Utility of FFRCT in Patients with Chest Pain.

PURPOSE OF REVIEW: The goal of this article is to review the data supporting the use of fractional flow reserve derived from coronary computed tomography angiography (FFRCT) in patients with chest pain. REVIEW FINDINGS: Numerous clinical trials have demonstrated that the diagnostic accuracy of coronary computed tomography angiography (CCTA) can be improved with the use of FFRCT, primarily due to its superior specificity when compared to CCTA alone. This promising development may help reduce the need for invasive angiography in patients presenting with chest pain. Furthermore, some studies have indicated that incorporating FFRCT into decision-making is safe, with an FFRCT value of ≥ 0.8 being associated with favorable outcomes. While FFRCT has been shown to be feasible in patients with acute chest pain, further large-scale studies are warranted to confirm its utility. The emergence of FFRCT as a tool for the management of patients with chest pain is promising. However, potential limitations require the interpretation of FFRCT in conjunction with clinical context.

Role of nuclear cardiology in diagnosis and risk stratification of coronary microvascular disease.

Coronary flow reserve (CFR) with positron emission tomography/computed tomography (PET/CT) has an important role in the diagnosis of coronary microvascular disease (CMD), aids risk stratification and may be useful in monitoring therapy. CMD contributes to symptoms and a worse prognosis in patients with coronary artery disease (CAD), nonischemic cardiomyopathies, and heart failure. CFR measurements may improve our understanding of the role of CMD in symptoms and prognosis in CAD and other cardiovascular diseases. The clinical presentation of CAD has changed. The prevalence of nonobstructive CAD has increased to about 50% of patients with angina undergoing angiography. Ischemia with nonobstructive arteries (INOCA) is recognized as an important cause of symptoms and has an adverse prognosis. Patients with INOCA may have ischemia due to CMD, epicardial vasospasm or diffuse nonobstructive CAD. Reduced CFR in patients with INOCA identifies a high-risk group that may benefit from management strategies specific for CMD. Although measurement of CFR by PET/CT has excellent accuracy and repeatability, use is limited by cost and availability. CFR measurement with single-photon emission tomography (SPECT) is feasible, validated, and would increase availability and use of CFR. Patients with CMD can be identified by reduced CFR and selected for specific therapies.

Exponential dosing to standardize myocardial perfusion image quality with rubidium-82 PET.

BACKGROUND: 82Rb PET is commonly performed using the same injected activity in all patients, resulting in lower image quality in larger patients. This study compared 82Rb dosing with exponential vs proportional functions of body weight on the standardization of myocardial perfusion image (MPI) quality. METHODS: Two sequential cohorts of N = 60 patients were matched by patient weight. Rest and dipyridamole stress 82Rb PET was performed using 0.1 MBq·kg-2 exponential and 9 MBq·kg-1 proportional dosing. MPI scans were compared qualitatively with visual image quality scoring (IQS) and quantitatively using the myocardium-to-blood contrast-to-noise ratio (CNR) and blood background signal-to-noise ratio (SNR) as a function of body weight. RESULTS: Average (min-max) patient body weight was 81 ± 18 kg (46-137 kg). Proportional dosing resulted in decreasing CNR, SNR, and visual IQS with increasing body weight (P < 0.05). Exponential dosing eliminated the weight-dependent decreases in these image quality metrics that were observed in the proportional dosing group. CONCLUSION: 82Rb PET dosing as an exponential (squared) function of body weight produced consistent stress perfusion image quality over a wide range of patient weights. Dramatically lower doses can be used in lighter patients, with the equivalent population dose shifted toward the heavier patients to standardize diagnostic image quality.

Non-invasive diagnosis of vasospastic angina.

Vasospastic angina (VSA), or variant angina, is an under-recognized cause of chest pain and myocardial infarction, especially in Western countries. VSA leads to a declined quality of life and is associated with increased morbidity and mortality. Currently, the diagnosis of VSA relies on invasive testing that requires the direct intracoronary administration of ergonovine or acetylcholine. However, invasive vasoreactivity testing is underutilized. Several non-invasive imaging alternatives have been proposed to screen for VSA. This review aims to discuss the strengths and limitations of available non-invasive imaging tests for vasospastic angina.

NT-proBNP level as a substitute for myocardial perfusion scan in preoperative cardiovascular risk assessment in noncardiac surgery.

