A comparison of systematic stenting and conventional balloon angioplasty during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction. STENTIM-2 Investigators

A comprehensive review of biological and materials properties of Tantalum and its alloys

Tantalum (Ta) and its alloys have been used for various cardiovascular, orthopedic, fracture fixation, dental, and spinal fusion implants. This review evaluates the biological and material properties of Ta and its alloys. Specifically, the biological properties including hemocompatibility and osseointegration, and material properties including radiopacity, MRI compatibility, corrosion resistance, surface characteristics, semiconductivity, and mechanical properties are covered. This review highlights how the material properties of Ta and its alloys contribute to its excellent biological properties for use in implants and medical devices.

Microcatheter-Facilitated Primary Angioplasty in ST-Segment Elevation Myocardial Infarction

BACKGROUND

Direct stenting is the best method for achieving reperfusion in primary percutaneous coronary intervention (PPCI). We hypothesized that the use of a microcatheter (MC) during PPCI when Thrombolysis in Myocardial Infarction (TIMI) flow ≤ 1 after wire crossing would allow visualization of the downstream artery with an optimal TIMI 3 flow at the end of the procedure.

METHODS

In this pilot study, PPCI patients with TIMI flow ≤ 1 after wire crossing formed the MC group (n = 60); the MC was positioned in the distal part of the culprit artery and a small amount of contrast was injected through it to determine stent size and length to treat the culprit lesion. The MC group was compared with previous consecutive patients treated using standard PPCI (n = 94; similar characteristics except for the rate of previous percutaneous coronary intervention).

RESULTS

In the MC group, downstream arteries were visualized in 98% of cases and direct stenting was achieved in 72% vs 31% (P < 0.0001). Final TIMI 3 flow was similar in both groups (97%). There was less manual thrombectomy (20% vs 63%; P < 0.001) and bailout glycoprotein IIb/IIIa inhibitor use (6.7% vs 29.8%; P < 0.002). The incidence of major adverse events (death, shock, severe arrhythmia) and left ventricular ejection fraction were similar. The peak cardiac enzymes level was significantly lower in the MC group.

CONCLUSIONS

The MC strategy appears feasible and safe. It could allow exploring new strategies on the basis of more systematic direct stenting and prepared reperfusion by injecting drugs through the MC before reperfusion.

Immediate and 1-year follow-up with the novel nanosurface modified COBRA PzF stent

BACKGROUND

The COBRA PzF coronary stent, which has a unique nano-coating of Polyzene-F, was developed to reduce the risk of stent thrombosis.

AIMS

To report procedural and 1-year clinical outcomes following COBRA PzF coronary stent implantation in a real-world percutaneous coronary intervention (PCI) registry.

METHODS

All patients assigned to treatment with the COBRA PzF in the GCS Axium Rambot Center, Aix-en-Provence, France between February 2013 to June 2014 were prospectively enrolled.

RESULTS

Among 100 patients (71% men, mean±standard error age 71.4±11.0 years), 38% had acute coronary syndromes. The population was consistent with real-world experience and included patients with multiple co-morbidities and 26% with diffuse multivessel disease. A total of 151 lesions were treated with 166 stents, including 26% of lesions with a type B2 or C classification. Pre- and post-procedural quantitative coronary angiography analyses showed a mean acute gain of 2.2±0.2mm. Angiographic success was achieved in all cases. One-year follow-up was available for all patients and the target vessel failure (composite of all-cause mortality, myocardial infarction or target vessel revascularization) rate was 12%, including 2% mortality (end-stage cardiomyopathy), 5% myocardial infarction (five periprocedural myocardial infarctions with isolated troponin elevation without chest pain or Q waves) and 5% target lesion revascularization. There were no cases of definite stent thrombosis.

CONCLUSION

The COBRA PzF stent was safe and effective in routine practice. One-year follow-up was associated with excellent clinical outcomes and compared favourably with current devices. These results are very promising in a real-world population of complex patients, and further study is warranted.

Primary percutaneous coronary intervention by drug-eluting balloon angioplasty: the nonrandomized fourth arm of the DEB-AMI (drug-eluting balloon in ST-segment elevation myocardial infarction) trial

OBJECTIVE

To evaluate a paclitaxel drug-eluting balloon (DEB) only strategy in primary percutaneous coronary intervention (PPCI), aiming at a comparison with bare metal stent (BMS) alone, DEB followed by BMS, and paclitaxel eluting stent (PES), as assessed in the randomized Drug Eluting Balloon in Acute ST-Segment Elevation Myocardial Infarction (DEB-AMI) trial.

BACKGROUND

DEB-only seems an attractive strategy in PPCI, as it obviates the risk of stent thrombosis.

METHODS

This study is a prospective registry with the same inclusion/exclusion criteria used in the DEB-AMI trial, as it constitutes the fourth, nonrandomized, treatment arm of this trial. Patients presenting with ST-elevation myocardial infarction were allocated to DEB-only (DIOR II, Eurocor GmbH, Bonn, Germany) after successful thrombus aspiration and predilatation. Primary endpoint was 6-month angiographic in-balloon/stent late-luminal loss (LLL). Secondary endpoints were in-balloon/stent binary restenosis and major adverse cardiac events (MACE: death, myocardial infarction, target-vessel revascularization).

