Sex-based differences in outcomes with bivalirudin or unfractionated heparin for transcatheter aortic valve replacement: Results from the BRAVO-3 randomized trial.

BACKGROUND: Women comprise almost 50% of patients undergoing transcatheter aortic valve replacement (TAVR) and previous studies have indicated higher rates of procedural complications and bleeding in women compared to men. It is unknown whether men and women demonstrate a differential response to bivalirudin versus unfractionated heparin (UFH) in TAVR. We sought to evaluate outcomes by sex and type of anticoagulant from the Bivalirudin Versus Heparin Anticoagulation in Transcatheter Aortic Valve Replacement (BRAVO-3) trial of transfemoral TAVR. METHODS: BRAVO-3 was a randomized multicenter trial comparing transfemoral TAVR with bivalirudin versus UFH (31 centers, n = 802). The primary endpoint was 48 h major bleeding defined as Bleeding Academic Research Consortium (BARC) type ≥3b. Major adverse cardiovascular events (MACE) were a composite of 30-day death, myocardial infarction, or stroke. Net adverse cardiovascular events (NACE) were a composite of BARC ≥3b bleeding or 30-day MACE. We examined the outcomes in men and women. RESULTS: The total cohort included 49% women (n = 391, 195 received bivalirudin and 196 UFH) and 51% men (n = 411, 209 received bivalirudin and 202 UFH). Women were older than men with fewer comorbidities including coronary artery disease, atrial fibrillation, diabetes but similar EuroSCORE I. Women received smaller sheath and device sizes compared with men without differences in the use of vascular closure devices. At 48-hr post-TAVR there was no difference in bleeding or vascular complications in women compared to men. The use of bivalirudin did not result in significantly lower bleeding at 48 hr or 30-days compared to UFH. CONCLUSIONS: There was no difference in early outcomes with bivalirudin versus UFH in men or women undergoing contemporary TAVR. © 2016 Wiley Periodicals, Inc.

Long-term safety of intramuscular gene transfer of non-viral FGF1 for peripheral artery disease.

Peripheral artery disease is a progressive disease. Primary ischemic leg symptoms are muscle fatigue, discomfort or pain during ambulation, known as intermittent claudication. The most severe manifestation of peripheral artery disease is critical limb ischemia (CLI). The long-term safety of gene therapy in peripheral artery disease remains unclear. This four center peripheral artery disease registry was designed to evaluate the long-term safety of the intramuscular non-viral fibroblast growth factor-1 (NV1FGF), a plasmid-based angiogenic gene for local expression of fibroblast growth factor-1 versus placebo in patients with peripheral artery disease who had been included in five different phase I and II trials. Here we report a 3-year follow-up in patients suffering from CLI or intermittent claudication. There were 93 evaluable patients, 72 of them in Fontaine stage IV (47 NV1FGF versus 25 placebo) and 21 patients in Fontaine stage IIb peripheral artery disease (15 NV1FGF versus 6 placebo). Safety parameters included rates of non-fatal myocardial infarction (MI), stroke, death, cancer, retinopathy and renal dysfunction. At 3 years, in 93 patients included this registry, there was no increase in retinopathy or renal dysfunction associated with delivery of this angiogenic factor. There was also no difference in the number of strokes, MI or deaths, respectively, for NV1FGF versus placebo. In the CLI group, new cancer occurred in two patients in the NV1FGF group. Conclusions that can be drawn from this relatively small patient group are limited because of the number of patients followed and can only be restricted to safety. Yet, data presented may be valuable concerning rates in cancer, retinopathy, MI or strokes following angiogenesis gene therapy in the absence of any long-term data in angiogenesis gene therapy. It may take several years until data from larger patient populations will become available.

Insights on the role of diabetes and geographic variation in patients with critical limb ischaemia.

