Long-term follow-up of a randomized study of primary stenting versus angioplasty in acute myocardial infarction

Unravelling Surface Modification Strategies for Preventing Medical Device-Induced Thrombosis

The use of biomaterials in implanted medical devices remains hampered by platelet adhesion and blood coagulation. Thrombus formation is a prevalent cause of failure of these blood-contacting devices. Although systemic anticoagulant can be used to support materials and devices with poor blood compatibility, its negative effects such as an increased chance of bleeding, make materials with superior hemocompatibility extremely attractive, especially for long-term applications. This review examines blood-surface interactions, the pathogenesis of clotting on blood-contacting medical devices, popular surface modification techniques, mechanisms of action of anticoagulant coatings, and discusses future directions in biomaterial research for preventing thrombosis. In addition, this paper comprehensively reviews several novel methods that either entirely prevent interaction between material surfaces and blood components or regulate the reaction of the coagulation cascade, thrombocytes, and leukocytes.

Utilization of Non-Drug-Eluting Devices for Inpatient Percutaneous Coronary Intervention in the United States

There is a paucity of data on the contemporary use of non-drug-eluting devices (balloon angioplasty or bare-metal stents) in contemporary percutaneous coronary intervention (PCI) in the United States. We utilized the Nationwide Readmissions Database to identify patients hospitalized to undergo PCI with non-drug-eluting devices from 2016 to 2019. The main outcome of interest was the trends in utilization over the study years. Among 1,870,262 PCI procedures, 127,810 (6.8%) were performed with non-drug-eluting devices; 72% of these were in the setting of acute myocardial infarction (MI). The use of non-drug-eluting devices decreased throughout the study period from 12.9% of all PCI in the first quarter of 2016 to 3.4% in the last quarter of 2019 (p <0.001). Factors associated with their use included advanced age and high bleeding risk. Only a small percentage were used as a bridge to coronary artery bypass graft surgery (2%) and for treatment of in-stent restenosis (3%). The in-hospital mortality was 5.8% for the entire cohort and 6.6% when the indication for use was an acute MI. In patients presenting with an acute MI, reinfarction within 30 days was common and occurred in 18% of the patients. In conclusion, the use of non-drug-eluting devices in PCI in the United States decreased from 2016 to 2019. Factors associated with their use included old age and high bleeding risk. Due to suboptimal outcomes in patients currently being treated with non-drug-eluting devices, there remains an unmet clinical need for alternative treatment options.

Evaluation of chemical stability of polymers of XIENCE everolimus-eluting coronary stents in vivo by pyrolysis-gas chromatography/mass spectrometry

The polymers poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(n-butyl methacrylate) (PBMA) are employed in manufacturing the XIENCE family of coronary stents. PBMA serves as a primer and adheres to both the stent and the drug coating. PVDF-HFP is employed in the drug matrix layer to hold the drug everolimus on the stent and control its release. Chemical stability of the polymers of XIENCE stents in the in-vivo environment was evaluated by pyrolysis-gas chromatography with mass spectrometry (Py-GC/MS) detection. For this evaluation, XIENCE stents explanted from porcine coronary arteries and from human coronary artery specimens at autopsy after 2-4 and 5-7 years of implantation, respectively, were compared to freshly manufactured XIENCE stents (controls). The comparison of pyrograms of explanted stent samples and controls showed identical fragmentation fingerprints of polymers, indicating that PVDF-HFP and PBMA maintained their chemical integrity after multiple years of XIENCE coronary stent implantation. The findings of the present study demonstrate the chemical stability of PVDF-HFP and PBMA polymers of the XIENCE family of coronary stents in the in-vivo environment, and constitute a further proof of the suitability of PVDF-HFP as a drug carrier for the drug eluting stent applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1721-1729, 2018.

Coronary stenting versus balloon angioplasty for acute myocardial infarction: A meta-regression analysis of randomized trials

INTRODUCTION

Although stenting has been shown to reduce the need for target vessel revascularization (TVR) in acute myocardial infarction (AMI), the benefits in terms of mortality and reinfarction are still unclear. Previous meta-analyses have failed to include all currently available randomized trials. The aim of the current study was to perform an updated meta-analysis to evaluate the benefits of coronary stenting for AMI in terms of mortality, reinfarction, and TVR, and whether these benefits correlated with the patient's risk profile.

