Management of Transcatheter Aortic Valve Implantation and Complex Aorta Anatomy: The Importance of Pre-Procedural Planning.

Aortic stenosis is the most common primary valve lesion requiring surgery or, especially for older patients, transcatheter intervention (TAVI). We showcase a successful transfemoral TAVI procedure in a very high-risk patient and an extremely tortuous S-shaped descending aorta, characterized by heavy calcifications and multiple strong resistance points. We demonstrated that transfemoral TAVI using the "buddy stiff guidewire" technique could be a feasible, simple, quick, and easy procedure able to straighten an extremely abdominal aorta tortuosity. With all techniques available and careful pre-procedural planning, and thanks to the flexibility of new generation TAVI delivery systems, it is possible to safely perform the procedure even in the most challenging patients.

[Transcatheter approach in patients with severe aortic stenosis and concomitant severe mitral regurgitation]. / Gestione dei pazienti affetti da stenosi aortica severa e concomitante insufficienza mitralica severa.

Patients with severe aortic valve stenosis who are candidates for transcatheter aortic valve replacement represent a high-risk population for the presence of frequent comorbidities (reduced left ventricular ejection fraction, associated valve insufficiency, right ventricular dysfunction and/or pulmonary hypertension). Aortic valve stenosis can be associated with any other valve defects but among these mitral regurgitation is the most commonly associated valve disease. The simultaneous presence of severe mitral regurgitation in patients with aortic stenosis is a negative prognostic factor, resulting in increased mortality and a high diagnostic complexity, in particular in the accuracy of the evaluation of the two valve defects and therapeutic management which, at present, are not supported by strong scientific evidence.

Endothelial progenitor cells as factors in neovascularization and endothelial repair.

Endothelial progenitor cells (EPCs) are a heterogeneous population of cells that are provided by the bone marrow and other adult tissue in both animals and humans. They express both hematopoietic and endothelial surface markers, which challenge the classic dogma that the presumed differentiation of cells into angioblasts and subsequent endothelial and vascular differentiation occurred exclusively in embryonic development. This breakthrough stimulated research to understand the mechanism(s) underlying their physiologic function to allow development of new therapeutic options. One focus has been on their ability to form new vessels in injured tissues, and another has been on their ability to repair endothelial damage and restore both monolayer integrity and endothelial function in denuded vessels. Moreover, measures of their density have been shown to be a better predictor of cardiovascular events, both in healthy and coronary artery disease populations than the classical tools used in the clinic to evaluate the risk stratification. In the present paper we review the effects of EPCs on revascularization and endothelial repair in animal models and human studies, in an attempt to better understand their function, which may lead to potential advancement in clinical management.

Coronary microvascular dysfunction in diabetes mellitus: A review.

The exploration of coronary microcirculatory dysfunction in diabetes has accelerated in recent years. Cardiac function is compromised in diabetes. Diabetic patients manifest accelerated atherosclerosis in coronary arteries. These data are confirmed in diabetic animal models, where lesions of small coronary arteries have been described. These concepts are epitomized in the classic microvascular complications of diabetes, i.e. blindness, kidney failure and distal dry gangrene. Most importantly, accumulating data indicate that insights gained from the link between inflammation and diabetes can yield predictive and prognostic information of considerable clinical utility. This review summarizes the evidence for the predisposing factors and the mechanisms involved in diabetes, and assesses the current state of knowledge regarding the triggers for inflammation in this disease. We evaluate the roles of hyperglycemia, oxidative stress, polyol pathway, protein kinase C, advanced glycation end products, insulin resistance, peroxisome proliferator-activated receptor-γ, inflammation, and diabetic cardiomyopathy as a "stem cell disease". Furthermore, we discuss the mechanisms responsible for impaired coronary arteriole function. Finally, we consider how new insights in diabetes may provide innovative therapeutic strategies.

Role of EDHF in type 2 diabetes-induced endothelial dysfunction.

