Biodegradable polymer biolimus-eluting stent versus durable polymer everolimus-eluting stent: a randomized, controlled, noninferiority trial

OBJECTIVES

NEXT (NOBORI Biolimus-Eluting Versus XIENCE/PROMUS Everolimus-Eluting Stent Trial) was designed for evaluating the noninferiority of a biolimus-eluting stent (BES) relative to an everolimus-eluting stent (EES) in terms of target lesion revascularization (TLR) at 1 year.

BACKGROUND

Efficacy and safety data comparing biodegradable polymer BES with durable polymer cobalt-chromium EES are currently limited.

METHODS

The NEXT trial is a prospective, multicenter, randomized, open-label, noninferiority trial comparing BES with EES. Between May and October 2011, 3,235 patients were randomly assigned to receive either BES (n = 1,617) or EES (n = 1,618).

RESULTS

At 1 year, the primary efficacy endpoint of TLR occurred in 67 patients (4.2%) in the BES group, and in 66 patients (4.2%) in the EES group, demonstrating noninferiority of BES relative to EES (p for noninferiority <0.0001, and p for superiority = 0.93). Cumulative incidence of definite stent thrombosis was low and similar between the 2 groups (0.25% vs. 0.06%, p = 0.18). An angiographic substudy enrolling 528 patients (BES: n = 263, and EES: n = 265) demonstrated noninferiority of BES relative to EES regarding the primary angiographic endpoint of in-segment late loss (0.03 ± 0.39 mm vs. 0.06 ± 0.45 mm, p for noninferiority <0.0001, and p for superiority = 0.52) at 266 ± 43 days after stent implantation.

CONCLUSIONS

One-year clinical and angiographic outcome after BES implantation was noninferior to and not different from that after EES implantation in a mostly stable coronary artery disease population. One-year clinical outcome after both BES and EES use was excellent, with a low rate of TLR and extremely low rate of stent thrombosis.

Meta-analysis comparing efficacy and safety of first generation drug-eluting stents to bare-metal stents in patients with diabetes mellitus undergoing primary percutaneous coronary intervention

Several concerns have emerged regarding the higher risk for stent thrombosis (ST) after drug-eluting stent (DES) implantation, especially in the setting of ST-segment elevation myocardial infarction (STEMI). Few data have been reported so far in patients with diabetes mellitus, which is associated with high rates of target vessel revascularization after bare-metal stent (BMS) implantation but also higher rates of ST after DES implantation. Therefore, the aim of this study was to perform a meta-analysis of individual patients' data to evaluate the long-term safety and effectiveness of DES compared with BMS in patients with diabetes who undergo primary percutaneous coronary intervention for STEMI. Published reports were scanned by formal searches of electronic databases (MEDLINE and CENTRAL). All completed randomized trials of DES for STEMI were examined. No language restrictions were enforced. Individual patients' data were obtained from 11 of 13 trials, including a total of 972 patients with diabetes (616 [63.4%] randomized to DES and 356 [36.6%] to BMS). At long-term follow-up (median 1,095 days, interquartile range 1,087 to 1,460), DES significantly reduced the occurrence of target vessel revascularization (hazard ratio 0.42, 95% confidence interval 0.29 to 0.59, p <0.0001), without any significant difference in terms of mortality, late reinfarction, and ST (>1 year) with DES. In conclusion, this meta-analysis, based on individual patients' data from 11 randomized trials, showed that among patients with diabetes with STEMIs who undergo primary percutaneous coronary intervention, sirolimus-eluting stents and paclitaxel-eluting stents, compared with BMS, are associated with a significant reduction in target vessel revascularization at long-term follow-up, without any apparent concern in terms of mortality, despite the trend toward higher rates of reinfarction and ST.

Metformin impairs vascular endothelial recovery after stent placement in the setting of locally eluted mammalian target of rapamycin inhibitors via S6 kinase-dependent inhibition of cell proliferation

OBJECTIVES

This study sought to examine the effect of oral metformin (Mf) therapy on endothelialization in the setting of drug-eluting stents (DES).

BACKGROUND

Mf is a commonly used therapy in diabetic patients receiving DES. Mf and locally eluted mammalian target of rapamycin (mTOR) inhibitors used in DES have convergent molecular signaling; however, the impact of this drug interaction on stent endothelialization is unknown.

METHODS

We examined human endothelial aortic cells (HAECs) and a rabbit model of stenting to determine points on molecular convergence between these 2 agents and their impact on stent endothelialization.