METHODS

The literature was scanned by formal searches of electronic databases (MEDLINE and CENTRAL) from January 1990 to September 2006. We examined all completed, published, randomized trials of coronary stenting for AMI. The following key words were used for study selection: randomized trial, myocardial infarction, reperfusion, primary angioplasty, rescue angioplasty, stenting, and balloon angioplasty. Information on study design, type of stent, inclusion and exclusion criteria, primary endpoint, number of patients, angiographic and clinical outcome, were extracted by two investigators. Disagreements were resolved by consensus.

RESULTS

A total of 13 randomized trials were identified and analyzed involving 6922 patients (3460 or 50% randomized to stent and 3462 or 50% to balloon). Stenting was not associated with a significant reduction in 30-day (2.9% versus 3.0%, p=0.81) and 1-year mortality (5.1% versus 5.2%, p=0.81), as compared to balloon angioplasty. However, a significant relationship was observed between patient's risk profile and mortality benefits from coronary stenting at 30-day (beta -0.63 [-25.4; -2.45], p=0.022) and 1-year follow-up (beta -0.61 [-15.9; -0.76], p=0.034). Stenting was associated with benefits in terms of TVR at both 30-day (3.1% versus 5.1%, p<0.0001) and 6 to 12 months (11.3% versus 18.4%, p<0.0001) follow-up, without any difference in terms of reinfarction.

CONCLUSIONS

Among AMI patients undergoing primary angioplasty, coronary stent implantation, when anatomically and technically feasible, may be considered, in addition to benefits in terms of TVR, to reduce mortality in high-risk patients, who may be identified by the use of validated risk scores.

A quantitative estimate of bare-metal stenting compared with balloon angioplasty in patients with acute myocardial infarction: angiographic measures in relation to clinical outcome

We performed a systematic review of all randomised controlled trials (RCTs) from the pre-drug-eluting-stent era comparing bare-metal stenting (BMS) with balloon angioplasty in patients with acute myocardial infarction (MI) to examine coronary angiographic parameters of infarct-related vessel patency and to relate the angiographic measures to clinical outcome. The search was restricted to published RCTs in humans. 10 RCTs, (6192 patients) were analysed. Compared with balloon angioplasty, BMS was associated with reduced rates of reocclusion (6.7% vs 10.1%, OR 0.62, 95% CI 0.40 to 0.96, p = 0.03) and restenosis (23.9% vs 39.3%, OR 0.45, 95% CI 0.34 to 0.59, p<0.001), but not with reduced rates of subacute thrombosis (1.7% in both groups). BMS showed a reduction in target vessel revascularisation (TVR; 12.2% vs 19.2%, OR 0.50, 95% CI 0.37 to 0.69, p<0.001), but not in mortality (5.3% vs 5.1%) or reinfarction (3.9% vs 4%). The findings of this study support BMS placement in acute MI. The discrepancy between angiographic and clinical parameters has important implications for future studies investigating further technical improvements in mechanical reperfusion therapy.

Results of primary percutaneous coronary intervention in a consecutive group of patients with acute ST elevation myocardial infarction at a tertiary Australian centre

BACKGROUND

Multicentre randomized controlled trials (RCT) of primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI) have consistently shown lower mortality compared with fibrinolysis, if carried out in a timely manner. Although primary PCI is now standard of care in many centres, it remains unknown whether results from RCT of selected patients are generalizable to a 'real-world' Australian setting. The primary goal of this study was to evaluate whether a strategy of routine invasive management for patients with STEMI can achieve 30-day and 12-month mortality rates comparable with multicentre RCT. Secondary goals were to determine 30-day mortality rates in prespecified high-risk subgroups, and symptom-onset- and door-to-balloon-inflation times.

METHODS

A retrospective observational study of 189 consecutive patients treated with primary PCI for STEMI in a single Australian centre performing PCI for acute STEMI.

