Left Ventricular Pressure Strain Loops for Evaluation of Myocardial Work in Type 2 Diabetic Patients with Hypertension

Abstract

Background: Type 2 diabetes mellitus (T2DM) and hypertension (HT) are the two most common underlying diseases worldwide, and they often coexist. The long-term existence of both may lead to left ventricular dysfunction. Therefore, evaluating the cardiac function of T2DM patients with HT is vital to guide treatment and improve prognosis. Left ventricular pressure strain loops (LVPSL) combine left ventricular strain and afterload, which can quantify left ventricular energy expenditure and detect left ventricular subclinical systolic dysfunction. Many studies have focused on myocardial work (MW) in uncomplicated T2DM patients or simple HT patients, but a few have focused on T2DM patients with HT.

Objective: The study aimed to evaluate the MW changes in T2DM patients with HT using LVPSL and to find independent related factors of MW parameters.

Methods: 40 T2DM patients, 35 HT patients, 40 T2DM patients with HT (T2DM+HT group), and 35 controls were enrolled. The differences between clinical data, conventional ultrasound parameters, and MW parameters were analyzed among the four groups.

Results: The global longitudinal strain (GLS) of the T2DM group, HT group, and T2DM+HT group was lower than the control group (P<0.05). The global work index (GWI) and global constructive work (GCW) in the T2DM group were lower than other groups (P<0.05). The GWI of the HT group was higher than other groups (P<0.05), while GCW was only higher than the T2DM group and T2DM+HT group (P<0.05). The GWI and GCW of the T2DM+HT group were higher than the T2DM group and were lower than the HT group(P<0.05), while there was no significant difference with the control group. HT group and T2DM+HT group had higher global work waste (GWW) (P<0.05). The global work efficiency (GWE) of the T2DM+HT group was lower than other groups (P<0.05). Systolic blood pressure (SBP) and glycosylated hemoglobin (HbA1c) were independent factors of each MW parameter.

Conclusion: LVPSL can recognize left ventricular subclinical systolic dysfunction early in patients with T2DM and HT. Compared to simple T2DM or HT, the combination of T2DM and HT had greater damage to left ventricular systolic function. SBP and HbA1c are two factors that have a considerable impact on MW parameters. The impact of afterload on MW parameters should be paid more attention to.

Keywords: Hypertension; Left ventricular pressure strain loops; Myocardial work; Type 2 diabetes mellitus; Ultrasound.