Coronary Atherosclerosis Across the Glycemic Spectrum Among Asymptomatic Adults: The Miami Heart Study at Baptist Health South Florida.

BACKGROUND: The contemporary burden and characteristics of coronary atherosclerosis, assessed using coronary computed tomography angiography (CCTA), is unknown among asymptomatic adults with diabetes and prediabetes in the United States. The pooled cohort equations and coronary artery calcium (CAC) score stratify atherosclerotic cardiovascular disease risk, but their association with CCTA findings across glycemic categories is not well established. METHODS: Asymptomatic adults without atherosclerotic cardiovascular disease enrolled in the Miami Heart Study were included. Participants underwent CAC and CCTA testing and were classified into glycemic categories. Prevalence of coronary atherosclerosis (any plaque, noncalcified plaque, plaque with ≥1 high-risk feature, maximal stenosis ≥50%) assessed by CCTA was described across glycemic categories and further stratified by pooled cohort equations-estimated atherosclerotic cardiovascular disease risk and CAC score. Adjusted logistic regression was used to evaluate the associations between glycemic categories and coronary outcomes. RESULTS: Among 2352 participants (49.5% women), the prevalence of euglycemia, prediabetes, and diabetes was 63%, 30%, and 7%, respectively. Coronary plaque was more commonly present across worsening glycemic categories (euglycemia, 43%; prediabetes, 58%; diabetes, 69%), and similar pattern was observed for other coronary outcomes. In adjusted analyses, compared with euglycemia, prediabetes and diabetes were each associated with higher odds of any coronary plaque (OR, 1.30 [95% CI, 1.05-1.60] and 1.75 [1.17-2.61], respectively), noncalcified plaque (OR, 1.47 [1.19-1.81] and 1.99 [1.38-2.87], respectively), and plaque with ≥1 high-risk feature (OR, 1.65 [1.14-2.39] and 2.53 [1.48-4.33], respectively). Diabetes was associated with stenosis ≥50% (OR, 3.01 [1.79-5.08]; reference=euglycemia). Among participants with diabetes and estimated atherosclerotic cardiovascular disease risk <5%, 46% had coronary plaque and 10% had stenosis ≥50%. Among participants with diabetes and CAC=0, 30% had coronary plaque and 3% had stenosis ≥50%. CONCLUSIONS: Among asymptomatic adults, worse glycemic status is associated with higher prevalence and extent of coronary atherosclerosis, high-risk plaque, and stenosis. In diabetes, CAC was more closely associated with CCTA findings and informative in a larger population than the pooled cohort equations.

Coronary Atherosclerosis in an Asymptomatic U.S. Population: Miami Heart Study at Baptist Health South Florida.

BACKGROUND: The burden of total coronary plaque, plaque subtypes, and high-risk plaque features was unknown in asymptomatic individuals from the general U.S. primary prevention population. OBJECTIVES: In a large, asymptomatic U.S. cohort evaluated using coronary computed tomography angiography (CCTA), we aimed to assess the burden of total coronary plaque, plaque subtypes, and high-risk plaque features; the interplay between CCTA findings and coronary artery calcium (CAC) scores; and identify independent predictors of coronary plaque. METHODS: Cross-sectional analysis in the MiHeart (Miami Heart Study), a cohort of 2,359 asymptomatic individuals from the Greater Miami Area (mean age 53 years, 50% women, 47% Hispanic/Latino, 43% non-Hispanic White). We estimated the burden of CAC (=0, >0 to <100, ≥100), CCTA-based plaque features (any plaque, stenosis ≥50%, ≥70%, high-risk features), and their interplay. RESULTS: Overall, 58% participants had CAC = 0, 28% CAC >0 to <100, and 13% CAC ≥100. A total of 49% participants had plaque on the CCTA, including 16% among those with CAC = 0. Overall, 6% participants had coronary stenosis ≥50% (12% among those with coronary plaque), 1.8% had stenosis ≥70% (3.7% among those with plaque), and 7% had at least 1 coronary plaque with ≥1 high-risk feature (13.8% among those with plaque). Only 0.8% participants with CAC = 0 had stenosis ≥50%, 0.1% stenosis ≥70%, and 2.3% plaque with high-risk features. In logistic regression models, independent predictors of coronary plaque and high-risk plaque were older age, male sex, tobacco use, diabetes, overweight, and obesity. Male sex, overweight, and obesity were independent predictors of plaque if CAC = 0. CONCLUSIONS: The Miami Heart Study confirms substantial prevalence of coronary plaque in asymptomatic individuals. Overall, 49% of participants had coronary plaque, 6% had stenosis ≥50%, and 7% had plaques with at least 1 high-risk feature. These proportions were 16%, 0.8%, and 2.3%, respectively, among those with CAC = 0. Longitudinal follow-up will shed further light on the prognostic implications of these findings in asymptomatic individuals.

