Habib Samady

Emory University | EU · Division of Cardiology

Background: Anatomical vessel location affects post-percutaneous coronary intervention (PCI) physiology. Aims: We aimed to compare the post-PCI instantaneous wave-free ratio (iFR) in left anterior descending (LAD) versus non-LAD vessels and to identify the factors associated with a suboptimal post-PCI iFR. Methods: DEFINE PCI was a multicentre...

While there is a strong need to assess the safety and efficacy of novel therapies prior to evaluation in human patients, the ability to accurately model the complexities of coronary disease in-vitro and/or animal models is somewhat limited. Animal models, even those with genetic predispositions toward coronary disease do not exhibit high grade sten...

No clear recommendations are endorsed by the different scientific societies on the clinical use of repeat coronary computed tomography angiography (CCTA) in patients with non-obstructive coronary artery disease (CAD). This study aimed to develop and validate a practical CCTA risk score to predict medium-term disease progression in patients at a low...

To evaluate the differential associations of high-risk plaque characteristics (HRPC) with resting or hyperemic physiologic indexes (instantaneous wave-free ratio [iFR] or fractional flow reserve [FFR]), a total of 214 vessels from 127 patients with stable angina or acute coronary syndrome who underwent coronary computed tomography angiography (CCTA...

Aims: To investigate the impact of statins on plaque progression according to high-risk coronary atherosclerotic plaque (HRP) features and to identify predictive factors for rapid plaque progression in mild coronary artery disease (CAD) using serial coronary computed tomography angiography (CCTA). Methods and results: We analyzed mild stenosis (...

Coronary stent underexpansion is associated with restenosis and stent thrombosis. In clinical studies of atherosclerosis, high wall shear stress (WSS) has been associated with activation of prothrombotic pathways, upregulation of matrix metalloproteinases, and future myocardial infarction. We hypothesized that stent underexpansion is predictive of...

Background and hypothesis: The recently introduced Bayesian quantile regression (BQR) machine-learning method enables comprehensive analyzing the relationship among complex clinical variables. We analyzed the relationship between multiple cardiovascular (CV) risk factors and different stages of coronary artery disease (CAD) using the BQR model in...

Assessment and prediction of vulnerable plaque progression and rupture risk are of utmost importance for diagnosis, management and treatment of cardiovascular diseases and possible prevention of acute cardiovascular events such as heart attack and stroke. However, accurate assessment of plaque vulnerability assessment and prediction of its future c...

Background: Statins reduce the incidence of major cardiovascular events, but residual risk remains. The study examined the determinants of atherosclerotic statin nonresponse. Objectives: This study aimed to investigate factors associated with statin nonresponse-defined atherosclerosis progression in patients treated with statins. Methods: The...

Despite advancements in early detection and treatment, atherosclerosis remains the leading cause of death across all cardiovascular diseases (CVD). Biomechanical analysis of atherosclerotic lesions has the potential to reveal biomechanically instable or rupture-prone regions. Treatment decisions rarely consider the biomechanics of the stenosed lesi...

Abstract Background The baseline coronary plaque burden is the most important factor for rapid plaque progression (RPP) in the coronary artery. However, data on the independent predictors of RPP in the absence of a baseline coronary plaque burden are limited. Thus, this study aimed to investigate the predictors for RPP in patients without coronary...

Introduction: Statins reduce major cardiovascular events, but residual risk remains. The study examined determinants of atherosclerotic statin non-response in patients using statins. Hypothesis: We hypothesized that a comprehensive evaluation of atherosclerosis identifies patients that progress atherosclerosis despite the use of statin therapy. Met...

Introduction: Coronary CT Angiogram (CCTA) has become a powerful tool in the diagnosis and risk stratification of coronary artery disease (CAD), but can also provide unique insight into the effects of pharmacotherapy on the progression of atherosclerosis. Although Renin-Angiotensin-Aldosterone-System (RAAS) inhibitors are indicated in patients with...

Aims The temporal instability of coronary atherosclerotic plaque preceding an incident acute coronary syndrome (ACS) is not well defined. We sought to examine differences in the volume and composition of coronary atherosclerosis between patients experiencing an early (≤90 days) versus late ACS (>90 days) after baseline coronary computed tomography...

