Citations

Uric acid is a risk factor for coronary artery disease in postmenopausal women, but the association with inflammation and coronary endothelial dysfunction (CED) is not well defined. The aim of this study was to determine the relationship of serum uric acid (SUA), inflammatory markers, and CED. In this prospective cohort study, SUA, high-sensitivity C-reactive protein levels, and neutrophil count were measured in 229 postmenopausal women who underwent diagnostic catheterization, were found to have no obstructive coronary artery disease, and underwent coronary microvascular function testing, to measure coronary blood flow response to intracoronary acetylcholine. The average age was 58 years (interquartile range, 52–66 years). Hypertension was present in 48%, type 2 diabetes mellitus in 5.6%, and hyperlipidemia in 61.8%. CED was diagnosed in 59% of postmenopausal women. Mean uric acid level was 4.7±1.3 mg/dL. Postmenopausal women with CED had significantly higher SUA compared with patients without CED (4.9±1.3 versus 4.4±1.3 mg/dL; P =0.02). There was a significant correlation between SUA and percent change in coronary blood flow to acetylcholine ( P =0.009), and this correlation persisted in multivariable analysis. SUA levels were significantly associated with increased neutrophil count ( P =0.02) and high-sensitivity C-reactive protein levels ( P =0.006) among patients with CED, but not among those without CED. SUA is associated with CED in postmenopausal women and may be related to inflammation. These findings link SUA levels to early coronary atherosclerosis in postmenopausal women.

Valvular interstitial cells from diseased aortic valve leaflets show their ability to regenerate–to proliferate and grow, to express appropriate genes and to deposit suitable proteins–in a non-degenerative nanofibrous substrate.

Background The study compared downstream coronary and conduit disease progression in the left anterior descending coronary artery treated with coronary artery bypass grafting using the left internal mammary artery ( LIMA ) versus percutaneous coronary intervention with bare metal stent ( BMS ) or drug eluting stent ( DES ). Methods and Results A total of 12 301 consecutive patients underwent isolated primary coronary revascularization, of which 2386 met our inclusion criteria (Percutaneous coronary intervention, n=1450; coronary artery bypass grafting, n=936). Propensity score analysis matched 628 patients, of which 468 were treated to the left anterior descending with coronary artery bypass grafting with LIMA (n=314), percutaneous coronary intervention with BMS (n=94), and DES (n=60). Coronary angiograms were analyzed by quantitative coronary angiography ( QCA ; n=433). Cumulative downstream coronary and conduit disease progression were estimated by Kaplan–Meier method and effect of treatment type by Cox proportional hazard models. Patients treated with LIMA had significantly lower risk of downstream coronary disease progression at follow‐up angiogram compared with BMS and DES (hazard ratio [ HR ] [95% CI ], 0.34; [0.20–0.59]; P =0.0002; and HR [95% CI ], 0.39; [0.20–0.79]; P =0.01, respectively). LIMA was associated with a lower risk of conduit disease progression compared to BMS and DES ( HR [95% CI ], 0.18; [0.12–0.28]; P <0.001; and HR [95% CI ], 0.27; [0.16–0.46]; P <0.001, respectively). BMS was associated with higher HR for downstream coronary and conduit disease progression compared with DES , but the difference did not reach statistical significance ( HR [95% CI], 1.13; [0.57–2.36]; P =0.73; and HR [95% CI ], 1.46; [0.88–2.50]; P =0.14, respectively). Conclusions LIMA grafting to left anterior descending is associated with significantly lower risk of downstream coronary and conduit disease progression compared to percutaneous coronary intervention with BMS and DES .

Background The mechanisms of atrial fibrillation (AF) are highly divergent. The prevalence of AF increases significantly with age, and underling mechanisms might vary with age. Endothelial dysfunction may be associated with AF and atrial arrhythmia recurrence after catheter ablation. We tested the hypothesis that the impact of endothelial dysfunction on arrhythmia recurrence following catheter ablation is age dependent. Methods and Results This study enrolled 92 participants with AF undergoing catheter ablation. Endothelial function was assessed by peripheral arterial tonometry before ablation, and the natural logarithmic transformation of reactive hyperemia index was calculated. Endothelial dysfunction was defined as a natural logarithmic transformation of reactive hyperemia index <0.618 (median). Participants were followed for atrial tachycardia, flutter, and fibrillation recurrence for a median of 14 months. The mean age was 57±10 years. There was significant interaction between age and endothelial dysfunction in association with recurrence of AF ( P =0.029) and any atrial arrhythmia ( P =0.015), and the risk associated with endothelial dysfunction for arrhythmia recurrence was higher in younger versus older participants. Participants were divided into 2 age groups at a threshold of 60 years. Among participants aged ≤60 years, multivariate Cox proportional hazards analysis revealed the independent association between endothelial dysfunction and increased risk of arrhythmia recurrence (hazard ratio for AF 4.18 [95% CI 1.33–15.82], P =0.014, and for any atrial arrhythmia 3.62 [95% CI 1.29–11.81], P =0.014). Kaplan–Meier analysis showed that participants with endothelial dysfunction had significantly higher rates of recurrence of AF ( P =0.01) and any atrial arrhythmia ( P =0.002). Conclusions The risk associated with endothelial dysfunction for arrhythmia recurrence following catheter ablation was age dependent and was higher in younger participants.