RESULTS

All-cause mortality was 6.9% at 30 days, and 10.4% at 12 months. Mortality in patients presenting without cardiogenic shock was low (2.4% at 30 days; 5.0% at 12 months), whereas 12-month mortality in patients with shock was higher, particularly in the elderly (29.4% for patients <75 years; 85.7% for patients > or =75 years, P = 0.01). Symptom-onset-to-balloon-inflation time was < or =4 h in 56% of patients (median 231 min); however, a door-to-balloon time of <90 min was achieved in only 20% (median 133 min).

CONCLUSION

Mortality and symptom-onset-to-balloon-inflation times reported in RCT of primary PCI for STEMI are generalizable to 'real-world' Australian practice; however, further efforts to reduce door-to-balloon times are required.

Angioscopic evaluation of neointima coverage: sirolimus drug-eluting stent versus bare metal stent

BACKGROUND

The process of neointima formation after bare metal stent (BMS) implantation has been previously elucidated by angioscopic observations; however, that after drug-eluting stent (DES) implantation has not been clarified. Therefore, we compared the angioscopic appearance of neointima over DESs with that over BMSs 6 months after implantation.

METHODS AND RESULTS

Patients who received an implantation of a BMS (n = 13) or a sirolimus DES (n = 24) were included in this study. Angiographic and angioscopic examinations were performed at 6 months. The color of the stented lesion (white or yellow), coverage of stent by neointima (not covered, covered by a thin layer, or buried under neointima), and thrombus at the stented lesion (presence or absence) were angioscopically evaluated. Of the 24 lesions in which a DES was implanted, 11 (46%) had a part where the stent strut had no coverage, 21 (88%) had a part where it was covered by a thin layer, and 11 (46%) had a part where it was buried under neointima. Of the 13 lesions in which a BMS was implanted, 1 (8%) lesion had a part where the stent strut had no coverage, 4 (31%) lesions had a part where it was covered by a thin layer, and 13 (100%) lesions had a part where it was buried under neointima. The prevalence of a stent buried under neointima (46% vs 100%, P = .001) was lower and that of thrombus (42% vs 8%, P = .03) was higher in DES-implanted lesions as compared with BMS-implanted lesions. The prevalence of thrombus (64% vs 17%, P = .005) was higher in the yellow area than in the white area when a DES was implanted.

CONCLUSION

Sirolimus DESs, as compared with BMSs, were poorly covered by neointima and were accompanied by thrombus especially when there was a yellow plaque under the stents. Thus, the thrombogenic potential in DES-implanted lesions may be sustained by the inhibition of neointima formation over thrombogenic plaques.

Long-term outcome after primary stenting versus balloon angioplasty for acute myocardial infarction

The objective of the present prospective multicenter case-control study was to investigate the long-term clinical outcome (5 years) of primary stenting compared to primary percutaneous transluminal coronary angioplasty (PTCA) without stenting (POBA) in patients with acute myocardial infarction at 7 cardiovascular centers in Hokkaido, Japan. Forty-one patients with acute myocardial infarction treated with successful primary stenting (stent group: case) and paired with 41 matched control subjects with acute myocardial infarction treated by successful primary PTCA without stenting (POBA group: control) were analyzed. After 1 year, the stent group had a lower incidence of the combined clinical endpoint (death, rehospitalization due to congestive heart failure, nonfatal myocardial infarction, repeat angioplasty, CABG, or cerebrovascular events) compared to the POBA group (17.1% versus 39.0%, P = 0.049). After 5 years, the incidences of congestive heart failure and cardiac death were the same in both groups. However, compared to the POBA group, the stent group had a lower combined clinical endpoint (34.1% versus 61.0%, P = 0.027). The Kaplan-Meier event-free survival curves of the stent group showed a significantly lower occurrence of clinical events compared to the POBA group (P = 0.0116). Multiple logistic regression analysis of clinical events identified age > or = 69 years (P = 0.0092, odds ratio = 4.179) and stenting (P = 0.0158, odds ratio = 0.279) as explanatory factors. Compared with POBA, primary stenting for acute myocardial infarction results in a better long-term clinical outcome.

