1,721,211 research outputs found
Imaging and Physiological Assessment After Stent Implantation Ready to Enjoy Both Apples and Oranges?
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Difference in basic concept of coronary bifurcation intervention between Korea and Japan. Insight from questionnaire in experts of Korean and Japanese bifurcation clubs
No full text© 2021, The Author(s).The coronary bifurcation intervention varies among countries due to the differences in assessment of lesion severity and treatment devices. We sought to clarify the difference in basic strategy between South Korea and Japan. A total of 19 and 32 experts from Korean (KBC) and Japanese Bifurcation Clubs (JBC), respectively, answered a survey questionnaire concerning their usual procedure of coronary bifurcation intervention. JBC experts performed less two-stent deployment in the left main (LM) bifurcation compared to KBC experts (JBC vs. KBC: median, 1–10% vs. 21–30%, p < 0.0001) instead of higher performance of side branch dilation after cross-over stenting in both LM (60% vs. 21%, p = 0.001) and non-LM bifurcations (30% vs. 5%, p = 0.037). KBC experts more frequently performed proximal optimization technique (POT) in non-LM bifurcation (41–60% vs. 81–99%, p = 0.028) and re-POT in both LM (1–20% vs. 81–99%, p = 0.017) and non-LM bifurcations (1–20% vs. 81–99%, p = 0.0003). JBC experts more frequently performed imaging-guided percutaneous coronary intervention, whereas KBC experts more often used a pressure wire to assess side branch ischemia. JBC experts used a rotablator more aggressively under the guidance of optical coherence tomography. We clarified the difference in the basic strategy of coronary bifurcation intervention between South Korea and Japan for better understanding the trend in each country.N
Interactions Between Morphological Plaque Characteristics and Coronary Physiology
No full text© 2021 American College of Cardiology FoundationHigh-risk coronary plaque refers to a distinct set of plaque characteristics prone to future coronary events. Coronary physiology represents a group of indexes reflective of the local physiological environment and hemodynamic changes in the macrovascular and microvascular system. Although a large body of evidence has supported the clinical relevance of these 2 factors, currently, identifying plaque morphology cannot reliably capture the lesion subset that causes hard events. Also, the guideline-directed approach based on physiological indexes cannot fully predict and prevent clinical events. In parallel, there is accumulating evidence that these 2 aspects of coronary artery disease influence each other with significant clinical implications, despite traditionally being considered to have separate effects on significances, treatments, and outcomes. In this state-of-the-art review, we explore the clinical evidence of pathophysiological interplay of physiological indexes related to local hemodynamics, epicardial stenosis, and microvascular dysfunction with plaque morphological characteristics that provide a better understanding of the nature of coronary events. Furthermore, we examine the emerging data on the complementary role between plaque morphology and coronary physiology in prognostication and how to apply this concept to overcome the limitations of individual assessment alone. Finally, we propose the potential benefit of integrative assessment of coronary anatomy, plaque quantity and quality, and physiological aspects of a target lesion and vessels for personalized risk profiling and optimized treatment strategy.N
Sensitivity of Pulsatile Parameters of Computed Fractional Flow Reserve using a Reduced-order Model
No full textFractional flow reserve (FFR) is the clinical gold standard for diagnosing coronary artery disease, yet many computational methods rely on steady flow assumptions even though clinical FFR values are measured under pulsatile flow conditions. To address the computational cost and uncertainty associated with pulsatile blood flow simulations, we present a reduced-order model combined with a polynomial chaos expansion (PCE) method. The coronary geometry is represented by thin slabs defined by consecutive centerline points and radius, while a polynomial function approximates pressure differences as a function of flow and its time derivative based on minimal three-dimensional simulations. Diverse pulsatile flow conditions are modeled using lumped parameter models which approximate a wide range of pulsatile flow conditions. Uncertainties in pulsatile parameters, including cardiac output, heart rate, and pulse pressure, are modeled using a third-order Chebyshev PCE to maintain a mean relative error below 1.0%. Validation was conducted using a cylindrical model across stenosis severities from 40% to 90%, as well as a patient-specific model with diverse disease conditions. In both cases, the computed FFR distributions agreed with clinical observations. Sensitivity analysis showed that myocardial compression, distal aortic resistance, and contractility are the primary factors influencing FFR variability, with FFR variation exhibiting a linear correlation with its value. This reduced-order approach enables efficient pulsatile FFR simulations and provides valuable insights into key parameters affecting FFR
SENSITIVITY OF PULSATILE PARAMETERS OF COMPUTED FRACTIONAL FLOW RESERVE USING A REDUCED ORDER MODEL
No full textFractional flow reserve (FFR) has been recognized as a gold standard in diagnosing coronary artery disease and many endeavors have been conducted to compute FFR using computational methods. The majority of them, however, have utilized steady flow analysis but FFR in reality is measured by averaging pulsatile pressure quantities. Pulsatile blood flow simulations are often avoided due to the computational expense and the uncertainties in approximating pulsatile blood flow conditions.To address these two limitations, we develop a reduced-order model to efficiently approximate three-dimensional pulsatile blood flow simulations and integrate with a non-invasive polynomial chaos expansion (PCE) method for the uncertainty quantification of the pulsatile parameters, such as cardiac outputs and heart rates. A three-dimensional coronary geometry is approximated as a collection of thin slabs comprising two consecutive centerline points and the corresponding radius values. The relationship between the flow and pressure difference for each slab is approximated by conducting three-dimensional simulations at three different flow conditions and fitting to a polynomial function of flow and flow time derivative. A lumped