Turkish Cardiology Congresswith International Participation, Antalya, Turkey, 20 - 23 October 2016, no.107, pp.35
Background and Aim: Coronary microvascular functional and structural impairment may be the underlying
mechanism behind subclinical myocardial dysfunction in patients with diabetes mellitus (DM). The aim of
our study was to investigate the possible link between subclinical myocardial dysfunction as evaluated by
myocardial strain assessment and coronary microvascular function in diabetic patients with normal epicardial coronary arteries.
Methods: In this study, 59 diabetic and 36 non-diabetic patients, who had symptoms suggestive of ischemic
heart disease and yet the coronary angiographies did not show any epicardial coronary stenosis, were
included. In all patients, left ventricular strain was measured with 2D speckle tracking echocardiography.
Coronary flow velocities in distal left anterior descending coronary artery were assessed by transthoracic
Doppler echocardiography. Coronary flow velocity reserve (CFVR), hyperemic coronary microvascular resistance (HMR) were assessed using these Doppler recordings and simultaneously measured non-invasive
brachial blood pressure. HMR was calculated by mean systemic pressure divided by average peak velocity
Results: When compared to non-diabetic group, the left ventricular global strain was found to be significantly lower in diabetic patients (diabetic: -17.84+3.18, non-diabetic: -19.75+2.14, p=0.002). When diabetic
patients were divided into two groups according to proposed cut off value of -20% for global longitudinal strain, diabetic patients with impaired strain (<-20%) had significantly lower CFVR (2.01+0.46 versus
2.28+0.53, p=0.045) and significantly higher HMR (1.98+0.42 versus 1.70+0.38, p=0.03) values as compared to
those with normal strain values (>-20%). Furthermore, CFVR (r=0.322, p=0.003) and HMR (r=-0,229, p=0.035)
were found to be significantly related to global longitudinal strain in patients with DM.
Conclusions: Coronary microvascular structural and functional features are related to the left ventricular
global strain parameters in diabetic patients with normal epicardial coronaries. Negative effect of diabetes mellitus on global strain parameters might therefore be related to coronary microvascular dysfunction
caused by diabetes.