Background The association between the change in vessel inflammation, as quantified by perivascular adipose tissue (PVAT) density, and the progression of coronary atherosclerosis remains to be determined. Objectives The purpose of this study was to explore the association between the change in PVAT density and the progression of total and composit...

Introduction: Coronary stenosis due to atherosclerosis restricts blood flow. Stenosis progression would lead to increased clinical risk such as heart attack. Although many risk factors were found to contribute to atherosclerosis progression, factors associated with fatigue is underemphasized. Our goal is to investigate the relationship between fati...

Background We examined age differences in whole-heart volumes of non-calcified and calcified atherosclerosis by coronary computed tomography angiography (CCTA) of patients with future ACS. Methods A total of 234 patients with core-lab adjudicated ACS after baseline CCTA were enrolled. Atherosclerotic plaque was quantified and characterized from th...

Background Despite a potential role of hemoglobin in atherosclerosis, data on coronary plaque volume changes (PVC) related to serum hemoglobin levels are limited. Objectives The authors sought to evaluate coronary atherosclerotic plaque burden changes related to serum hemoglobin levels using serial coronary computed tomographic angiography (CCTA)....

Atherosclerotic plaque progression and rupture play an important role in cardiovascular disease development and the final drastic events such as heart attack and stroke. Medical imaging and image-based computational modeling methods advanced considerably in recent years to quantify plaque morphology and biomechanical conditions and gain a better un...

Importance: Distinct plaque locations and vessel geometric features predispose to altered coronary flow hemodynamics. The association between these lesion-level characteristics assessed by coronary computed tomographic angiography (CCTA) and risk of future acute coronary syndrome (ACS) is unknown. Objective: To examine whether CCTA-derived adver...

Objectives The aim of this study was to identify the post–percutaneous coronary intervention (PCI) target value of instantaneous wave-free ratio (iFR) that would best discriminate clinical events at 1 year in the DEFINE PCI (Physiologic Assessment of Coronary Stenosis Following PCI) study. Background The impact of residual ischemia detected by iFR...

PurposeThe interplay between geometry and hemodynamics is a significant factor in the development of cardiovascular diseases. This is particularly true for stented coronary arteries. To elucidate this factor, an accurate patient-specific analysis requires the reconstruction of the geometry following the stent deployment for a computational fluid dy...

Aims Plaque structural stress (PSS) is a major cause of atherosclerotic plaque rupture and major adverse cardiovascular events (MACE). We examined the predictors of changes in peak and mean PSS (ΔPSSpeak, ΔPSSmean) in three studies of patients receiving either standard medical or high-intensity statin (HIS) treatment. Methods and results We examin...

Introduction: Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is an evolving field. Methods: We examined the clinical and angiographic characteristics and procedural outcomes of 8,666 CTO PCIs performed at 36 centers between 2012 and 2021. Results: Mean age was 64±10 years and 82% of the patients were men. The prevalence of p...

Objectives To investigate potential differences in plaque progression (PP) between in East Asians and Caucasians as well as to determine clinical predictors of PP in East Asians. Background Studies have demonstrated differences in cardiovascular risk factors as well as plaque burden and progression across different ethnic groups. Methods The stud...

Aims The magnitude of alterations in which coronary arteries remodel and narrow over time is not well understood. We aimed to examine changes in coronary arterial remodelling and luminal narrowing by three-dimensional (3D) metrics from serial coronary computed tomography angiography (CCTA). Methods and results From a multicentre registry of patien...

The association between thrombogenicity and coronary microvascular dysfunction (CMD) has been poorly explored in patients with acute myocardial infarction (AMI). In our real-world clinical practice (N = 116), thrombogenicity was evaluated with thromboelastography and conventional hemostatic measures, and CMD was defined as index of microcirculatory...

Accurate plaque cap thickness quantification and cap stress/strain calculations are of fundamental importance for vulnerable plaque research. To overcome uncertainties due to intravascular ultrasound (IVUS) resolution limitation, IVUS and optical coherence tomography (OCT) coronary plaque image data were combined together to obtain accurate and rel...