RESULTS

Forty patients underwent PPCI by DEB-only. Procedural success was achieved in 97.5% with bail-out stenting required in 10.0% of procedures. In DEB-only, LLL was 0.51 ± 0.59 mm as compared to 0.74 ± 0.57 mm in BMS (P = 0.44), 0.64 ± 0.56 mm in DEB+BMS (P = 0.88) and 0.21 ± 0.32 mm in PES (P < 0.01); in-balloon/stent binary restenosis rates were 22.2%, 23.8% (P = 0.67), 28.6% (P = 0.97), and 4.5% (P = 0.07), respectively; and MACE rates were 17.5%, 23.5% (P = 0.20), 20.0% (P = 0.26), and 4.1% (P = 0.90), respectively. No acute or late thrombotic events occurred in the DEB-only group.

CONCLUSIONS

PPCI by DEB-only in selected patients yielded an angiographic outcome comparable to BMS alone and DEB followed by BMS. PES proved angiographic superiority to DEB-only. DEB-only is therefore a potential treatment alternative during PPCI in patients with contra-indications to drug-eluting stents.

Sudden cardiac death from the perspective of coronary artery disease

Sudden cardiac death accounts for approximately 50% of all deaths attributed to cardiovascular disease in the United States. It is most commonly associated with coronary artery disease and can be its initial manifestation or may occur in the period after an acute myocardial infarction. Decreasing the rate of sudden cardiac death requires the identification and treatment of at-risk patients through evidence-based pharmacotherapy and interventional strategies aimed at primary and secondary prevention. For this review, we searched PubMed for potentially relevant articles published from January 1, 1970, through March 1, 2014, using the following key search terms: sudden cardiac death, ischemic heart disease, coronary artery disease, myocardial infarction, and cardiac arrest. Searches were enhanced by scanning bibliographies of identified articles, and those deemed relevant were selected for full-text review. This review outlines various mechanisms for sudden cardiac death in the setting of coronary artery disease, describes risk factors for sudden cardiac death, explores the management of cardiac arrest, and outlines optimal practice for the monitoring and treatment of patients after an acute ST-segment elevation myocardial infarction to decrease the risk of sudden death.

Very late hazard with stenting versus balloon angioplasty for ST-elevation myocardial infarction: a 16-year single-center experience

OBJECTIVES

This study compares very late outcomes following primary percutaneous coronary intervention for ST-elevation myocardial infarction (STEMI) with stenting versus balloon angioplasty (BA).

BACKGROUND

Stenting compared with BA for STEMI improves outcomes at 6-12 months, but comparisons beyond 6-12 months have not been studied. Recent studies have shown that stent thrombosis (ST) continues to increase beyond 3-5 years and may be higher with drug-eluting stents (DES) than bare metal stents (BMS). We hypothesized that there may be a very late hazard with stenting versus BA due to very late ST.

METHODS

From 1994 to 2010 consecutive patients with STEMI treated with BA (n = 601) or stenting (n = 1,594) were prospectively enrolled in our registry and followed for 1-16 years.

RESULTS

Patients treated with BA were older, were more often female, had more three-vessel disease, and had smaller vessels. Stented patients had trends for less stent/lesion thrombosis (ST/LT) and target vessel (TV) reinfarction at 1 year. In landmark analyses >1 year, stented patients had more very late ST/LT (6.1% vs. 2.9%, P = 0.002) and more TV reinfarction (7.9% vs. 3.1%, P < 0.001) which remained significant after adjusting for baseline risk. The greatest differences in very late outcomes were between DES and BA, but there were also significant differences between BMS and BA.

CONCLUSIONS

There appears to be a very late hazard with stenting versus BA for STEMI. These data should encourage new strategies for prevention of very late ST with both BMS and DES including the development of bio-absorbable polymers and stent platforms.

Medication, reperfusion therapy and survival in a community-based setting of hospitalised myocardial infarction

OBJECTIVE

To examine the survival benefit of multiple medical therapies in a large, community-based population of validated myocardial infarction (MI) events.

DESIGN

Retrospective observational cohort study.

SETTING

Population-based sample of 30 986 definite or probable MIs in residents of four US communities aged 35-74 years randomly sampled between 1987 and 2008 as part of the Atherosclerosis Risk in Communities Surveillance Study.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

All-cause mortality 30, 90 and 365 days after discharge.

RESULTS

We used unadjusted and propensity score (PS) adjusted models to examine the relationship between medical therapy use and mortality. In unadjusted models, each medication and procedure was inversely associated with 30-day mortality. After PS adjustment, the crude survival benefits were attenuated for all therapies except for intravenous tissue plasminogen activator therapy (IV-tPA) and stent use. After inclusion of other therapies received during the event in regression models, risk ratio effect estimates (RR; (95% CI)) were attenuated for aspirin (0.66; (0.58 to 0.76) to 0.91 (0.80 to 1.03)), non-aspirin antiplatelets (0.74; (0.59 to 0.92) to 0.92 (0.72 to 1.18)), IV-tPA (0.50; (0.41 to 0.62) to 0.65 (0.52 to 0.80)) and stents (0.53 (0.40 to 0.69) to 0.68 (0.49 to 0.94)). Effect estimates remained stable for all other therapies and were similar for 90- and 365-day mortality endpoints.

