Muscle microvascular surface area determines substrate and hormonal exchanges between plasma and muscle interstitium. GLP-1 (glucagon-like peptide-1) regulates glucose-dependent insulin secretion and ...has numerous extrapancreatic effects, including a salutary vascular action. To examine whether GLP-1 recruits skeletal and cardiac muscle microvasculature in healthy humans, 26 overnight-fasted healthy adults received a systemic infusion of GLP-1 (1.2 pmol/kg of body mass per min) for 150 min. Skeletal and cardiac muscle MBV (microvascular blood volume), MFV (microvascular flow velocity) and MBF (microvascular blood flow) were determined at baseline and after 30 and 150 min. Brachial artery diameter and mean flow velocity were measured and total blood flow was calculated before and at the end of the GLP-1 infusion. GLP-1 infusion raised plasma GLP-1 concentrations to the postprandial levels and suppressed plasma glucagon concentrations with a transient increase in plasma insulin concentrations. Skeletal and cardiac muscle MBV and MBF increased significantly at both 30 and 150 min (P<0.05). MFV did not change in skeletal muscle, but decreased slightly in cardiac muscle. GLP-1 infusion significantly increased brachial artery diameter (P<0.005) and flow velocity (P=0.05) at 150 min, resulting in a significant increase in total brachial artery blood flow (P<0.005). We conclude that acute GLP-1 infusion significantly recruits skeletal and cardiac muscle microvasculature in addition to relaxing the conduit artery in healthy humans. This could contribute to increased tissue oxygen, nutrient and insulin delivery and exchange and therefore better prandial glycaemic control and tissue function in humans.
Co-morbidities increase markedly with aging, and they often negatively affect its prognosis. Although mortality with transcatheter mitral valve repair (TMVr) is significantly less than for open ...mitral valve surgery in patients at high surgical risk, it remains a concern to identify which patients will benefit from this treatment. Some prognostic metrics have been reported to guide better patient selection; however, universal risk stratification measures have not been established. This study aimed to determine if age-adjusted Charlson co-morbidity index (CCI) could predict mortality in patients who underwent TMVr and to assess its discriminatory performance in long-term outcomes. We retrospectively reviewed 222 patients who underwent TMVr, and 7 who died in hospital was excluded. Cox proportional hazard models were applied to select the demographic characteristics that were associated with cumulative mortality. Receiver-operating characteristic analyses were performed for predicting all-cause mortality, and discriminatory performance was assessed. We found that the age-adjusted CCI (hazard ratio 1.33, 95% confidence interval 1.16 to 1.51, p <0.001), New York Heart Association classification, and atrial fibrillation were independently associated with mortality. The age-adjusted CCI demonstrated good discriminative performance for predicting mortality at 3 and 5 years (area under the curve 0.71 and 0.77, respectively) and were greater than those of the Society of Thoracic Surgeons score in receiver-operating characteristic analysis. Kaplan-Meier curve demonstrated that the age-adjusted CCI ≥ 8 had poor prognosis after TMVr. In conclusions, the age-adjusted CCI could predict mortality and had a good discriminative performance for predicting longer term outcomes in patients who underwent TMVr.
Free fatty acids induce insulin resistance in both cardiac and skeletal muscle microvasculature in humans, which may contribute to cardiac complications and insulin resistance in diabetes.
Context:
...Insulin recruits microvasculature in both cardiac and skeletal muscle, which increases the endothelial exchange surface area. Plasma concentrations of free fatty acids (FFAs) are elevated in patients with diabetes, which impairs insulin-mediated skeletal muscle microvascular recruitment.
Objective:
The objective of the study was to examine whether elevated FFAs likewise cause insulin resistance in cardiac muscle microvasculature.
Setting:
The study was conducted at the General Clinical Research Center at the University of Virginia.
Methods:
Twenty-two healthy, young adults were studied twice in random order after an overnight fast. Each subject received a 5-h systemic infusion of either saline or Intralipid/heparin with a 1 mU/min · kg euglycemic insulin clamp superimposed for the last 2 h. Cardiac and forearm skeletal muscle microvascular blood volume (MBV) and flow velocity were measured and microvascular blood flow (MBF) calculated before and at the end of the insulin infusion.