Acute reperfusion therapy in acute myocardial infarction

The ECG classification of acute myocardial infarctions has had a profound influence on the treatment of patients with AMI. Deciding whether a patient has ST-segment elevations or a new left bundle branch block or neither of these findings on ECG launches the treating physician down two different treatment pathways: patients with ST-elevation MI need to be assessed for immediate re-perfusion therapy, whereas patients with non-ST-elevation MI are best treated with aggressive medical management without acute reperfusion.

Distal Protection Improved Reperfusion and Reduced Left Ventricular Dysfunction in Patients With Acute Myocardial Infarction Who Had Angioscopically Defined Ruptured Plaque

Background— Distal protection, in the Saphenous Vein Graft Angioplasty Free of Emboli (SAFER) trial, is demonstrated to prevent distal embolism in the percutaneous coronary intervention of saphenous vein graft. However, in the Enhanced Myocardial Efficacy and Recovery by Aspiration of Liberated Debris (EMERALD) trial, it was not effective in the percutaneous coronary intervention of native coronary arteries in patients with acute myocardial infarction (AMI). We hypothesized that its effectiveness would be determined by lesion characteristics. Therefore, we classified the type of culprit lesion by angioscopy and examined its influence on the effectiveness of distal protection, comparing patients with AMI treated with and without distal protection.

Methods and Results— Consecutive patients with AMI treated without distal protection (n=110) from July 2000 to July 2002 and those treated with distal protection (n=81) from July 2002 to July 2004 were included. Patients in each group were subdivided according to whether or not they had angioscopically defined ruptured plaque at culprit lesion. Among those groups, incidence of no-reflow phenomenon, ST-segment resolution, myocardial blush grade, and left ventricular ejection fraction at 6 months were compared. Aspirated samples by distal protection were semiquantitatively and histologically analyzed and compared between patients with and without ruptured plaque. No-reflow phenomenon was most frequently ( P <0.05) observed in patients with ruptured plaque treated without distal protection. ST-segment resolution (68±15% versus 40±21%, P <0.001), myocardial blush grade (2.6±0.5 versus 1.8±0.3, P <0.001), and left ventricular ejection fraction (47.2±6.7% versus 41.0±9.7%, P <0.01) were improved by distal protection among patients with ruptured plaque but not among patients without ruptured plaque. Aspirated samples >1 mm were detected more frequently (97.3% versus 78.5%, P <0.05) in patients with ruptured plaque than those without ruptured plaque. Histologically, aspirated samples contained plaque debris (95.3% versus 31.1%, P <0.05) more frequently in patients with ruptured plaque than in those without ruptured plaque.

Conclusions— Distal protection reduced microcirculation damage and left ventricular dysfunction in patients with AMI who had angioscopically defined ruptured plaque. Distal embolization of plaque debris was detected more frequently in patients with ruptured plaque. These results suggest that microcirculation damage and left ventricular dysfunction are increased mainly by distal embolization of plaque debris rather than of thrombus.

Primary stenting versus primary balloon angioplasty for treating acute myocardial infarction

BACKGROUND

Balloon angioplasty following myocardial infarction (MI) reduces death, non-fatal MI and stroke compared to thrombolytic reperfusion. However up to 50% of patients experience restenosis and 3% to 5% recurrent myocardial infarction. Therefore, primary stenting may offer additional benefits compared to balloon angioplasty in patients with acute myocardial infarction.

OBJECTIVES

To examine whether primary stenting compared to primary balloon angioplasty reduces clinical outcomes in patients with acute myocardial infarction.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, Pascal, Index medicus and The Cochrane Controlled Trials Register (The Cochrane Library) from 1979 to March 2002.

SELECTION CRITERIA

Randomised controlled trials of primary stenting or balloon angioplasty prior to the invasive procedure; intervention in native coronary arteries within 24 hours after onset of symptoms of myocardial infarction; report of death or reinfarction; and follow-up of at least 1 month. Trials were excluded when randomisation occurred after an invasive procedure and if they exclusively included patients with cardiogenic shock.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected and extracted data from identified trials. Outcomes included mortality, reinfarction, coronary artery bypass grafting, target vessel revascularization, need for vascular repair or blood transfusion. Peto odds ratios were calculated. To explore the stability of the overall treatment effect various sensitivity analyses were performed.