The Miami Heart Study (MiHeart) at Baptist Health South Florida, A prospective study of subclinical cardiovascular disease and emerging cardiovascular risk factors in asymptomatic young and middle-aged adults: The Miami Heart Study: Rationale and Design.

OBJECTIVE: The Miami Heart Study (MiHeart) at Baptist Health South Florida is an ongoing, community-based, prospective cohort study aimed at characterizing the prevalence, characteristics, and prognostic value of diverse markers of early subclinical coronary atherosclerosis and of various potential demographic, psychosocial, and metabolic risk factors. We present the study objectives, detailed research methods, and preliminary baseline results of MiHeart. METHODS: MiHeart enrolled 2,459 middle-aged male and female participants from the general population of the Greater Miami Area. Enrollment occurred between May 2015 and September 2018 and was restricted to participants aged 40-65 years free of clinical cardiovascular disease (CVD). The baseline examination included assessment of demographics, lifestyles, medical history, and a detailed evaluation of psychosocial characteristics; a comprehensive physical exam; measurement of multiple blood biomarkers including measures of inflammation, advanced lipid testing, and genomics; assessment of subclinical coronary atherosclerotic plaque and vascular function using coronary computed tomography angiography, the coronary artery calcium score, carotid intima-media thickness, pulse wave velocity, and peripheral arterial tonometry; and other tests including 12-lead electrocardiography and assessment of pulmonary function. Blood samples were biobanked to facilitate future ancillary research. RESULTS: MiHeart enrolled 1,261 men (51.3%) and 1,198 women (48.7%). Mean age was 53 years, 85.6% participants were White and 47.4% were of Hispanic/Latino ethnicity. The study included 7% individuals with diabetes, 33% with hypertension, and 15% used statin therapy at baseline. Overweight or obese participants comprised 72% of the population and 3% were smokers. Median 10-year estimated atherosclerotic CVD risk using the Pooled Cohort Equations was 4%. CONCLUSION: MiHeart will provide important, novel insights into the pathophysiology of early subclinical atherosclerosis and further our understanding of its role in the genesis of clinical CVD. The study findings will have important implications, further refining current cardiovascular prevention paradigms and risk assessment and management approaches moving forward.

Combined stress myocardial CT perfusion and coronary CT angiography as a feasible strategy among patients presenting with acute chest pain to the emergency department.

BACKGROUND: A combined approach of myocardial CT perfusion (CTP) with coronary CT angiography (CTA) was shown to have better diagnostic accuracy than coronary CTA alone. However, data on cost benefits and length of stay when compared to other perfusion imaging modalities has not been evaluated. Therefore, we aim to perform a feasibility study to assess direct costs and length of stay of a combined stress CTP/CTA and use SPECT myocardial perfusion imaging (SPECT-MPI) as a benchmark, among chest pain patients at intermediate-risk for acute coronary syndrome (ACS) presenting to the emergency department (ED). METHODS: This is a prospective two-arm clinical trial (NCT02538861) with 43 patients enrolled in stress CTP/CTA arm (General Electric Revolution CT) and 102 in SPECT-MPI arm. Mean age of the study population was 65 â€‹± â€‹12 years; 56% were men. We used multivariable linear regression analysis to compare length of stay and direct costs between the two modalities. RESULTS: Overall, 9 out of the 43 patients (21%) with CTP/CTA testing had an abnormal test. Of these 9 patients, 7 patients underwent invasive coronary angiography and 6 patients were found to have obstructive coronary artery disease. Normal CTP/CTA test was found in 34 patients (79%), who were discharged home and all patients were free of major adverse cardiac events at 30 days. The mean length of stay was significantly shorter by 28% (mean difference: 14.7 â€‹h; 95% CI: 0.7, 21) among stress CTP/CTA (20 â€‹h [IQR: 16, 37]) compared to SPECT-MPI (30 â€‹h [IQR: 19, 44.5]). Mean direct costs were significantly lower by 44% (mean difference: $1535; 95% CI: 987, 2082) among stress CTA/CTP ($1750 [IQR: 1474, 2114] compared to SPECT-MPI ($2837 [IQR: 2491, 3554]). CONCLUSION: Combined stress CTP/CTA is a feasible strategy for evaluation of chest pain patients presenting to ED at intermediate-risk for ACS and has the potential to lead to shorter length of stay and lower direct costs.

