Impact of flow-mediated dilatation and coronary calcification in providing complementary information on the severity of coronary artery disease

The effects of water-based circuit exercise training on vascular function in people with coronary heart disease

Impaired endothelial function in people with coronary heart disease (CHD) is associated with increased mortality. Water immersion can increase peripheral artery shear stress which may provide an additional stimulus to the endothelium during exercise. This study compared the effects of water-based circuit exercise training (WEX) and gym-based circuit exercise training (GEX) on vascular function in people with stable CHD. Participants were randomized to 12 wk of WEX (n = 20), GEX (n = 20), or a control group (usual activities; n = 12). Endothelium-dependent flow-mediated dilation (FMD) and glyceryl trinitrate-mediated dilation (GTN) of the brachial artery were assessed pre- and postintervention. FMD increased following WEX [4.0% (3.0%-5.1%) to 5.3% (4.1%-6.5%); P = 0.016], but was unchanged following GEX [4.9% (3.8%-5.9%) to 5.0% (3.8%-6.1%); P = 0.822]. There were no between-group differences in the change in FMD and no significant changes in GTN-mediated dilation percentage. Triglycerides decreased following GEX [1.2 mmol·L-1 (1.0-1.4 mmol·L-1) to 1.0 mmol·L-1 (0.8-1.3 mmol·L-1); P = 0.022], but there were no further differences in lipid profiles. WEX improved endothelial function of the brachial artery in people with stable CHD, suggesting that WEX is an effective alternative to gym-based exercise in people living with CHD, which may specifically address vascular health.NEW & NOTEWORTHY This study found that 12 wk of water-based circuit exercise training was well tolerated and improved vascular endothelial function in people with stable coronary heart disease. However, there was no effect on endothelium-independent function. Water-based exercise appears to be an effective alternative to gym-based exercise for people with coronary heart disease, which has specific benefits to vascular health and function.

Impact of glycemic control on the association of endothelial dysfunction and coronary artery disease in patients with type 2 diabetes mellitus

Background

We investigated whether glycemic control affects the relation between endothelial dysfunction and coronary artery disease in patients with type 2 diabetes mellitus (T2DM).

Methods

In 102 type 2 diabetic patients with stable angina, endothelial function was evaluated using brachial artery flow-mediated dilation (FMD) with high-resolution ultrasound, and significant stenosis of major epicardial coronary arteries (≥ 50% diameter narrowing) and degree of coronary atherosclerosis (Gensini score and SYNTAX score) were determined. The status of glycemic control was assessed by blood concentration of glycated hemoglobin (HbA1c).

Results

The prevalence of significant coronary artery stenosis (67.9% vs. 37.0%, P = 0.002) and degree of coronary atherosclerosis (Gensini score: 48.99 ± 48.88 vs. 15.07 ± 21.03, P < 0.001; SYNTAX score: 15.88 ± 16.36 vs. 7.28 ± 10.54, P = 0.003) were higher and FMD was lower (6.03 ± 2.08% vs. 6.94 ± 2.20%, P = 0.036) in diabetic patients with poor glycemic control (HbA1c ≥ 7.0%; n = 56) compared to those with good glycemic control (HbA1c < 7.0%; n = 46). Multivariate regression analysis revealed that tertile of FMD was an independent determinant of presence of significant coronary artery stenosis (OR = 0.227 95% CI 0.056–0.915, P = 0.037), Gensini score (β =  − 0.470, P < 0.001) and SYNTAX score (β =  − 0.349, P = 0.004) in diabetic patients with poor glycemic control but not for those with good glycemic control (P > 0.05).

Conclusion

Poor glycemic control negatively influences the association of endothelial dysfunction and coronary artery disease in T2DM patients.

Nox2+ myeloid cells drive vascular inflammation and endothelial dysfunction in heart failure after myocardial infarction via angiotensin II receptor type 1

AIMS

Heart failure (HF) ensuing myocardial infarction (MI) is characterized by the initiation of a systemic inflammatory response. We aimed to elucidate the impact of myelomonocytic cells and their activation by angiotensin II on vascular endothelial function in a mouse model of HF after MI.

METHODS AND RESULTS

HF was induced in male C57BL/6J mice by permanent ligation of the left anterior descending coronary artery. Compared to sham, HF mice had significantly impaired endothelial function accompanied by enhanced mobilization of Sca-1+c-Kit+ haematopoietic stem cells and Sca-1-c-Kit+ common myeloid and granulocyte-macrophage progenitors in the bone marrow as well as increased vascular infiltration of CD11b+Ly6G-Ly6Chigh monocytes and accumulation of CD11b+ F4/80+ macrophages, assessed by flow cytometry. Using mice with Cre-inducible expression of diphtheria toxin receptor in myeloid cells, we selectively depleted lysozyme M+ myelomonocytic cells for 10 days starting 28 days after MI. While the cardiac phenotype remained unaltered until 38 days post-MI, myeloid cell depletion attenuated vascular accumulation of Nox2+CD45+ cells, endothelial dysfunction, oxidative stress, and vascular expression of adhesion molecules and angiotensin II receptor type 1 (AT1R). Pharmacological blockade of this receptor for 4 weeks did not significantly alter cardiac function, but mimicked the effects of myeloid cell depletion: telmisartan (20 mg/kg/day, fed to C57BL/6J mice) diminished bone marrow myelopoesis and myeloid reactive oxygen species production, attenuated endothelial leucocyte rolling and vascular accumulation of CD11b+Ly6G-Ly6Chigh monocytes and macrophages, resulting in improved vascular function with less abundance of Nox2+CD45+ cells.

CONCLUSION

Endothelial dysfunction in HF ensuing MI is mediated by inflammatory Nox2+ myeloid cells infiltrating the vessel wall that can be targeted by AT1R blockade.