parameter model is coupled to the boundaries of the geometry as a boundary condition and the parameter values are chosen to span a wide, physiologically realistic pressure and flow values. For the PCE method, the Chebyshev polynomial order of three is chosen to maintain the mean relative error of the PCE results within 1.0%.The methodology was validated using both a simple cylindrical geometry with degrees of stenosis ranging from 40% to 90% and a patient-specific coronary model with a randomly generated degree of stenosis between 40% and 90% and varying numbers of serial lesions between one and three. In both cases, the variations in the computed FFR values were comparable to those of the clinical data. The sensitivity analysis revealed that among the pulsatile parameters, myocardial pressure effect, aortic distal resistance, and heart contractility significantly influence the pulsatile FFR computation. Further, the variation in FFR was found to exhibit a linear correlation with its value. We show that the developed methodology can simulate FFR with uncertainties in pulsatile parameters at a reasonable computational expense, while also providing insights into the key factors affecting FFR
Unseen branch model based on physiologic principles for perfusion simulation of coronary arteries
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Angiographic complete revascularization versus incomplete revascularization in patients with diabetes mellitus
No full textBackground Considering the nature of diabetes mellitus (DM) in coronary artery disease, it is unclear whether complete revascularization is beneficial or not in patients with DM. We investigated the clinical impact of angiographic complete revascularization in patients with DM. Methods A total of 5516 consecutive patients (2003 patients with DM) who underwent coronary stenting with 2nd generation drug-eluting stent were analyzed. Angiographic complete revascularization was defined as a residual SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery) score of 0. The patient-oriented composite outcome (POCO, including all-cause death, any myocardial infarction, and any revascularization) and target lesion failure (TLF) at three years were analyzed. Results Complete revascularization was associated with a reduced risk of POCO in DM population [adjusted hazard ratio (HR) 0.70, 95% confidence interval (CI) 0.52-0.93, p = 0.016], but not in non-DM population (adjusted HR 0.90, 95% CI 0.69-1.17, p = 0.423). The risk of TLF was comparable between the complete and incomplete revascularization groups in both DM (adjusted HR 0.75, 95% CI 0.49-1.16, p = 0.195) and non-DM populations (adjusted HR 1.11, 95% CI 0.75-1.63, p = 0.611). The independent predictors of POCO were incomplete revascularization, multivessel disease, left main disease and low ejection fraction in the DM population, and old age, peripheral vessel disease, and low ejection fraction in the non-DM population. Conclusions The clinical benefit of angiographic complete revascularization is more prominent in patients with DM than those without DM after three years of follow-up. Relieving residual disease might be more critical in the DM population than the non-DM population. Trial registration The Grand Drug-Eluting Stent registry NCT03507205.N
Differential Prognostic Implications of Pre- and Post-Stent Fractional Flow Reserve in Patients Undergoing Percutaneous Coronary Intervention
No full textBackground and Objectives: The influence of pre-intervention coronary physiologic status on outcomes post percutaneous coronary intervention (PCI) is not well known. We sought to investigate the prognostic implications of pre-PCI fractional flow reserve (FFR) combined with post-PCI FFR. Methods: A total of 1,479 PCI patients with pre-and post-PCI PER, data were analyzed. The patients were classified according to the median values of pre-PCI FFR (0.71) and post-PCI FFR (0.88). The primary outcome was target vessel failure (TVF) at 2 years. Results: The risk of TVF was higher in the low pre-PCI FFR group than in the high pre- PCI FFR group (hazard ratio, 1.82; 95% confidence interval, 1.15-2.87; p=0.011). In 4 group comparisons, the cumulative incidences ofTVF at 2 years were 3.8%, 4.1%, 4.8%, and 10.2% in the high pre-/high post-, low pre-/high post-, high pre-/low post-, and low pre-/low post-PCI FFR groups, respectively. The risk ofTVF was the highest in the low pre-/low post-PCI FFR group among the groups (p values for comparisons <0.05). In addition, the high pre-/low post-PCI FFR group presented a comparable risk ofTVF with the high post-PCI FFR groups (p values for comparison >0.05). When the prognostic value of the post-PCI FFR was evaluated according to the pre-PCI FFR, the risk of TVF significantly decreased with an increase in post-PCI FFR in the low pre-PCI FFR group, but not in the high pre-PCI FFR group. Conclusions: Pre-PCI FFR was associated with clinical outcomes after PCI, and the prognostic value of post-PCI FFR differed according to the pre-PCI FFR.N
Differences in Plaque Characteristics and Myocardial Mass: Implications for Physiological Significance
No full textBACKGROUND: The mechanism of the fractional flow reserve (FFR) difference according to sex has not been clearly understood. OBJECTIVES: This study sought to evaluate sex differences in coronary stenosis, plaque characteristics, and left ventricular (LV) mass and their implications for physiological significance. METHODS: This was a post hoc analysis of a pooled population of multicenter, international prospective cohorts. Patients (166 women and 489 men) underwent coronary computed tomography angiography (CCTA) within 90 days before invasive FFR measurements were included. The minimal lumen area, percent of plaque burden, whole vessel plaque volume by composition, high-risk plaque characteristics, and LV mass were analyzed from CCTA images. RESULTS: Among 1,188 vessels analyzed, the FFR value was higher in women than that in men (0.85 ± 0.13 vs 0.82 ± 0.14; P = 0.001) despite a similar percentage of diameter stenosis between the sexes (45.9% ± 18.9% vs 46.1% ± 17.7%; P = 0.920). The composition of fibrofatty plaque + necrotic core (13.1% ± 16.9% vs 21.2% ± 19.9%; P 0.10). Sex was not an independent predictor of the FFR value after adjustment for stenosis severity, plaque characteristics, and LV mass. CONCLUSIONS: Higher FFR values for the same stenosis severity in women can be explained by fewer high-risk plaque characteristics and smaller myocardial mass in women than that in men. (CCTA-FFR Registry for Risk Prediction; NCT04037163
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