Umberto Campia

Enhanced Vascular Activity of Endogenous Endothelin-1 in Obese Hypertensive Patients

Abstract—Hypertensive patients have increased endothelin-1–dependent vasoconstrictor tone. This abnormality, however, might not be uniformly present in all forms of hypertension, as suggested by experimental studies showing that endothelin-1 activity is enhanced predominantly in low-renin, high-volume models and in insulin-resistant states. Because hypertension in obesity is commonly associated with both expanded plasma volume and insulin resistance, this study sought to determine whether increased body mass index (BMI) in hypertensive patients relates to activation of the endothelin-1 system. Forearm blood flow (FBF) responses (plethysmography) to intra-arterial infusion of an ETA receptor blocker (BQ-123) were analyzed in hypertensive patients and normotensive control subjects according to BMI. The vasodilator response to BQ-123 was significantly higher in hypertensive patients than in control subjects (P <0.001). During BQ-123, a significant increase in FBF from baseline was observed in obese (BMI ≥30 kg/m2; P <0.001) and overweight (BMI, 27 to 29.9 kg/m2; P =0.04) but not in lean (BMI <27 kg/m2; P =0.83) hypertensive patients. In contrast, no significant change in FBF was observed during BQ-123 either in obese (P =0.53), overweight (P =0.76), or lean (P =0.93) normotensive subjects. Moreover, a significant correlation between BMI and the vasodilator response to ETA blockade was observed in hypertensive subjects (R =0.53; P =0.005) but not in control subjects (R =0.11; P =0.58). In human hypertension, increased BMI is associated with enhanced ETA-dependent vasoconstrictor activity, suggesting that this abnormality may play a role in the pathophysiology of obesity-related hypertension and that targeting the endothelin-1 system may be useful in the treatment of these patients.

Effects of n-3 Polyunsaturated Fatty Acids on Left Ventricular Function and Functional Capacity in Patients With Dilated Cardiomyopathy

Methods Patients with chronic HF due to NICM and minimal symptoms while receiving evidence-based therapy were enrolled. LV function and functional capacity were assessed prospectively by echocardiography, cardiopulmonary exercise test, and New York Heart Association functional class at baseline and at 12 months after randomization to eithe r2go f n-3PUFAs or placebo. Results At 12 months after randomization, the n-3 PUFAs group and the placebo group differed significantly (p 0.001) in regard to: 1) LV ejection fraction (increased by 10.4% and decreased by 5.0%, respectively); 2) peak VO2 (increased by 6.2% and decreased by 4.5%, respectively); 3) exercise duration (increased by 7.5% and decreased by 4.8%, respectively); and 4) mean New York Heart Association functional class (decreased from 1.88 0.33 to 1.61 0.49 and increased from 1.83 0.38 to 2.14 0.65, respectively). The hospitalization rates for HF were 6% in the n-3 PUFAs and 30% in the placebo group (p 0.0002). Conclusions In patients with NICM and minimal symptoms in response to evidence-based medical therapy, n-3 PUFAs treatment increases LV systolic function and functional capacity and may reduce hospitalizations for HF. Given these promising results, larger studies are in order to confirm our findings. (J Am Coll Cardiol 2011;57:870‐9)

Effects of n-3 polyunsaturated fatty acids on left ventricular function and functional capacity in patients with dilated cardiomyopathy.

OBJECTIVES This study was designed to test the effects of n-3 polyunsaturated fatty acids (PUFAs) on left ventricular (LV) systolic function in chronic heart failure (HF) due to nonischemic dilated cardiomyopathy (NICM). BACKGROUND One hundred thirty-three patients with NICM and minimal symptoms on standard therapy were randomized to 2 g of n-3 PUFAs or placebo. LV function and functional capacity were assessed prospectively by echocardiography and cardiopulmonary exercise testing at baseline and at 12 months after randomization. METHODS Patients with chronic HF due to NICM and minimal symptoms while receiving evidence-based therapy were enrolled. LV function and functional capacity were assessed prospectively by echocardiography, cardiopulmonary exercise test, and New York Heart Association functional class at baseline and at 12 months after randomization to either 2 g of n-3 PUFAs or placebo. RESULTS At 12 months after randomization, the n-3 PUFAs group and the placebo group differed significantly (p <0.001) in regard to: 1) LV ejection fraction (increased by 10.4% and decreased by 5.0%, respectively); 2) peak VO(2) (increased by 6.2% and decreased by 4.5%, respectively); 3) exercise duration (increased by 7.5% and decreased by 4.8%, respectively); and 4) mean New York Heart Association functional class (decreased from 1.88 ± 0.33 to 1.61 ± 0.49 and increased from 1.83 ± 0.38 to 2.14 ± 0.65, respectively). The hospitalization rates for HF were 6% in the n-3 PUFAs and 30% in the placebo group (p = 0.0002). CONCLUSIONS In patients with NICM and minimal symptoms in response to evidence-based medical therapy, n-3 PUFAs treatment increases LV systolic function and functional capacity and may reduce hospitalizations for HF. Given these promising results, larger studies are in order to confirm our findings.

