Non-invasive Angiographic-based Fractional Flow Reserve: Technical Development, Clinical Implications, and Future Perspectives

New non- and less-invasive techniques have been developed to overcome the procedural and operator related burden of the fractional flow reserve (FFR) for the assessment of potentially significant stenosis in the coronary arteries. Virtual FFR-techniques can obviate the need for the additional flow or pressure wires as used for FFR measurements. This review provides an overview of the developments and validation of the virtual FFR-algorithms, states the challenges, discusses the upcoming clinical trials, and postulates the future role of virtual FFR in the clinical practice

Diagnostic performance and clinical implications for enhancing a hybrid quantitative flow ratio-FFR revascularization decision-making strategy

Invasive fractional flow reserve (FFR) adoption remains low mainly due to procedural and operator related factors as well as costs. Alternatively, quantitative flow ratio (QFR) achieves a high accuracy mainly outside the intermediate zone without the need for hyperaemia and wire-use. We aimed to determine the diagnostic performance of QFR and to evaluate a QFR-FFR hybrid strategy in which FFR is measured only in the intermediate zone. This retrospective study included 289 consecutive patients who underwent invasive coronary angiography and FFR. QFR was calculated for all vessels in which FFR was measured. The QFR-FFR hybrid approach was modelled using the intermediate zone of 0.77-0.87 in which FFR-measurements are recommended. The sensitivity, specificity, and accuracy on a per vessel-based analysis were 84.6%, 86.3% and 85.6% for QFR and 88.0%, 92.9% and 90.3% for the QFR-FFR hybrid approach. The diagnostic accuracy of QFR-FFR hybrid strategy with invasive FFR measurement was 93.4% and resulted in a 56.7% reduction in the need for FFR. QFR has a good correlation and agreement with invasive FFR. A hybrid QFR-FFR approach could extend the use of QFR and reduces the proportion of invasive FFR-measurements needed while improving accuracy

Effect of Adding Ticagrelor to Standard Aspirin on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting (POPular CABG) A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND: Approximately 15% of saphenous vein grafts (SVGs) occlude during the first year after coronary artery bypass graft surgery (CABG) despite aspirin use. The POPular CABG trial (The Effect of Ticagrelor on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting Surgery) investigated whether ticagrelor added to standard aspirin improves SVG patency at 1 year after CABG. METHODS: In this investigator-initiated, randomized, double-blind, placebo-controlled, multicenter trial, patients with ≥1 SVGs were randomly assigned (1:1) after CABG to ticagrelor or placebo added to standard aspirin (80 mg or 100 mg). The primary outcome was SVG occlusion at 1 year, assessed with coronary computed tomography angiography, in all patients that had primary outcome imaging available. A generalized estimating equation model was used to perform the primary analysis per SVG. The secondary outcome was 1-year SVG failure, which was a composite of SVG occlusion, SVG revascularization, myocardial infarction in myocardial territory supplied by a SVG, or sudden death. RESULTS: Among 499 randomly assigned patients, the mean age was 67.9±8.3 years, 87.1% were male, the indication for CABG was acute coronary syndrome in 31.3%, and 95.2% of procedures used cardiopulmonary bypass. Primary outcome imaging was available in 220 patients in the ticagrelor group and 223 patients in the placebo group. The SVG occlusion rate in the ticagrelor group was 10.5% (51 of 484 SVGs) versus 9.1% in the placebo group (43 of 470 SVGs), odds ratio, 1.29 [95% CI, 0.73-2.30]; P=0.38. SVG failure occurred in 35 (14.2%) patients in the ticagrelor group versus 29 (11.6%) patients in the placebo group (odds ratio, 1.22 [95% CI, 0.72-2.05]). CONCLUSIONS: In this randomized, placebo-controlled trial, the addition of ticagrelor to standard aspirin did not reduce SVG occlusion at 1 year after CABG. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02352402

Aspirin with or without Clopidogrel after Transcatheter Aortic-Valve Implantation