Background: The outcomes of distal radial access (dRA) in chronic total occlusion percutaneous coronary intervention (CTO-PCI) have received limited study. Methods: We compared the clinical, angiographic, and procedural characteristics of 120 CTO-PCIs performed via dRA access with 2625 CTO-PCIs performed via proximal radial access (pRA) in a lar...

Importance The density of atherosclerotic plaque forms the basis for categorizing calcified and noncalcified morphology of plaques. Objective To assess whether alterations in plaque across a range of density measurements provide a more detailed understanding of atherosclerotic disease progression. Design, Setting, and Participants This cohort stu...

Several image-based computational models have been used to perform mechanical analysis for atherosclerotic plaque progression and vulnerability investigations. However, differences of computational predictions from those models have not been quantified at multi-patient level. In vivo intravascular ultrasound (IVUS) coronary plaque data were acquire...

Objectives This study sought to investigate the impact of low tube voltage scanning heterogeneity of coronary luminal attenuation on plaque quantification and characterization with coronary computed tomography angiography (CCTA). Background The impact of low tube voltage and coronary luminal attenuation on quantitative coronary plaque remains unce...

The purpose of this study is to investigate the effect of varying coronary flow reserve (CFR) values on the calculation of computationally-derived fractional flow reserve (FFR). CFR reflects both vessel resistance due to an epicardial stenosis, and resistance in the distal microvascular tissue. Patients may have a wide range of CFR related to the t...

Background The current study aimed to examine the independent prognostic value of whole-heart atherosclerosis progression by serial coronary computed tomography angiography (CCTA) for major adverse cardiovascular events (MACE). Methods The multi-center PARADIGM study includes patients undergoing serial CCTA for symptomatic reasons, ≥2 years apart....

Numerical simulations of coupled hemodynamics and leukocyte transport and adhesion inside coronary arteries have been performed. Realistic artery geometries have been obtained for a set of four patients from intravascular ultrasound and angiography images. The numerical model computes unsteady three-dimensional blood hemodynamics and leukocyte conc...

The structural morphology of coronary stents (e.g. stent expansion, lumen scaffolding, strut apposition, tissue protrusion, side branch jailing, strut fracture), and the local hemodynamic environment after stent deployment are key determinants of procedural success and subsequent clinical outcomes. High-resolution intracoronary imaging has the pote...

Coronary physiological assessment using fractional flow reserve or nonhyperemic pressure ratios has become a standard of care for patients with coronary atherosclerotic disease. However, most evidence has focused on the pre-interventional use of physiological assessment to aid revascularization decision-making, whereas post-interventional physiolog...

Objectives To investigate the long-term vasomotor response and inflammatory changes in Absorb bioresorbable vascular scaffold (BVS) and metallic drug-eluting stent (DES) implanted artery. Background Clinical evidence has demonstrated that compared to DES, BVS is associated with higher rates of target lesion failure. However, it is not known whethe...

Background Aortic valve calcification (AVC) is a key feature of aortic stenosis, and patients with aortic stenosis often have coronary -artery disease. Therefore, proving the association between the progression of AVC and coronary atherosclerosis could improve follow-up and treatment strategies. Purpose To explore the association between the progre...

Chronic kidney disease (CKD) in patients with ST-elevation myocardial infarction (STEMI) is associated with worse outcomes. We assessed the impact of CKD on guideline directed coronary revascularization and outcomes among STEMI patients. The Nationwide Inpatient Sample dataset from 2012-2014 was used to identify patients with STEMI using Internatio...

Intracoronary thrombus from plaque erosion could cause fatal acute coronary syndrome (ACS). A conservative anti-thrombotic therapy has been proposed to treat ACS patients in lieu of stenting. It is speculated that the residual thrombus after aspiration thrombectomy would influence the prognosis of this treatment. However, biomechanical mechanisms a...

Background Coronary plaque vulnerability prediction is difficult because plaque vulnerability is non-trivial to quantify, clinically available medical image modality is not enough to quantify thin cap thickness, prediction methods with high accuracies still need to be developed, and gold-standard data to validate vulnerability prediction are often...

