scholarly journals Myocardial Perfusion Simulation for Coronary Artery Disease: A Coupled Patient-Specific Multiscale Model

Author(s):  
Lazaros Papamanolis ◽  
Hyun Jin Kim ◽  
Clara Jaquet ◽  
Matthew Sinclair ◽  
Michiel Schaap ◽  
...  

AbstractPatient-specific models of blood flow are being used clinically to diagnose and plan treatment for coronary artery disease. A remaining challenge is bridging scales from flow in arteries to the micro-circulation supplying the myocardium. Previously proposed models are descriptive rather than predictive and have not been applied to human data. The goal here is to develop a multiscale patient-specific model enabling blood flow simulation from large coronary arteries to myocardial tissue. Patient vasculatures are segmented from coronary computed tomography angiography data and extended from the image-based model down to the arteriole level using a space-filling forest of synthetic trees. Blood flow is modeled by coupling a 1D model of the coronary arteries to a single-compartment Darcy myocardium model. Simulated results on five patients with non-obstructive coronary artery disease compare overall well to [$$^{15}$$ 15 O]$$\text {H}_{{2}}$$ H 2 O PET exam data for both resting and hyperemic conditions. Results on a patient with severe obstructive disease link coronary artery narrowing with impaired myocardial blood flow, demonstrating the model’s ability to predict myocardial regions with perfusion deficit. This is the first report of a computational model for simulating blood flow from the epicardial coronary arteries to the left ventricle myocardium applied to and validated on human data.

2020 ◽  
Vol 26 ◽  
Author(s):  
Maria Bergami ◽  
Marialuisa Scarpone ◽  
Edina Cenko ◽  
Elisa Varotti ◽  
Peter Louis Amaduzzi ◽  
...  

: Subjects affected by ischemic heart disease with non-obstructive coronary arteries constitute a population that has received increasing attention over the past two decades. Since the first studies with coronary angiography, female patients have been reported to have non-obstructive coronary artery disease more frequently than their male counterparts, both in stable and acute clinical settings. Although traditionally considered a relatively infrequent and low-risk form of myocardial ischemia, its impact on clinical practice is undeniable, especially when it comes to infarction, where the prognosis is not as benign as previously assumed. Unfortunately, despite increasing awareness, there are still several questions left unanswered regarding diagnosis, risk stratification and treatment. The purpose of this review is to provide a state of the art and an update on current evidence available on gender differences in clinical characteristics, management and prognosis of ischemic heart disease with non-obstructive coronary arteries, both in the acute and stable clinical setting.


Author(s):  
Jenifer M Brown ◽  
Wunan Zhou ◽  
Brittany Weber ◽  
Sanjay Divakaran ◽  
Leanne Barrett ◽  
...  

Abstract Aims The transition from hypertension to heart failure (HF) remains poorly understood. We hypothesized that insufficient perfusion to match global metabolic demand, reflected by a low ratio of myocardial blood flow to global myocardial mass, may be a HF risk marker. Methods and results A retrospective cohort (n = 346) of patients with hypertension who underwent clinical positron emission tomography (PET) myocardial perfusion imaging for chest pain and/or dyspnoea at Brigham and Women’s Hospital (Boston, MA, USA) were studied. Patients without obstructive coronary artery disease by history or PET perfusion (summed stress score <3), HF, cardiomyopathy, or ejection fraction (EF) <40% were followed for HF hospitalization (primary outcome), all-cause death, and their composite. Myocardial blood flow, left ventricular (LV) mass, volumes, and EF were obtained from PET, and a ‘flow/mass ratio’ was determined as hyperaemic myocardial blood flow over LV mass indexed to body surface area. A lower flow/mass ratio was independently associated with larger end-diastolic (β = −0.44, P < 0.001) and end-systolic volume (β = −0.48, P < 0.001) and lower EF (β = 0.33, P < 0.001). A flow/mass ratio below the median was associated with an adjusted hazard ratio of 2.47 [95% confidence interval (CI) 1.24–4.93; P = 0.01] for HF hospitalization, 1.95 (95% CI 1.12–3.41; P = 0.02) for death, and 2.20 (95% CI 1.39–3.49; P < 0.001) for the composite. Conclusion An integrated physiological measure of insufficient myocardial perfusion to match global metabolic demand identifies subclinical hypertensive heart disease and elevated risk of HF and death in symptomatic patients with hypertension but without flow-limiting coronary artery disease.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Ara H Rostomian ◽  
Derek Q Phan ◽  
Mingsum Lee ◽  
Ray X Zadegan