BACKGROUND: Preoperative cardiovascular risk assessment is one of the main principles before noncardiac surgeries. Cardiac stress imaging, such as myocardial perfusion scan (MPS), is a proposed cardiovascular risk evaluation method according to the latest guidelines. Yet, its efficacy, along with the cost-effectiveness of the method, has been questioned in previous studies. Our study aims to evaluate the utility of N-terminal pro-b-type natriuretic peptide (NT-proBNP) level measurement in predicting postoperative cardiovascular complications in candidates who have undergone an MPS before surgery and compare the results. METHODS: A cohort of 80 patients with a revised cardiac risk index score of one or more who were scheduled for moderate to high-risk noncardiac surgeries and met the criteria to undergo an MPS for risk assessment were included in the study. All of them underwent an MPS one week before surgery. Their preoperative NT-proBNP, troponin levels, and electrocardiograms were obtained one day before surgery and again on day three postoperative. The predictive efficacy of NT-proBNP levels and MPS were compared. RESULTS: Seventy-eight patients underwent surgery, three of which exhibited a rise in troponin level, six showed changes on electrocardiogram, and pulmonary edema was detected in one, three days after surgery. There was no mortality in our patients. The sensitivity and specificity of the MPS for predicting postoperative cardiovascular complications were 100% and 66%, respectively. MPS also had a positive predictive value of 20% and a negative predictive value of 100% in our study. A 332.5 pg/ml cut-off value for NT-proBNP level yielded a sensitivity of 100%, specificity of 79.2%, positive predictive value of 40%, and negative predictive value of 100%. CONCLUSIONS: Our study reveals the incremental specificity and positive predictive value of NT-proBNP level measurement in preoperative cardiovascular risk evaluation compared to MPS. Given the low feasibility, high costs, and disappointing predictive value of MPS, preoperative NT-proBNP level assessment can be substituted. This method can assist anesthesiologists and surgeons with precisely detecting at-risk patients resulting in taking proper measures to reduce the morbidity and mortality of the proposed patients before and during surgeries.

Radiolabeled Thioflavin-T Derivative PET Imaging for the Assessment of Cardiac Amyloidosis.

PURPOSE OF REVIEW: Cardiac amyloidosis (CA) is an often under-recognized cause of heart failure with preserved ejection fraction. The goal of the current paper was to review imaging modalities available for detecting cardiac amyloidosis. We wished to determine what modalities are available for the diagnosis of cardiac amyloidosis and what modalities could be utilized in the future. RECENT FINDINGS: Early and delayed planar imaging of the chest currently plays a central role in the workup and diagnosis of CA. However, novel positron emission tomography (PET) tracers could play a large role in CA imaging in the future. There is an increasing body of literature supporting the use of targeted amyloid-binding PET radiotracers such as 11C-Pittsburgh compound B (11C-PIB), 18F-florbetapir, -flutemetamol, and -florbetaben for the detection of cardiac amyloid. While planar imaging currently plays a large role in the workup of CA, PET imaging could play an increasing important role in the future. The quantitative abilities of novel PET tracers could theoretically allow for the serial monitoring of patients and detection of response to therapy, and the sensitive nature of the tracers could allow for even earlier disease detection. Further work with large randomized controlled trial data is needed in the development and validation of PET tracers for cardiac amyloid and represents an exciting development within the realm of nuclear cardiology.

Right ventricular diastolic function predicts clinical atrial fibrillation after coronary artery bypass graft.

