Abstract 027: Correlates of Cardiac Structure and Function from the First Population-based Study of Echocardiography in the African Caribbean Diaspora: a preliminary report of the Tobago Heart Study

Abstract

Abnormal cardiac structure and function are associated with increased risk of heart failure and cardiovascular (CV) events. Persons with African ancestry are at high risk for hypertensive-related cardiac abnormalities; yet, there have been no population-based echocardiographic studies in African Caribbeans. Therefore, we aimed to perform echocardiography in men and women aged 50-80 years from Tobago (the Tobago Heart Study: THS). Between 2021-2024, 623 participants (81% female, mean age 60.7 years) underwent clinical examination including brachial-ankle pulse-wave velocity (PWV) and ankle brachial index (ABI, peripheral artery disease, PAD= ABI<0.9), and transthoracic echocardiography. Images were analyzed by a core lab to include left ventricular (LV) ejection fraction (EF), LV mass index (LVMI), diastolic dysfunction, and LV geometry (normal, concentric remodeling, or left ventricular hypertrophy [LVH]). Multivariable linear or logistic regressions were used. Risk factors were common in the THS, with 50% obesity and 78% hypertension yet only 12% BP control. Mean PWV was 1609 cm/s and 4.4% had PAD. Abnormal LV geometry was present in the majority (80%), most being concentric remodeling (68%). LVH was seen in 12% overall and was more prevalent in men than women (29% vs 9%, P<0.01). Mean EF was 64% with EF<50% in 1.4%. Diastolic dysfunction prevalence was 13.6%. In addition to age and sex, CV risk factors associated with echocardiographic indices in multivariable models included SBP, DBP and antihypertensive medication use. BMI, diabetes, statin use, smoking and sedentary behavior were not independent predictors of any echocardiography measure. Though greater alcohol intake (>4/week) was independently associated with greater odds of LVH (OR (95%CI): 4.1 [1.6-10.3]). After adjusting for CV risk factors, PWV was associated with greater odds of concentric remodeling (P=0.03; Table). Also, lower ABI was associated with lower LVEF (P=0.02, Table) and PAD presence was associated with greater odds of EF<50% (OR: 6.8; 95% CI: 1.3-37.6, not shown). The THS presents the first population-based assessment of cardiac structure and function in the African Caribbean diaspora. Cardiac structural remodeling is highly prevalent in the THS and is associated with arterial stiffness and PAD. Thus, these results further highlight the need for blood pressure control in this high-risk population.