Results:
Insulin significantly increased MBV and MBF in both cardiac (P < 0.0001 for both) and skeletal (P = 0.008 and < 0.03, respectively) muscle. Microvascular flow velocity increased slightly but significantly in the skeletal (P = 0.04) but not in cardiac muscle. Lipid infusion lowered insulin-stimulated whole-body glucose disposal and abolished insulin-mediated increases in MBV and MBF in both cardiac and skeletal muscle. Whole-body insulin sensitivity predicted skeletal but not cardiac muscle microvascular responses to insulin. Insulin even decreased skeletal muscle MBV during lipid infusion in subjects who were moderately sensitive to insulin metabolically.
Conclusions:
In conclusion, high plasma concentrations of FFAs cause insulin resistance in cardiac as well as skeletal muscle microvasculature in healthy humans. This may contribute to the association of cardiac complications with metabolic insulin resistance in diabetes.
Surgical management of isolated tricuspid regurgitation (TR) is associated with high morbidity and mortality, thereby creating a significant need for a lower-risk transcatheter solution.
The ...single-arm, multicenter, prospective CLASP TR (Edwards PASCAL TrAnScatheter Valve RePair System in Tricuspid Regurgitation CLASP TR Early Feasibility Study) evaluated 1-year outcomes of the PASCAL transcatheter valve repair system (Edwards Lifesciences) to treat TR.
Study inclusion required a previous diagnosis of severe or greater TR and persistent symptoms despite medical treatment. An independent core laboratory evaluated echocardiographic results, and a clinical events committee adjudicated major adverse events. The study evaluated primary safety and performance outcomes, with echocardiographic, clinical, and functional endpoints. Study investigators report 1-year all-cause mortality and heart failure hospitalization rates.
Sixty-five patients were enrolled: mean age of 77.4 years; 55.4% female; and 97.0% with severe to torrential TR. At 30 days, cardiovascular mortality was 3.1%, the stroke rate was 1.5%, and no device-related reinterventions were reported. Between 30 days and 1 year, there were an additional 3 cardiovascular deaths (4.8%), 2 strokes (3.2%), and 1 unplanned or emergency reintervention (1.6%). One-year postprocedure, TR severity significantly reduced (P < 0.001), with 31 of 36 (86.0%) patients achieving moderate or less TR; 100% had at least 1 TR grade reduction. Freedom from all-cause mortality and heart failure hospitalization by Kaplan-Meier analyses were 87.9% and 78.5%, respectively. Their New York Heart Association functional class significantly improved (P < 0.001) with 92% in class I or II, 6-minute walk distance increased by 94 m (P = 0.014), and overall Kansas City Cardiomyopathy Questionnaire scores improved by 18 points (P < 0.001).
The PASCAL system demonstrated low complication and high survival rates, with significant and sustained improvements in TR, functional status, and quality of life at 1 year. (Edwards PASCAL TrAnScatheter Valve RePair System in Tricuspid Regurgitation CLASP TR Early Feasibility Study CLASP TR EFS; NCT03745313)
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Context: Insulin recruits muscle microvasculature, which increases the endothelial exchange surface area to facilitate substrate delivery. Elevated plasma concentrations of free fatty acids (FFAs) ...cause insulin resistance.
Objectives: The aim of the study was to examine whether FFAs cause insulin resistance in human muscle microvasculature.
Setting: The study was conducted at the General Clinical Research Center at the University of Virginia.
Methods: Twenty-two healthy subjects were studied under two protocols designed to raise plasma insulin concentrations to postprandial levels using either an insulin infusion or a mixed meal challenge. Within each protocol, subjects were studied twice. In random order, they received a 5-h systemic infusion of either saline or Intralipid/heparin. Three hours into the infusion, baseline muscle microvascular blood volume (MBV), microvascular flow velocity, and microvascular blood flow (MBF) were measured. Each subject was then given either the mixed meal or a 1 mU/kg · min insulin clamp for 2 h. Microvascular parameters were again obtained 2 h after the meal or at the end of insulin infusion.
Results: Meal feeding and insulin infusion raised plasma insulin concentrations to approximately 200 pm, and each significantly increased muscle MBV (P = 0.03 and P < 0.01, respectively). MBF trended up after meal feeding (P = 0.08) and increased significantly after insulin infusion (P = 0.02). In the presence of Intralipid, neither the meal nor the insulin infusion increased muscle MBV and MBF.
