Differences and Disparities Among Self-Referred and Physician-Referred Populations Undergoing Coronary Artery Calcium Scanning.

BACKGROUND: Coronary artery calcium computed tomography (CAC) is an important tool for identifying subclinical atherosclerosis and cardiovascular risk stratification. Despite robust evidence and inclusion in current guidelines, CAC is considered investigational by some US insurance carriers and requires out-of-pocket expenses. CAC can be obtained via self-referral (SR) or physician referral (PR). We aimed to examine differences in patient, socioeconomic, and CAC characteristics between referral groups. METHODS: We evaluated demographic, medical history, and CAC results of consecutive patients with a CAC completed at one of multiple Wisconsin sites from March 1, 2019, to June 30, 2021. We separated patients into SR and PR groups. Through census data, we analyzed socioeconomic variables at the block level including race and ethnicity, median income, average household size, and high school completion in the areas where patients resided at the time of CAC. RESULTS: The final analysis included 19 726 patients: 13 835 (70.1%) PR and 5891 (29.9%) SR. Most patients in both groups were White (95.2% versus 95.1%), with the Black/African American population representing 2.7% (SR) and 2.3% (PR). The PR group had a higher prevalence of cardiovascular risk factors. SR patients were more likely to have a score of 0 (41.2% versus 38.1%; P<0.001); PR patients had a higher prevalence of CAC >300 (16.8% versus 14.8%; P<0.001). SR patients were more likely to be women (55.1% versus 48.9%; P<0.001) and were found to live in higher income areas (19.5% versus 16.4%; P<0.001). Patients from low-income areas comprised the smallest proportion in both groups (7.5%). CONCLUSIONS: Patients who obtain out-of-pocket CAC live predominantly in medium- and high-income areas, and patients from lower income locations are less likely to obtain CAC despite having more cardiovascular disease risk factors. Consideration should be made from a policy perspective to promote health equity and improve utilization of CAC testing among underrepresented groups.

Myocardial Work in Echocardiography.

Myocardial work is an emerging tool in echocardiography that incorporates left ventricular afterload into global longitudinal strain analysis. Myocardial work correlates with myocardial oxygen consumption, and work efficiency can also be assessed. Myocardial work has been evaluated in a variety of clinical conditions to assess the added value of myocardial work compared to left ventricular ejection fraction and global longitudinal strain. This review showcases the current use of myocardial work in adult echocardiography and its possible role in cardiac pathologies.

Feasibility of exercise treadmill 13N-ammonia positron emission tomography myocardial perfusion imaging using an off-site cyclotron.

BACKGROUND: Myocardial perfusion imaging with treadmill exercise nitrogen-13 (13N)-ammonia positron emission tomography (PET) presents a logistical challenge. We investigated the feasibility of exercise treadmill (GXT) 13N-ammonia PET MPI using an off-site cyclotron for production of 13N-ammonia. METHODS: Thirty-three patients underwent GXT 13N-ammonia PET MPI over 23 months. 13N-ammonia doses were prepared at an off-site cyclotron. Patients underwent 13N-ammonia resting and 13N-ammonia GXT emission and transmission scans at our facility. Image quality, perfusion data, and clinical variables were evaluated. RESULTS: We analyzed 33 patients (7/26 female/male). Mean age was 63 ± 12 years and mean BMI was 33.7 ± 6.9. GXT PET was feasible in all patients. Image quality was good in 29 patients, adequate in 3, and severely compromised in 1 patient. Summed stress score was 4.5 ± 5.7. Resting and GXT left ventricular ejection fractions were 63.7 ± 10.9% and 66.3 ± 13.1%. TID ratio was 1.0 ± 0.1. CONCLUSIONS: Treadmill exercise 13N-ammonia PET is feasible in a large medical center without access to an on-site cyclotron. This technique requires close coordination with an off-site cyclotron but expands the role of PET to patients for whom exercise is more appropriate than pharmacologic stress imaging.

Left Ventricular Mechanics Differ in Subtypes of Aortic Stenosis Following Transcatheter Aortic Valve Replacement.

