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.