BACKGROUND: Patients with critical limb ischaemia (CLI) unsuitable for revascularisation have a high rate of amputation and mortality (30% and 25% at 1 year, respectively). Localised gene therapy using plasmid DNA encoding acidic fibroblast growth factor (NV1FGF, riferminogene pecaplasmid) has showed an increased amputation-free survival in a phase II trial. This article provides the rationale, design and baseline characteristics of CLI patients enrolled in the pivotal phase III trial (EFC6145/TAMARIS). METHODS: An international, double-blind, placebo-controlled, randomised study composed of 525 CLI patients recruited from 170 sites worldwide who were unsuitable for revascularisation and had non-healing skin lesions was carried out to evaluate the potential benefit of repeated intramuscular administration of NV1FGF. Randomisation was stratified by country and by diabetic status. RESULTS: The mean age of the study cohort was 70 ± 10 years, and included 70% males and 53% diabetic patients. Fifty-four percent of the patients had previous lower-extremity revascularisation and 22% had previous minor amputation of the index leg. In 94% of the patients, the index leg had distal occlusive disease affecting arteries below the knee. Statins were prescribed for 54% of the patients, and anti-platelet drugs for 80%. Variation in region of origin resulted in only minor demographic imbalance. Similarly, while diabetic status was associated with a frequent history of coronary artery disease, it had little impact on limb haemodynamics and vascular lesions. CONCLUSIONS: Clinical characteristics and vascular anatomy of CLI patients with ischaemic skin lesions who were unsuitable for revascularisation therapy show little variations by region of origin and diabetic status. The findings from this large CLI cohort will contribute to our understanding of this disease process. This study is registered with ClinicalTrials.gov, number NCT00566657.

Drug-eluting stents: trading restenosis for thrombosis?

Within the last 6 years, it has been demonstrated that drug-eluting stents (DES) reduce significantly angiographic and clinical restenosis after percutaneous coronary interventions. These results are consistent across several clinical randomized controlled trials comparing these new devices with bare metallic stents (BMS), which themselves have already markedly improved the results obtained with balloon angioplasty in the early days of this method of myocardial revascularization. Nevertheless, some concerns have been raised regarding a delayed endothelialization of the coated prostheses leading to late stent thrombosis occurring mainly when antiplatelet therapy is discontinued in the follow-up. The most recent data show that, in comparison with BMS, there is a small excess of late (> 1 year) stent thrombosis but this is not associated with an increased risk of death or myocardial infarction or all cause mortality. These concerns do not outweigh the strong benefits of DES in preventing restenosis but require a number of measures concerning a longer dual antiplatelet treatment (than initially expected), to control patient treatment compliance and to provide a complete education of patients and physicians. Future devices dealing with the two issues (antiproliferative properties with rapid controlled endothelialization preventing thrombosis) would be the next major advance in this rapidly evolving field.

Functional mitral regurgitation and chronic heart failure.

Functional mitral regurgitation (MR) frequently develops during the progression of chronic heart failure and predicts poor outcome. Impaired left ventricular (LV) function, LV remodeling associated with papillary muscle apical displacement and annular enlargement result in decreased mitral closing forces and tenting of the mitral valve at closure. Reduced closing forces and tenting both promote MR. Active myocardial ischemia, myocardial asynchronism and excessive loading conditions worsen MR at rest and during exercise. The therapeutic target in functional MR is the left ventricle and not the valve.

Angiographically documented late reocclusion after successful coronary angioplasty of an infarct-related lesion is a powerful predictor of long-term mortality.

BACKGROUND: Late reocclusion of an infarct-related artery (IRA) that was patent in the early days after acute myocardial infarction (MI) is a frequent event; the reocclusion rate may be as high as 30%. Few studies have been designed to analyze the impact of late reocclusion of the IRA on late survival. METHODS AND RESULTS: We studied 528 patients who all had a patent IRA after a successful PTCA procedure 10+/-6 days after MI and who underwent systematic 6-month angiographic follow-up to assess late patency of the IRA. We compared long-term survival of patients with and without late reocclusion. Based on the results of 6-month follow-up angiography, 2 groups of patients were defined: (1) 90 patients (17%) with reocclusion (Thrombolysis In Myocardial Infarction [TIMI] flow 0 or 1) and (2) 438 patients (83%) without reocclusion. Long-term clinical follow-up was obtained for all 528 patients at a median of 5.7 years after follow-up angiography (6.4 years after PTCA). The overall actuarial 8-year total mortality rate was 13%. At the end of follow-up, there were 35 deaths (8%) among the 438 patients without reocclusion and 18 deaths (20%) among the 90 patients with reocclusion (P=0.002). The actuarial 8-year total mortality rate was 10% in patients without reocclusion and 28% in patients with reocclusion (P=0.0003). The actuarial cardiovascular mortality rate was 7% in patients without reocclusion and 25% in patients with reocclusion (P<0.0001). The impact of reocclusion on long-term mortality was greater in patients with anterior MI. CONCLUSIONS: Late IRA patency is strongly associated with long-term survival after MI. These observations should encourage prospective studies to evaluate the impact of strategies designed to prevent late reocclusion in postinfarction patients.

