OBJECTIVES: To determine the feasibility of using whole body cardiovascular MRI (WB-CVMR) to compare South Asians (SA) - a population known to have a higher risk of cardiovascular disease (CVD) but paradoxically lower prevalence of peripheral arterial disease (PAD) - and Western Europeans (WE).
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% as assessed by the ATPIII risk score. WB-CVMR was performed, comprising a whole body angiogram (WBA) and cardiac MR (CMR), on a 3T MRI scanner following dual phase injection of gadolinium based contrast agent. A standardized 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/m(2), p=0.008), end diastolic volume (63.9±10.4 vs 75.2±11.4ml/m(2), p=0.001), end systolic volume (20.5±6.1 vs 24.6±6.8ml/m(2), p=0.03) and stroke volume (43.4±6.6 vs 50.6±7.9ml/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.
CONCLUSIONS: Whole body cardiovascular MRI (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.