Evaluation of left ventricular filling pressure by echocardiography in patients with atrial fibrillation.

BACKGROUND: Echocardiography is widely used to evaluate left ventricular (LV) diastolic function in patients suspected of heart failure. For patients in sinus rhythm, a combination of several echocardiographic parameters can differentiate between normal and elevated LV filling pressure with good accuracy. However, there is no established echocardiographic approach for the evaluation of LV filling pressure in patients with atrial fibrillation. The objective of the present study was to determine if a combination of several echocardiographic and clinical parameters may be used to evaluate LV filling pressure in patients with atrial fibrillation. RESULTS: In a multicentre study of 148 atrial fibrillation patients, several echocardiographic parameters were tested against invasively measured LV filling pressure as the reference method. No single parameter had sufficiently strong association with LV filling pressure to be recommended for clinical use. Based on univariate regression analysis in the present study, and evidence from existing literature, we developed a two-step algorithm for differentiation between normal and elevated LV filling pressure, defining values ≥ 15 mmHg as elevated. The parameters in the first step included the ratio between mitral early flow velocity and septal mitral annular velocity (septal E/e'), mitral E velocity, deceleration time of E, and peak tricuspid regurgitation velocity. Patients who could not be classified in the first step were tested in a second step by applying supplementary parameters, which included left atrial reservoir strain, pulmonary venous systolic/diastolic velocity ratio, and body mass index. This two-step algorithm classified patients as having either normal or elevated LV filling pressure with 75% accuracy and with 85% feasibility. Accuracy in EF ≥ 50% and EF < 50% was similar (75% and 76%). CONCLUSIONS: In patients with atrial fibrillation, no single echocardiographic parameter was sufficiently reliable to be used clinically to identify elevated LV filling pressure. An algorithm that combined several echocardiographic parameters and body mass index, however, was able to classify patients as having normal or elevated LV filling pressure with moderate accuracy and high feasibility.

Pericardial Disease in Cardiac Amyloidosis: A Comprehensive Review.

In patients with cardiac amyloidosis, pericardial involvement is common, with up to half of patients presenting with pericardial effusions. The pathophysiological mechanisms of pericardial pathology in cardiac amyloidosis include chronic elevations in right-sided filling pressures, myocardial and pericardial inflammation due to cytotoxic effects of amyloid deposits, and renal involvement with subsequent uremia and hypoalbuminemia. The pericardial effusions are typically small; however, several cases of life-threatening cardiac tamponade with hemorrhagic effusions have been described as a presenting clinical scenario. Constrictive pericarditis can also occur due to amyloidosis and its identification presents a clinical challenge in patients with cardiac amyloidosis who concurrently manifest signs of restrictive cardiomyopathy. Multimodality imaging, including echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging, is useful in the evaluation and management of this patient population. The recognition of pericardial effusion is important in the risk stratification of patients with cardiac amyloidosis as its presence confers a poor prognosis. However, specific treatment aimed at the effusions themselves is seldom indicated. Cardiac tamponade and constrictive pericarditis may necessitate pericardiocentesis and pericardiectomy, respectively.

REDV-Functionalized Recombinant Spider Silk for Next-Generation Coronary Artery Stent Coatings: Hemocompatible, Drug-Eluting, and Endothelial Cell-Specific Materials.

Coronary artery stents are life-saving devices, and millions of these devices are implanted annually to treat coronary heart disease. The current gold standard in treatment is drug-eluting stents, which are coated with a biodegradable polymer layer that elutes antiproliferative drugs to prevent restenosis due to neointimal hyperplasia. Stenting is commonly paired with systemic antiplatelet therapy to prevent stent thrombosis. Despite their clinical success, current stents have significant limitations including inducing local inflammation that drives hyperplasia; a lack of hemocompatibility that promotes thrombosis, increasing need for antiplatelet therapy; and limited endothelialization, which is a critical step in the healing process. In this research, we designed a novel material for use as a next-generation coating for drug-eluting stents that addresses the limitations described above. Specifically, we developed a recombinant spider silk material that is functionalized with an REDV cell-adhesive ligand, a peptide motif that promotes specific adhesion of endothelial cells in the cardiovascular environment. We illustrated that this REDV-modified spider silk variant [eADF4(C16)-REDV] is an endothelial-cell-specific material that can promote the formation of a near-confluent endothelium. We additionally performed hemocompatibility assays using human whole blood and demonstrated that spider silk materials exhibit excellent hemocompatibility under both static and flow conditions. Furthermore, we showed that the material displayed slow enzyme-mediated degradation. Finally, we illustrated the ability to load and release the clinically relevant drug everolimus from recombinant spider silk coatings in a quantity and at a rate similar to that of commercial devices. These results support the use of REDV-functionalized recombinant spider silk as a coating for drug-eluting stents.