CONCLUSIONS

We observed inverse associations between receipt of six medications and procedures for MI and all-cause mortality at 30, 90 and 365 days after adjustment for PS. The mortality benefits observed in this population-based setting are consistent with those reported in clinical trials.

Stenting in Acute STEMI Intervention

Stenting in acute myocardial infarction (AMI) has the benefits of achieving acute optimal angiographic results and correcting residual dissection to decrease the incidence of restenosis and reocclusion. Studies have shown that percutaneous transluminal coronary angioplasty for primary treatment after AMI is superior to thrombolytic therapy regarding the restoration of normal coronary blood flow. Coronary stenting improves initial success rates, decreases the incidence of abrupt closure, and is associated with a reduced rate of restenosis. In the presence of thrombus-containing lesions, coronary stenting constitutes an effective therapeutic strategy, either after failure of initial angioplasty or electively as the primary procedure.

Rationale and design of the MASS COMM trial: A randomized trial to compare percutaneous coronary intervention between MASSachusetts hospitals with cardiac surgery on-site and COMMunity hospitals without cardiac surgery on-site

BACKGROUND

Emergency surgery has become an increasingly rare event after percutaneous coronary intervention (PCI). There have been no randomized trials evaluating whether cardiac surgery services on-site are essential for patient safety and optimal outcomes during and after PCI.

STUDY DESIGN

The MASS COMM trial (ClinicalTrials.gov no. NCT01116882) is a randomized trial comparing the safety and effectiveness of nonemergency PCI at hospitals without surgery on-site (SOS) (non-SOS hospitals) and hospitals with SOS (SOS hospitals). A total of 3,690 subjects will be randomized in a 3:1 fashion to undergo PCI at non-SOS and SOS hospitals, with follow-up at hospital discharge, 30 days, and 12 months after PCI. The rate of major adverse cardiac events (all-cause mortality, myocardial infarction, repeat revascularization, and stroke) will serve as the primary safety end point at 30 days and the primary effectiveness end point at 12 months. The design is a 1-way randomized trial with a statistical hypothesis of noninferiority of nonemergency PCI at non-SOS hospitals for both safety and effectiveness end points.

CONCLUSIONS

This multicenter, randomized trial will compare the relative safety and effectiveness of nonemergency PCI at sites with and without cardiac SOS.

Manual aspiration thrombectomy in acute ST elevation myocardial infarction: New gold standard

Percutaneous coronary intervention (PCI) is the preferred method to treat ST segment myocardial infarction (STEMI). The use of thrombus aspiration (TA) may be particularly helpful as part of the PCI process, insofar as the presence of thrombus is essentially a universal component of the STEMI process. This article reviews evidence favoring the routine use of TA, and the limitations of these data. Based on current evidence, we consider TA to be an important maneuver during STEMI PCI, even in the absence of visible angiographic thrombus, and recommend it whenever the presence of thrombus is likely.

Cavity volume of ruptured plaque is an independent predictor for angiographic no-reflow phenomenon during primary angioplasty in patients with ST-segment elevation myocardial infarction

BACKGROUND

Plaque rupture plays a critical role for the development of acute myocardial infarction. However, whether quantitative parameters with regard to the cavity size of ruptured plaque are associated with no-reflow (NR) phenomenon following primary angioplasty remains to be elucidated.

METHODS AND RESULTS

A total of 53 patients with de novo ST-elevation myocardial infarction (STEMI) who had plaque rupture at the culprit lesion defined by pre-intervention virtual histology intravascular ultrasound (VH-IVUS) were enrolled. Patients were divided into two groups according to the presence of NR phenomenon: NR group (n=19) and non-NR group (n = 34). By VH-IVUS, we evaluated cavity length, maximum area, and volume of ruptured plaque in culprit lesions. The cavity length, maximum area, and volume were significantly higher in the NR group than those of the non-NR group (4.8 ± 2.1 mm vs. 2.9 ± 4.8 mm, p < 0.001; 3.6 ± 1.4 mm² vs. 1.9 ± 0.5 mm², p < 0.001; 11.5 ± 6.3 mm³ vs. 3.7 ± 2.2 cm³, p < 0.001). A multiple logistic regression analysis revealed that the cavity volume was an independent risk for NR phenomenon. Receiver-operating characteristic analysis revealed that the cavity volume could predict NR phenomenon.

CONCLUSIONS

The cavity size of ruptured plaque is closely associated with NR phenomenon in patients with STEMI. Evaluation of the cavity volume by VH-IVUS may provide useful information for the prediction of NR phenomenon.

The incidence and clinical predictors of early stent thrombosis in patients with acute coronary syndrome

BACKGROUND

Acute coronary syndrome (ACS) is associated with activation of platelets and the coagulation system which could influence the incidence of early stent thrombosis (EST). We aimed to determine the incidence and predictors of EST in patients undergoing coronary stenting during ACS.

METHODS

The study comprised 1202 consecutive patients, drawn from a nationwide ACS survey, who underwent coronary stenting during ACS and were followed up for 30 days. Early stent thrombosis was based on the Academic Research Consortium definition.

