Whole-body cardiovascular MRI for the comparison of atherosclerotic burden and cardiac remodelling in healthy South Asian and European adults

Abstract

Objective: To determine the feasibility of using whole-body cardiovascular MRI (WB-CVMR) to compare South Asians (SAs)-a population known to have a higher risk of cardiovascular disease (CVD) but paradoxically lower prevalence of peripheral arterial disease-and Western Europeans (WEs).

Methods: 19 SAs and 38 age-, gender- and body mass index-matched WEs were recruited. All were aged 40 years and over, free from CVD and with a 10-year risk of CVD <20% as assessed by the adult treatment panel (ATP) III risk score. WB-CVMR was performed, comprising a whole-body angiogram (WBA) and cardiac MR (CMR), on a 3-T MRI scanner (Magnetom(®) Trio; Siemens, Erlangen, Germany) following dual-phase injection of gadolinium-based contrast agent. A standardized atheroma score (SAS) was calculated from the WBA while indexed left ventricular mass and volumes were calculated from the CMR.

Results: SAs exhibited a significantly lower iliofemoral atheroma burden (regional SAS 0.0 ± 0.0 vs 1.9 ± 6.9, p = 0.048) and a trend towards lower overall atheroma burden (whole-body SAS 0.7 ± 0.8 vs 1.8 ± 2.3, p = 0.1). They had significantly lower indexed left ventricular mass (46.9 ± 11.8 vs 56.9 ± 13.4 ml m(-2), p = 0.008), end diastolic volume (63.9 ± 10.4 vs 75.2 ± 11.4 ml m(-2), p=0.001), end systolic volume (20.5 ± 6.1 vs 24.6 ± 6.8 ml m(-2), p = 0.03) and stroke volume (43.4 ± 6.6 vs 50.6 ± 7.9 ml m(-2), p = 0.001), but with no significant difference in ejection fraction, mass-volume ratio or global functioning index. These differences persisted after accounting for CVD risk factors.

Conclusion: WB-CVMR can quantify cardiac and atheroma burden and can detect differences in these metrics between ethnic groups that, if validated, may suggest that the paradoxical high risk of CVD compared with PVD risk may be due to an adverse cardiac haemodynamic status incurred by the smaller heart rather than atherosclerosis.

Advances in knowledge: WB-CVMR can be used to stratify and compare disease between ethnicities.

Figure 1.

Four-chamber balanced steady state free precession image of the heart demonstrating the measurement of epicardial adipose tissue (blue) and paracardial adipose tissue (red) areas. SA, South Asian; WE, Western European. For colour image see online.

Figure 2.

Scatter plot comparing whole-body standardized atheroma score (SAS) between the South Asian (SA) and Western European (WE) cohorts.