Temporal Outcomes of Patients Diagnosed With Transthyretin Cardiac Amyloidosis.

BACKGROUND: Transthyretin cardiac amyloidosis (ATTR-CA) is increasingly recognized. Clinical outcomes have evolved over time amid changes in the diagnostic pathway and advances in therapeutics. We sought to evaluate clinical outcomes over time of patients with ATTR-CA with access to disease-modifying therapy. METHODS AND RESULTS: This is a retrospective cohort study of 419 patients diagnosed with ATTR-CA during 2001-2021, comparing clinical characteristics across eras. The primary end point was composite all-cause mortality or orthotopic heart transplantation (OHT). Time-to-event analysis was performed using Cox proportional hazard modeling controlling for differences among cohorts. Patients diagnosed in the more recent years had higher median age (2017-2021, 78 years; 2014-2016, 75 years; 2001-2013, 74 years) and more often had wild-type ATTR (81.9% vs 82.5% vs 56.4%), but less severe phenotypes as evidenced by more individuals with Columbia stage I disease (47.6% vs 35.9% vs 22.4%), owing to lower biomarkers, more patients in New York Heart Association functional classes I and II (68.9% vs 47.6% vs 43.6%), and lower use of loop diuretics (67.0% vs 78.6% vs 89.1%). Over time, patients were treated more frequently with tafamidis (74% vs 37% vs 32%). On multivariable analysis, greater Columbia score (hazard ratio 1.42, 95% confidence interval 1.30-1.54, P < .001) was predictive of death or OHT, whereas tafamidis (hazard ratio 0.31, 95% confidence interval 0.22-0.44, P < .001) was associated with greater survival and freedom from OHT. CONCLUSIONS: Patients recently diagnosed with ATTR-CA have earlier stage disease and substantially lower mortality. Tafamidis is associated with significantly improved survival and freedom from OHT.

Maternal and Fetal Radiation-Induced Cancer Risk From Computed Tomography Pulmonary Angiography During Pregnancy: A Retrospective Cohort Study Across a Multihospital Integrated Health Care Network.

OBJECTIVE: Computed tomography pulmonary angiogram (CTPA) is important to evaluate suspected pulmonary embolism in pregnancy but has maternal/fetal radiation risks. The objective of this study was to estimate maternal and fetal radiation-induced cancer risk from CTPA during pregnancy. METHODS: Simulation modeling via the National Cancer Institute's Radiation Risk Assessment Tool was used to estimate excess cancer risks from 17 organ doses from CTPA during pregnancy, with doses determined by a radiation dose indexing monitoring system. Organ doses were obtained from a radiation dose indexing monitoring system. Maternal and fetal cancer risks per 100,000 were calculated for male and female fetuses and several maternal ages. RESULTS: The 534 CTPA examinations had top 3 maternal organ doses to the breast, lung, and stomach of 17.34, 15.53, and 9.43 mSv, respectively, with a mean uterine dose of 0.21 mSv. The total maternal excess risks of developing cancer per 100,000 were 181, 151, 121, 107, 94.5, 84, and 74.4, respectively, for a 20-, 25-, 30-, 35-, 40-, 45-, and 50-year-old woman undergoing CTPA, compared with baseline cancer risks of 41,408 for 20-year-old patients. The total fetal excess risks of developing cancer per 100,000 were 12.3 and 7.3 for female and male fetuses, respectively, when compared with baseline cancer risks of 41,227 and 48,291. DISCUSSION: Excess risk of developing cancer from CTPA was small relative to baseline cancer risk for pregnant patients and fetuses, decreased for pregnant patients with increasing maternal age, and was greater for female fetuses than male fetuses.

Intracardiac Thrombus in COVID-19 Inpatients: A Nationwide Study of Incidence, Predictors, and Outcomes.