RESULTS

Western blotting of HAECs treated with Mf and the mTOR inhibitor sirolimus and 14-day rabbit iliacs treated with the combination of zotarolimus-eluting stents (ZES) and oral Mf demonstrated greater inhibition of S6 kinase (S6K), a downstream effector of mTOR complex 1, than either treatment alone. HAEC proliferation was significantly inhibited by Mf or sirolimus treatments alone and further reduced when they were combined. Knockdown of S6K via short interfering RNA in HAECs impaired cell proliferation via a cyclin D1-dependent mechanism, whereas its overexpression rescued the antiproliferative effects of both agents. Last, endothelialization and endothelial cell proliferation at 14 days were assessed in rabbits receiving ZES or bare-metal stents and Mf or placebo by scanning electron microscopy and bromodeoxyuridine/CD31 labeling, respectively. Both endpoints were inhibited by ZES treatment alone and were further reduced by the combination of Mf and ZES.

CONCLUSIONS

Significant convergence of signaling occurs between Mf and locally delivered mTOR inhibitors at S6K. This further impairs endothelial recovery/proliferation via an S6K-dependent mechanism. Patients receiving Mf in combination with stents that elute mTOR inhibitors are potentially at increased risk of delayed endothelial healing and stent thrombosis.

Very late stent thrombosis after sirolimus-eluting stent implantation: evaluation by intravascular ultrasound and optical coherence tomography

A 58-year-old man was admitted to our hospital with acute anterior myocardial infarction that occurred 4 years after single sirolimus-eluting stent (SES) implantation in the left anterior descending artery. He had been undergoing continuous dual antiplatelet therapy. Emergency coronary angiography showed total thrombotic occlusion and peri-stent contrast staining at the SES site. The lesion was evaluated using intravascular ultrasound (IVUS) and optical coherence tomography (OCT) after thrombectomy. Vessel remodeling was detected on IVUS, and multiple interstrut hollows and thrombi were observed on OCT. These findings were associated with very late stent thrombosis after SES implantation.

3.0-T MR imaging of intracoronary local delivery of motexafin gadolinium into coronary artery walls

PURPOSE

To develop a technique with clinical 3.0-T magnetic resonance (MR) imaging to delineate local contrast agent distribution in coronary artery walls for potential molecular MR imaging-guided local gene or drug therapy of atherosclerotic coronary artery disease.

MATERIALS AND METHODS

This animal protocol was approved by the institutional animal care and use committee and was in compliance with the Guide for the Care and Use of Laboratory Animals. For in vitro confirmation, human arterial smooth muscle cells (SMCs) were used to determine capability of SMCs in uptake of motexafin gadolinium (MGd) and its optimal dose. For ex vivo evaluation, a 2-mL mixture of MGd and trypan blue was locally infused into coronary artery walls of six cadaveric pig hearts with MR monitoring and an MR imaging guidewire, surface coils, or both. For in vivo validation, the balloon catheter was placed into coronary arteries of seven living pigs, and the MGd and trypan blue mixture was infused into arterial walls with MR guidance. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of coronary artery walls were recorded by using different coils between pre- and postcontrast infusion, with subsequent histologic confirmation. Paired Student t tests were used to compare average SNRs and CNRs of arterial walls before and after contrast agent infusion with different coils.

RESULTS

SMCs could take up MGd with the optimal concentration at 150 µmol/L. Average SNR with the MR imaging guidewire and surface coil combination was significantly higher than that with the MR imaging guidewire only or with surface coils only (P < .05), and average SNR and CNR of postinfusion MR imaging was significantly higher than that of preinfusion MR imaging (P < .05). Histologic analysis was used to confirm successful intracoronary infiltration of MGd and trypan blue within coronary artery walls.

CONCLUSION

MR imaging can be used to delineate locally infused contrast agent distribution in coronary artery walls. This establishes groundwork for development of molecular MR imaging-guided intracoronary therapy.

Renal dysfunction and atherosclerosis of the neointima following bare metal stent implantation

BACKGROUND

Recently, neoatherosclerosis within the neointima after bare metal stent (BMS) implantation, which could cause late restenosis and very late stent thrombosis, has been a cause of concern. Renal dysfunction has been related to late cardiovascular events after coronary intervention. The present study was conducted focusing on the relationship between renal dysfunction and neointimal tissue characteristics with BMS restenosis using integrated backscatter intravascular ultrasound (IB-IVUS).

