1,721,052 research outputs found
Derivation of a novel angiography-based method to assess coronary microvascular dysfunction in patients with acute myocardial infarction
Full text linkST-segment elevation myocardial infarction (STEMI) is still associated with a 10% one-year mortality and up to 25% risk of heart failure. The pressure-wire index of microcirculatory resistance (IMR) may have an important role in the assessment of the downstream microcirculatory function of the IRA, providing prognostically relevant information and identifying patients at risk of suboptimal reperfusion who are eligible for additional novel therapies. However, the penetration of IMR in the clinical practice is still limited mainly because of the technical complexity of the procedure and increased costs and procedural time. Nevertheless, the implementation of a risk stratification using coronary physiology in patients with STEMI would be highly desirable to further improve the clinical outcomes. In this PhD thesis we aimed to assess the long-term prognostic implications of CMD investigated using IMR. Furthermore, we aim to develop alternative methods to simplify the assessment of CMD in the catheterization laboratory and increase the penetration of physiology in the clinical practice. The current thesis consists of five main chapters. In Chapter one we explored the long-term clinical outcome of patients with STEMI stratified according to IMR and cardiovascular magnetic resonance imaging (CMR) in the cohort of the OxAMI Study. Importantly, CMD defined by IMR>40 U or by MVO demonstrated a more than 4-fold increase in mortality, heart failure or cardiac arrest at a median follow-up of 40 months. In Chapter two, pressure-bounded coronary flow reserve (pb-CFR), an index derived using standard pressure-wire technology was compared with IMR and CFR in predicting microvascular obstruction and the extent of the infarct size at CMR imaging. Pb-CFR provided a fair prognostic stratification identifying a subgroup of patients with satisfactory myocardial reperfusion after PPCI. Nonetheless, the prognostic value of pb-CFR was inferior compared with IMR. Chapter three reports the derivation of an angiography-derived pressure-wire free index of microcirculatory resistance (IMRangio). IMRangio has been developed to overcome some of the limitations of IMR, using the Quantitative Flow Ratio (QFR) algorithm to obtain Pd and contrast frame count to estimate coronary flow. IMRangio demonstrated to be significantly correlated with invasive IMR in a prospective 3 cohort of patients with STEMI. Importantly, IMRangio was also correlated with the presence of MVO at CMR. In Chapter four, IMRangio was assessed in a prospective cohort of patients across the spectrum of acute and chronic coronary syndromes. Interestingly, IMRangio was well-correlated with IMR not only in STEMI but also in patients with NSTEMI e stable coronary syndromes. Moreover, we observed that IMRangio measured in non- hyperemic conditions (NH-IMRangio) provided good diagnostic performance in the subgroup of patients with STEMI. Chapter five reports on the long-term prognostic implications of patients with STEMI stratified according to NH-IMRangio in a retrospective analysis of the OxAMI Study. Notably, NH IMRangio demonstrated a prognostic value equivalent to invasively measured IMR. In conclusion, CMD has important prognostic implications at long-term after STEMI. IMRangio has the potential to guide additional novel additional therapies in patients undergoing PPCI. Abolishing the need for pressure-wire, IMRangio may increase the penetration of CMD assessment in the catheterization laboratory and physiology-guided additional therapies. Further additional data are needed to explore the role of IMRangio as a routine addition to diagnostic and interventional procedures in STEMI patients
Coronary Artery Plaque Phenotype and 5-Year Clinical Outcomes in Older Patients with Non-ST Elevation Acute Coronary Syndrome.
Full text linkBACKGROUND
Lesions with thin-cap fibroatheroma (TCFA), small luminal area and large plaque burden (PB) have been considered at high risk of cardiovascular events. Older patients were not represented in studies which demonstrated correlation between clinical outcome and plaque characteristics. This study aims to investigate the prognostic role of high-risk plaque characteristics and long-term outcome in older patients presenting with non-ST elevation acute coronary syndrome (NSTEACS).
METHODS
This study recruited older patients aged 75 years with NSTEACS undergoing virtual-histology intravascular ultrasound (VH-IVUS) imaging from the Improve Clinical Outcomes in high-risk patieNts with acute coronary syndrome (ICON-1). Primary endpoint was the composite of major adverse cardiovascular events (MACE) consisting of all-cause mortality, myocardial infarction (MI), and any revascularisation. Every component of MACE and target vessel failure (TVF) including MI and any revascularisation were considered as secondary endpoints.
RESULTS
Eighty-six patients with 225 vessels undergoing VH-IVUS at baseline completed 5-year clinical follow-up. Patients with minimal lumen area (MLA) 4 demonstrated increased risk of MACE (hazard ratio [HR] 2.37, 95% confidence interval [CI] 1.00-5.59, p = 0.048) with a worse event-free survival (Log Rank 4.17, p = 0.041) than patients with MLA 4 . Patients with combination of TCFA, MLA 4 and PB 70% showed high risk of MI (HR 5.23, 95% CI 1.05-25.9, p = 0.043). Lesions with MLA 4 had 6-fold risk of TVF (HR 6.16, 95% CI 1.24-30.5, p = 0.026).
