Cardiac Resynchronization Therapy Outcomes in Type 2 Diabetic Patients: Role of MicroRNA Changes

Abstract

Heart failure (HF) and type 2 diabetes mellitus (T2DM) are two growing and related diseases in general population and particularly in elderly people. In selected patients affected by HF and severe dysfunction of left ventricle ejection fraction (LVEF), with left bundle brunch block, the cardiac resynchronization therapy with a defibrillator (CRT) is the treatment of choice to improve symptoms, NYHA class, and quality of life. CRT effects are related to alterations in genes and microRNAs (miRs) expression, which regulate cardiac processes involved in cardiac apoptosis, cardiac fibrosis, cardiac hypertrophy and angiogenesis, and membrane channel ionic currents. Different studies have shown a different prognosis in T2DM patients and T2DM elderly patients treated by CRT-D. We reviewed the literature data on CRT-D effect on adult and elderly patients with T2DM as compared with nondiabetic patients.

Figure 1

In this figure, the representation of CRT (cardiac resynchronization therapy) effect on T2DM (type 2 diabetes mellitus) and T2DM > 75 (type 2 diabetes mellitus older than 75 years) patients. In radioscopic image three catheters were placed in right atrial appendage (10 o'clock), right ventricular apex (5 o'clock), and coronary sinus lateral vein (3 o'clock). This is an example of biventricular pacing for cardiac resynchronization therapy. In responders there is a left ventricular reverse remodeling, a left ventricle ejection fraction (LVEF) improvement, an amelioration in New York Heart Association (NYHA) functional class, and 6 minutes walking test (6MWT) improvement. This last parameter (6MWT) is not improved in T2DM > 75.