Preoperative endothelial function and long-term cardiovascular events in patients undergoing cardiovascular surgery

New Noninvasive Methods to Evaluate Microvascular Structure and Function

The structural and functional alterations of microvessels are detected because of physiological aging and in several cardiometabolic diseases, including hypertension, diabetes, and obesity. The small resistance arteries of these patients show an increase in the media or total wall thickness to internal lumen diameter ratio (MLR or WLR), often accompanied by endothelial dysfunction. For decades, micromyography has been considered as a gold standard method for evaluating microvascular structural alterations through the measurement of MLR or WLR of subcutaneous small vessels dissected from tissue biopsies. Micromyography is the most common and reliable method for assessing microcirculatory endothelial function ex vivo, while strain-gauge venous plethysmography is considered the reference technique for in vivo studies. Recently, several noninvasive methods have been proposed to extend the microvasculature evaluation to a broader range of patients and clinical settings. Scanning laser Doppler flowmetry and adaptive optics are increasingly used to estimate the WLR of retinal arterioles. Microvascular endothelial function may be evaluated in the retina by flicker light stimulus, in the finger by tonometric approaches, or in the cutaneous or sublingual tissues by laser Doppler flowmetry or intravital microscopy. The main limitation of these techniques is the lack of robust evidence on their prognostic value, which currently reduces their widespread use in daily clinical practice. Ongoing and future studies will overcome this issue, hopefully moving the noninvasive assessment of the microvascular function and structure from bench to bedside.

Vasodilatation Measurement Using Finger Vascular Images by Near-Infrared Light and Comparison with RH-PAT

Examination of vascular endothelial function can help infer atherosclerosis progression. This study investigated whether vascular visualization by near-infrared (NIR) light can detect vasodilatation after cuff pressure release of the upper arm and what the correlation is between the brightness decrease ratio (R1) corresponding to vasodilation and the reactive hyperemia index (RHI). We obtained finger vascular images of 53 male subjects by photographing NIR light (wavelength 850 nm) transmitted through the middle phalanx of the middle finger with a charge-coupled device camera. The upper arm was compressed for 10 min using a cuff (200 mmHg), and vascular images before and after cuff compression release were obtained. We analyzed the finger vascular images by NIR light and digital pulse volume using endothelial peripheral arterial tonometry (Endo-PAT). We also calculated the average brightness of each vascular image. Using only the data of the ischemic finger, R1 was defined using the average brightness just before cuff release and the minimum average brightness after cuff release. The brightness of vascular images of the ischemic finger decreased after cuff release probably because of vasodilation. We found significant correlation between R1 and the RHI (r = 0.52; P < 0.001). R1 in the lowest RHI quartile was significantly smaller compared to the highest and second-highest RHI quartiles (P < 0.05). Vascular visualization by NIR light can detect vasodilation after cuff release. This is significantly correlated with the RHI on Endo-PAT.

Impact of Serum Uric Acid Level on Systemic Endothelial Dysfunction in Patients with a Broad Spectrum of Ischemic Heart Disease

Previous studies indicated that serum uric acid (SUA) level is a marker of endothelial function in subsets of ischemic heart disease (IHD). In the present study, we aimed to evaluate the relation between the SUA level and endothelial function in patients with a broad spectrum of IHD, including obstructive coronary artery disease (CAD) and ischemia with no obstructive CAD (INOCA). Three prospective studies and one retrospective study were pooled, in which the SUA level was measured, and systemic endothelial function was assessed using the reactive hyperemia index (RHI). The primary endpoint of the present study was a correlation of the SUA level with RHI. A total of 181 patients with a broad spectrum of IHD were included, among whom, 46 (25%) had acute coronary syndrome presentation and 15 (8%) had INOCA. Overall, the SUA level was negatively correlated with the RHI (r = −0.22, p = 0.003). Multivariable analysis identified the SUA level and INOCA as significant factors associated with RHI values. In conclusion, in patients with a broad spectrum of IHD, including obstructive epicardial CAD (chronic and acute coronary syndromes) and INOCA, the SUA level was significantly and negatively correlated with systemic endothelial function assessed with the RHI. INOCA, rather than obstructive CAD, was more associated with endothelial dysfunction.

Perioperative Neurological Evaluation and Management to Lower the Risk of Acute Stroke in Patients Undergoing Noncardiac, Nonneurological Surgery: A Scientific Statement From the American Heart Association/American Stroke Association

Perioperative stroke is a potentially devastating complication in patients undergoing noncardiac, nonneurological surgery. This scientific statement summarizes established risk factors for perioperative stroke, preoperative and intraoperative strategies to mitigate the risk of stroke, suggestions for postoperative assessments, and treatment approaches for minimizing permanent neurological dysfunction in patients who experience a perioperative stroke. The first section focuses on preoperative optimization, including the role of preoperative carotid revascularization in patients with high-grade carotid stenosis and delaying surgery in patients with recent strokes. The second section reviews intraoperative strategies to reduce the risk of stroke, focusing on blood pressure control, perioperative goal-directed therapy, blood transfusion, and anesthetic technique. Finally, this statement presents strategies for the evaluation and treatment of patients with suspected postoperative strokes and, in particular, highlights the value of rapid recognition of strokes and the early use of intravenous thrombolysis and mechanical embolectomy in appropriate patients.