A global registry of fractional flow reserve (FFR)-guided management during routine care: Study design, baseline characteristics and outcomes of invasive management.

BACKGROUND: The use and clinical outcomes of fractional flow reserve (FFR)-guided revascularization in patients presenting with either stable coronary artery disease (CAD) or an acute coronary syndrome (ACS) in daily clinical practice are uncertain. OBJECTIVE: To prospectively characterize the frequency of the change in treatment plan when FFR is performed compared to the initial decision based on angiography alone and procedure-related outcomes. METHODS: We undertook a prospective, multicenter, multinational, open-label, observational study of coronary physiologic measurements during clinically indicated coronary angiography. The treatment plan, including medical therapy, PCI or CABG, was prospectively recorded before and after performing FFR. Adverse events were pre-defined and prospectively recorded per local investigators (PRESSUREwire; ClinicalTrials.gov identifier: NCT02935088). RESULTS: Two thousand two hundred and seventeen subjects were enrolled in 70 hospitals across 15 countries between October 2016-February 2018. The mean FFR (all measurements) was 0.84. The treatment plan based on angiography-alone changed in 763/2196 subjects (34.7%) and 872/2931 lesions (29.8%) post-FFR. In the per-patient analysis, the initial treatment plan based on angiography versus the final treatment plan post-FFR were medical management 1,350 (61.5%) versus 1,470 (66.9%) (p = .0017); PCI 717 (32.7%) versus 604 (27.5%) (p = .0004); CABG 119 (5.4%) versus 121 (5.5%) (p = .8951). The frequency of intended revascularization changed from 38.1 to 33.0% per patient (p = .0005) and from 35.5 to 29.6% per lesion (p < .0001) following FFR. CONCLUSIONS: On an individual patient basis, use of FFR in everyday practice changes the treatment plan compared to angiography in more than one third of all-comers selected for physiology-guided managements. FFR measurement is safe, providing incremental information to guide revascularization decisions.

Pegnivacogin results in near complete FIX inhibition in acute coronary syndrome patients: RADAR pharmacokinetic and pharmacodynamic substudy.

AIMS: Establishing factor IX inhibition in patients with acute coronary syndrome/non-ST-elevation myocardial infarction (ACS/NSTEMI), a setting characterized by increased factor IX activity, is critical to investigate the REG1 system in this target population. The REG1 system (Regado Biosciences, Basking Ridge, NJ) consists of pegnivacogin (RB006), an RNA aptamer that directly inhibits factor IXa, and anivamersen (RB007), its complementary control agent. METHODS AND RESULTS: RADAR is a Phase 2b study investigating the use of pegnivacogin in patients (n = 800) with ACS undergoing planned early cardiac catheterization. To validate dose selection and stability of anticoagulation throughout the time of cardiac catheterization at an early stage of the clinical trial, 33 patients, 22 of whom had not received recent prior heparin, underwent thorough pharmacokinetic and pharmacodynamic assessment. Fold prolongation of activated partial thromboplastin time (aPTT) was used to impute factor IX inhibition. Pegnivacogin 1 mg/kg rapidly achieved a high pegnivacogin plasma concentration (26.1 ± 4.6 µg/mL), prolonged the aPTT (mean aPTT 93.0 ± 9.5 s), and approached near complete factor IX inhibition (mean fold increase from baseline 2.9 ± 0.3). These levels remained stable from the time of drug administration through completion of the catheterization. CONCLUSION: Pegnivacogin administered at a weight-adjusted dose of 1 mg/kg consistently achieves a high level of factor IX activity inhibition among patients with ACS and provides stable anticoagulation during cardiac catheterization. These findings support the dose of pegnivacogin selected for the RADAR study.

Comparing cardiac ejection fraction estimation algorithms without a gold standard.

RATIONALE AND OBJECTIVES: Imaging and estimation of left ventricular function have major diagnostic and prognostic importance in patients with coronary artery disease. It is vital that the method used to estimate cardiac ejection fraction (EF) allows the observer to best perform this task. To measure task-based performance, one must clearly define the task in question, the observer performing the task, and the patient population being imaged. In this report, the task is to accurately and precisely measure cardiac EF, and the observers are human-assisted computer algorithms that analyze the images and estimate cardiac EF. It is very difficult to measure the performance of an observer by using clinical data because estimation tasks typically lack a gold standard. A solution to this "no-gold-standard" problem recently was proposed, called regression without truth (RWT). MATERIALS AND METHODS: Results of three different software packages used to analyze gated, cardiac, and nuclear medicine images, each of which uses a different algorithm to estimate a patient's cardiac EF, are compared. The three methods are the Emory method, Quantitative Gated Single-Photon Emission Computed Tomographic method, and the Wackers-Liu Circumferential Quantification method. The same set of images is used as input to each of the three algorithms. Data were analyzed from the three different algorithms by using RWT to determine which produces the best estimates of cardiac EF in terms of accuracy and precision. RESULTS AND DISCUSSION: In performing this study, three different consistency checks were developed to ensure that the RWT method is working properly. The Emory method of estimating EF slightly outperformed the other two methods. In addition, the RWT method passed all three consistency checks, garnering confidence in the method and its application to clinical data.

A syndrome of transient left ventricular apical wall motion abnormality in the absence of coronary disease: a perspective from the United States.

BACKGROUND: The syndrome of chest pain associated with characteristic anterior electrocardiographic changes, moderate increases in cardiac enzymes, and a reversible apical wall motion abnormality in the absence of coronary artery disease has been documented in Japan, but has received relatively little attention in other countries. METHODS: The clinical and echocardiographic data of 12 patients (11 women, mean age 64 +/-14 years) who presented with chest symptoms, electrocardiographic (ECG) changes indicative of an acute anteroapical myocardial infarction, abnormal cardiac enzyme levels and echocardiography showing an apical wall motion abnormality were collected. Coronary angiography was performed in 10 patients. A follow-up echocardiogram was obtained within 2 weeks of the initial diagnosis in most cases. RESULTS: An identifiable, precipitating ("trigger") event could be identified in all 12 individuals. Respiratory distress was present in 7, the death of a relative in 3, in 4 a surgical or medical procedure had been performed, and in 1 a panic disorder was diagnosed. The echocardiograms showed a characteristic wall motion pattern of significant apical dysfunction. All of the patients who underwent coronary arteriography had noncritical coronary artery disease. Follow-up echocardiography showed normalization of the LV dysfunction in all instances. CONCLUSION: We identified a syndrome of chest pain, dyspnea, ECG and enzyme changes mimicking acute myocardial infarction, similar to the "Takotsubo" syndrome described in Japan. It is likely that the widespread use of echocardiography, coupled with increased recognition of this syndrome, will result in this diagnosis being made more commonly.