Introduction: Myocardial Infarction with non-obstructive coronary artery disease (MINOCA) is found in 5%-6% of patients with acute myocardial infarction (AMI). As such, the diagnosis and management of AMI patients with non-obstructive coronary artery disease (NOCAD) poses a challenge as compared to patients with MI with coronary artery disease (MICAD). Hypothesis: To evaluate the characteristics and outcomes of MINOCA in older patients as compared with MICAD patients, with and without revascularization. Methods: This was a retrospective observational study of patients ≥80 years old who underwent invasive coronary angiography (ICA) for AMI between 2009-2019 at Kaiser Permanente Los Angeles Medical Center. MINOCA was defied as <50% stenosis of coronary arteries on angiography with a troponin level ≥0.05 ng/ml. Patients with MINOCA vs MICAD were compared. Multivariate logistic regression was used to identify independent predictors of MINOCA and Kaplan-Meier survival analysis was used to analyze all-cause mortality between cohorts. Results: A total of 259 patients with MINOCA (mean ± SD age 83.8±2.7 years, 68% female) and 687 patients with MICAD (84.7±3.4 years, 40% female) were analyzed. Younger age (odds ratio [OR]=1.11; 95% confidence interval [CI]=1.05-1.18), female sex (OR=3.14; CI=2.20-4.48), black race (OR=2.53; CI=1.61-3.98), no history of prior stroke (OR=1.56; CI=1.06-2.33), atrial fibrillation or flutter (OR=2.04; CI:1.38-3.02), lower troponin levels (OR=1.08; CI:1.03-1.11), and lower triglyceride levels per 10 mg/dl increments (OR=1.06; CI:1.03-1.11) increased the odds of having MINCOA as compared to MICAD. At median follow-up of 2.4 years, MINOCA was associated with a lower rate of death (44.8% vs 55.2%, p<0.01) compared to un-revascularized MICAD, but no difference (31.3% vs 40.4%, p=0.68) when compared to re-vascularized MICAD. Conclusions: Patients age ≥80 years with MINOCA have fewer traditional risk factors compared to their counterparts with MICAD and fewer deaths compared to un-revascularized MICAD, but similar mortality compared to revascularized MICAD


Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1181
Author(s):  
Paul Simion ◽  
Bogdan Artene ◽  
Ionut Achiței ◽  
Iulian Theodor Matei ◽  
Antoniu Octavian Petriș ◽  
...  

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) accounts for approximately 5–15% of acute myocardial infarctions (MI). This infarction type raises a series of questions about the underlying mechanism of myocardial damage, the diagnostic pathway, optimal therapy, and the outcomes of these patients when compared to MI associated with obstructive coronary artery disease. We present the case of a 60-year-old patient with multiple cardiovascular risk factors and comorbidities who is admitted in an emergency setting. The patient is known with a conservatively treated inferior myocardial infarction which occurred 3 months prior, with reduced left ventricular ejection fraction. Emergency coronary angiography revealed normal epicardial coronary arteries, which led to further investigations of the underlying cause. Considering the absence of epicardial and microvascular spasm, CMR (cardiac magnetic resonance) confirmation of two transmural myocardial infarctions in the territories tributary to coronary arteries, and a high index of myocardial resistance in culprit arteries, we concluded the diagnosis of MINOCA due to the microvascular endothelial dysfunction. Although the concept of MINOCA was devised almost a decade ago, and these patients are an important part of MI presentations, it still represents a diagnostic challenge with multiple explorations required to establish the precise etiology.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
K Otsuka ◽  
H Ishikawa ◽  
H Yamaura ◽  
K Shirasawa ◽  
N Kasayuki

Abstract Background Low-attenuation plaque (LAP) with a CT value of less than or equal 30 HU on coronary CT angiography (CCTA) is a marker of high-risk plaque features that leads to future acute coronary syndromes. Perivascular and epicardial adipose tissue (EAT) have been shown to be associated with progression of high-risk coronary plaques through metabolic and inflammatory mechanisms. However, association of EAT with LAP volume in three coronary arteries in subjects with or without visceral obesity remain unclear. Aims This study aimed to investigate the association of EAT volume (EAV) and coronary 3-vessel LAP volume in subjects with or without visceral obesity who underwent CCTA. Methods Patients who underwent CCTA without known coronary artery disease were included in the study (525 patients). Study subjects were classified as having non-obstructive or obstructive coronary artery disease according to the degree of coronary artery stenosis on CCTA. The plaque volume and EAV of the main vessel of the left anterior descending artery, left circumflex artery, and right coronary artery were measured with VINCENT software. Coronary plaque composition was classified as calcified plaque (CP, &gt;150HU), noncalcified plaque (NCP, 30–150HU), and Lap (&lt;30HU). The %LAP volume of the three coronary arteries was classified into quartiles. Multiple logistic regression analysis was used to analyze the factors associated with the %LAP volume. Results Compared with subjects without increase visceral fat, subjects with increased visceral fat had a significantly higher BMI, a greater total plaque volume, a greater total %LAP volume, a greater EAV, and a lower mean CT value of EAT. A significant correlation was observed between EAV and %LAP volume (R=0.24, p&lt;0.001). EAV (odds ratio; 1.83, 95% confidence interval 1.071–3.141, p-value 0.027) and type 2 diabetes mellitus (odds ratio 1.76, 95%confidence interval 1.042–3.000, p-value 0.034) appeared to be independent predictors of %LAP volume (Q4), when adjusted by age, gender, BMI&gt;25 kg/m2, visceral fat &gt;100cm2, LogCRP, coronary artery calcium score&gt;300, and obstructive coronary artery disease requiring revascularization. Conclusion This study suggests that LAP volume, which reflects the high-risk plaques in the three coronary arteries, is associated with EAV in subjects with or without increased visceral fat. Further research is needed whether pharmacological therapeutic intervention enables the prevention of coronary plaque progression and destabilization through the reduction of EAV in patients. FUNDunding Acknowledgement Type of funding sources: None.


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