RESULTS

Thirty patients (2.5%) sustained EST. The occurrence of EST in patients with unstable angina/non-ST-elevation myocardial infarction and ST-elevation myocardial infarction (STEMI) was 0.9% and 3.9%, respectively (P < .05), and was even higher (5.2%) in STEMI patients who underwent primary percutaneous coronary intervention. On multivariate analysis, STEMI (OR 6.3, 95% CI 2.1-18, P = .0008), multivessel disease (OR 5.9, 95% CI 1.9-21, P = .003) and Killip class >/=2 (OR 2.9, 95% CI 1.3-6.6, P = .008) were independent correlates of EST. The use of bare versus drug-eluting stents was not associated with any significant difference in EST.

CONCLUSIONS

Patients presenting with STEMI who are hemodynamically unstable and have multivessel coronary disease undergoing coronary stenting during ACS, are at increased risk of EST.

Drug-eluting stents versus bare-metal stents in diabetic patients with ST-segment elevation acute myocardial infarction: a pooled analysis of individual patient data from seven randomized trials

INTRODUCTION AND OBJECTIVES

The performance of drug-eluting stents (DESs) in high-risk patients with diabetes and acute ST-elevation myocardial infarction (STEMI) who have undergone primary angioplasty has not been previously studied. The objective was to evaluate the efficacy and safety of DESs in diabetic patients with STEMI.

METHODS

We performed a pooled analysis of individual patient data from seven randomized trials that compared DESs (i.e., sirolimus- or paclitaxel-eluting stents) with bare-metal stents (BMSs) in patients with STEMI. The analysis involved 389 patients with diabetes mellitus from a total of 2476 patients. The outcomes of interest were target-lesion revascularization, stent thrombosis, death and the composite endpoint of death or recurrent myocardial infarction during a follow-up of 12-24 months.

RESULTS

Overall, 206 diabetic patients received a DES and 183, a BMS. The risk of target-lesion revascularization was significantly lower in patients treated with a DES compared to those treated with a BMS (hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.23-0.88; P=.02). There was no significant difference in the risk of stent thrombosis between those treated with a DES or a BMS (HR 0.33, 95% CI 0.09-1.13; P=.08). Similarly, the risk of the combined endpoint of death or myocardial infarction was not significantly different between patients treated with a DES or a BMS (HR 0.64, 95% CI 0.36-1.13; P=.12).

CONCLUSIONS

Compared with BMSs, DES use improved clinical outcomes in diabetic patients undergoing primary angioplasty for STEMI: the need for reintervention was reduced, with no increase in mortality or myocardial infarction.

Comparison of six-month outcomes for primary percutaneous revascularization for acute myocardial infarction with drug-eluting versus bare metal stents (from the APEX-AMI study)

We evaluated the use and outcomes of drug-eluting stents (DESs) and bare metal stents (BMSs) in a large primary percutaneous coronary intervention (PCI) acute ST-elevation myocardial infarction (MI) trial. Recently concerns have been raised with "off-label" use of DESs for short- and long-term clinical outcomes. Limited randomized data exist evaluating DESs versus BMSs in ST-elevation MI. Patients (n=5,745) in the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial were categorized by stent type used. Baseline variables and clinical outcomes were collected at 90 days and 6 months. Outcomes by stent type were adjusted for using conventional multivariable predictors of 90-day mortality (age, anterior location, total ST-segment deviation, and Killip class), time to PCI, and Thrombolysis In Myocardial Infarction grade flow. Stents were deployed (at the investigator's discretion) in 5,124 patients (89.2%) with acute MI, with DES use in 2,221 (43.3%) and BMS use in 2,903 (56.7%). Patients receiving DESs were younger (median 59 vs 63 years of age, p<0.001), had left anterior descending coronary artery PCI (57.9% vs 48.1%, p<0.001), and often were treated in the United States (58.2%). DES-treated patients had a lower adjusted mortality at 90 days (hazard ratio 0.73, 95% confidence interval [CI] 0.54 to 0.99, p=0.046) and trended toward lower mortality (hazard ratio 0.77, 95% CI 0.58 to 1.03, p=0.084) and recurrent MI (hazard ratio 0.81, 95% CI 0.59 to 1.11, p=0.186) at 6 months compared with BMSs. In conclusion, in this observational analysis of stent use from a large primary percutaneous intervention for acute MI trial, DESs appear as safe as BMSs with similar 6-month clinical outcomes with regard to death and recurrent MI.

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.

Angiographic No-Reflow Phenomenon and Plaque Characteristics by Virtual Histology Intravascular Ultrasound in Patients with Acute Myocardial Infarction

OBJECTIVE

This study aimed to evaluate the relationship between the occurrence of the angiographic no-reflow phenomenon in patients with acute myocardial infarction (AMI) and the preintervention plaque composition as assessed by virtual histology intravascular ultrasound (VH-IVUS).

BACKGROUND

The angiographic no-reflow phenomenon is an adverse prognostic factor in patients with AMI.

METHOD

We enrolled consecutive 50 patients with ST-elevation AMI was treated by primary stent implantation. All culprit lesions were imaged by VH-IVUS before stent implantation. The angiographic no-reflow phenomenon was defined as a decrease in final TIMI flow grade compared with TIMI flow grade before stent implantation.