COronaVIrus Disease-2019 (COVID-19) is associated with a hypercoagulable state. Intracardiac thrombosis is a potentially serious complication but has seldom been evaluated in COVID-19 patients. We assessed the incidence, associated factors, and outcomes of COVID-19 patients with intracardiac thrombosis. In 2020, COVID-19 inpatients were identified from the National Inpatient Sample (NIS) database. Data on clinical characteristics, intracardiac thrombosis, and adverse outcomes were collected. Multivariable logistic regression was used to identify factors associated with intracardiac thrombosis, in-hospital mortality, and morbidities. In 2020, 1,683,785 COVID-19 inpatients (mean age 63.8 years, 32.2% females) were studied. Intracardiac thrombosis occurred in 0.10% (1830) of cases. In-hospital outcomes included 13.2% all-cause mortality, 3.5% cardiovascular mortality, 2.6% cardiac arrest, 4.4% acute coronary syndrome (ACS), 16.1% heart failure, 1.3% stroke, and 28.3% acute kidney injury (AKI). Key factors for intracardiac thrombosis were congestive heart failure history and coagulopathy. Intracardiac thrombosis independently linked to higher risks of all-cause mortality (odds ratio [OR]: 3.32 (2.42-4.54)), cardiovascular mortality (OR: 2.95 (1.96-4.44)), cardiac arrest (OR: 2.04 (1.22-3.43)), ACS (OR: 1.62 (1.17-2.22)), stroke (OR: 3.10 (2.11-4.56)), and AKI (OR: 2.13 (1.68-2.69)), but not heart failure. While rare, intracardiac thrombosis in COVID-19 patients independently raised in-hospital mortality and morbidity risks.

Psychometric properties of health-related quality of life instruments used in survivors of critical illness: a systematic review.

BACKGROUND AND OBJECTIVES: Health-related quality of life (HRQoL) is a patient-reported measure of health status. However, research on the psychometric properties of HRQoL instruments used post-critical care is less common. We conducted a systematic review assessing the psychometric properties of HRQoL instruments used in adult survivors following critical illness. METHODS: Three databases were systematically searched between 1990 and June 2022. Screening articles for eligibility, we selected either development studies for new tools or studies that evaluated psychometric properties, and whose target population represented adult survivors following critical illness. Methodological quality was assessed using the COnsensus-Based Standards for the selection of health Measurement INstruments (COSMIN) checklist. The results of each psychometric property were then assessed for criteria of good psychometric properties (sufficient, insufficient or indeterminate) and qualitatively summarised. Finally, we graded the quality of the evidence using a modified GRADE approach. RESULTS: We retrieved 13 eligible studies from 2,983 records identifying 10 HRQoL instruments used post-critical illness. While high-quality evidence for the considered PROMs was limited primarily due to risk of bias, seven instruments demonstrated sufficient levels of reliability, four instruments presented sufficient hypothesis testing, and two instruments showed sufficient responsiveness. Except the Short Form-36, evidence for psychometric properties of other individual measures was limited to a few studies. CONCLUSION: There was limited evidence demonstrated for the psychometric properties of the included PROMs evaluating HRQoL. Further research is warranted to evaluate the psychometric properties of HRQoL measures, strengthening the evidence for administering these instruments in survivors following critical illness.

Impact of Bariatric Surgery on Left Ventricular Structure and Function.

BACKGROUND: Obesity leads to an increased risk of cardiovascular disease morbidity and death, including heart failure. Bariatric surgery has been proven to be the most effective long-term weight management treatment. This study investigated the changes in cardiac structure and function after bariatric surgery, including left ventricular global longitudinal strain. METHODS AND RESULTS: There were 398 consecutive patients who underwent bariatric surgery with pre- and postoperative transthoracic echocardiographic imaging at a US health system between 2004 and 2019. We compared cardiovascular risk factors and echocardiographic parameters between baseline and follow-up at least 6 months postoperatively. Along with decreases in weight postoperatively, there were significant improvements in cardiovascular risk factors, including reduction in systolic blood pressure levels from 132 mm Hg (25th-75th percentile: 120-148 mm Hg) to 127 mm Hg (115-140 mm Hg; P=0.003), glycated hemoglobin levels from 6.5% (5.9%-7.6%) to 5.7% (5.4%-6.3%; P<0.001), and low-density lipoprotein levels from 97 mg/dL (74-121 mg/dL) to 86 mg/dL (63-106 mg/dL; P<0.001). Left ventricular mass decreased from 205 g (165-261 g) to 190 g (151-236 g; P<0.001), left ventricular ejection fraction increased from 58% (55%-61%) to 60% (55%-64%; P<0.001), and left ventricular global longitudinal strain improved from -15.7% (-14.3% to -17.5%) to -18.6% (-16.0% to -20.3%; P<0.001) postoperatively. CONCLUSIONS: This study has shown the long-term impact of bariatric surgery on cardiac structure and function, with reductions in left ventricular mass and improvement in left ventricular global longitudinal strain. These findings support the cardiovascular benefits of bariatric surgery.

