Introduction South Asians (SAs) have a higher risk of cardiovascular disease (CVD) and stroke, but paradoxically lower prevalence of peripheral arterial disease (PAD) than Western Europeans (WEs). The aim of this study was to determine early changes in systemic atherosclerotic burden and cardiac remodelling as measured using whole body cardiovascular MRI (WB-CVMR).

Methods 19 SA and 38 age, gender and BMI matched WE were recruited. All were ≥40 years, free from CVD and with a 10-year risk of CVD <20%. WB-CVMR was performed which comprised a whole body angiogram (WBA) and cardiac magnetic resonance (CMR). These were performed on a 3T MRI scanner following dual phase injection of gadoteric acid. A standardised atherosclerotic 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 (WB 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 ± 13.4ml/m², p = 0.008), end diastolic volume (63.9 ± 10.4 vs 75.2 ± 11.4ml/m², p = 0.001), end systolic volume (20.5 ± 6.1 vs 24.6 ± 6.8ml/m², p = 0.03) and stroke volume (43.4 ± 6.6 vs 50.6 ± 7.9ml/m², p = 0.001), but with no significant difference in functional indices.

Conclusion South Asians have a lower peripheral atherosclerotic burden and smaller hearts than Western Europeans even in a healthy population. Thus 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.