Background: The influence of age-dependent changes on fractional flow reserve (FFR) or instantaneous free-wave ratio (iFR) and the response to pharmacological hyperaemia has not been investigated. Aims: We investigated the impact of age on these indices. Methods: This is as post-hoc analysis of the ADVISE II trial, including a total of 690 pre...

Aims To investigate the change in atherosclerotic plaque volume in patients with chronic kidney disease (CKD) and declining renal function, using coronary computed tomography angiography (CCTA). Methods and results In total, 891 participants with analysable serial CCTA and available glomerular filtration rate (GFR, derived using Cockcroft–Gault f...

Background and aims The atherogenic index of plasma (AIP) has been suggested as a marker of plasma atherogenicity. This study aimed to assess the association between AIP and the rapid progression of coronary atherosclerosis using serial coronary computed tomography angiography (CCTA). Methods A total of 1,488 adults (60.9 ± 9.2 years, 58.9% male)...

The structural morphology of stents (e.g. expansion, lumen scaffolding, strut apposition, tissue protrusion, side branch jailing, strut fracture), and the local hemodynamic environment after stent deployment in coronary arteries are key determinants of procedural success and subsequent clinical outcomes. High-resolution intracoronary imaging has th...

Objectives This study sought to identify distinct patient groups and their association with outcome based on the patient similarity network using quantitative coronary plaque characteristics from coronary computed tomography angiography (CTA). Background Coronary CTA can noninvasively assess coronary plaques quantitatively. Methods Patients who u...

Resumen Introducción y objetivos El algoritmo híbrido se diseñó para ayudar en la selección de las estrategias de cruce inicial y siguientes en la intervención coronaria percutánea (ICP) para la oclusión crónica total (OTC); sin embargo, el éxito de la estrategia de inicio seleccionada se ha estudiado poco hasta ahora. Métodos Se estudió el impac...

To determine whether the assessment of individual plaques is superior in predicting the progression to obstructive coronary artery disease (CAD) on serial coronary computed tomography angiography (CCTA) than per-patient assessment. From a multinational registry of 2252 patients who underwent serial CCTA at a ≥ 2-year inter-scan interval, patients w...

Background Microvascular dysfunction is known to play a key role in patients with angina and nonobstructive coronary artery disease. We investigated the impact of ranolazine among patients with angina and nonobstructive coronary artery disease. Methods In this randomized, double-blinded, placebo-controlled pilot trial, 26 patients with angina once...

Background Detecting coronary vulnerable plaques in vivo and assessing their vulnerability have been great challenges for clinicians and the research community. Intravascular ultrasound (IVUS) is commonly used in clinical practice for diagnosis and treatment decisions. However, due to IVUS limited resolution (about 150–200 µm), it is not sufficient...

Aims: Anatomic series commonly report the extent and severity of coronary artery disease (CAD), regardless of location. The aim of this study was to evaluate differences in atherosclerotic plaque burden and composition across the major epicardial coronary arteries. Methods and results: A total of 1271 patients (age 60 ± 9 years; 57% men) with su...

Introduction: Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has been advancing due to improvement of equipment, operator experience, and techniques. Methods: We examined contemporary outcomes of CTO PCI by analyzing the clinical, angiographic, and procedural characteristics of 7,031 CTO interventions performed in 6,984 pati...

Objectives The aim of the current study was to explore the impact of plaque calcification in terms of absolute calcified plaque volume (CPV) and in the context of its percentage of the total plaque volume at a lesion and patient level on the progression of coronary artery disease. Background Coronary artery calcification is an established marker o...

Introduction and objectives The hybrid algorithm was designed to assist with initial and subsequent crossing strategy selection in chronic total occlusion (CTO) percutaneous coronary interventions (PCIs). However, the success of the initially selected strategy has received limited study. Methods We examined the impact of adherence to the hybrid al...