Objectives Percutaneous coronary intervention (PCI) for acute coronary syndromes frequently fails to restore myocardial perfusion despite establishing epicardial vessel patency. Endothelin-1 (ET-1) is a potent vasoconstrictor, and its expression is increased in atherosclerosis and after PCI. In this study, we aim to define the role of endothelin in regulating coronary microvascular blood flow and myocardial perfusion following PCI in patients with non-ST elevation acute coronary syndromes (NSTACS), by assessing whether adjunctive therapy with a selective endothelin A (ETA) receptor antagonist acutely improves postprocedural coronary microvascular blood flow. Methods In a randomised, double-blinded, placebo-controlled trial, 23 NSTACS patients were enrolled to receive an intracoronary infusion of placebo (n=11) or BQ-123 (n=12) immediately before PCI. Post-PCI coronary microvascular blood flow and myocardial perfusion were assessed by measuring Doppler-derived average peak velocity (APV), and cardiac biomarker levels were quantified. Results Compared with the placebo group, APV was significantly higher in the drug group immediately after PCI (30 (20, 37) vs 19 (9, 26) cm/s; p=0.03). Hyperaemic APV, measured post-adenosine administration, was higher in the BQ-123 group, but the difference did not achieve statistical significance (56 (48, 72) vs 46 (34, 64) cm/s; p=0.090). Maximum coronary flow reserve postprocedure was not different between the two groups (2.1 (1.6, 2.3) vs 2.5 (1.8, 3.0)). Per cent change in creatine kinase isoenzyme MB from the time of PCI to 8 and 16 hours post-PCI was significantly lower in the drug group compared with the placebo group (−17 (−26, −10) vs 26 (−15, 134); p=0.02 and −17 (−38, 14) vs 107 (2, 446); p=0.007, respectively). Conclusions Endothelin is a mediator of microvascular dysfunction during PCI in NSTACS, and adjunctive selective ETA antagonist may augment myocardial perfusion during PCI. Trial registration number NCT00586820; Results.

Mitochondrial injury contributes to renal dysfunction in several models of renal disease, but its involvement in human hypertension remains unknown. Fragments of the mitochondrial genome released from dying cells are considered surrogate markers of mitochondrial injury. We hypothesized that hypertension would be associated with increased urine mitochondrial DNA (mtDNA) copy numbers. We prospectively measured systemic and urinary copy number of the mtDNA genes cytochrome-c oxidase-3 and NADH dehydrogenase subunit-1 by quantitative polymerase chain reaction in essential (n=25) and renovascular (RVH, n=34) hypertensive patients and compared them with healthy volunteers (n=22). Urinary kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin served as indices of renal injury. Renal blood flow and oxygenation were assessed by multidetector computed tomography and blood oxygen level–dependent magnetic resonance imaging. Blood pressure, urinary neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 were similarly elevated in essential hypertension and RVH, and estimated glomerular filtration rate was lower in RVH versus healthy volunteers and essential hypertension. Renal blood flow was lower in RVH compared with essential hypertension. Urinary mtDNA copy number was higher in hypertension compared with healthy volunteers, directly correlated with urinary neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 and inversely with estimated glomerular filtration rate. In RVH, urinary mtDNA copy number correlated directly with intrarenal hypoxia. Furthermore, in an additional validation cohort, urinary mtDNA copy number was higher in RVH compared with healthy volunteers (n=10 each). The change in serum creatinine levels and estimated glomerular filtration rate 3 months after medical therapy without or with revascularization correlated with the change in urinary mtDNA. Therefore, elevated urinary mtDNA copy numbers in hypertensive patients correlated with markers of renal injury and dysfunction, implicating mitochondrial injury in kidney damage in human hypertension.

Microvascular rarefaction distal to renal artery stenosis is linked to renal dysfunction and poor outcomes. Low–energy shockwave therapy stimulates angiogenesis, but the effect on the kidney microvasculature is unknown. We hypothesized that low–energy shockwave therapy would restore the microcirculation and alleviate renal dysfunction in renovascular disease. Normal pigs and pigs subjected to 3 weeks of renal artery stenosis were treated with six sessions of low–energy shockwave (biweekly for 3 consecutive weeks) or left untreated. We assessed BP, urinary protein, stenotic renal blood flow, GFR, microvascular structure, and oxygenation in vivo 4 weeks after completion of treatment, and then, we assessed expression of angiogenic factors and mechanotransducers (focal adhesion kinase and β 1-integrin) ex vivo . A 3-week low–energy shockwave regimen attenuated renovascular hypertension, normalized stenotic kidney microvascular density and oxygenation, stabilized function, and alleviated fibrosis in pigs subjected to renal artery stenosis. These effects associated with elevated renal expression of angiogenic factors and mechanotransducers, particularly in proximal tubular cells. In additional pigs with prolonged (6 weeks) renal artery stenosis, shockwave therapy also decreased BP and improved GFR, microvascular density, and oxygenation in the stenotic kidney. This shockwave regimen did not cause detectable kidney injury in normal pigs. In conclusion, low–energy shockwave therapy improves stenotic kidney function, likely in part by mechanotransduction-mediated expression of angiogenic factors in proximal tubular cells, and it may ameliorate renovascular hypertension. Low–energy shockwave therapy may serve as a novel noninvasive intervention in the management of renovascular disease.