CONCLUSIONS
Small luminal area appears as the major prognostic factor in older patients with NSTEACS at long-term follow-up. Combination of TCFA, MLA 4 and PB 70% was associated with high risk of MI.
CLINICAL TRIAL REGISTRATION
NCT01933581
Significant Drop in Right Atrial Pressure Does Not Influence Fractional Flow Reserve Coronary Assessment
No full textThe effect of a highly elevated level of right atrial filling pressure on fractional flow reserve (FFR) measurement remains unclear. Transcatheter tricuspid valve intervention, a recently introduced option for inoperable or high-risk patients, represents a unique model of in-vivo physiology to investigate the eventual influence of central venous pressure on coronary FFR measurements. The case is reported of a patient with a degenerated tricuspid surgical bioprosthesis who underwent transcatheter tricuspid valve-in-valve replacement and concomitant coronary functional assessment with FFR. In an experimental model, the significant fall in right atrial pressure did not influence FFR measurements in the presence of angiographically proven mild coronary artery disease
First Observation of a "Golden Tube" After Complete Resorption of a Bioresorbable Vascular Scaffold in a Transplanted Patient With Cardiac Allograft Vasculopathy
No full textFirst Observation of a "Golden Tube" After Complete Resorption of a Bioresorbable Vascular Scaffold in a Transplanted Patient With Cardiac Allograft Vasculopathy
Impact of Severe Serial Coronary Stenoses on iFR Pullback Assessment
No full textCase report on the impact of severe serial lesions on non hyperemic coronary physiology assessment
Preventive left main and right coronary artery stenting to avoid coronary ostia occlusion in high-risk stentless valve-in-valve transcatheter aortic valve implantation
No full textTranscatheter aortic valve implantation is becoming an attractive and promising alternative to redo surgery for aortic bioprosthetic valves degeneration, especially in high-risk patients. However, valve-in-valve transcatheter aortic valve implantation itself carries some procedural risks and potential challenges that interventionists must be aware of. An accurate preprocedural planning is fundamental for the prevention of potentially fatal complications. This case describes a novel strategy of simultaneous right and left coronary artery stenting preventing bilateral coronary obstruction in a patient with a stentless surgical aortic valve and extremely low origin of the 2 coronary arteries
Repeat revascularization: Percutaneous coronary intervention after coronary artery bypass graft surgery
No full textRepeat myocardial revascularization procedures are markedly different from de novo interventions, with increased procedural risk and technical-demanding complexity. However the number of patients previously treated with coronary artery bypass graft (CABG) that need a repeat revascularization due to graft failure is increasing consistently. Late graft failure, usually caused by saphenous vein grafts (SVG) attrition, is certainly not uncommon. However PCI on degenerated SVG presents higher complication rate and worse clinical outcome compared with native arteries interventions. In acute graft failure setting, PCI represents a valuable option to treat postoperative myocardial infarction.Repeat myocardial revascularization procedures are markedly different from de novo interventions, with increased procedural risk and technical-demanding complexity.However the number of patients previously treated with coronary artery bypass graft (CABG) that need a repeat revascularization due to graft failure is increasing consistently. Late graft failure, usually caused by saphenous vein grafts (SVG) attrition, is certainly not uncommon. However PCI on degenerated SVG presents higher complication rate and worse clinical outcome compared with native arteries interventions.In acute graft failure setting, PCI represents a valuable option to treat postoperative myocardial infarction. (C) 2016 Elsevier Inc. All rights reserved
Long-term variations of FFR and iFR after transcatheter aortic valve implantation
No full textLong-term variations of fractional flow reserve (FFR) and instantaneous wave-free-ratio (iFR) after transcatheter aortic valve implantation (TAVI) have not been previously assessed. A total of 23 coronary lesions in 14 patients with aortic stenosis (AS) underwent physiology assessment at baseline, immediately after TAVI and at 14(7-29) months of follow-up. The angiographic severity of the lesions did not progress at follow-up (54[45-64] vs 54[49-63], p = .53). Overall, FFR (0.87[0.85-0.92] vs 0.88[0.82-0.92], p = .45) and iFR (0.88[0.85-0.96] vs 0.91[0.86-0.97], p = .30) did not change significantly compared with the baseline. FFR decreased in 3(13%) lesions with abnormal baseline value, whereas it remained stable in lesions with FFR > 0.80. Conversely, iFR did not show a systematic trend at long-term after TAVI. However, iFR demonstrated a higher reclassification rate at follow-up compared with FFR (p = .02). In conclusions, in this exploratory study, only minor variations of coronary physiology indices were observed at long-term after TAVI. Nevertheless, caution should be exercised in the interpretation of borderline FFR and iFR values in severe AS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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