Diastolic Dysfunction in Diabetic Patients Assessed With Doppler Echocardiography: Relationship With Coronary Atherosclerotic Burden and Microcirculatory Impairment

Abstract

Diabetes mellitus (DM) is associated with the development of both impaired left ventricular diastolic function (LVDF) and pathological changes in the coronary macro- and microcirculation. The aim of this study was to investigate the relationship between these manifestations of diabetic heart disease. The severity of atherosclerosis in the left anterior descending coronary artery (LAD) was quantified using intravascular ultrasound (IVUS) in 13 patients with DM and ischemic heart disease. The coronary flow velocity reserve (CFVR), instantaneous hyperemic diastolic velocity pressure slope index (IHDVPS) and zero-flow pressure were derived from digital intracoronary pressure and flow velocity measurements. The relationships between indices of LVDF (i.e. E/A and E/e' ratios) and intracoronary measurements were assessed. The left ventricular ejection fraction was 66+/-7%, and the LVDF indices were: E/A=0.92+/-0.38 and E/e'=9.90+/-2.80. There was a direct proportional relationship (r=0.62; P=.02) between E/e' and coronary resistance (1.93+/-0.74 mmHg/s) and an inverse proportional relationship (r=-0.64; P=.02) between E/e' and IHDVPS (1.56+/-0.50 cm/s/mmHg). However, no significant relationship was found between either LVDF index and CFVR (2.43+/-0.56) or coronary zero-flow pressure (40.41+/-10.66 mmHg). The volume of atheroma in the proximal 20 mm of the LAD (179.34+/-57.48 .l, with an average plaque area of 8.39+/-2.20 mm2) was not related to either LVDF index. In patients with DM and coronary atherosclerosis, there appeared to be a relationship between LVDF impairment (assessed by the E/e' ratio) and structural changes in the microcirculation.