Endothelium-derived hyperpolarizing factor (EDHF) plays a crucial role in modulating vasomotor tone, especially in microvessels when nitric oxide-dependent control is compromised such as in diabetes. Epoxyeicosatrienoic acids (EETs), potassium ions (K+), and hydrogen peroxide (H2O2) are proposed as EDHFs. However, the identity (or identities) of EDHF-dependent endothelial dilators has not been clearly elucidated in diabetes. We assessed the mechanisms of EDHF-induced vasodilation in wild-type (WT, normal), db/db (advanced type 2 diabetic) mice, and db/db mice null for TNF (dbTNF-/dbTNF-). In db/db mice, EDHF-induced vasodilation [ACh-induced vasodilation in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME, 10 micromol/l) and prostaglandin synthase inhibitor indomethacin (Indo, 10 mumol/l)] was diminished after the administration of catalase (an enzyme that selectively dismutates H2O2 to water and oxygen, 1,000 U/ml); administration of the combination of charybdotoxin (a nonselective blocker of intermediate-conductance Ca2+-activated K+ channels, 10 micromol/l) and apamin (a selective blocker of small-conductance Ca2+-activated K+ channels, 50 micromol/l) also attenuated EDHF-induced vasodilation, but the inhibition of EETs synthesis [14,15-epoxyeicosa-5(Z)-enoic acid; 10 mumol/l] did not alter EDHF-induced vasodilation. In WT controls, EDHF-dependent vasodilation was significantly diminished after an inhibition of K+ channel, EETs synthesis, or H2O2 production. Our molecular results indicate that mRNA and protein expression of interleukin-6 (IL-6) were greater in db/db versus WT and dbTNF-/dbTNF- mice, but neutralizing antibody to IL-6 (anti-IL-6; 0.28 mg.ml(-1).kg(-1) ip for 3 days) attenuated IL-6 expression in db/db mice. The incubation of the microvessels with IL-6 (5 ng/ml) induced endothelial dysfunction in the presence of l-NAME and Indo in WT mice, but anti-IL-6 restored ACh-induced vasodilation in the presence of L-NAME and Indo in db/db mice. In db(TNF-)/db(TNF-) mice, EDHF-induced vasodilation was greater and comparable with controls, but IL-6 decreased EDHF-mediated vasodilation. Our results indicate that EDHF compensates for diminished NO-dependent dilation in IL-6-induced endothelial dysfunction by the activation of H2O2 or a K+ channel in type 2 diabetes.

Tumor necrosis factor-alpha induces endothelial dysfunction in Lepr(db) mice.

BACKGROUND: We hypothesized that the inflammatory cytokine tumor necrosis factor-alpha (TNF) produces endothelial dysfunction in type 2 diabetes. METHODS AND RESULTS: In m Lepr(db) control mice, sodium nitroprusside and acetylcholine induced dose-dependent vasodilation, and dilation to acetylcholine was blocked by the NO synthase inhibitor N(G)-monomethyl-L-arginine. In type 2 diabetic (Lepr(db)) mice, acetylcholine- or flow-induced dilation was blunted compared with m Lepr(db), but sodium nitroprusside produced comparable dilation. In Lepr(db) mice null for TNF (db(TNF-)/db(TNF-)), dilation to acetylcholine or flow was greater than in diabetic Lepr(db) mice and comparable to that in controls. Plasma concentration of TNF was significantly increased in Lepr(db) versus m Lepr(db) mice. Real-time polymerase chain reaction and Western blotting showed that mRNA and protein expression of TNF and nuclear factor-kappaB were higher in Lepr(db) mice than in controls. Administration of anti-TNF or soluble receptor of advanced glycation end products attenuated nuclear factor-kappaB and TNF expression in the Lepr(db) mice. Immunostaining results show that TNF in mouse heart is localized predominantly in vascular smooth muscle cells rather than in endothelial cells and macrophages. Superoxide generation was elevated in vessels from Lepr(db) mice versus controls. Administration of the superoxide scavenger TEMPOL, NAD(P)H oxidase inhibitor (apocynin), or anti-TNF restored endothelium-dependent dilation in Lepr(db) mice. NAD(P)H oxidase activity, protein expression of nitrotyrosine, and hydrogen peroxide production were increased in Lepr(db) mice (compared with controls), but these variables were restored to control levels by anti-TNF. CONCLUSIONS: Advanced glycation end products/receptor of advanced glycation end products and nuclear factor-kappaB signaling play pivotal roles in TNF expression through an increase in circulating and/or local vascular TNF production in the Lepr(db) mouse with type 2 diabetes. Increases in TNF expression induce activation of NAD(P)H oxidase and production of reactive oxidative species, leading to endothelial dysfunction in type 2 diabetes.

Erythropoietin improves anemia exercise tolerance and renal function and reduces B-type natriuretic peptide and hospitalization in patients with heart failure and anemia.

