Quantitative flow ratio versus fractional flow reserve for guiding percutaneous coronary intervention: design and rationale of the randomised FAVOR III Europe Japan trial.

Quantitative flow ratio (QFR) is a computation of fractional flow reserve (FFR) based on invasive coronary angiographic images. Calculating QFR is less invasive than measuring FFR and may be associated with lower costs. Current evidence supports the call for an adequately powered randomised comparison of QFR and FFR for the evaluation of intermediate coronary stenosis. The aim of the FAVOR III Europe Japan trial is to investigate if a QFR-based diagnostic strategy yields a non-inferior 12-month clinical outcome compared with a standard FFR-guided strategy in the evaluation of patients with intermediary coronary stenosis. FAVOR III Europe Japan is an investigator-initiated, randomised, clinical outcome, non-inferiority trial scheduled to randomise 2,000 patients with either 1) stable angina pectoris and intermediate coronary stenosis, or 2) indications for functional assessment of at least 1 non-culprit lesion after acute myocardial infarction. Up to 40 international centres will randomise patients to either a QFR-based or a standard FFR-based diagnostic strategy. The primary endpoint of major adverse cardiovascular events is a composite of all-cause mortality, any myocardial infarction, and any unplanned coronary revascularisation at 12 months. QFR could emerge as an adenosine- and wire-free alternative to FFR, making the functional evaluation of intermediary coronary stenosis less invasive and more cost-effective.

Early versus delayed invasive strategy for intermediate- and high-risk acute coronary syndromes managed without P2Y12 receptor inhibitor pretreatment: Design and rationale of the EARLY randomized trial.

According to recent literature, pretreatment with a P2Y12 ADP receptor antagonist before coronary angiography appears no longer suitable in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) due to an unfavorable risk-benefit ratio. Optimal delay of the invasive strategy in this specific context is unknown. We hypothesize that without P2Y12 ADP receptor antagonist pretreatment, a very early invasive strategy may be beneficial. The EARLY trial (Early or Delayed Revascularization for Intermediate- and High-Risk Non-ST-Segment Elevation Acute Coronary Syndromes?) is a prospective, multicenter, randomized, controlled, open-label, 2-parallel-group study that plans to enroll 740 patients. Patients are eligible if the diagnosis of intermediate- or high-risk NSTE-ACS is made and an invasive strategy intended. Patients are randomized in a 1:1 ratio. In the control group, a delayed strategy is adopted, with the coronary angiography taking place between 12 and 72 hours after randomization. In the experimental group, a very early invasive strategy is performed within 2 hours. A loading dose of a P2Y12 ADP receptor antagonist is given at the time of intervention in both groups. Recruitment began in September 2016 (n = 558 patients as of October 2017). The primary endpoint is the composite of cardiovascular death and recurrent ischemic events at 1 month. The EARLY trial aims to demonstrate the superiority of a very early invasive strategy compared with a delayed strategy in intermediate- and high-risk NSTE-ACS patients managed without P2Y12 ADP receptor antagonist pretreatment.

Preclinical evaluation of a novel polyphosphazene surface modified stent.

BACKGROUND: Treatment options for patients with coronary artery disease at high risk for bleeding complications are limited. The aim of the current preclinical study was to evaluate neointimal coverage, endothelial recovery, inflammation and thrombogenicity in a novel thin-strut (71µm thickness) Cobalt Chromium (CoCr) stent modified with a nano-thin Polyzene®-F (PzF) surface coating. METHODS AND RESULTS: Twenty-eight single PzF nano-coated stents and 20 bare metal control stents (BMS) were implanted in the coronary arteries of 24 pigs, with scheduled 5- (n=5), 28- (n=13), and 90-day (n=6) follow-up in addition to overlapping configuration (n=6 each), examined at 28-days. Histomorphometric analysis showed significantly lower neointimal thickness in PzF nano-coated stents than BMS controls at both 28- and 90-days (p=0.023 and 0.005) and reduced inflammation (p=0.06 and 0.13). Endothelial coverage over luminal surfaces at all time points was similar between nano-coated stents and BMS controls. We conducted supplementary in-vitro experiments using human monocytes and an ex-vivo swine carotid-jugular arterio-venous shunt model to better understand the healing properties afforded by the PzF nano-coating. Overall, the PzF-nano-coating showed reduced monocyte adhesion and thrombus formation compared to the un-coated controls. CONCLUSIONS: Stents modified with a nano-thin PzF-coating implanted in healthy swine indicate favorable vascular healing properties shown by reduced neointimal hyperplasia and inflammation, along with resistance to thrombus formation in an ex-vivo shunt model over unmodified stents.

A randomized trial of platelet reactivity monitoring-adjusted clopidogrel therapy versus prasugrel therapy to reduce high on-treatment platelet reactivity.