MAIN RESULTS

We included nine trials of 4433 participants. Odds ratios for mortality after stenting compared to balloon angioplasty at 30 days, 6 and 12 months were 1.16 (95% CI 0.78 to 1.73), 1.27 (95% CI 0.89 to 1.83), and 1.06 (95% CI 0.77 to 1.45). At 30 days, 6 and 12 months odds ratios for reinfarction after stenting compared to balloon angioplasty were 0.52 (95% CI 0.31 to 0.87), 0.67 (95% CI 0.45 to 1.00), and 0.67 (95% CI 0.45-0.98) and odds ratio for target vessel revascularization after stenting compared to balloon angioplasty were 0.45 (95%CI 0.34 to 0.60), 0.42 (95% CI 0.35 to 0.51), and 0.47 (95% CI 0.38 to 0.57). The odds ratio for post-interventional bleeding complications after stenting compared to balloon angioplasty was 1.34 (95% CI 0.95 to 1.88; test of heterogeneity p > 0.1).

AUTHORS' CONCLUSIONS

There is no evidence to suggest that primary stenting reduces mortality when compared to balloon angioplasty. Stenting seems to be associated with a reduced risk of reinfarction and target vessel revascularization, but potential confounding due to unbalanced post-interventional antithrombotic/anticoagulant therapies can not be ruled out on basis of this review.

Color of culprit lesion at 6 months after plain old balloon angioplasty versus stenting in patients with acute myocardial infarction

BACKGROUND

Although the healing process of disrupted yellow plaques at myocardial infarction (MI) culprit lesions has been reported, the effect of stenting on this process has not been clarified. Stenting has been reported to deteriorate the endothelial function after percutaneous coronary intervention (PCI). Therefore, we compared the angioscopic morphology of culprit lesions at 6 months after plain old balloon angioplasty (POBA) and stenting to clarify the effect of stenting on the healing of disrupted culprit plaques of acute MI.

METHODS

Patients with acute MI who had yellow culprit plaque, successful reperfusion therapy with POBA (n = 21) or stenting (n = 22), and a successful 6-month follow-up angioscopic examination were included in this study. Oral ticlopidine (200 mg/day) was administered for 3 to 6 months after stenting.

RESULTS

At 6 months after reperfusion therapy, the color of the culprit lesion became white in significantly more patients treated with stenting than treated with POBA (50% vs 14%; P = .01). However, the prevalence of thrombus appeared to be higher in patients treated with stenting than in patients treated with POBA (27% vs 5%; P = .04). Although there was some difference in the patients' characteristics in the groups, logistic regression analysis revealed no significant influence of those factors on the color of or on the prevalence of thrombus at the culprit lesion.

CONCLUSIONS

Coronary stenting in patients with acute MI leads to the disappearance of yellow color at a significantly higher rate than POBA; however, whether it stabilizes the plaque requires further investigation.

Cardiac protection during acute myocardial infarction: Where do we stand in 2004?

Despite better outcomes with early coronary artery reperfusion for the treatment of acute ST-elevation myocardial infarction (MI), morbidity and mortality from acute myocardial infarction (AMI) remain significant, the incidence of congestive heart failure continues to increase, and there is a need to provide better cardioprotection (therapy that reduces the amount of necrosis that may be coupled with better clinical outcome) in the setting of AMI. Since the introduction of the concept of cardiac protection over a quarter of a century ago, various interventions have been investigated to reduce myocardial infarct size. Intravenous beta-blockers administered in the early hours of infarction were clearly shown to be of benefit. Intravenous adenosine appeared promising for anterior wall AMIs, as did cariporide in some studies. Glucose-insulin-potassium infusion was beneficial in certain subgroups of patients, particularly diabetics. A variety of other medications were studied with negative or marginal results. The best strategy to limit infarct size is early reperfusion with percutaneous coronary stenting or thrombolytic therapy. Stenting is superior and should be adopted whenever there is a qualified laboratory available. Available resources should focus on decreasing time from onset of symptoms to start of reperfusion and maintaining vessel patency. Future studies powered to better assess clinical outcome are needed for adjunctive therapy with adenosine, K(ATP) channel openers, Na(+)/H(+) exchange inhibitors, and hypothermia.

