Reduced peak pressure gradient in patients with aortic stenosis and type 2 diabetes.

Abstract

Diabetes impairs energy metabolism throughout the body, including the heart. However, the clinical effect of diabetes on left ventricular (LV) contractility remains unclear. To address this knowledge gap, we investigated the effect of diabetes on patients with aortic stenosis (AS), a model of increased LV afterload. We analyzed data from 276 consecutive patients with AS who underwent transthoracic surgery, echocardiography, cardiac catheterization, and fasting blood sampling. The peak aortic velocity was determined using continuous-wave Doppler echocardiography, and the peak pressure gradient (peak-PG) was calculated using the simplified Bernoulli equation. The aortic valve area (AVA) was determined using planimetry Risk factors, including age, glycated hemoglobin (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR) level, sex, hemoglobin level, hypertension, and dyslipidemia, that influenced the peak PG were examined using regression analysis. Structural equation modeling (SEM) was performed to identify the direct and indirect effects of these variables on the peak PG. SEM revealed a significant association between the AVA and peak-PG (p<0.001). The peak- PG significantly decreased with higher HbA1c (p<0.001) and increased with age (p=0.004). Other factors, including HOMA-IR, sex, hypertension, and dyslipidemia, had no significant effects. AVA decreased significantly with age (p=0.007) and increased with sex (male) (p=0.034). Diabetes reduces LV contractility, as evidenced in patients with AS. Insufficient glucose metabolism may contribute to LV dysfunction. Clinically, the severity of AS in patients with diabetes should not be underestimated based on the PG alone.