Volumetric Single-Beat Coronary Computed Tomography Angiography: Relationship of Image Quality, Heart Rate, and Body Mass Index. Initial Patient Experience With a New Computed Tomography Scanner.

BACKGROUND: Cardiac computed tomography (CT) image quality (IQ) is very important for accurate diagnosis. We propose to evaluate IQ expressed as Likert scale, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) from coronary CT angiography images acquired with a new volumetric single-beat CT scanner on consecutive patients and assess the IQ dependence on heart rate (HR) and body mass index (BMI). METHODS: We retrospectively analyzed the data of the first 439 consecutive patients (mean age, 55.13 [SD, 12.1] years; 51.47% male), who underwent noninvasive coronary CT angiography in a new single-beat volumetric CT scanner (Revolution CT) to evaluate chest pain at West Kendall Baptist Hospital. Based on patient BMI (mean, 29.43 [SD, 5.81] kg/m), the kVp (kilovolt potential) value and tube current were adjusted within a range of 80 to 140 kVp and 122 to 720 mA, respectively. Each scan was performed in a single-beat acquisition within 1 cardiac cycle, regardless of the HR. Motion correction software (SnapShot Freeze) was used for correcting motion artifacts in patients with higher HRs. Autogating was used to automatically acquire systolic and diastolic phases for higher HRs with electrocardiographic milliampere dose modulation. Image quality was assessed qualitatively by Likert scale and quantitatively by SNR and CNR for the 4 major vessels right coronary, left main, left anterior descending, and left circumflex arteries on axial and multiplanar reformatted images. Values for Likert scale were as follows: 1, nondiagnostic; 2, poor; 3, good; 4, very good; and 5, excellent. Signal-to-noise ratio and CNR were calculated from the average 2 CT attenuation values within regions of interest placed in the proximal left main and proximal right coronary artery. For contrast comparison, a region of interest was selected from left ventricular wall at midcavity level using a dedicated workstation. We divided patients in 2 groups related to the HR: less than or equal to 70 beats/min (bpm) and greater than 70 bpm and also analyzed them in 2 BMI groupings: BMI less than or equal to 30 kg/m and BMI greater than 30 kg/m. RESULTS: Mean SNR was 8.7 (SD, 3.1) (n = 349) for group with HR 70 bpm or less and 7.7 (SD, 2.4) (n = 78) for group with HR greater than 70 bpm (P = 0.008). Mean CNR was 6.9 (SD, 2.7) (n = 349) for group with HR 70 bpm or less and 5.9 (SD, 2.2) (n = 78) for group with HR 70 bpm or greater (P = 0.002). Mean SNR was 8.8 (SD, 3.2) (n = 249) for group with BMI 30 kg/m or less and 8.1 (SD, 2.6) (n = 176) for group with BMI greater than 30 kg/m (P = 0.008). Mean CNR was 7.0 (SD, 2.8) (n = 249) for group with BMI 30 kg/m or less and 6.4 (SD, 2.4) (n = 176) for group with BMI greater than 30 kg/m (P = 0.002). The results for mean Likert scale values were statistically different, reflecting difference in IQ between people with HR 70 bpm or less and greater than 70 bpm, BMI 30 kg/m or less, and BMI greater than 30 kg/m.

Initial multicentre experience of high-speed myocardial perfusion imaging: comparison between high-speed and conventional single-photon emission computed tomography with angiographic validation.