Reduced endothelium-dependent and -independent dilation of conductance arteries in African Americans.

OBJECTIVES The goal of this study was to determine whether racial differences exist in the functional behavior of conduit vessels. BACKGROUND Compared with Caucasians, African Americans have a higher prevalence of cardiovascular disease and its complications, which may be related to reduced nitric oxide (NO)-dependent and -independent vasodilation of the microvasculature. However, whether a similar impairment is also present at the level of the conductance arteries is unknown. METHODS To this end, we studied endothelium-dependent (posthyperemia flow-mediated dilation) and -independent (nitroglycerin) vascular responses of the brachial artery by high-resolution ultrasound imaging. There were 46 black subjects (23 men and 23 women; age 37 +/- 8 years and 38 +/- 9 years, respectively) and 46 white subjects (23 men and 23 women; age 38 +/- 11 years and 36 +/- 9 years, respectively) in this study. RESULTS Baseline diameter was similar in blacks and in whites (4.4 +/- 0.9 mm and 4.1 +/- 0.7 mm, respectively). Mean reactive hyperemia after cuff deflation was similar in the two groups (793 +/- 653% in black and 852 +/- 734% in white subjects, respectively; p = 0.5). Flow-mediated dilation was significantly lower in black compared with white individuals (4.79 +/- 3.5% vs. 8.87 +/- 4.5%, respectively; p < 0.0001). Nitroglycerin-mediated dilation was also significantly lower in black individuals compared with white individuals (10.99 +/- 4.6% vs. 14.98 +/- 5.4%, respectively; p = 0.0002). CONCLUSIONS African Americans show reduced responsiveness of conductance vessels to both endogenous and exogenous NO compared with Caucasian Americans. These findings expand our understanding of racial differences in vascular function and suggest a mechanistic explanation for the increased incidence and severity of cardiovascular disease observed in African Americans.

Peroxisome Proliferator–Activated Receptor-γ Activation With Pioglitazone Improves Endothelium-Dependent Dilation in Nondiabetic Patients With Major Cardiovascular Risk Factors

Background— Patients with cardiovascular risk factors have endothelial dysfunction, a key element in the pathogenesis of atherosclerosis. The thiazolidinediones have been shown to exert multiple antiatherosclerotic actions in diabetic patients. This study tested the hypothesis that pioglitazone improves endothelial function in nondiabetic patients with major risk factors. Methods and Results— The study had a randomized, double-blind, placebo-controlled, crossover design. Eighty patients with either hypertension or hypercholesterolemia were enrolled. Insulin sensitivity was assessed by the Quantitative Insulin Sensitivity Check Index (QUICKI), and patients were further classified as insulin sensitive or insulin resistant. In each treatment phase, patients received either pioglitazone 45 mg daily or placebo for 8 weeks. Endothelial function and laboratory tests were performed at the end of each 8-week period. Treatment with pioglitazone significantly lowered plasma insulin (−22.9%; P<0.001), improved QUICKI insulin sensitivity index (3.7%; P<0.001), increased HDL cholesterol (8.2%; P<0.001), and reduced triglycerides (−15.1%; P=0.003), free fatty acids (−14%; P=0.005), and C-reactive protein (−28.6%; P=0.001). Pioglitazone treatment significantly improved endothelium-dependent dilation to bradykinin (P=0.01) without affecting the response to sodium nitroprusside (P=0.31). In multivariable analysis, only changes in total cholesterol were predictors of improved endothelial reactivity with pioglitazone. Conclusions— In nondiabetic patients with cardiovascular risk factors, pioglitazone treatment enhances insulin sensitivity, decreases C-reactive protein, and improves endothelial vasodilator function. These effects do not appear to be closely related, suggesting that pioglitazone may have beneficial vascular properties independent of its effect on insulin sensitivity and inflammation.