Patency of percutaneous transluminal coronary angioplasty sites at 6-month angiographic follow-up: A key determinant of survival in diabetics after coronary balloon angioplasty.

BACKGROUND: Several reports have demonstrated a high mortality rate in diabetic patients treated by standard coronary balloon angioplasty. No clear explanation has been provided for this finding. METHODS AND RESULTS: Consecutive diabetic patients successfully treated by standard coronary balloon angioplasty (n=604) were enrolled in a follow-up program including repeated angiography at 6 months and long-term clinical follow-up. Clinical follow-up was available in 603 patients (99.8%). Twelve patients died, 2 underwent bypass surgery before scheduled repeated angiography, and 76 declined angiography. Determinants of long-term mortality were analyzed in the 513 patients with angiography at 6 months and long-term clinical follow-up (mean follow-up, 6.5+/-2.4 years). On the basis of the results of repeated angiography, 3 groups of patients were defined: group 1, 162 patients without restenosis (32%); group 2, 257 patients with nonocclusive restenosis (50%); and group 3, 94 patients with coronary occlusion (18%). Overall actuarial 10-year mortality rate was 36%. Actuarial 10-year mortality was 24% in group 1, 35% in group 2, and 59% in group 3 (P:<0.0001). Multivariate analysis demonstrated that coronary occlusion was a strong and independent correlate of long-term total mortality (hazard ratio, 2.16; 95% CI, 1.43 to 3.26; P:=0.0003) and cardiac mortality (hazard ratio, 2.38; 95% CI, 1.48 to 3.85; P:=0.0004). CONCLUSIONS: This study demonstrates that restenosis, especially in its occlusive form, is a major determinant of long-term mortality in diabetic patients after coronary balloon angioplasty.

Passivation of metallic stents after arterial gene transfer of phVEGF165 inhibits thrombus formation and intimal thickening.

OBJECTIVES: This study sought to test the hypothesis that direct gene transfer of an endothelial cell mitogen could passivate metallic stents by accelerating endothelialization of the prosthesis. BACKGROUND: Thrombosis and restenosis comprise the principal clinical manifestations of compromised biocompatibility of endovascular stents. Previous studies have demonstrated that endothelial recovery at sites of balloon injury is a critical determinant of consequent intimal thickening and mural thrombus. We therefore investigated the potential for an endothelial cell mitogen delivered as plasmid DNA to optimize stent biocompatibility. METHODS: Naked plasmid DNA encoding vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF) (phVEGF165) was delivered locally using a hydrogel-coated balloon angioplasty catheter to 16 rabbit iliac arteries in which metallic stents had been placed at the site of balloon injury; the contralateral iliac artery of each rabbit was balloon injured and stented but not transfected. RESULTS: Stent endothelialization was accelerated by phVEGF165 gene transfer (87.38 +/- 5.06% vs. 33.13 +/- 9.73% [mean +/- SEM] of the planimetered stent surface in the treated vs. contralateral limb, p = 0.005). This was associated with a significant reduction in mural thrombus (3.7 +/- 2.4% vs. 32.7 +/- 9.7%, p = 0.01) at day 7 and intimal thickening (maximal intimal area 0.61 +/- 0.09 vs. 1.44 +/- 0.12 mm2, p < 0.0001) at day 28. No benefit was observed from pCMV-luciferase in 14 similarly instrumented control rabbits. CONCLUSIONS: These findings indicate that arterial gene transfer of naked plasmid DNA encoding for an endothelial cell mitogen may successfully passivate endovascular stents by accelerating stent endothelialization, thereby reducing in-stent thrombus and obstruction due to intimal thickening.