PURPOSE: High-speed (HS) single-photon emission computed tomography (SPECT) with a recently developed solid-state camera shows comparable myocardial perfusion abnormalities to those seen in conventional SPECT. We aimed to compare HS and conventional SPECT images from multiple centres with coronary angiographic findings. METHODS: The study included 50 patients who had sequential conventional SPECT and HS SPECT myocardial perfusion studies and coronary angiography within 3 months. Stress and rest perfusion images were visually analysed and scored semiquantitatively using a 17-segment model by two experienced blinded readers. Global and coronary territorial summed stress scores (SSS) and summed rest scores (SRS) were calculated. Global SSS ≥3 or coronary territorial SSS ≥2 was considered abnormal. In addition the total perfusion deficit (TPD) was automatically derived. TPD >5% and coronary territorial TPD ≥3% were defined as abnormal. Coronary angiograms were analysed for site and severity of coronary stenosis; ≥50% was considered significant. RESULTS: Of the 50 patients, 13 (26%) had no stenosis, 22 (44%) had single-vessel disease, 6 (12%) had double-vessel disease and 9 (18%) had triple-vessel disease. There was a good linear correlation between the visual global SSS and SRS (Spearman's ρ 0.897 and 0.866, respectively; p < 0.001). In relation to coronary angiography, the sensitivities, specificities and accuracies of HS SPECT and conventional SPECT by visual assessment were 92% (35/38), 83% (10/12) and 90% (45/50) vs. 84% (32/38), 50% (6/12) and 76% (38/50), respectively (p < 0.001). The sensitivities, specificities and accuracies of HS SPECT and conventional SPECT in relation to automated TPD assessment were 89% (31/35), 57% (8/14) and 80% (39/49) vs. 86% (31/36), 77% (10/13) and 84% (41/49), respectively. CONCLUSION: HS SPECT allows fast acquisition of myocardial perfusion images that correlate well with angiographic findings with overall accuracy by visual assessment better than conventional SPECT. Further assessment in a larger patient population may be needed to confirm this observation.

Triage of patients presenting with chest pain to the emergency department: implementation of coronary CT angiography in a large urban health care system.

OBJECTIVE: There is growing evidence supporting the use of coronary CT angiography (CTA) to triage patients in the emergency department (ED) with acute chest pain and low risk of acute coronary syndrome (ACS). We hypothesized that coronary CTA can guide early management and safely discharge patients by introducing a dedicated patient management protocol. SUBJECTS AND METHODS: We conducted a prospective cohort study in three EDs of a large health care system (> 1300 beds). Five hundred twenty-nine patients (mean age, 52.1 years; 56% women) with chest pain, negative cardiac enzyme results, normal or nondiagnostic ECG findings, and a thrombolysis in myocardial infarction (TIMI) risk score of 2 or less were admitted and underwent CTA. A new dedicated chest pain triage protocol (levels 1-5) was implemented. On the basis of CTA findings, patients were stratified into one of the following four groups: 0, low (negative CTA findings); 1, mild (1-49% stenosis); 2, moderate (50-69% stenosis); or 3, severe (≥ 70% stenosis) risk of ACS. Outcome measures included major adverse cardiac events (MACEs) during the first 30 days after CTA, downstream testing results, and length of stay (LOS). LOS was compared before and after implementation of our chest pain triage protocol. RESULTS: Three hundred seventeen patients (59.9%) with negative CTA findings and 151 (28.5%) with mild stenosis were discharged from the ED with a very low downstream testing rate and a very low MACE rate (negative predictive value = 99.8%). Twenty-five patients (4.7%) had moderate stenosis (n = 17 undergoing further testing). Thirty-six patients (6.8%) had stenosis of 70% or greater by CTA (n = 34 positive by invasive angiography or SPECT-myocardial perfusion imaging). The sensitivity of CTA was 94%. The rate of MACEs in patients with stenosis of 70% or greater (8.3%) was significantly higher (p < 0.001) than in patients with negative CTA findings (0%) or those with mild stenosis (0.2%). A 51% decrease in LOS-from 28.8 to 14.0 hours--was noted after implementation of the dedicated chest pain protocol (p < 0.001). CONCLUSION: Chest pain patients with negative or mild nonobstructive CTA findings can be safely discharged from the ED without further testing. Implementation of a dedicated chest pain triage protocol is critical for the success of a coronary CTA program.

Cardiac CT in the emergency department: convincing evidence, but cautious implementation.

In clinical practice, assessment of chest pain patients presenting to the emergency department is difficult and the work-up can be lengthy and costly. There is growing evidence supporting the use of coronary computed tomography angiography (CTA) in early assessment of patients presenting with acute chest pain to the emergency department. CTA appears to be a faster and more accurate way to diagnosis or rule out coronary stenosis, leading to reduced hospital admissions, decreased time in the ED and lower costs. The focus of this article is to review the current literature of the use of Coronary CTA and "triple rule out" protocols in the emergency department setting and to provide a chest pain algorithm, showing how Coronary CTA can be implemented effectively in clinical practice. Potential pitfalls and requirements for implementation will also be discussed.