Ultra-Widefield Imaging as a Teleophthalmology Screening Tool for Ocular Pathology.

Background: Prior studies have validated ultra-widefield imaging as a remote screening tool for diabetic retinopathy. The aim of this study was to determine its use in screening for any fundus pathology in a routine patient population. Methods: In this prospective randomized study, patients underwent both slit lamp indirect ophthalmoscopy and ultra-widefield imaging. Ultra-widefield images were independently reviewed by two optometrists, and discrepancies were adjudicated by a retina specialist. Clinical findings from slit-lamp examiners and image-reviewers were coded into themes and clinically meaningful findings were extracted. Cohen's kappa was used to estimate agreement for these findings between the two image-reviewers and between the image-reviewers and slit-lamp examiners. Results: Nine-hundred eyes of 450 patients were examined and imaged, of which 616 eyes were analyzed. At least one abnormal fundus finding was present on ophthalmoscopy in 71 eyes (11%) and on adjudicated image interpretation in 166 eyes (27%). Agreement between the two image-reviewers was moderate to substantial for most clinically meaningful findings, including optic disc hemorrhage (κ = 0.8), macular exudates (κ = 0.7), and macular pigmentary changes (κ = 0.7). Agreement between examiners and image-reviewers was moderate to substantial for optic disc hemorrhage (κ = 1), indistinct optic disc margins (κ = 0.5), drusen (κ = 0.4), pigmentary changes (κ = 0.4), and hemorrhage (κ = 0.8). A total of 187 findings were detected by imaging but not examination, compared with 42 that were detected on examination but not imaging. Conclusion: In a routine patient population, ultra-widefield imaging agreed with standard-of-care slit-lamp examinations and detected more fundus findings.

All polymer microfluidic chips-A fixed target sample delivery workhorse for serial crystallography.

The development of x-ray free electron laser (XFEL) light sources and serial crystallography methodologies has led to a revolution in protein crystallography, enabling the determination of previously unobtainable protein structures and near-atomic resolution of otherwise poorly diffracting protein crystals. However, to utilize XFEL sources efficiently demands the continuous, rapid delivery of a large number of difficult-to-handle microcrystals to the x-ray beam. A recently developed fixed-target system, in which crystals of interest are enclosed within a sample holder, which is rastered through the x-ray beam, is discussed in detail in this Perspective. The fixed target is easy to use, maintains sample hydration, and can be readily modified to allow a broad range of sample types and different beamline requirements. Recent innovations demonstrate the potential of such microfluidic-based fixed targets to be an all-around "workhorse" for serial crystallography measurements. This Perspective will summarize recent advancements in microfluidic fixed targets for serial crystallography, examine needs for future development, and guide users in designing, choosing, and utilizing a fixed-target sample delivery device for their system.

Contemporary Review of Transcatheter Mitral Valve Interventions for Mitral Regurgitation.

Mitral regurgitation (MR) is the most common form of valvular heart disease in the United States, and there are established guidelines for indications for requiring mitral valve surgeries. However, there is an unmet clinical need for a subset of high-risk MR patients, especially those with advanced age, heart failure and/or secondary MR. Following the successes of transcatheter aortic valve replacements, significant advances have occurred over the last decade in transcatheter mitral valve interventions in order to manage these patients in both clinical practice and trials. The three main types of these interventions include a transcatheter edge-to-edge repair, percutaneous mitral annuloplasty (both direct and indirect) and transcatheter mitral valve replacement (including when applied to a prior prosthetic valve, annuloplasty ring and mitral annuloplasty ring). This review aims to discuss the contemporary techniques, evidence, indications, multimodality imaging evaluations and outcomes of the various transcatheter mitral valve interventions.

Prognostic Power of Quantitative Assessment of Functional Mitral Regurgitation and Myocardial Scar Quantification by Cardiac Magnetic Resonance.