CD8+ T Lymphocytes Regulate the Arteriogenic Response to Ischemia by Infiltrating the Site of Collateral Vessel Development and Recruiting CD4+ Mononuclear Cells Through the Expression of Interleukin-16

Background— Previous studies have demonstrated that macrophages and CD4+ T lymphocytes play pivotal roles in collateral development. Indirect evidence suggests that CD8+ T cells also play a role. Thus, after acute cerebral ischemia, CD8+ T cells infiltrate the perivascular space and secrete interleukin-16 (IL-16), a potent chemoattractant for monocytes and CD4+ T cells. We tested whether CD8+ T lymphocytes contribute to collateral vessel development and whether the lack of circulating CD8+ T cells prevents IL-16 expression, impairs CD4+ mononuclear cell recruitment, and reduces collateral vessel growth after femoral artery ligation in CD8−/− mice. Methods and Results— After surgical excision of the femoral artery, laser Doppler perfusion imaging demonstrated reduced blood flow recovery in CD8−/− mice compared with C57/BL6 mice (ischemic/nonischemic limb at day 28, 0.66±0.04 versus 0.87±0.04, respectively; P<0.01). This resulted in greater calf muscle atrophy (mean fiber area, 785±68 versus 1067±69 &mgr;m2, respectively; P<0.01) and increased fibrotic tissue content (10.8±1.2% versus 7±1%, respectively; P<0.01). Moreover, CD8−/− mice displayed reduced IL-16 expression and decreased CD4+ T-cell recruitment at the site of collateral vessel development. Exogenous CD8+ T cells, infused into CD8−/− mice immediately after femoral artery ligation, selectively homed to the ischemic hind limb and expressed IL-16. The restoration of IL-16 expression resulted in significant CD4+ mononuclear cell infiltration of the ischemic limb, faster blood flow recovery, and reduced hindlimb muscle atrophy/fibrosis. When exogenous CD8+ T cells deficient in IL-16 (IL-16−/−) were infused into CD8−/− mice immediately after femoral artery ligation, they selectively homed to the ischemic hind limb but were unable to recruit CD4+ mononuclear cells and did not improve blood flow recovery. Conclusions— These results demonstrate that CD8+ T cells importantly contribute to the early phase of collateral development. After femoral artery ligation, CD8+ T cells infiltrate the site of collateral vessel growth and recruit CD4+ mononuclear cells through the expression of IL-16. Our study provides further evidence of the significant role of the immune system in modulating collateral development in response to peripheral ischemia.

Enhanced Endothelium-Dependent Vasodilation in Fabry Disease

Background and Purpose— Fabry disease is an X-linked lysosomal storage disease secondary to deficiency of &agr;-galactosidase A with resulting glycolipid accumulation, particularly globotriaosylceramide in arterial smooth muscle and endothelial cells. A systemic vasculopathy, including early-onset stroke, is prevalent without a clear pathogenesis. Methods— Seventeen normotensive and normocholesterolemic hemizygous Fabry patients (aged 21 to 49 years) and 13 control subjects (aged 21 to 48 years) were investigated by venous plethysmography, allowing assessment of forearm blood flow. Plethysmographic measurements were obtained at baseline and during intra-arterial infusion of acetylcholine and sodium nitroprusside both with and without NG-monomethyl-l-arginine (L-NMMA). Results— Forearm blood flow was significantly higher in patients than in control subjects at all 3 acetylcholine doses (P =0.014). Patients had a greater response to acetylcholine even after the addition of L-NMMA (P =0.036). Conclusions— These results demonstrate an increased endothelium-mediated vascular reactivity in Fabry disease. The increased vessel response to acetylcholine with and without L-NMMA suggests altered functionality of non-NO endothelium-dependent vasodilatory pathways.

Methods for Evaluating Endothelial Function in Humans

The endothelium is the main regulator of vascular wall homeostasis. Physiologically, endothelial cells maintain a relaxed vascular tone and low levels of oxidative stress, in part by releasing mediators, including NO, prostacyclin (PGI2), and endothelin (ET-1), and controlling local angiotensin II activity.1 In addition, the endothelium actively regulates vascular permeability to plasma constituents, platelet and leukocyte adhesion and aggregation, and thrombosis.1 This state of balanced endothelial regulation of blood vessel function is, however, altered by a number of conditions. Thus, in response to a variety of noxious stimuli, the endothelium undergoes a phenotypic modulation to a nonadaptive state, commonly termed “endothelial dysfunction,” characterized by loss or dysregulation of homeostatic mechanisms operative in healthy endothelial cells. This pathophysiological condition is associated with increased expression of adhesion molecules, increased synthesis of proinflammatory and prothrombotic factors, increased oxidative stress, and abnormal modulation of vascular tone, which may lead to different functional manifestations, including impaired endothelium-dependent vasodilation.2 Current evidence suggests that endothelial dysfunction occurs early in the process of atherogenesis and contributes to the formation, progression, and complications of the atherosclerotic plaque.3 Several studies from our and other laboratories have shown that patients with cardiovascular risk factors but no clinical evidence of atherosclerosis have endothelial dysfunction, indicated by an impaired response to endothelial vasodilator agents, such as acetylcholine and bradykinin.4 Combined with the pathophysiological role of the endothelium described above, these observations strongly suggest that endothelial dysfunction is a common mechanistic link between risk factors and the development of atherosclerosis. Furthermore, recent reports have demonstrated that endothelial dysfunction is an independent predictor of future cardiovascular events in patients with atherosclerotic risk factors,5,6 in patients with stable ischemic heart disease,7 and in patients with acute coronary syndromes.8 Thus, endothelial dysfunction appears to be a systemic vascular …