BACKGROUND: Anemia is now recognized as being a common finding in CHF and is associated with increased mortality and morbidity. However, it is uncertain whether the anemia is actually causing the worse prognosis or is merely a marker of more severe cardiac disease. Previous intervention studies with subcutaneous (s.c.) beta-EPO in combination with iron have either been uncontrolled or case-controlled studies. We report a randomized, double-blind, placebo-controlled study of the combination of s.c. EPO and oral iron versus oral iron alone in patients with anemia and resistant CHF. OBJECTIVES: The present study examines, in patients with advanced congestive heart failure (CHF) and anemia, the effects of beta-erythropoietin (EPO) and oral iron on the anemia and on cardiac and renal functional parameters. METHODS: Forty consecutive subjects with moderate to severe CHF and anemia (hemoglobin [Hb] <11 g/dL) were studied. They were randomized to receive, in a double-blind fashion, either (a) (group A, the treatment group, 20 patients) s.c. beta-EPO for 3 months twice weekly, in addition to daily oral iron, or (b) (group B, the placebo group, 20 patients) normal saline in s.c. injections and daily oral iron. Two patients in group B were eventually excluded because of a fall of Hb <8 g/dL requiring transfusion, leaving 18 patients in group B. After the 3-months study, the group A patients were maintained on the same treatment for an additional 9 months, whereas in Group B, the placebo and oral iron were stopped. RESULTS: In group A, after a mean of 3.5 +/- 0.8 months of treatment, there was a significant increase in Hb from 10.4 +/- 0.6 to 12.4 +/- 0.8 g/dL (P < .01); a significant improvement in New York Heart Association functional class from 3.5 +/- 0.6 to 2.8 +/- 0.5 (P < .05); a longer endurance time on exercise testing, from 5.8 +/- 2.2 to 7.8 +/- 2.5 minutes (P < .01); a greater distance walked on exercise testing, from 278 +/- 55 to 356 +/- 88 meters (P < .01); a significant increase in the peak oxygen consumption (VO2) from 12.8 +/- 2.8 to 15.1 +/- 2.8 mL/kg per minute (<.05); and the VO2 at the anaerobic threshold, from 9.2 +/- 2.0 to 13.2 +/- 3.6 mL/kg minute (P < .01). There was also a significant fall in plasma B-type natriuretic peptide levels from 568 +/- 320 to 271 +/- 120 pg/mL (P < .01), a significant reduction in serum creatinine (P < .01), and an increase in estimated creatinine clearance (P < .05). In group B, there were no significant changes in any of the above parameters over the study period. At the end of the 1-year study, the Hb was still higher in group A than group B, and the rate of hospital admissions/patients over the year averaged 0.8 +/- 0.2 in group A and 1.7 +/- 0.8 in group B (P < .01). CONCLUSIONS: In anemic CHF patients, correction of anemia with EPO and oral iron leads to improvement in New York Heart Association status, measured exercise endurance, oxygen use during exercise, renal function and plasma B-type natriuretic peptide levels and reduces the need for hospitalization.

Rise and fall of B-type natriuretic peptide levels in patients with coronary artery disease and normal left ventricular function after cardiac revascularization.

BACKGROUND: Recently, it was shown that B-type natriuretic peptide levels are increased in patients with acute coronary syndromes. AIMS: To assess the relation between B-type natriuretic peptide and ischemia in patients with stable and unstable angina pectoris with normal left ventricular function in relation to the extent of ischemia and response to revascularization. METHODS: Fifty-nine consecutive patients were enrolled in the study, patients were divided into two groups: stable angina patients (group I, n=18), and unstable coronary patients (group II, n=41). Baseline characteristics were compared with 15 age-matched and sex-matched participants. B-type natriuretic peptide levels were measured at baseline and 3, 7 and 90 days after coronary revascularization in group I and II. RESULTS: Patients with unstable angina pectoris had increased B-type natriuretic peptide levels compared with stable angina pectoris patients (B-type natriuretic peptide levels: controls 15.5+/-13 pg/ml, stable angina pectoris group 28.4+/-19 pg/ml, unstable angina pectoris group 104+/-81 pg/ml; P<0.01). A relationship between the number of affected coronary vessels and B-type natriuretic peptide was assessed (one-vessel 29.9+/-21 pg/ml, two-vessel 93.8+/-87 pg/ml, three-vessel 119+/-88 pg/ml; P<0.01). After revascularization, B-type natriuretic peptide levels decreased in groups I and II (25+/-20 vs. 39+/-28 pg/ml) and were similar after 90 days in percutaneous transluminal coronary angiograghy and in coronary artery bypass grafting groups (percutaneous transluminal coronary angiography 26+/-22 pg/ml, coronary artery bypass grafting 36+/-26 pg/ml; NS). CONCLUSIONS: B-type natriuretic peptide levels increase in unstable angina pectoris patients and are linked to the extent of coronary disease in patients with normal left ventricular systolic function, and returned to baseline level after surgical or catheter revascularization.