Hypertension
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Dilated cardiomyopathy is a major cause of heart failure (HF) that affects millions. Corin cleaves and biologically activates pro-atrial natriuretic peptide (pro-ANP) and pro-B-type natriuretic peptide (pro-BNP). High corin levels reduce the development of systolic dysfunction and HF in experimental dilated cardiomyopathy. ⋯ Immunoreactive plasma ANP and BNP levels were positively associated with plasma cyclic guanosine monophosphate levels (r=0.82, P=0.01 and r=0.8, P=0.02, respectively). In experimental dilated cardiomyopathy, corin levels declined early with progressive systolic dysfunction before the development of HF, whereas significant increases in plasma ANP, BNP, and cyclic guanosine monophosphate levels were found only in later stage (C and D) HF. This dyssynchrony in expression of corin versus ANP/BNP may impair cleavage activation of pro-natriuretic peptides, and thereby promote the transition from earlier to later stage HF.
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Overnutrition and insulin resistance are especially prominent risk factors for the development of cardiac diastolic dysfunction in females. We recently reported that consumption of a Western diet (WD) containing excess fat (46%), sucrose (17.5%), and high fructose corn syrup (17.5%) for 16 weeks resulted in cardiac diastolic dysfunction and aortic stiffening in young female mice and that these abnormalities were prevented by mineralocorticoid receptor blockade. Herein, we extend those studies by testing whether WD-induced diastolic dysfunction and factors contributing to diastolic impairment, such as cardiac fibrosis, hypertrophy, inflammation, and impaired insulin signaling, are modulated by excess endothelial cell mineralocorticoid receptor signaling. ⋯ WD also induced cardiomyocyte stiffening, assessed ex vivo using atomic force microscopy. Conversely, endothelial cell mineralocorticoid receptor deficiency prevented WD-induced diastolic dysfunction, profibrotic, and progrowth signaling, in conjunction with reductions in macrophage proinflammatory polarization and improvements in insulin metabolic signaling. Therefore, our findings indicate that increased endothelial cell mineralocorticoid receptor signaling associated with consumption of a WD plays a key role in the activation of cardiac profibrotic, inflammatory, and growth pathways that lead to diastolic dysfunction in female mice.
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High nighttime and early morning blood pressure (BP) have been associated with greater risk for cardiovascular events than high clinic or daytime BP. BP is typically highest in the rising hours, when morning activities typically begin. We examined the effect of renal denervation on morning (6:00-8:59 AM), daytime (9:00 AM-8:59 PM), and nighttime (1:00-5:59 AM) ambulatory BP. Patient data from 2 prospective, randomized controlled trials of patients with treatment-resistant, uncontrolled hypertension, one conducted in a US population (Renal Denervation in Patients With Uncontrolled Hypertension [SYMPLICITY HTN-3]) and the other in a Japanese population (SYMPLICITY HTN-Japan [HTN-Japan]), were analyzed. Patients in SYMPLICITY HTN-3 and HTN-Japan were prescribed a similar number of baseline antihypertensive medications (5.2±1.4 versus 4.9±1.6, P=0.28), but the classes prescribed and changes in prescription varied by study. Among patients treated with renal denervation, although the number of ablation treatments were similar in both studies (11.2±2.8 versus 11.5±1.9, P=0.55), patients in SYMPLICITY HTN-3 were less likely to receive at least 1 four-quadrant ablation treatment (25% versus 82%, P<0.001). In SYMPLICITY HTN-3, compared with controls (n=159), patients treated with renal denervation (n=325) experienced a significantly greater change in morning (-7.3±19.8 mm Hg, P<0.001) and nighttime (-6.1±18.2 versus -1.6±19.7 mm Hg, P=0.02) but not daytime systolic BP (-7.2±16.2 versus -6.4±18.6 mm Hg, P=0.67). This same trend was observed in the pooled analysis with HTN-Japan. Reduction of BP during these high-risk periods might provide cardiovascular protection in drug-resistant hypertensive patients, although this will need to be proved in future randomized trials. ⋯ URL: www.clinicaltrials.gov; Unique identifiers: NCT01418261 (SYMPLICITY HTN-3) and NCT01644604 (HTN-Japan).
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In the article by Narayan et al (Narayan O, Davies JE, Hughes AD, Dart AM, Parker KH, Reid C, Cameron JD. Central aortic reservoir-wave analysis improves prediction of cardiovascular events in elderly hypertensives. ⋯ In panel B, the text by the upward arrow, "10% increase in kd,” has been corrected to read, "10% decrease in kd." The corrected figure is shown below. The authors apologize for these errors.
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In preeclampsia, the antiangiogenic factor soluble fms-like tyrosine kinase-1 (sFLT-1) is released from placenta into the maternal circulation, causing endothelial dysfunction and organ injury. A recently described splice variant, sFLT-1 e15a, is primate specific and the most abundant placentally derived sFLT-1. Therefore, it may be the major sFLT-1 isoform contributing to the pathophysiology of preeclampsia. sFLT-1 e15a protein remains poorly characterized: its bioactivity has not been comprehensively examined, and serum levels in normal and preeclamptic pregnancy have not been reported. ⋯ Administering sFLT-1 e15a blocked vascular endothelial growth factor induced sprouts from mouse aortic rings ex vivo. We have demonstrated that sFLT-1 e15a is increased in preeclampsia, antagonizes vascular endothelial growth factor signaling, and has antiangiogenic activity. Future development of diagnostics and therapeutics for preeclampsia should consider targeting placentally derived sFLT-1 e15a.