Can combined assessment of baroreflex sensitivity and iodine-123 metaiodobenzylguanidine imaging be used for risk stratification of patients with type 2 diabetes mellitus?

he sympathetic nervous system of the heart is critically involved in the maintenance of cardiovascular homoeostasis by regulating cardiac contractility, conduction, heart frequency and peripheral vasoconstriction.1 It has been shown that a dysfunctional cardiac sympathetic nervous system exerts detrimental effects on the structural and functional integrity of the myocardium, leading to a marked increase in the morbidity and mortality of patients with cardiac disease.2 Myocardial imaging with 123I-metaiodobenzylguanidine (MIBG), an analog of norepinephrine, is useful for detecting abnormalities of the sympathetic nervous system of the heart in patients with heart failure.3,4 Because the washout rate (WR) evaluated by 123I-MIBG scintigraphy is known to reflect the degree of cardiac sympathetic nerve activity,4 a high WR has useful prognostic value in patients with cardiovascular disease.5,6