RESULTS

Eight of 50 patients developed angiographic no-reflow after stent implantation. Gray-scale intravascular ultrasound (IVUS) showed significantly larger external elastic membrane volume and plaque burden in the no-reflow group. VH-IVUS showed a trend toward larger percentage of fibro-fatty plaque volume in the no-reflow group than in the reflow group (23.1 +/- 3.5 vs. 17.0 +/- 1.1%, P = 0.05). The presence of "marble"-like image, mainly consisting of fibro-fatty and fibrous plaque (plaque volume of fibro-fatty + fibrous >80% and containing fibro-fatty plaque volume >10%) was associated with angiographic no-reflow (P = 0.02). Corrected TIMI frame counts of the cases with "marble"-like image were significantly larger than the cases without it (46.8 +/- 5.6 vs. 27.4 +/- 2.3, P = 0.01).

CONCLUSION

The culprit lesions with large plaque burden, or with "marble"-like image by VH-IVUS, are associated with the angiographic no-reflow phenomenon in patients with AMI.

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.

Time to reperfusion in acute myocardial infarction. It is time to reduce it!

BACKGROUND AND OBJECTIVES

Mortality from ST-segment elevation myocardial infarction remains high, with most deaths occurring before hospital admission. Despite effective pre- and in-hospital reperfusion strategies becoming standard over the past 2 decades, time-to-admission and time-to-treatment remain prolonged. We reviewed temporal trends in these times in published clinical trials.

METHODS

All major randomized clinical trials reporting on reperfusion strategies for acute myocardial infarction published between 1993 and 2003 were evaluated. Strategies included pre- and in-hospital thrombolysis, primary percutaneous coronary intervention (pPCI) with or without transfer, and "facilitated" PCI. We generated overall estimates of time-to-admission, time-to-treatment, door-to-balloon (DTB), and door-to-needle (DTN) times and evaluated temporal trends in the length of time-to-admission and time-to-treatment.

RESULTS

In studies that evaluated only in-hospital thrombolysis, the time-to-admission was 149 +/- 45 minutes; the mean time-to-treatment was 181 +/- 29 minutes. In studies that considered only in-hospital pPCI (without transfer), the mean time-to-admission was 153 +/- 41 minutes; the mean time-to-treatment was 234 +/- 43 minutes. In studies that compared in-hospital pPCI with in-hospital thrombolytic therapy, the mean time-to-admission was 155 +/- 47 and 150 +/- 48 minutes, respectively. The DTN time was 65 +/- 10 minutes, whereas DTB time was 81 +/- 39 minutes. In other trials evaluating in-hospital thrombolysis and pPCI with transfer to a referral center, the time-to-admission in subjects treated with thrombolysis (n = 1345) was 127 +/- 32 minutes vs 131 +/- 36 minutes for pPCI (n = 1528). For in-hospital thrombolysis, time-to-treatment was 151 +/- 23 minutes vs 203 +/- 15 minutes for pPCI patients with transfer. The DTN time in the thrombolysis group was 44 +/- 28 minutes as compared with DTB time of 78 +/- 38 minutes in the pPCI group. Throughout the last decade, time-to-admission decreased significantly (P = .02) but time-to-treatment remained unchanged (P = .38) for patients undergoing thrombolysis. In the pPCI arm, time-to-admission remained unchanged (P = .11) but a insignificant trend toward reduction was demonstrated in time-to-treatment (P = .11).

CONCLUSION

Time-to-admission and time-to-treatment for ST-segment elevation myocardial infarction are still prolonged. Resources should be directed to early recognition of the acute myocardial infarction, improved utilization of emergency services for transportation, and prehospital diagnosis and triaging. Ambulances equipped with wireless capability to transmit electrocardiograms to the on-call cardiologist seem to be promising tools to achieve earlier diagnosis and triaging with high diagnostic sensitivity and specificity.

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.

Sirolimus-eluting versus uncoated stents in acute myocardial infarction

BACKGROUND

Sirolimus-eluting stents reduce rates of restenosis and reintervention, as compared with uncoated stents. Data are limited regarding the safety and efficacy of such stents in primary percutaneous coronary intervention (PCI) for acute myocardial infarction with ST-segment elevation.

METHODS

We performed a single-blind, multicenter, prospectively randomized trial to compare sirolimus-eluting stents with uncoated stents in primary PCI for acute myocardial infarction with ST-segment elevation. The trial included 712 patients at 48 medical centers. The primary end point was target-vessel failure at 1 year after the procedure, defined as target-vessel-related death, recurrent myocardial infarction, or target-vessel revascularization. A follow-up angiographic substudy was performed at 8 months among 174 patients from selected centers.

RESULTS

The rate of the primary end point was significantly lower in the sirolimus-stent group than in the uncoated-stent group (7.3% vs. 14.3%, P=0.004). This reduction was driven by a decrease in the rate of target-vessel revascularization (5.6% and 13.4%, respectively; P<0.001). There was no significant difference between the two groups in the rate of death (2.3% and 2.2%, respectively; P=1.00), reinfarction (1.1% and 1.4%, respectively; P=1.00), or stent thrombosis (3.4% and 3.6%, respectively; P=1.00). The degree of neointimal proliferation, as assessed by the mean (+/-SD) in-stent late luminal loss, was significantly lower in the sirolimus-stent group (0.14+/-0.49 mm, vs. 0.83+/-0.52 mm in the uncoated stent group; P<0.001).

CONCLUSIONS

Among selected patients with acute myocardial infarction, the use of sirolimus-eluting stents significantly reduced the rate of target-vessel revascularization at 1 year. (ClinicalTrials.gov number, NCT00232830 [ClinicalTrials.gov].).