BACKGROUND: Left ventricular (LV) mechanics are impaired in patients with severe aortic stenosis (AS). We hypothesized that there would be differences in myocardial mechanics, measured by global longitudinal strain (GLS) recovery in patients with four subtypes of severe AS after transcatheter aortic valve replacement (TAVR), stratified based upon flow and gradient. METHODS: We retrospectively evaluated 204 patients with severe AS who underwent TAVR and were followed post-TAVR at our institution for clinical outcomes. Speckle-tracking transthoracic echocardiography was performed pre- and post-TAVR. Patients were classified as: (1) normal-flow and high-gradient, (2) normal-flow and high-gradient with reduced LV ejection fraction (LVEF), (3) classical low-flow and low-gradient, or (4) paradoxical low-flow and low-gradient. RESULTS: Both GLS (-13.9 ± 4.3 to -14.8 ± 4.3, P < 0.0001) and LVEF (55 ± 15 to 57 ± 14%, P = 0.0001) improved immediately post-TAVR. Patients with low-flow AS had similar improvements in LVEF (+2.6 ± 9%) and aortic valve mean gradient (-23.95 ± 8.34 mmHg) as patients with normal-flow AS. GLS was significantly improved in patients with normal-flow (-0.93 ± 3.10, P = 0.0004) compared to low-flow AS. Across all types of AS, improvement in GLS was associated with a survival benefit, with GLS recovery in alive patients (mean GLS improvement of -1.07 ± 3.10, P < 0.0001). CONCLUSIONS: LV mechanics are abnormal in all patients with subtypes of severe AS and improve immediately post-TAVR. Recovery of GLS was associated with a survival benefit. Patients with both types of low-flow AS showed significantly improved, but still impaired, GLS post-TAVR, suggesting underlying myopathy that does not correct post-TAVR.

Transthoracic echocardiography is adequate for intraprocedural guidance of transcatheter aortic valve implantation.

BACKGROUND: While transcatheter aortic valve implantation (TAVI) has traditionally been supported intraprocedurally by transoesophageal echocardiography (TOE), transthoracic echocardiography (TTE) is increasingly being used. We evaluated echocardiographic imaging characteristics and clinical outcomes in patients who underwent TTE during TAVI (TTE-TAVI). METHODS AND RESULTS: A select team of dedicated sonographers and interventional echocardiographers performed TTE-TAVI in 278 patients, all of whom underwent TAVI through transfemoral access. We implanted the Medtronic EVOLUT R valve in 258 patients (92.8%). TTE images were acquired immediately pre-procedure by a dedicated sonographer in the cardiac catheterization laboratory with the patient in the supine position. TTE was then performed post deployment of TAVI. In the procedure, TTE image quality was fair or better in 249 (89.6%) cases. Color-flow Doppler was adequate or better in 275 (98.9%) cases. In 2 cases, paravalvular regurgitation (PVL) could not be assessed confidently by echocardiography due to poor image quality; in those cases, PVL was assessed by fluoroscopy, aortic root injection and invasive hemodynamics. Both TTE and invasive hemodynamics were used in the assessment of need for post-deployment stent ballooning (n = 23, 8.3%). TTE adequately recognized new pericardial effusion in 3 cases. No case required TOE conversion for image quality. There was only 1 case of intraprocedural TTE failing to recognize moderate PVL, without clinical implication. In 99% of patients, TTE-TAVI adequately assessed PVL compared with 24-h and 1-month follow-up TTE. CONCLUSIONS: With the current generation of TAVI, TTE-TAVI is adequate intraprocedurally when performed by specialized sonographers and dedicated cardiologists in a highly experienced TAVI center.

20-HETE increases superoxide production and activates NAPDH oxidase in pulmonary artery endothelial cells.

Reactive oxygen species (ROS) signal vital physiological processes including cell growth, angiogenesis, contraction, and relaxation of vascular smooth muscle. Because cytochrome P-450 family 4 (CYP4)/20-hydroxyeicosatetraenoic acid (20-HETE) has been reported to enhance angiogenesis, pulmonary vascular tone, and endothelial nitric oxide synthase function, we explored the potential of this system to stimulate bovine pulmonary artery endothelial cell (BPAEC) ROS production. Our data are the first to demonstrate that 20-HETE increases ROS in BPAECs in a time- and concentration-dependent manner as detected by enhanced fluorescence of oxidation products of dihydroethidium (DHE) and dichlorofluorescein diacetate. An analog of 20-HETE elicits no increase in ROS and blocks 20-HETE-evoked increments in DHE fluorescence, supporting its function as an antagonist. Endothelial cells derived from bovine aortas exhibit enhanced ROS production to 20-HETE quantitatively similar to that of BPAECs. 20-HETE-induced ROS production in BPAECs is blunted by pretreatment with polyethylene-glycolated SOD, apocynin, inhibition of Rac1, and a peptide-based inhibitor of NADPH oxidase subunit p47(phox) association with gp91. These data support 20-HETE-stimulated, NADPH oxidase-derived, and Rac1/2-dependent ROS production in BPAECs. 20-HETE promotes translocation of p47(phox) and tyrosine phosphorylation of p47(phox) in a time-dependent manner as well as increased activated Rac1/2, providing at least three mechanisms through which 20-HETE activates NADPH oxidase. These observations suggest that 20-HETE stimulates ROS production in BPAECs at least in part through activation of NADPH oxidase within minutes of application of the lipid.