METHODS

We prospectively performed IB-IVUS in 80 consecutive patients requiring target lesion revascularization after BMS implantation; the patients were divided into two groups according to the estimated glomerular filtration [eGFR: ≥60 (n = 49) and <60 ml/min/1.73 m(2) (n = 31)].

RESULTS

Patients with eGFR <60 ml/min/1.73 m(2) had a significantly higher percentage of lipid tissue volume within the neointima and a lower percentage of fibrous tissue volume than those with eGFR ≥60 ml/min/1.73 m(2) (23.2 ± 9.4 vs. 18.0 ± 7.0%, p = 0.005, and 75.3 ± 9.3 vs. 80.4 ± 7.0%, p = 0.007, respectively). Using logistic regression analysis, eGFR <60 ml/min/1.73 m(2) and duration from stent implantation ≥48 months were independent predictors of increased lipid tissue volume within the neointima (odds ratio, 3.93; 95% confidence interval, 1.15-13.46, p = 0.03, and odds ratio, 7.56; 95% confidence interval, 2.02-28.30, p = 0.003, respectively).

CONCLUSIONS

Lower eGFR levels were associated with greater lipid tissue volume within the neointima after BMS deployment, suggesting the development of atherosclerosis. Renal dysfunction may affect neointimal tissue characteristics and thus leading to an increased risk of late stent failure.

Pathologic Etiologies of Late and Very Late Stent Thrombosis following First-Generation Drug-Eluting Stent Placement

Several randomized and observational studies have reported steady increase in cumulative incidence of late and very late ST (LST/VLST) following first-generation drug-eluting stents (DES: sirolimus-(SES) and paclitaxel-(PES)) up to 5 years. Pathologic studies have identified uncovered struts as the primary substrate responsible for LST/VLST following DES, where delayed arterial healing is associated with stent struts penetrating into the necrotic core, long/overlapping stents, and bifurcation stenting especially in flow divider region. Grade V stent fracture also induces LST/VLST and restenosis. Hypersensitivity reaction is exclusive to SES as an etiology of LST/VLST, whereas malapposition secondary to excessive fibrin deposition is associated with PES. Uncovered struts can be identified in SES and PES with duration of implant beyond 12 months, particularly in stents placed for "off-label" indications. Neoatherosclerosis is another important contributing factor for VLST in DES and bare metal stents (BMS); however, DES shows rapid and more frequent development of neoatherosclerosis than BMS. Future pathologic studies should address the long-term safety of newer generation DES including zotarolimus- and everolimus-eluting stents in terms of the improvement in reendothelialization, decreased inflammation and fibrin deposition as well as a lower incidence of stent fracture-related adverse events, and reduced neoatherosclerosis, which likely contribute to the decreased risk of LST/VLST and better patient outcomes.

Comparison of five-year outcome of sirolimus-eluting stent implantation for chronic total occlusions versus for non-chronic total occlusion (from the j-Cypher registry)

The aim of this study was to evaluate the 5-year clinical outcomes of patients who underwent sirolimus-eluting stent implantation for chronic total occlusion (CTO). Among 10,759 patients treated exclusively with sirolimus-eluting stent in the j-Cypher registry, clinical outcomes were compared between 1,210 patients with revascularization for CTO and 9,549 patients with revascularization for non-CTO only. The cumulative 5-year incidence of all-cause death (13.2% vs 14.3%, p = 0.56) and definite stent thrombosis (1.9% vs 1.6%, p = 0.76) was similar between the 2 groups. The adjusted risk for CTO relative to non-CTO for all-cause death and definite stent thrombosis was insignificant (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.81 to 1.16, and HR 0.99, 95% CI 0.6 to 1.65, respectively). The cumulative incidence of target lesion revascularization was significantly higher in the CTO group (20.7% vs 14.8%, p <0.001). The adjusted risk for target lesion revascularization was significant (HR 1.31, 95% CI 1.13 to 1.52, p <0.001). In the subgroup analysis, the risk for CTO for all-cause death tended to be lower in the subgroup of patients with left ventricular ejection fractions ≤40% (HR 0.68, 95% CI 0.45 to 1.01, p = 0.053), while the risk was significantly higher in the subgroup of patients with end-stage renal disease without hemodialysis (HR 1.66, 95% CI 1.02 to 2.70, p = 0.04). In conclusion, sirolimus-eluting stent implantation for CTO appears to be as safe as that for non-CTO for up to 5 years, except for the modestly elevated risk for target lesion revascularization and the higher risk for all-cause death in patients with end-stage renal disease without hemodialysis.