Outcome after coronary artery bypass graft surgery, coronary angioplasty and stenting

AIMS

We undertook this prospective observational study to investigate the long-term prognosis after balloon angioplasty (PTCA), coronary stenting (CS) and coronary artery bypass grafting (CABG).

METHODS AND RESULTS

A total number of 1038 patients with PTCA (n=499), CS (n=294) or CABG (n=245) were followed-up over a mean time of 6.4+/-1.8 years. Forty-two patients (4.0%) were lost to follow-up, leaving a study population of 996 subjects who were available for analyses. The primary and secondary endpoints were mortality and major adverse cardiac events (MACE), respectively. Overall death rate was 19.3%. Age, pulse pressure, smoking, diabetes, serum LDL cholesterol levels and left ventricular ejection fraction rather than the intervention type independently predicted mortality. The incidence rate of MACE was 53.7%. Compared to PTCA patients, CS patients had lower (hazard ratio 0.693; 95% confidence interval 0.514-0.793) and CABG patients the lowest risk of MACE (hazard ratio 0.343; 95% confidence interval 0.261-0.450). Further risk factors for MACE were serum LDL cholesterol levels, three-vessel coronary artery disease and left ventricular ejection fraction of <30%.

CONCLUSION

Long-term mortality does not differ among patients who received percutaneous interventions or CABG. Major adverse cardiac events occur more often in patients with previous percutaneous interventions, whereby CS has advantage over PTCA.

A new approach of primary angioplasty for ST-elevation acute myocardial infarction based on minimalist immediate mechanical intervention

OBJECTIVES

No reflow has been reported in 12-30% of the patients directly revascularized by angioplasty for acute ST elevation myocardial infarction with the highest incidence after primary stenting in patients with initial thrombolysis in myocardial infarction (TIMI) grade 0 flow. We hypothesized that a minimalist immediate mechanical intervention (MIMI) based on the use of very small size balloons to avoid both large dissection and distal embolization may be sufficient to restore flow in emergency and that recanalization may be sustained by maximized antithrombotic regimen (abcximab, clopidogrel, aspirin and heparin) allowing one to postpone stenting in better conditions.

METHODS

MIMI was performed in 93 patients for ST elevation myocardial infarction with initial TIMI grade 0 flow.

RESULTS

MIMI resulted in a TIMI grade 3 flow in 77/93 patients (83%). Immediate stenting was performed in the 16 patients with failed MIMI and resulted in a TIMI grade 3 flow in nine (56%). The residual stenosis after MIMI was 81+/-11% and ST segment resolution (> or =50%) at 1 h after reperfusion was obtained in 84%. Stenting was performed the following days in 52 patients with a post-stenting TIMI grade 3 flow in 50 (96%; 100% when stenting done beyond 24 h). No reocclusion occurred between MIMI and stenting. Among the 25 patients without stenting, six had mild stenosis at control angiogram and underwent medical treatment whereas 19 had multiple vessel disease and underwent bypass surgery.

CONCLUSIONS

MIMI combined with maximized antithrombotic therapy results in immediate and sustained recanalization with a high rate of ST resolution in a majority of patients with ST elevation myocardial infarction. This approach allows one to postpone stenting in more stable conditions with a low rate of TIMI flow deterioration or to schedule more appropriate medical or surgical alternative management.

Comparison of outcomes in acute myocardial infarction treated with coronary angioplasty alone versus coronary stent implantation

Randomized trials have demonstrated the superiority of primary angioplasty with stent implantation over balloon angioplasty alone in the treatment of acute myocardial infarction (AMI). However, it remains unknown whether the beneficial outcomes that are attained in clinical trials can be generalized to community-based practice. We conducted a retrospective cohort study of all patients who underwent primary angioplasty for AMI in New York State in 1998 and 1999. In total, 6,010 consecutive patients who presented within 23 hours of an AMI were identified for this analysis. In-hospital mortality was the primary end point. Stents were placed in 5,225 patients (87%). Patients who received stents were younger (61 vs 62 years, p = 0.011) and less often women (29% vs 33%, p = 0.018). Patients who received stents were less likely to have a history of hypertension (56% vs 61%, p = 0.013), diabetes (17% vs 24%, p <0.001), a creatinine level > or = 2.5 mg/dl (0.8% vs 2.0%, p = 0.002), 3-vessel coronary disease (14% vs 19%, p <0.001), and left main disease (2.4% vs 4.6%, p <0.001). Stent use was associated with significant decreases in length of stay (5.9 vs 8.1 day, p <0.001), major adverse cardiovascular events (4.1% vs 12%, p <0.001), and in-hospital mortality (3.5% vs 9.3%, p <0.001). After multivariate logistic regression analysis to adjust for differences in baseline characteristics, stent use was associated with a 50% decrease in risk of in-hospital mortality (odds ratio 0.474, 95% confidence interval 0.311 to 0.723, p = 0.001).