BACKGROUND The effect of single as compared with dual antiplatelet treatment on bleeding and thromboembolic events after transcatheter aortic-valve implantation (TAVI) in patients who do not have an indication for long-term anticoagulation has not been well studied. METHODS In a randomized, controlled trial, we assigned a subgroup of patients who were undergoing TAVI and did not have an indication for long-term anticoagulation, in a 1:1 ratio, to receive aspirin alone or aspirin plus clopidogrel for 3 months. The two primary outcomes were all bleeding (including minor, major, and life-threatening or disabling bleeding) and non-procedure-related bleeding over a period of 12 months. Most bleeding at the TAVI puncture site was counted as non-procedure-related. The two secondary outcomes were a composite of death from cardiovascular causes, non-procedure-related bleeding, stroke, or myocardial infarction (secondary composite 1) and a composite of death from cardiovascular causes, ischemic stroke, or myocardial infarction (secondary composite 2) at 1 year, with both outcomes tested sequentially for noninferiority (noninferiority margin, 7.5 percentage points) and superiority. RESULTS A total of 331 patients were assigned to receive aspirin alone and 334 were assigned to receive aspirin plus clopidogrel. A bleeding event occurred in 50 patients (15.1%) receiving aspirin alone and in 89 (26.6%) receiving aspirin plus clopidogrel (risk ratio, 0.57; 95% confidence interval [CI], 0.42 to 0.77; P=0.001). Non-procedure-related bleeding occurred in 50 patients (15.1%) and 83 patients (24.9%), respectively (risk ratio, 0.61; 95% CI, 0.44 to 0.83; P=0.005). A secondary composite 1 event occurred in 76 patients (23.0%) receiving aspirin alone and in 104 (31.1%) receiving aspirin plus clopidogrel (difference, −8.2 percentage points; 95% CI for noninferiority, −14.9 to −1.5; P<0.001; risk ratio, 0.74; 95% CI for superiority, 0.57 to 0.95; P=0.04). A secondary composite 2 event occurred in 32 patients (9.7%) and 33 patients (9.9%), respectively (difference, −0.2 percentage points; 95% CI for noninferiority, −4.7 to 4.3; P=0.004; risk ratio, 0.98; 95% CI for superiority, 0.62 to 1.55; P=0.93). A total of 44 patients (13.3%) and 32 (9.6%), respectively, received oral anticoagulation during the trial. CONCLUSIONS Among patients undergoing TAVI who did not have an indication for oral anticoagulation, the incidence of bleeding and the composite of bleeding or thromboembolic events at 1 year were significantly less frequent with aspirin than with aspirin plus clopidogrel administered for 3 months

Effects of CYP3A4*22 and CYP3A5 on clinical outcome in patients treated with ticagrelor for ST-segment elevation myocardial infarction: POPular Genetics sub-study

Aims: To determine the clinical efficacy, adverse events and side-effect dyspnea of CYP3A4*22 and CYP3A5 expressor status in ticagrelor treated patients.Methods and results: Ticagrelor treated patients from the POPular Genetics randomized controlled trial were genotyped for CYP3A4*22 and CYP3A5*3 alleles. Patients were divided based on their genotype. In total 1,281 patients with ST-segment elevation myocardial infarction (STEMI) were included. CYP3A4*22 carriers (n = 152) versus CYP3A4*22 non-carrier status (n = 1,129) were not found to have a significant correlation with the primary thrombotic endpoint: cardiovascular death, myocardial infarction, definite stent thrombosis and stroke [1.3% vs. 2.5%, adjusted hazard ratio 1.81 (0.43–7.62) p = 0.42], or the primary bleeding endpoint: PLATO major and minor bleeding [13.2% vs. 11.3%, adjusted hazard ratio 0.93 (0.58–1.50) p = 0.77]. Among the CYP3A4*1/*1 patients, CYP3A5 expressors (n = 196) versus non-expressors (n = 926) did not show a significant difference for the primary thrombotic [2.6% vs. 2.5%, adjusted hazard ratio 1.03 (0.39–2.71) p = 0.95], or the primary bleeding endpoint [12.8% vs. 10.9%, adjusted hazard ratio 1.13 (0.73–1.76) p = 0.58]. With respect to dyspnea, no significant difference was observed between CYP3A4*22 carriers versus CYP3A4*22 non-carriers [44.0% vs. 45.0%, odds ratio 1.04 (0.45–2.42) p = 0.93], or in the CYP3A4*1/*1 group, CYP3A5 expressors versus CYP3A5 non-expressors [35.3% vs. 47.8%, odds ratio 0.60 (0.27–1.30) p = 0.20].Conclusion: In STEMI patients treated with ticagrelor, neither the CYP3A4*22 carriers, nor the CYP3A5 expressor status had a statistical significant effect on thrombotic and bleeding event rates nor on dyspnea.Clinical Trial Registration:ClinicalTrials.gov, identifier NCT01761786