Clinical outcomes of primary stenting versus balloon angioplasty in patients with myocardial infarction: a meta-analysis of randomized controlled trials

PURPOSE

To examine whether primary stenting as compared with primary balloon angioplasty reduces clinical outcomes in patients with myocardial infarction.

METHODS

Major medical databases from 1979 to March 2002 were searched for randomized controlled trials that compared primary stenting with balloon angioplasty in patients with myocardial infarction. Two independent reviewers selected and extracted data from identified trials. The outcomes were mortality at 30 days, 6 months, and 12 months; recurrent events; and bleeding.

RESULTS

Nine trials with a total of 4433 patients fulfilled the inclusion criteria. The odds ratios for mortality after stenting as compared with balloon angioplasty were 1.17 (95% confidence interval [CI]: 0.78 to 1.74) at 30 days, 1.07 (95% CI: 0.76 to 1.52) at 6 months, and 1.09 (95% CI: 0.80 to 1.50) at 12 months (P for heterogeneity >0.1 for each comparison). The odds ratios for reinfarction after stenting as compared with balloon angioplasty were 0.52 (95% CI: 0.31 to 0.87) at 30 days, 0.67 (95% CI: 0.45 to 1.00) at 6 months, and 0.67 (95% CI: 0.45 to 0.99) at 12 months; for target vessel revascularization, they were 0.46 (95% CI: 0.34 to 0.61) at 30 days, 0.42 (95% CI: 0.35 to 0.51) at 6 months, and 0.48 (95% CI: 0.39 to 0.59) at 12 months (P for heterogeneity >0.1 for all estimates with the exception of reinfarction at 12 months where P=0.08). The odds ratio for postinterventional bleeding complications after stenting as compared with balloon angioplasty was 1.34 (95% CI: 0.95 to 1.88; P for heterogeneity >0.1).

CONCLUSION

Compared with balloon angioplasty, primary stenting is not associated with lower mortality, but is associated with a lower risk of reinfarction and target vessel revascularization.

Synergistic effects of a novel nanoporous stent coating and tacrolimus on intima proliferation in rabbits

To overcome the problem of in-stent restenosis, the concept of local delivery of antiproliferative or immunosuppressive drugs has been introduced into interventional cardiology. Local drug delivery can be achieved by drug-eluting stents coated with polymer surfaces used for controlled drug release. However, several polymer coatings have shown an induction of inflammatory response and increased neointima formation. In the present study, the effect of a new inorganic ceramic nanoporous aluminum oxide (Al(2)O(3)) coating on neointima proliferation and its suitability as a carrier for the immunosuppressive drug tacrolimus have been investigated. 316 L stainless steel coronary stents were coated with a 500 nm thin nanoporous aluminum oxide layer. This ceramic nanolayer was used as a carrier for tacrolimus. Bare stents (n = 6), ceramic coated stents (n = 6), and ceramic coated stents loaded with 60 (n = 7) and 120 mug (n = 6) tacrolimus were implanted in the common carotid artery of New Zealand rabbits. The ceramic coating caused no significant reduction of neointimal thickness after 28 days. Loading the ceramic stents with tacrolimus led to a significant reduction of neointima thickness by 52% for 60 mug (P = 0.047) and 56% for 120 mug (P = 0.036) as compared to the bare stents. The ceramic coating alone as well as in combination with tacrolimus led to a reduced infiltration of lymphocytes and macrophages in the intima in response to stent implantation. Ceramic coating of coronary stents with a nanoporous layer of aluminum oxide in combination with tacrolimus resulted in a significant reduction in neointima formation and inflammatory response. The synergistic effects of the ceramic coating and tacrolimus suggest that this new approach may have a high potential to translate into clinical benefit.