Background: Patients with moderate-severe left ventricular systolic dysfunction undergoing coronary artery bypass graft (CABG) surgery are at high risk of mortality and morbidity. Our aim is to evaluate the right ventricular (RV) diastolic function in these patients, and monitor its effects on postoperation outcomes. Materials and Methods: In a cohort study, patients with moderate-severe left ventricular systolic dysfunction (ejection fraction ≤35%) who were candidate for CABG were included. Baseline transthoracic echocardiography (TTE) was performed, and RV diastolic function measures were obtained. After CABG, the length of intubation, inotrope dependency, hospital stay in intensive care unit and ward, in-hospital and after discharge mortality, postoperative atrial fibrillation (POAF) were evaluated in all patients. Results: Sixty-seven patients were prospectively included in the study. The mean ± standard deviation age of our patients was 61.4 ± 9.3. There was no difference between grades of RV diastolic function and postoperative outcomes. However, we found significant difference between grades of RV diastolic function and onset of in hospital, and total POAF (P-value = 0.017). Multivariate analysis demonstrated that preoperative tricuspidEt/E't (ratio of peak early-diastolic flow rate across the tricuspid valve orifice to peak early-diastolic velocity at the lateral tricuspid annulus), left atrial volume and "high risk" Euroscore II were independent predictors for POAF during hospitalization and total POAF in patients with moderate to severely impaired left ventricular systolic function (P-values were 0.04, 0.003 and 0.001, respectively). Conclusion: We believe that patients with increased tricuspid Et/E't are high risk for POAF; therefore, any risk score for POAF should include a comprehensive TTE including evaluation of RV diastolic function before surgery.

Lessons learnt from COVID-19 in adult congenital heart patient in Tehran: a survey-based study of prevention, exposure, susceptibility, and outcomes.

BACKGROUND: COVD-19 pandemic has overwhelmed many healthcare systems worldwide. Underlying cardiovascular disease predisposes to greater disease susceptibility and more complications including mortality. Such data is unverified in adults with congenital heart disease (ACHD). The aim of the study is to report the Tehran experience with respect to preventative self-care measures, disease exposure, susceptibility, and outcomes after COVD-19 infection in ACHD patients. METHODS: A telephone-based survey was conducted in ACHD patients, focusing on new-onset symptoms that might indicate COVID-19 infection, prevention measures, confirmed infection rates, and outcomes. RESULTS: Three-hundred and nine ACHD patients, with a mean age of 29.13 years (range from 14 to 72 years, SD = 10.64), and 170 (55%) women were assessed. The majority (86.7%) had moderate or complex ACHD. Two-thirds (67.3%) of the patients practiced high-level preventative self-care measures. After community exposure, 33.3% developed COVID-19, and after household exposure, 43.7% developed COVID-19. There was only one mortality in a post-operative patient. Thirty-seven patients (12%) reported new symptoms including cough (10%), fatigue (8%), fever (7%), and new dyspnoea (6.5%). Amongst 18 (6%) with confirmed COVID-19, there was only 1 mortality in a post-operative patient. Age (adjusted OR = 1.19, 95% CI: 1.07-1.31, p = 0.001), contact with confirmed COVID-19 cases (adjusted OR = 59.34, 95% CI: 3.68-955.10, p = 0.004) were independently associated with COVID-19 infection. CONCLUSIONS: Mortality risk associated with COVID-19 infection in ACHD patients with moderate or severe disease appears to be relatively low, similar to the general population. Such risk appears to act through conventional risk factors, and in this cohort, we demonstrated age as a significant risk factor in addition to exposure to the development of COVID-19 infection. Preventative self-care measures are a potentially significant and impactful intervention target for intervention and for improving outcomes.

Board examination stress effect on diastolic function.

BACKGROUND: To this date, effects of mental stress on cardiac function have not been clearly investigated. Although hemodynamic and neuroendocrine adverse effects of daily mental stress on cardiovascular morbidity and mortality have been reported, its direct impact on diastolic function of the heart has not been previously studied. In this study, we aimed to assess the role of Board Exam anxiety on right and left ventricular diastolic function in medical residents. METHODS: Forty medical residents prior to participation in the medical board exam were enrolled in our study. Right prior to as well as 2 month after the exam, all residents underwent trans-thoracic Doppler echocardiography. Right ventricular systolic and diastolic functions and echocardiography indices were measured. Levels of anxiety were measured using Beck Anxiety Inventory Questionnaire before and after the exam. Pre exam and post exam results of study population as well as low and high anxiety groups were evaluated. RESULTS: Early to late mitral inflow velocity (E/A ratio) in LV inflow increased after board exam (P-value <.001). E/A ratio in RV inflow increased after board exam (P-value: .002). Early mitral inflow to its annular velocity (E/E' ratio) in septal wall decreased after board exam (P-value<.001). The change in E/E' RV free wall did not reach statistical significance (P = .57). Mitral annuls velocities measured by TDI in septal and lateral wall and also tricuspid annulus velocity increased after board exam (P-value<.05). The comparison of these changes between the high-stress and low-stress groups of residents revealed significant differences. Comparison of changes of E/A ratio in the mitral and tricuspid inflow as well as the E/E' in the septum and free wall of the right ventricle before and after the Board Exam between high-stress and low-stress groups was not statistically significant, although there was a trend of more changes in high- stress group residents. CONCLUSION: This is the first report of comprehensive sequential assessment of left and right ventricular diastolic functions during and after a real subacute stress occasion. The finding of a decreased E/A and E' in response to mental stress suggests that repetitive mental stress may induce diastolic dysfunction which is a mechanism of diastolic heart failure in individuals at risk.