Changes in renal function during hospitalization and soon after discharge in patients admitted for worsening heart failure in the placebo group of the EVEREST trial

AIM To provide an in-depth clinical characterization and analysis of outcomes of the patients hospitalized for heart failure (HF) who subsequently develop worsening renal function (WRF) during hospitalization or soon after discharge. METHODS AND RESULTS Of the 4133 patients hospitalized with worsening HF and reduced left ventricular ejection fraction (LVEF) (≤40%) in the EVEREST trial, 2072 were randomized to tolvaptan, a selective vasopressin-2 receptor antagonist, and 2061 were randomized to placebo, both in addition to standard therapy. This analysis included the 2021 (98%) patients in the placebo group with a complete set of renal function parameters. Renal function parameters and clinical variables were measured prospectively during hospitalization and after discharge. Worsening renal function was defined as an increase in sCr ≥0.3 mg/dL during the in-hospital (randomization to discharge or Day 7) and post-discharge (discharge or Day 7 to 4 weeks post-discharge) periods. Blood pressure (BP), body weight (BW), natriuretic peptides (NPs), and congestion score were correlated with WRF. The prognostic value of baseline renal function at admission and WRF during hospitalization and post-discharge on long-term outcomes were assessed using a Cox proportional hazards model adjusted for other baseline covariates. At randomization, 53.2% of patients had moderately or severely reduced estimated glomerular filtration rate (eGFR) (<60.0 mL/min/1.73 m2). Worsening renal function was observed in 13.8% in-hospital and 11.9% post-discharge. Worsening renal function during hospitalization and post-discharge was associated with greater reductions in BP, BW, and NPs. Baseline renal dysfunction as well as in-hospital and post-discharge WRF were predictive of a composite endpoint of cardiovascular (CV) mortality/HF rehospitalization. CONCLUSION The prevalence of renal dysfunction is high in patients hospitalized for HF with reduced LVEF. Worsening renal function may occur not only during hospitalization, but also in the early post-discharge period. Since worsening renal function during hospitalization is associated with a significant decrease in signs and symptoms of congestion, body weight and natriuretic peptides, which are good prognostic indicators, worsening renal function during hospitalization as an endpoint in clinical trials should be re-evaluated.

Cardiovascular Mortality in Chronic Kidney Disease Patients Undergoing Percutaneous Coronary Intervention Is Mainly Related to Impaired P2Y12 Inhibition by Clopidogrel

OBJECTIVES We sought to determine whether low platelet response to the P2Y(12) receptor antagonist clopidogrel as assessed by vasodilator-stimulated phosphoprotein flow cytometry test (VASP-FCT) differentially affects outcomes in patients with or without chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI). BACKGROUND Although both CKD and impaired platelet responsiveness to clopidogrel are strong predictors of unfavorable outcome after PCI, the impact of their association is unknown. The platelet VASP-FCT assay is specific for the P2Y(12) ADP receptor pathway. In this test, platelet activation is expressed as the platelet reactivity index (PRI). METHODS Four-hundred forty unselected patients (CKD: 126, estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m(2)), no-CKD: 314 eGFR >60 ml/min/1.73 m(2)) undergoing urgent (n = 336) or planned (n = 104) PCI were prospectively enrolled. In each subgroup, patients were classified as low-responders (LR: PRI ≥ 61%) or responders (R: PRI <61%) to clopidogrel. RESULTS At a mean follow-up of 9 ± 2 months, all-cause mortality, cardiac death, and possible stent thrombosis were higher in CKD than in no-CKD patients. Within the CKD group, the LR status was associated with higher rates of all-cause mortality (25.5% vs. 2.8%, p < 0.001), cardiac death (23.5% vs. 2.8%, p < 0.001), all stent thrombosis (19.6% vs. 2.7%, p = 0.003), and MACE (33.3% vs. 12.3%, p = 0.007). Conversely, in no-CKD patients, the LR status did not affect outcomes. Multivariate analysis identified Killip class ≥ 3, drug-eluting stent implantation, and the interaction between LR and CKD (hazard ratio: 11.96, 95% confidence interval: 1.22 to 116.82; p = 0.033) as independent predictors of cardiac death. CONCLUSIONS In CKD patients, the presence of low platelet response to clopidogrel is associated with worse outcomes after PCI.