BACKGROUND: The severity classification of functional mitral regurgitation (FMR) remains controversial despite adverse prognosis and rapidly evolving interventions. Furthermore, it is unclear if quantitative assessment with cardiac magnetic resonance can provide incremental risk stratification for patients with ischemic cardiomyopathy (ICM) or non-ICM (NICM) in terms of FMR and late gadolinium enhancement (LGE). We evaluated the impact of quantitative cardiac magnetic resonance parameters on event-free survival separately for ICM and NICM, to assess prognostic FMR thresholds and interactions with LGE quantification. METHODS: Patients (n=1414) undergoing cardiac magnetic resonance for cardiomyopathy (ejection fraction<50%) assessment from April 1, 2001 to December 31, 2017 were evaluated. The primary end point was all-cause death, heart transplant, or left ventricular assist device implantation during follow-up. Multivariable Cox analyses were conducted to determine the impact of FMR, LGE, and their interactions with event-free survival. RESULTS: There were 510 primary end points, 395/782 (50.5%) in ICM and 114/632 (18.0%) in NICM. Mitral regurgitation-fraction per 5% increase was independently associated with the primary end point, hazards ratios (95% CIs) of 1.04 (1.01-1.07; P=0.034) in ICM and 1.09 (1.02-1.16; P=0.011) in NICM. Optimal mitral regurgitation-fraction threshold for moderate and severe FMR were ≥20% and ≥35%, respectively, in both ICM and NICM, based on the prediction of the primary outcome. Similarly, optimal LGE thresholds were ≥5% in ICM and ≥2% in NICM. Mitral regurgitation-fraction×LGE emerged as a significant interaction for the primary end point in ICM (P=0.006), but not in NICM (P=0.971). CONCLUSIONS: Mitral regurgitation-fraction and LGE are key quantitative cardiac magnetic resonance biomarkers with differential associations with adverse outcomes in ICM and NICM. Optimal prognostic thresholds may provide important clinical risk prognostication and may further facilitate the ability to derive selection criteria to guide therapeutic decision-making.

Echocardiographic Evaluation of Diastolic Function in Special Populations.

Left ventricular (LV) diastolic dysfunction results from a combination of impaired relaxation, reduced restoring forces, and increased chamber stiffness. Noninvasive assessment of diastology uses a multiparametric approach involving surrogate markers of increased filling pressures, which include mitral inflow, septal and lateral annular velocities, tricuspid regurgitation velocity, and left atrial volume index. However, these parameters must be used cautiously. This is because the traditional algorithms for evaluating diastolic function and estimation of LV filling pressures (LVFPs), as recommended by the American Society of Echocardiography and European Association of Cardiovascular Imaging 2016 guidelines, do not apply to unique patients with underlying cardiomyopathies, significant valvular disease, conduction abnormalities, arrhythmias, LV assist devices, and heart transplants, which alter the relation between the conventional indexes of diastolic function and LVFP. The purpose of this review is to provide solutions for evaluating LVFP through illustrative examples of these special populations, incorporating supplemental Doppler indexes, such as isovolumic relaxation time, mitral deceleration time, and pulmonary venous flow analysis, as needed to formulate a more comprehensive approach.

Prevalence and significance of extracardiac uptake on pyrophosphate imaging in the SCAN-MP study: the first 379 cases.

INTRODUCTION: Technetium-labeled bone-avid radiotracers can be used to diagnose transthyretin cardiac amyloidosis (ATTR-CA). Extracardiac uptake of technetium pyrophosphate (Tc-99m PYP) in this context has not been extensively explored and its significance is not well characterized. We assessed extracardiac Tc-99m PYP uptake in individuals undergoing nuclear scintigraphy and the extent of clinically actionable findings. METHODS: The Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Populations (SCAN-MP) study utilizes Tc-99m PYP imaging to identify ATTR-CA in self-identified Black and Caribbean Hispanic participants ≥ 60 years old with heart failure. We characterized the distribution of extracardiac uptake, including stratification of findings by timing of scan (1 hour vs 3 hours after Tc-99m PYP administration) and noted any additional testing in these subjects. RESULTS: Of 379 participants, 195 (51%) were male, 306 (81%) Black race, and 120 (32%) Hispanic ethnicity; mean age was 73 years. Extracardiac Tc-99m PYP uptake was found in 42 subjects (11.1%): 21 with renal uptake only, 14 with bone uptake only, 4 with both renal and bone uptake, 2 with breast uptake, and 1 with thyroid uptake. Extracardiac uptake was more common in subjects with Tc-99m PYP scans at 1 hour (23.8%) than at 3 hours (6.2%). Overall, four individuals (1.1%) had clinically actionable findings. CONCLUSION: Extracardiac Tc-99m PYP uptake manifested in about 1 in 9 SCAN-MP subjects but was clinically actionable in only 1.1% of cases.