Two-dimensional echocardiographic right ventricle measurements adjusted to body mass index and surface area in a normal population.

BACKGROUND: To determine reference echocardiographic values in a normal population and assess their correlation with body mass index (BMI) and body surface area. METHODS: An expert cardiologist performed two-dimensional echocardiography with triplicate right ventricle (RV) size measurements in 80 subjects with normal heart condition. Results were correlated with anthropometric data. RESULTS: Base-to-apex length in four-chamber view (RVD3) and above-pulmonic valve in short-axis view in males, as well as mid-RV diameter in standard four-chamber view (RVD), basal RV diameter, and mid RV diameter in RV-focused four-chamber view in females, were significantly correlated with BMI. All RV variables were significantly correlated with BMI in 20-30-year-old subjects. All RV variables except RVD3 and above-aortic valve in short-axis view (proximal) were significantly correlated with BMI in 35-55-year-old subjects. All RV parameters were significantly correlated with body surface area, except for RVD and in 20-35-year-old subjects. CONCLUSIONS: RV echocardiographic values must be adjusted to anthropometric characteristics for proper diagnosis and management of cardiac disorders. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:204-210, 2017.

Acceleration rate of mitral inflow E wave: a novel transmitral doppler index for assessing diastolic function.

BACKGROUND: We performed comprehensive transmitral and pulmonary venous Doppler echocardiographic studies to devise a novel index of diastolic function. This is the first study to assess the utility of the acceleration rate (AR) of the E wave of mitral inflow as a primary diagnostic modality for assessing diastolic function. METHODS: Study group consisted of 84 patients (53 + 11 years) with left ventricle (LV) diastolic dysfunction and 34 healthy people (35 ± 9 years) as control group, who were referred for clinically indicated two-dimensional transthoracic echocardiogram (TTE) during 2012 and 2013 to Imam Hospital. Normal controls were defined as patients without clinical evidence of cardiac disease and had normal TTE. LV diastolic function was determined according to standardized protocol of American Society of Echocardiography (ASE). As our new parameter, AR of E wave of mitral inflow was also measured in all patients. It was represented by the slope of the line between onset of E wave and peak of it. Correlation between AR of E wave and LV diastolic function grade was measured using the Spearman correlation coefficient. Receiver operating characteristic (ROC) curve was used to determine the sensitivity and specificity of AR of E wave in diagnosing LV diastolic dysfunction in randomly selected two-thirds of population then its derived cutoff was evaluated in rest of the population. The institutional review board of the hospital approved the study protocol. All participants gave written informed consent. This investigation was in accordance with the Declaration of Helsinki. RESULTS: The mean value of AR was 1010 ± 420 cm/s(2) in patients whereas the mean value for the normal controls was 701 ± 210 cm/s(2). There was a strong and graded relation between AR of E wave of mitral inflow and LV diastolic function grade (Spearman P ≤0.0001, rs =0.69). ROC curve analysis revealed that AR of E wave of mitral inflow =750 cm/s(2) predicted moderate or severe LV diastolic dysfunction with 89 % sensitivity and 89 % specificity (area under curve [AUC] = 0.903, P <0.0001). Application of this cutoff on test group showed 96 % sensitivity and 77 % specificity with AUC = 0.932 and P <0.0001. CONCLUSION: AR of E wave of mitral inflow could be used for assessment of diastolic function, especially moderate or severe diastolic dysfunction. However, before its clinical application, external validation should be considered.

Racial referral bias in cardiac computed tomography: Differences, disparities or discrimination?