Percutaneous coronary intervention: recommendations for good practice and training

Cardiologists undertaking percutaneous coronary intervention (PCI) are excited by the combination of patient and physician satisfaction and technological advance occurring on the background of the necessary manual dexterity. Progress and applicability of percutaneous techniques since their inception in 1977 have been remarkable; a sound evidence base coupled with the enthusiasm and ingenuity of the medical device industry has resulted in a sea change in the treatment of coronary heart disease (CHD), which continues to evolve at breakneck speed. This is the third set of guidelines produced by the British Cardiovascular Intervention Society and the British Cardiac Society. Following the last set of guidelines published in 2000, we have seen PCI activity in the UK increase from 33,652 to 62,780 (87% in four years) such that the PCI to coronary artery bypass grafting ratio has increased to 2.5:1. The impact of drug eluting stents has been profound, and the Department of Health is investigating the feasibility of primary PCI for acute myocardial infarction. Nevertheless, the changes in the structure of National Health Service funding are likely to focus our attention on cost effective treatments and will require physician engagement and sensitive handling if we are to continue the rapid and appropriate growth in our chosen field. It is important with this burgeoning development now occurring on a broad front (in both regional centres and district general hospitals) that we maintain our vigilance on audit and outcome measures so that standards are maintained for both operators and institutions alike. This set of guidelines includes new sections on training, informed consent, and a core evidence base, which we hope you will find useful and informative.

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.

Comparison of coronary stenting versus conventional balloon angioplasty on five-year mortality in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention

Little is known about the influence of stenting versus balloon angioplasty on long-term outcomes (particularly mortality) after primary percutaneous coronary intervention (PCI). We evaluated 2,087 patients with ST-elevation myocardial infarction enrolled in various Primary Angioplasty in Myocardial Infarction (PAMI) trials in the United States, who underwent primary PCI. The main outcome was all-cause mortality at 5 years, obtained through the National Death Index. Of the 2,087 patients, stenting was performed in 692 (33%). The absolute difference in the hospital (2.2% vs 3.3%), 1-year (3.3% vs 5.2%), and 5-year (10% vs 13%) mortality rates favored patients receiving a stent versus conventional balloon therapy, with the difference increasing with time. A multivariate Cox model identified stent use (vs balloon alone) as an independent correlate of lower 5-year mortality (hazard ratio 0.60, 95% confidence interval 0.42 to 0.85). The absolute reduction in mortality was greatest in the highest risk group. In conclusion, compared with balloon angioplasty, stenting during primary PCI not only resulted in better angiographic and short-term outcomes, but also in a sustained beneficial effect on mortality at 5 years. These data support the routine use of coronary stenting in most patients undergoing primary PCI, when feasible.

Effects of Percutaneous Coronary Thrombectomywith the X-Sizer Catheter on Epicardial Flow and Microvascular Function in Acute Coronary Syndromes

During percutaneous coronary intervention, slow coronary flow and distal embolization are still important problems, especially in cases with intracoronary thrombus. The aim of this study was to learn the effectiveness and early term results of thrombectomy with the X-SIZER catheter system in acute coronary syndrome. Twenty-nine patients (22 [76%] men; 55.9 ± 11.1 years) with acute coronary syndrome and intracoronary thrombus detected in coronary angiography were included into the study. X-sizer thrombectomy was applied to 14 of the patients, and conventional percutaneous transluminal coronary angioplasty (PTCA) was applied to the others. Baseline characteristics were similar in both groups. Mean thrombolysis in myocardial infarction (TIMI) flow increased from 0.8 ± 0.9 to 2.4 ± 0.6 in X-sizer-treated patients (p<0.001) and TIMI 3 flow was maintained in 71.4% of the patients. Similary, mean TIMI flow increased from 0.36 ± 0.81 to 2.73 ± 0.47 in conventional PTCA-treated patients (p<0.001) and TIMI 3 flow was maintained in 73% of the patients (NS). Mean myocardial blush grade (MBG) increased from 0.7 ± 0.7 to 2.6 ± 0.6 in X-sizer-treated patients (p<0.001) and from 0.27 ± 0.65 to 2.36 ± 0.67 in the conventional PTCA-treated patients (p<0.001). Postprocedural MBG 3 was obtained in 64.3% of X-Sizer-treated patients and in 45% of controls. Although microvascular function in the thrombectomy-applied patients was found better, there was no significant difference between the two groups. Furthermore it was detected that the use of tirofiban yielded no additional improvement in epicardial and microvascular flow. In acute coronary syndromes, use of X-sizer in addition to primary percutaneous coronary interventions is a safe and relatively effective method in the prevention of distal embolization.

Direct versus conventional stent implantation in patients with acute coronary syndrome just before the era of drug-eluting stents

BACKGROUND

Direct stent implantation in patients, who undergo elective percutaneous coronary intervention (PCI) can be performed with a high success rate and clinical results that are comparable to those after predilatation. It was the aim of this prospective study to compare clinical, angiographic and procedural parameter of direct stent implantation (DS) and conventional stent implantation (CS) in patients with acute coronary syndrome (ACS).

PATIENTS AND METHODS

We analysed 194 patients with ACS (ST-elevation myocardial infarction 66%, non-ST-elevation myocardial infarction 18%, unstable angina 16%), in whom primary PCI was performed between January and December 2002. In 156 (80%) patients glycoprotein IIb/IIIa inhibitors were administered during the procedure. In 73 patients (38%) direct stent implantation could be performed successfully. In 12 patients (6%) direct stent implantation failed due to the inability to pass the stenosis. In 121 patients (62%) the stent was implanted after predilatation.