Non-invasive Fractional Flow Reserve and Antiplatelet Therapy in Cardiac Interventions: An Epidemiological Perspective

The first part of this thesis evaluates alternative less- and non-invasive methods to determine fractional flow reserve (FFR) in patients with stable chest pain. The focus is on CT-based FFR (CT-FFR) and angiography-based FFR (QFR). This thesis demonstrates that new, less- and non-invasive imaging techniques combining both anatomical and functional information have good diagnostic accuracy for demonstrating hemodynamically relevant coronary artery disease. The impact of QFR on clinical workflow and how it may lead to a reduction in invasive FFR measurements is also evaluated. Currently, there is no consensus on the optimal diagnostic pathway of patients with chest pain and the role of new diagnostic tests. The first part concludes with the trial design of the iCORONARY study in which we evaluate different diagnostic pathways. The second part of this thesis focuses on research on antiplatelet therapies for patients undergoing cardiac interventions and the methodological challenges these studies face. In this dissertation, we evaluate the effect of adding ticagrelor on venous graft patency in a double-blind randomized trial. However, we found no beneficial effect of ticagrelor on graft occlusions. Also in this thesis, we evaluate antiplatelet therapy after TAVI in patients with and without indication for oral anticoagulants. In both patient groups, we showed that omission of clopidogrel led to reduced bleeding but not to an increase in the composite endpoint of thromboembolic events

Marine Lab Library focus groups report - November 2014

In 2013, the User Experience Department conducted a university-wide library satisfaction survey.2 In order to follow up on findings from this survey related to the Marine Lab Library, focus groups were requested by Janil Miller. Two focus groups were conducted on November 14, 2014 at Duke Marine Lab library in Beaufort, NC: one with faculty and staff (five participants) and another with students and visiting researchers (eight participants). Each focus group was an hour long. Sessions were recorded but the recordings were deleted after reliable notes were taken. The focus groups were led by Michael Peper (Head, Natural Sciences and Engineering Section) and Joyce Chapman (Assessment Coordinator) took notes. The goals of the focus groups were to determine how people typically use the library, how they would like to use the library in an ideal world, perspectives on the library’s physical space, and community needs related to the collection, training, and software/technology

Functional cardiac CT-Going beyond Anatomical Evaluation of Coronary Artery Disease with Cine CT, CT-FFR, CT Perfusion and Machine Learning

The aim of this review is to provide an overview of different functional cardiac CT techniques which can be used to supplement assessment of the coronary arteries to establish the significance of coronary artery stenoses. We focus on cine-CT, CT-FFR, CT-myocardial perfusion and how developments in machine learning can supplement these techniques

Electrocardiographic and echocardiographic abnormalities in urban African people living with HIV in South Africa.

BackgroundStudies from high income countries report that HIV-positive people have an impaired systolic and diastolic cardiac function compared to HIV-negative people. It is unclear if results can be translated directly to the Sub-Saharan Africa context. This study assesses electro- and echocardiographic characteristics in an urban African population, comparing HIV-positive people (treated and not yet treated) with HIV-negative controls.MethodsWe conducted a cross-sectional study in Johannesburg, South Africa. We enrolled HIV-positive participants from three randomized controlled trials that had recruited participants from routine HIV testing programs. HIV-negative controls were recruited from the community. Data were collected on demographics, cardiovascular risk factors, medical history and electrocardiographic and echocardiographic characteristics.ResultsIn total, 394 HIV-positive participants and 153 controls were enrolled. The mean age of HIV-positive participants was 40±9 years (controls: 35±10 years), and 34% were male (controls: 50%). Of HIV-positive participants 36% were overweight or obese (controls: 44%), 23% had hypertension (controls: 28%) and 12% were current smoker (controls: 37%). Median time since HIV diagnosis was 6.0 years (IQR 2.3-10.0) and median treatment duration was 4.0 years (IQR 0.0-8.0), 50% had undetectable viral load. The frequency of anatomical cardiac abnormalities was low and did not differ between people with and without HIV. We observed no relation between HIV or anti-retroviral therapy (ART) and systolic or diastolic heart function. There was an association between ART use and corrected QT interval: +11.8 ms compared to HIV-negative controls (pConclusionThe low number of major cardiac abnormalities in this relatively young, well managed urban African HIV-positive population is reassuring. The increase in corrected QT interval and left ventricular mass may contribute to higher cardiac mortality and morbidity in people living with HIV in the long term