Article Text
Abstract
Introduction International hypertension guidelines advise screening for hypertensive heart disease (HHD) to aid risk stratification. Cardiac magnetic resonance (CMR) is the current non-invasive gold-standard for assessing ventricular structure/function. We aimed to determine the additive value of CMR in hypertensives over echocardiography.
Methods 85 subjects (60% men, office systolic BP: 165 ± 28mmHg, office diastolic BP: 94 ± 14mmHg) from our tertiary hypertension clinic with preceding echo underwent 1.5T CMR. Left ventricular mass and volumes were estimated from short-axis steady-state free precession cines. LVH was defined on the basis of echo and CMR normal reference ranges. The presence and pattern of myocardial late gadolinium enhancement (LGE) was documented.
Results Overall, there was no difference in prevalence of LVH by echo compared to CMR (68% vs 66%, P = 0.746). However, there was a discrepancy between echo and CMR in 28%. Relative to CMR gold-standard, echo over-diagnosed LVH in 15% and missed LVH in 13%. The diagnostic performance of echo at detecting LVH was as follows: specificity 55%, sensitivity 80%, positive predictive value 78%, negative predictive value 59% and overall accuracy 72%. Ischaemic LGE was present in 7% of subjects and non-ischaemic LGE was present in 9%.
Conclusion Echocardiography over-diagnosed and under-diagnosed LVH in an important minority of patients. LGE tissue characterisation is unique to CMR and identified ischaemic and non-ischaemic myocardial fibrosis is an important minority of hypertensives. Our findings support an extended role of CMR in hypertension where documenting in the presence/absence of HHD may have clinical management implications.