Relationship between previous training and experience and results of the certification examination in cardiovascular computed tomography.

Examinees of the first Certifying Examination in Cardiovascular Computed Tomography were surveyed regarding their training and experience in cardiac computed tomography. The results support the current training pathways within the American College of Cardiology/American Heart Association competency criteria that include either experience-based or formal training program in cardiovascular computed tomography. Increased duration in clinical practice, the number of scans clinically interpreted in practice, and level 3 competency were associated with higher passing rates.

Multicenter trial of high-speed versus conventional single-photon emission computed tomography imaging: quantitative results of myocardial perfusion and left ventricular function.

OBJECTIVES: This prospective, multicenter trial compared quantitative results of myocardial perfusion imaging and function using a high-speed single-photon emission computed tomography (SPECT) system with those obtained with conventional SPECT. BACKGROUND: A novel SPECT camera was shown in a pilot study to detect a similar amount of myocardial perfusion abnormality compared with conventional SPECT in one-seventh of the acquisition time. METHODS: A total of 238 patients underwent myocardial perfusion imaging with conventional and high-speed SPECT at 4 U.S. centers. An additional 63 patients with a low pre-test likelihood of coronary artery disease underwent myocardial perfusion imaging with both technologies to develop method- and sex-specific normal limits. Rest/stress acquisition times were, respectively, 20/15 min and 4/2 min for conventional and high-speed SPECT. Stress and rest quantitative total perfusion deficit, post-stress left ventricular end-diastolic volume, and ejection fraction were derived for the 238 patients by the 2 methods. RESULTS: High-speed stress and rest total perfusion deficit correlated linearly with conventional SPECT total perfusion deficit (r = 0.95 and 0.97, respectively, p < 0.0001), with good concordance in the 3 vascular territories (kappa statistics for the left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery were 0.73, 0.73, and 0.70, respectively; >90% agreement). The percentage of ischemic myocardium by both imaging modalities was significantly larger in patients with a high coronary artery disease likelihood than in those with a low and intermediate likelihood (p < 0.001). The average amount of ischemia was slightly but significantly larger by high-speed SPECT compared with conventional SPECT in high-likelihood patients (4.6 +/- 4.6% vs. 3.9 +/- 4.0%, respectively; p < 0.05). Post-stress ejection fraction and end-diastolic volume by the 2 methods were linearly correlated (r = 0.89 and 0.97, respectively). CONCLUSIONS: The high-speed SPECT technology provides quantitative measures of myocardial perfusion and function comparable to those with conventional SPECT in one-seventh of the acquisition time.

Cardiac computed tomography in the emergency department: A patient with acute epigastric pain.

We report the application of coronary CT angiogram in urgent assessment of a patient presenting to the emergency department with acute and nonspecific cardiothoracic symptoms.

Blueprint of the certification examination in cardiovascular computed tomography.

Physician certification is critical in all areas of cardiovascular imaging to assure optimal performance and interpretation of quality studies for patient diagnosis and management. This is especially important in the field of cardiovascular computed tomography where practitioners have varied training and expertise that may not cover the full range of skills in the technical, image interpretative and clinical application of the results for patient management. The Certification Board of Cardiovascular Computed Tomography was developed to test the minimal level of competence of physicians performing cardiovascular computed tomography. In this article, the process of defining the content areas, determining candidate eligibility and the process of examination development and testing will be defined.

Acute chest pain imaging in the emergency department with cardiac computed tomography angiography.

In practice, the determination of ischemic chest pain in the emergency department (ED) population is difficult and errors are common. Cardiac computed tomography angiography has recently emerged for accurate noninvasive evaluation of coronary artery disease, and it may offer a promising new approach to improve the triage of patients presenting to the ED with acute chest pain, in particular in terms of a faster and accurate way to determine the diagnosis, which could effectively reduce hospital admissions and costs. The focus of this article is to review the current literature on the use of cardiac computed tomography angiography in the ED setting by providing pooled sensitivity, specificity, and positive and negative predictive values of the published literature to date. Moreover, different protocols for detection of patients with cardiac and other, noncardiac causes of chest pain (triple rule-out protocol) are discussed.