BACKGROUND: Peri-procedural platelet reactivity (PR) inhibition is critical in patients undergoing percutaneous coronary intervention (PCI). High on-treatment PR (HTPR) was associated with recurrent ischemic events in acute coronary syndrome (ACS) patients undergoing PCI. We aimed to compare a strategy of clopidogrel loading dose-adjustment (CDA) according to PR monitoring with standard prasugrel therapy to reduce the rate of patients exhibiting HTPR. METHODS: We enrolled 177 ACS patients in a prospective multicentre randomized trial comparing CDA according to PR monitoring and prasugrel therapy. The VASP index was used to measure PR and a VASP ≥ 50% defined HTPR. The primary endpoint of the study was the rate of HTPR on discharge. RESULTS: Baseline characteristics of the CDA group (n = 88) and of the prasugrel group (n = 89) were similar. CDA significantly reduced PR and the rate of HTPR compared to a single LD of clopidogrel (30.9 ± 13.9%; p < 0.0001 and 43 to 2.3%; p < 0.001, respectively). Following CDA the rate of patients with HTPR was significantly lower in the CDA group compared to the prasugrel group on discharge (2.3 vs 15.7%; p = 0.005). In addition fewer patients in the CDA group had a VASP < 16% on discharge (14.7 vs 50.5%; p <0.0001). CONCLUSION: In the present study, PR monitoring was superior to standard prasugrel therapy to reduce the rate of HTPR in ACS patients. In addition such strategy reduced the number of patients with very low PR.

High on-treatment platelet reactivity after prasugrel loading dose and cardiovascular events after percutaneous coronary intervention in acute coronary syndromes.

OBJECTIVES: The aim of this study was to investigate the relationship between platelet reactivity (PR) after a loading dose (LD) of prasugrel and thrombotic events. BACKGROUND: Post-treatment PR has been shown to be strongly associated with the occurrence of major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) in the clopidogrel era. Prasugrel is a new P2Y(12)-adenosine diphosphate receptor with a higher potency on PR. METHODS: A prospective multicenter study included patients who underwent successful PCI for acute coronary syndromes and received prasugrel therapy. Vasodilator-stimulated phosphoprotein (VASP) index was measured after the prasugrel LD. High on-treatment PR was defined as a VASP index ≥50%. MACE included cardiovascular death, myocardial infarction, and definite stent thrombosis at 1 month. RESULTS: Three hundred one patients were enrolled. The mean VASP index after 60 mg of prasugrel was 34.3 ± 23.1%. High on-treatment PR was observed in 76 patients (25.2%). Patients experiencing thrombotic events after PCI had significantly higher VASP indexes compared with those free of events (64.4 ± 14.4% vs. 33.4 ± 22.7%; range: 51% to 64% and 5% to 47.6%, respectively; p = 0.001). Kaplan-Meier analysis comparing good responders and patients with high on-treatment PR demonstrated a significantly higher rate of MACE in patients with suboptimal PR inhibition (log-rank p < 0.001). Receiver-operating characteristic curve analysis found a cutoff value of 53.5% of the VASP index to predict thrombotic events at 1 month (r = 0.86, p < 0.001). Patients with minor or major Thrombolysis In Myocardial Infarction unrelated to coronary artery bypass grafting bleeding and those without had similar VASP indexes (30 ± 17.8% vs. 34.3 ± 23%, p = 0.70). CONCLUSIONS: Despite the use of prasugrel, a significant number of patients undergoing PCI in the setting of acute coronary syndromes do not achieve optimal PR inhibition. Such patients have a higher risk for MACE after PCI.

Combined Abciximab REteplase Stent Study in acute myocardial infarction (CARESS in AMI).

BACKGROUND: Most patients with acute myocardial infarction (AMI) are admitted to hospitals without percutaneous transluminal coronary angioplasty (PTCA) facilities or are initially managed in a prehospital mobile unit. Thrombolysis remains the most readily available reperfusion treatment in those settings, but the optimal subsequent strategy in those patients is unclear. If a mechanical recanalization is likely to be performed in an emergency, it is probably desirable that the patient receives abciximab, the glycoprotein IIb/IIIa antagonist with the strongest evidence of benefit for angioplasty in AMI. OBJECTIVE: The aim of this trial is to compare the effects on clinical outcome and cost-effectiveness of 2 strategies after immediate treatment with abciximab and half-dose reteplase for ST-elevation AMI: to manage the patients conservatively (referring them for rescue PTCA only if needed) or to immediately send all patients for emergency coronary angioplasty. METHODS: The Combined Abciximab RE-teplase Stent Study in Acute Myocardial Infarction (CARESS in AMI) is an open, prospective, randomized, multicenter clinical trial conducted in patients with high-risk ST-segment elevation AMI treated within 12 hours from symptom onset in hospitals without PTCA facilities or in a prehospital mobile intensive care unit. Apart from contraindications to thrombolysis, the main exclusion criteria are age > or =75 years and a past history of CABG surgery or a percutaneous coronary intervention procedure involving the infarct-related artery. Enrollment will be performed in hospitals without PTCA facilities or directly in the ambulance if a dedicated system is in place for prehospital diagnosis and treatment of AMI. Patients will receive half-dose reteplase and full-dose abciximab and will subsequently be randomized to conventional medical therapy (with referral for emergency rescue PTCA allowed in selected cases) or emergency angioplasty. The primary end point is the 30-day combined incidence of mortality, reinfarction, and refractory ischemia. In order to obtain a 95% power (2-sided) to detect a 42% reduction in the primary end point, 900 patients are required in each arm of the study. Secondary end points include the 1-year composite end point of mortality, reinfarction, refractory ischemia, and hospital readmission because of heart failure; resource use at 30 days and 1 year; and the incidence of inhospital stroke and bleeding complications in the 2 groups. RESULTS: Seventy-four patients have been randomized (as of March 10, 2004); results are expected in June 2005. CONCLUSION: This study will establish whether angioplasty must be started as soon as possible in all patients who receive combined pharmacologic reperfusion with the glycoprotein IIb/IIIa inhibitor abciximab and half-dose thrombolysis or whether it can be postponed or skipped in patients with signs of successful reperfusion, with obvious organizational advantages.