BACKGROUND: Disparities exist in medicine and can affect patient care. We sought to understand influences of racial biases in diagnostic testing within a Cardiac CT (CCT) population. METHODS: Race of CCT patients, referring physicians and the population in the catchment area were captured between February 2006 and November 2021. The frequency of CCT referrals for each race was indexed to the catchment population. RESULTS: Of 21,241 CCT patients, 17,514 (82.5 â€‹%) patients were White. The Non-White population was comprised of 467(2.2 â€‹%) Indigenous, 656(3.1 â€‹%) Black, 932(4.4 â€‹%) Asian, 276(1.3 â€‹%) South Asian, 1100(5.2 â€‹%) Middle Eastern and 296(1.4 â€‹%) Latin American races. The catchment population was 907,675, with 619,514 individuals of whom 69.7 â€‹% identified as White. Compared to the catchment population, there was a disproportionately higher referral rate for Whites than Non-Whites. The referral index for Whites was higher than Non-Whites (1.2 versus 0.6, p â€‹< â€‹0.001)). This pattern was consistent across all racial minorities and age categories. A total of 356 physicians (236(66.3 â€‹%) White, 4(1.2 â€‹%) Black, 39(12.0 â€‹%) Asian, 30(9.2 â€‹%) South Asian, 43(13.2 â€‹%), Middle Eastern and 4 (1.2 â€‹%) Latin American) made referrals to CCT. The racial difference in referral patterns was independent of physician race and was independent of their years in practice. CONCLUSIONS: Racial differences exist in CCT referrals. These differences are independent of prevalence of disease, physician race or years in practice. This study supports the need to better understand reasons for disparity and strategies to mitigate potential bias.

Echocardiographic estimation of left ventricular filling pressures in heart transplant recipients.

BACKGROUND: Echocardiographic estimation of left ventricular filling pressure in heart transplant (HTx) recipients is challenging. The ability of echocardiography to detect elevated left ventricular end-diastolic pressure (LVEDP) in HTx patients was assessed in this study. RESULTS: This descriptive cross-sectional study included 39 HTx recipients who were candidates for endomyocardial biopsy as a part of their routine post-transplantation surveillance. Doppler transthoracic echocardiography was done before the procedure, and left heart catheterization was done during the endomyocardial biopsy. Thirty-nine patients (15 female, 24 male), with a mean age of 39.6 years (range 13-70), were enrolled. A strong relation was observed between lateral E/e' and LVEDP (R = 0.64, P value < 0.001) and average E/e' and LVEDP (R = 0.6, P value < 0.001). The best cutoff value for LVEDP prediction was the average E/e' ≥ 6.8 with a sensitivity of 96.15% and specificity of 68.5% for the prediction of LVEDP more than or equal to 20 mmHg. Two predictive models comprising age, gender, and lateral E/e' or average E/e' were also proposed. A significant relationship was also found between LVEDP and left ventricular global longitudinal strain (R = - 0.31, P value < 0.01). CONCLUSIONS: Lateral E/e' was the best predictor of LVEDP. The cutoff of average E/e' had the best validity for the estimation of LVEDP. Despite the strong observed association, echocardiographic parameters cannot be considered a surrogate for invasive LVEDP measurements when seeking information about left ventricle filling pressure on heart transplant recipients.

Challenges in the evaluation of aortic stenosis: A guide to multimodal imaging.

Severe Aortic stenosis (AS) is characterised by a late peaking crescendo-decrescendo systolic murmur and a diminished/absent second heart sound. Echocardiographic assessment of AS severity, based on transvalvular velocities / pressure gradients and calculated aortic valve area (AVA), confirms the diagnosis and allows timely intervention. Nevertheless, diagnostic uncertainty exists in cases of discordant measurements, confounders, and symptoms-measurement discrepancies. This guide outlines an approach to the use of multimodal imaging in the diagnosis and staging of AS.

Advances in Single-Photon Emission Computed Tomography: Hardware, Software, and Myocardial Flow Reserve.

The clinical presentation of coronary artery disease (CAD) has changed during the last 20 years with less ischemia on stress testing and more nonobstructive CAD on coronary angiography. Single-photon emission computed tomography (SPECT) myocardial perfusion imaging should include the measurement of myocardial flow reserve and assessment of coronary calcium for the diagnosis of nonobstructive CAD and coronary microvascular disease. SPECT/CT systems provide reliable attenuation correction for better specificity and low-dose CT for coronary calcium evaluation. SPECT MFR measurement is accurate, well validated, and repeatable.