Conclusions: Compared to saline, lipid infusion raises plasma FFA concentrations and blocks the ability of insulin or meal to recruit muscle microvasculature. High plasma FFA concentrations may contribute to muscle insulin resistance and the microvascular complications of diabetes.
Meal feeding and hyperinsulinemia each increase muscle microvascular perfusion, which is blocked by acute elevation of plasma levels of free fatty acids in healthy humans.
OBJECTIVE: Insulin recruits muscle microvasculature, thereby increasing endothelial exchange surface area. Free fatty acids (FFAs) cause insulin resistance by activating inhibitor of κB kinase β. ...Elevating plasma FFAs impairs insulin's microvascular and metabolic actions in vivo. Whether salsalate, an anti-inflammatory agent, prevents FFA-induced microvascular and/or metabolic insulin resistance in humans is unknown. RESEARCH DESIGN AND METHODS: Eleven healthy, young adults were studied three times in random order. After an overnight fast, on two occasions each subject received a 5-h systemic infusion of Intralipid ± salsalate pretreatment (50 mg/kg/day for 4 days). On the third occasion, saline replaced Intralipid. A 1 mU/kg/min euglycemic insulin clamp was superimposed over the last 2-h of each study. Skeletal and cardiac muscle microvascular blood volume (MBV), microvascular flow velocity (MFV), and microvascular blood flow (MBF) were determined before and after insulin infusion. Whole body glucose disposal rates were calculated from glucose infusion rates. RESULTS: Insulin significantly increased skeletal and cardiac muscle MBV and MBF without affecting MFV. Lipid infusion abolished insulin-mediated microvascular recruitment in both skeletal and cardiac muscle and lowered insulin-stimulated whole body glucose disposal (P < 0.001). Salsalate treatment rescued insulin's actions to recruit muscle microvasculature and improved insulin-stimulated whole body glucose disposal in the presence of high plasma FFAs. CONCLUSIONS: High plasma concentrations of FFAs cause both microvascular and metabolic insulin resistance, which can be prevented or attenuated by salsalate treatment. Our data suggest that treatments aimed at inhibition of inflammatory response might help alleviate vascular insulin resistance and improve metabolic control in patients with diabetes.
We describe a patient at high surgical risk who was successfully treated with a MitraClip (Abbott Vascular, Menlo Park, CA) without transmitral gradient. She received corticosteroid therapy for ...systemic lupus erythematosus, and progressive mitral stenosis developed late after MitraClip implantation. It gradually increased and reached 23 mm Hg at 28 months after the procedure; during the same period, her dose of prednisone had to be increased owing to lupus flare. Systemic inflammatory disease has the potential to result in mitral valve inflammation and fibrosis, ultimately causing thickening of the tissue bridge and worsening of the mitral valve obstruction. Preprocedural counseling regarding durability may help in this population.
Background
The 6‐minute walk test (6MWT) is a simple functional test that can predict exercise capacity and is widely employed to assess treatment outcomes. Although mortality with transcatheter ...mitral valve repair (TMVr) using the MitraClip (Abbott Vascular, Menlo Park, CA) is significantly less than for open mitral valve surgery in high‐risk patients, identifying which patient will benefit the most from TMVr remains a concern. There are limited prognostic metrics guiding patient selection and, no studies have reported relationship between prolonged hospitalization and 6MWT. This study aimed to determine if the 6MWT can predict prolonged hospitalization in patients undergoing TMVr by MitraClip.
Methods
We retrospectively reviewed 162 patients undergoing 6MWT before TMVr. Patients were divided into three groups according to the 6MWT distance (6MWTD) using the median (6MWTD ≥219 m, 6MWTD <219 m, and Unable to Walk). Multivariate logistic regression model was applied to select the demographic characteristics that were associated with the prolonged hospitalization defined as total length of stay ≥4 days in the study.
Results
We found that 6MWT (odds ratio 3.64, 95% confidence interval 2.03–6.52, P < 0.001) was independently associated with prolonged hospitalization after adjustment in multivariate analysis. Area under the curve of 6MWT for predicting prolonged hospitalization was 0.79 (95% confidence interval 0.72–0.85).
Conclusions
Our study demonstrates that 6MWT was independently associated with prolonged hospitalization in patients with TMVr, and has a good discriminatory performance for predicting prolonged hospitalization.
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