New science presented at AHA 2024 and simultaneously published in JACC: Advances provide insights on emerging topics such as the use of artificial intelligence (AI)-enabled left atrial (LA) volumetry in coronary artery calcium (CAC) scans to predict atrial fibrillation (AFib); the role of treating hospitals in facilitating cardiac rehabilitation (CR); the association between adjunctive systemic sirolimus therapy (SST) and the frequency of pediatric pulmonary vein stenosis (PVS) interventions; the effect of pregnancy on all-cause mortality in patients with hypertrophic cardiomyopathy (HCM);  and the efficacy of SGLT2 inhibitors on patients with transthyretin amyloid cardiomyopathy (ATTR-CM). 

Highlights include:

Morteza Naghavi, MD, et al., developed an AI-enabled tool to rapidly estimate cardiac chambers volume in noncontrast CT scans for CAC-score AI-enabled cardiac volumetry (AI-CAC) and tested it against LA volume as measured by human experts using cardiac MRI, the current gold standard in predictive value. Using data from the MESA study they showed that AI-CAC automated LA volumetry could predict incident AFib and stroke over 15 years as well as LA volume measured by human experts, and both methods outperformed the CHARGE-AF score, NT-proBNP and Agatston CAC score alone for short-term prediction.

“By applying AI to new or existing CT scans care providers can flag patients with enlarged cardiac chambers and direct them for necessary follow-up,” Neghavi and colleagues write. “Robustly measuring LA volume in a CAC scan without additional radiation exposure to patients or using any contrast-enhanced agent would be of significant clinical value.”

Quinn R. Pack, MD, MSc, FACC, et al., examined the progress individual hospitals are contributing toward the goal of the Million Hearts Cardiac Rehabilitation Collaborative, a national initiative aiming to enroll 70% of eligible patients into CR programs. Results found that while a minority of hospitals performed cardiac surgery, they cared for the majority of eligible patients, and Pack and colleagues identify these as “a logical place to focus improvement efforts.”  Other factors associated with higher hospital performance was Midwest location, higher number of hospital beds, directly affiliated CR program and <1 mile distance between hospital and closest CR facility. Furthermore, <1% of U.S. hospitals had achieved the goal CR risk-standardized enrollment rate of >70%.

Alyssa B. Kalustian, MD, et al., studied the association between SST and the frequency of interventions for moderate to severe PVS in a retrospective review of 45 pediatric patients with PVS treated with SST for one month or more. Results showed that median per-patient PVS intervention rate was 5.0 per year pre-SST compared to 1.7 per year on-SST. “SST was associated with reduced frequency of interventions compared with prior to therapy, both in unadjusted analysis and after controlling for clinically relevant covariates [age, PVS type, sex, prematurity and concurrent antiproliferative therapy] via multivariable regression analysis,” Kalustian and colleagues write. “Models taking into account patient demographic and disease-related factors might be able to accurately predict an individual’s benefits of therapy or anticipated disease trajectory following cessation.”

In a study of nearly 7,000 patients with HCM within the TriNetX Analytics Network database, Jasmin Abdeldayem, MD, et al., found there was no association between a history of pregnancy, compared with no history of pregnancy, and worse outcomes for the primary endpoint of all-cause mortality at 10 years follow-up, and no difference in arrhythmic events and major adverse cardiovascular events (MACE) between the two groups.

“However, given the aforementioned limitations with administrative data, interpretation of these results across more severe forms of HCM should be cautiously considered,” Abdeldayem and colleagues write. “Moreover, multidisciplinary cardio-obstetrics teams are integral to optimizing individuals’ cardiovascular health, including those with HCM.”

Lastly, in a brief report, Vikash Jaiswal, MD, et al., through propensity score matching more than 4,000 patients with ATTR-CM in the TriNetX database, found that SGLT2 inhibitors were associated with a lower risk of all-cause mortality, MACE and ischemic stroke at one month, one year and three years. Furthermore, SGLT2 inhibitors did not heighten the risk of heart failure (HF), AFib and ventricular tachycardia in that timeframe. Jaiswal and colleagues write, “Unlike many traditional HF therapies, [SGLT2 inhibitors] do not adversely affect hemodynamics in ATTR-CM, making it a potential ideal therapy for advanced disease stages where symptomatic tension is a concern.”

Clinical Topics: Cardiovascular Care Team, Heart Failure and Cardiomyopathies, Vascular Medicine

Keywords: American Heart Association, AHA Annual Scientific Sessions, AHA24, Sodium-Glucose Transporter 2 Inhibitors, Cardiac Rehabilitation, Artificial Intelligence, Stenosis, Pulmonary Vein, Cardiomyopathy, Hypertrophic