Left-ventricular structure in the Southall And Brent REvisited (SABRE) study: explaining ethnic differences

Area of Science:

• Cardiology
• Population Health
• Medical Imaging

Background:

• Cardiometabolic risk is notably higher in South Asian and African Caribbean populations compared to Europeans.
• Existing echocardiography methods for assessing left-ventricular mass and remodeling rely on geometric assumptions, potentially leading to inaccuracies.
• Ethnic variations in left-ventricular structure and their link to cardiometabolic risk remain unclear.

Purpose of the Study:

• To compare left-ventricular structure across European, South Asian, and African Caribbean ethnic groups.
• To investigate the influence of ethnic differences on left-ventricular mass, remodeling index, and relative wall thickness.
• To determine if advanced 3-dimensional echocardiography provides a more accurate assessment than conventional methods.

Main Methods:

• A triethnic population-based cohort of 895 individuals (aged 55-85 years) was studied.
• Conventional and 3-dimensional echocardiography were used to measure left-ventricular mass, remodeling index, and relative wall thickness.
• Multivariate analyses adjusted for anthropometry, blood pressure, and fasting blood parameters.

Main Results:

• Three-dimensional left-ventricular mass index was significantly lower in South Asians (28.1 ± 0.4 g/m(2.7)) compared to Europeans (29.8 ± 0.3 g/m(2.7)).
• Left-ventricular mass index was not significantly different between Europeans and African Caribbeans (29.9 ± 0.5 g/m(2.7)) using 3D methods.
• Conventional echocardiography showed higher left-ventricular mass in African Caribbeans than Europeans, highlighting potential inaccuracies of older methods. Left-ventricle remodeling index was highest in African Caribbeans and lowest in South Asians.

Conclusions:

• Left-ventricular mass is lower in South Asians and comparable in African Caribbeans relative to Europeans, independent of cardiometabolic risk factors.
• Differences in left-ventricular remodeling, rather than hypertrophy, may underlie the elevated heart failure risk observed in individuals of African Caribbean descent.
• 3-dimensional echocardiography offers a more precise assessment of ethnic variations in left-ventricular structure compared to conventional techniques.