Background The association of age with coronary plaque dynamics is not well characterized by coronary computed tomography angiography (CCTA). Methods From a multinational registry of patients who underwent serial CCTA, 1153 subjects (61 ± 5 years old, 61.1% male) were analyzed. Annualized volume changes of total, fibrous, fibrofatty, necrotic co...

Background: Patients without obstructive coronary artery disease (CAD) may have epicardial or microvascular dysfunction. The purpose of this study was to characterize patterns of epicardial and microvascular dysfunction in men and women with stable and unstable angina undergoing functional coronary angiography to inform medical therapy. Methods:...

Evaluation of coronary artery disease (CAD) using coronary computed tomography angiography (CCTA) has seen a paradigm shift in the last decade. Evidence increasingly supports the clinical utility of CCTA across various stages of CAD, from the detection of early subclinical disease to the assessment of acute chest pain. Additionally, CCTA can be use...

Aims: Although there is increasing evidence supporting coronary atherosclerosis evaluation by coronary computed tomography angiography (CCTA), no data are available on age and sex differences for quantitative plaque features. The aim of this study was to investigate sex and age differences in both qualitative and quantitative atherosclerotic featu...

Objectives The study sought to explore sex-based differences in total and compositional plaque volume (PV) progression. Background It is unclear whether sex has an impact on PV progression in patients with coronary artery disease (CAD). Methods The study analyzed a prospective multinational registry of consecutive patients with suspected CAD who...

Background There is a paucity of data regarding the optimum timing of PCI in relation to TAVR. Objective We compared the major adverse cardiovascular and cerebrovascular events (MACCE) rates among patients who underwent percutaneous coronary intervention (PCI) before transcatheter aortic valve replacement (TAVR) with those who received PCI with/af...

Importance Several studies have reported that the progression of coronary atherosclerosis, as measured by serial coronary computed tomographic (CT) angiography, is associated with the risk of future cardiovascular events. However, the cumulative consequences of multiple risk factors for plaque progression and the development of adverse plaque chara...

Background: The impact of intravascular ultrasound (IVUS) utilization for stent optimization on the long-term outcomes in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. Methods: We examined the outcomes of CTO-PCI with and without IVUS use for stent optimization in 922 CTO-PCIs performed betwee...

Background: The association between triglyceride glucose (TyG) index and coronary atherosclerotic change remains unclear. We aimed to evaluate the association between TyG index and coronary plaque progression (PP) using serial coronary computed tomography angiography (CCTA). Methods: A total of 1143 subjects (aged 60.7 ± 9.3 years, 54.6% male) w...

Objectives This study sought to identify culprit lesion (CL) precursors among acute coronary syndrome (ACS) patients based on qualitative and quantitative computed tomography–based plaque characteristics. Background Coronary computed tomography angiography (CTA) has been validated for patient-level prediction of ACS. However, the applicability of...

Objectives To understand the predictors of survival and indications for Impella RP in a single healthcare experience. Background The Impella RP can be used to temporarily support patients with right ventricular (RV) dysfunction after left ventricular assist device (LVAD) placement or myocardial infarction (MI). However, recent postmarket approval...

Background: The impact of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) on angina and subsequent incidence of major adverse cardiovascular event (MACE) rate remains controversial. Methods: We compared patient- reported angina change and the incidence of MACE (defined as death, myocardial infarction [MI], target-vessel re...

Aims: High-risk plaque (HRP) and non-obstructive coronary artery disease independently predict adverse events, but their importance to future culprit lesions has not been resolved. We sought to determine in patients prior to confirmed acute coronary syndrome (ACS) the association between lesion percent diameter stenosis (%DS), and the absolute num...

Objectives To develop, demonstrate and evaluate an automated deep learning method for multiple cardiovascular structure segmentation. Background Segmentation of cardiovascular images is resource-intensive. We design an automated deep learning method for the segmentation of multiple structures from Coronary Computed Tomography Angiography (CCTA) im...

Objectives The aim of this study was to evaluate temporal changes in coronary hemodynamic and physiological indexes in the non-infarct-related artery (IRA), which might be affected by adjacent infarcted myocardium, using an experimental animal model of acute myocardial infarction. Background There has been debate on the reliability of fractional f...