RESULTS

The clinical parameters were comparable in both groups. Reference luminal diameter before stent implantation did not differ in both groups (DS 3.01+/-0.54 vs. CS 2.84+/-0.43 mm). The final minimal luminal diameter was significantly higher in the DS group (DS 2.95+/-0.45 vs. CS 2.77+/-0.47 mm, p=0.01). The procedural time (DS 41.0+/-14.1 vs. CS 46.8+/-16.9 min, p=0.02), radiation exposure time (DS 7.3+/-4.6 vs. CS 8.9+/-4.6 min, p=0.002) and the amount of contrast agent (DS 216+/-90 vs. CS 235+/-79 ml, p=0.03) could be decreased by the technique of direct stent implantation. The incidence of major adverse cardiac events (death, myocardial infarction, CABG) during hospitalization was 4.1% in the DS group and 11.5% in the CS group (p=0.11).

CONCLUSIONS

Direct stent implantation is safe and feasible in patients with acute coronary syndromes. The procedural time, radiation exposure time and the amount of contrast agent can be significantly decreased using the technique of direct stent implantation. The incidence of major adverse cardiac events was not significantly different in this subset of patients.

Coronary stenting and abciximab in primary angioplasty for ST-segment-elevation myocardial infarction

Advances in anti-platelet therapy and improvement of stent deployment techniques have improved the safety and efficacy of stenting in the setting of ST-segment-elevation myocardial infarction (STEMI). However, in randomized trials, routine coronary stenting does not reduce mortality and re-infarction, compared to balloon angioplasty. Further, the benefits in target vessel revascularization seem to be reduced when applied to unselected patients with STEMI. Direct stenting represents an attractive strategy with potential benefits in terms of myocardial perfusion. Future large randomized trials are needed to evaluate whether this strategy has a significant impact on outcome, and to provide a cost-benefit analysis of the unrestricted use of drug-eluting stents in this high-risk subset of patients. The additional use of abciximab reduces mortality in primary angioplasty. Since the feasibility of long-distance transportation has been shown in several randomized trials, early pharmacological pre-treatment may confer further advantages by early recanalization and shorter ischaemic time, particularly in high-risk patients. Further randomized trials are needed to clarify the potential benefits from early abciximab administration and the potential role of small molecules in primary angioplasty for STEMI.

Ischemia-driven target vessel revascularization after-primary percutaneous coronary intervention: patients at risk and their outcomes

Clinical and angiographic correlates of ischemia-driven target vessel revascularization (ITVR) in patients undergoing primary percutaneous coronary interventions (PCI) are currently less well known. Accordingly, we examined 2,981 patients enrolled in different Primary Angioplasty in Myocardial Infarction trials, who underwent primary PCI to evaluate risk factors and outcomes of individuals requiring subsequent ITVR. At 6 months, ITVR was required in 321 patients (11%). Compared to the cohort without ITVR, patients requiring ITVR were younger (P=0.036), females (P=0.018), and more likely to have systolic blood pressure >100 mmHg on presentation (P=0.022), family history of premature coronary artery disease (P=0.035), and postprocedure dissection (P=0.001). In contrast, Killip Class >I on presentation (P=0.05), left circumflex as infarct-related artery (P=0.022), and the use of ticlopidine (P=0.044) and stents (p=0.057) were less frequent among ITVR patients. Multivariate analysis identified younger age (for each 10-year decrease, odds ratio [OR], 1.18; 95% confidence interval [CI], 1.06-1.32), female gender (OR: 1.41, 95% CI: 1.05-1.89), and final dissection (OR: 1.69, 95% CI: 1.23-2.33) as independent risk factors for ITVR. In-hospital reinfarction (P < 0.001) was increased and at 6 months remained higher in ITVR patients; in-hospital and 6-month mortality did not differ between the two groups. Our study identifies the incidence, risk factors, and outcomes of patients requiring ITVR after primary PCI. Importantly, our data suggest that no increase in mortality occur, if ITVR is promptly performed to treat recurrent ischemia after primary PCI.

Is routine stenting for acute myocardial infarction superior to balloon angioplasty? A randomised comparison in a large cohort of unselected patients

OBJECTIVE

To evaluate the impact of routine stenting, compared with balloon angioplasty, in unselected patients presenting with ST segment elevation myocardial infarction (STEMI).

DESIGN

Randomised trial.

SETTING

Tertiary referral centre.

PARTICIPANTS

All patients presenting with STEMI randomly assigned to stenting or balloon angioplasty. No exclusion criteria were applied.

MAIN OUTCOME MEASURE

The primary end point was combined death or reinfarction at one year's follow up.

RESULTS

1683 consecutive patients with STEMI were randomly assigned before angiography to stenting (n = 849) or balloon angioplasty (n = 834). A total of 785 patients (92.5%) in the stent group and 763 patients (91.5%) in the balloon group actually underwent primary angioplasty. The groups were comparable in terms of postprocedural TIMI (thrombolysis in myocardial infarction) flow, myocardial blush grade, and distal embolisation. No difference was observed in clinical outcome at both intention to treat (14% v 12.5%, not significant) and actual treatment analyses (12.4% v 11.3%, not significant).

CONCLUSIONS

Compared with balloon angioplasty, routine stenting does not seem to reduce death and reinfarction in a large cohort of unselected patients with STEMI.