A one-pot Pd- and P450-catalyzed chemoenzymatic synthesis of a library of oxyfunctionalized biaryl alkanoic acids leveraging a substrate anchoring approach.

A one-pot chemoenzymatic approach was developed by combining Palladium-catalysis with selective cytochrome P450 enzyme oxyfunctionalization. Various iodophenyl alkanoic acids could be coupled with alkylphenyl boronic acids to generate a series of alkyl substituted biarylalkanoic acids in overall high yield. The identity of the products could be confirmed by various analytical and chromatographic techniques. Addition of an engineered cytochrome P450 heme domain mutant with peroxygenase activity upon completion of the chemical reaction resulted in the selective oxyfunctionalization of those compounds, primarily at the benzylic position. Moreover, in order to increase the biocatalytic product conversion, a reversible substrate engineering approach was developed. This involves the coupling of a bulky amino acid such as L- phenylalanine or tryptophan, to the carboxylic acid moiety. The approach resulted in a 14 to 49% overall biocatalytic product conversion increase associated with a change in regioselectivity of hydroxylation towards less favored positions.

Anticoagulation after pulmonary vein isolation for atrial fibrillation: Associations with CHA2DS2-VASc score, sex, and rhythm.

Guidelines recommend using the CHA2DS2-VASc score to determine anticoagulation decisions in atrial fibrillation (AF) patients, including those who undergo pulmonary vein isolation (PVI), however this may not consistently occur in the real-world setting because of other clinical factors. We sought to evaluate the anticoagulation prescription rates patterns in AF patients 1 year PVI at our institution. Consecutive AF patients undergoing PVI in our prospective registry during 2014-2018 who were alive at 1-year post-PVI were studied. Anticoagulation prescription rates at this time-point were adjudicated, and correlated to CHA2DS2-VASc score, sex, and heart rhythm status at 1 year. Amongst 4596 patients undergoing PVI, mean age was 64.2 ± 10.0 years, 1328 (28.9%) were female, and based on CHA2DS2-VASc score anticoagulation was not indicated, can be considered and indicated in 872 (19.0%), 1183 (25.7%), and 2541 (55.3%) patients, respectively. At 1-year after PVI, 3504 (76.2%) patients were on anticoagulation, and 792 (17.2%) had recurrence of AF. Anticoagulation was continued in over half of AF patients without classic CHA2DS2-VASc indication particularly in those with AF recurrence and women, while they were mildly under-prescribed in those with indication, especially for those without AF recurrence and men. In a large real world cohort of patients after PVI, anticoagulation prescription is not solely depending on the CHA2DS2-VASc score and sex, but also heart rhythm status and other clinical or imaging factors.

Negative Predictive Value and Prognostic Associations of Rb-82 PET/CT with Myocardial Blood Flow in CAV.

BACKGROUND: Invasive coronary angiography (ICA) is the traditional screening modality for cardiac allograft vasculopathy (CAV). Positron emission tomography/computed tomography (PET/CT) scan with myocardial blood flow (MBF) quantification has emerged as a potential noninvasive alternative. OBJECTIVES: The aim of the study was to validate the diagnostic and prognostic value of a previously published algorithm for diagnosing CAV via PET/CT scans with MBF in a larger population. The study also sought to assess the downstream use of ICA when using PET/CT scanning as a screening modality. METHODS: Patients with heart transplantation without prior revascularization who underwent PET/CT scans with MBF were identified retrospectively. The accuracy of the algorithm was assessed in patients who underwent PET/CT scanning within 1 year of ICA. The prognostic value was assessed via a composite outcome of heart failure hospitalization, myocardial infarction, retransplantation, and all-cause mortality. RESULTS: A total of 88 patients for the diagnostic portion and 401 patients for the prognostic portion were included. PET CAV 0 had high negative predictive value for moderate to severe CAV (97%) and PET CAV 2/3 had a high positive predictive value for moderate to severe CAV (68%) by ICA. The cohort was followed for a median of 1.2 (IQR: 1.0-1.8) years with 46 patients having an adverse event. The annualized event rates were 6.9%, 9.3%, and 30.8% for PET CAV 0, 1, and 2/3, respectively (P < 0.001). CONCLUSIONS: An algorithm using PET/CT scanning with MBF demonstrates high a negative predictive value for CAV. PET CAV 2/3 is associated with a higher risk of adverse events and need for revascularization. PET/CT scanning with MBF is a reasonable alternative to ICA for screening for CAV.