Restenosis, late vessel occlusion and left ventricular function six months after balloon angioplasty in diabetic patients.

OBJECTIVES: We studied angiographic outcome and its predictors after traditional coronary balloon angioplasty in diabetics. We further examined whether changes in ejection fraction were influenced by the status of the dilated site(s) at follow-up. BACKGROUND: Recent studies have suggested that diabetics have a particularly poor outcome after balloon angioplasty. The reasons for this observation are not known. METHODS: We investigated procedural and six-month angiographic outcome, analyzed by quantitative coronary angiography, and left ventricular function in 485 consecutive diabetics (627 lesions) treated by balloon angioplasty without stent implantation. RESULTS: The procedure was successful in 455 (94%) patients; angiographic follow-up was available in 377 patients (83%). At follow-up, the rates of restenosis and total occlusion were 62% and 13%, respectively. Five independent predictors of restenosis were identified: the presence of organ damage, a saphenous vein graft (SVG) angioplasty, a bifurcation lesion, a Thrombolysis in Myocardial Infarction (TIMI) flow <3 preprocedure and the degree of residual stenosis. Four independent predictors of vessel occlusion were identified: treatment with insulin, a SVG angioplasty, a TIMI flow <3 preprocedure and the degree of residual stenosis after angioplasty. Late vessel occlusion at angioplasty site(s) was observed in 15% of patients, ranging from 11% for a one-site procedure to 37% for a three-site procedure. This complication was associated with a decrease in ejection fraction at follow-up (-6.2 +/- 9.9%, p = 0.0001), whereas no significant change was observed in patients without occlusion. CONCLUSIONS: This study shows that late vessel occlusion is a frequent mode of restenosis in diabetic patients and is associated with a significant decrease in ejection fraction. This could partly explain the poor long-term clinical outcome reported in such patients after traditional balloon angioplasty.

Role of nitric oxide in restenosis after experimental balloon angioplasty in the hypercholesterolemic rabbit: effects on neointimal hyperplasia and vascular remodeling.

OBJECTIVES: The purpose of this study was to assess the effects of L-arginine and N(G)-nitro-L-arginine methyl ester (L-NAME) on neointimal hyperplasia and vascular remodeling after balloon angioplasty in the hypercholesterolemic rabbit. BACKGROUND: Restenosis after balloon angioplasty is a consequence of both neointimal hyperplasia and vessel remodeling. Nitric oxide inhibits neointimal hyperplasia, but its effect on vessel remodeling is unknown. METHODS: Six weeks after induction of bilateral iliac atherosclerosis, 48 rabbits underwent successful angioplasty in 75 vessels. Eight rabbits (acute group) were sacrificed immediately after angioplasty. The remaining animals received either placebo (chronic control group), or a diet supplemented with either L-arginine (1.5 g/kg/day), or L-NAME (15 mg/kg/day) for 4 weeks after angioplasty. RESULTS: The intimal area was significantly greater in the chronic control group compared to the acute group (2.60+/-1.03 mm2 vs. 1.35+/-0.62 mm2). This increase in intimal area was lower in the L-arginine group (1.79+/-0.61 mm2), and greater in the L-NAME group (3.23+/-0.92 mm2). The area circumscribed by the internal elastic lamina (IEL) increased significantly in the control group compared to the acute group (from 2.52+/-0.66 to 3.33+/-0.85 mm2); a more marked increase occurred in the L-NAME group (3.90+/-0.85 mm2). By contrast, IEL area was unchanged in the L-arginine group (2.41+/-0.62 mm2). As a result, there was no significant difference in lumen area after 4 weeks in the chronic groups (control: 0.74+/-0.38 mm2; L-arginine: 0.50+/-0.43 mm2; L-NAME: 0.48+/-0.42 mm2). CONCLUSIONS: Our results demonstrate that L-arginine inhibits whereas L-NAME stimulates neointimal hyperplasia after experimental balloon angioplasty in the hypercholesterolemic rabbit. However, the lack of vessel enlargement in the L-arginine group resulted in a similar final lumen size in the L-NAME and L-arginine groups.

Predictors of restenosis after coronary stent implantation.

OBJECTIVES: We sought to determine predictors of restenosis after coronary stenting (CS) in a consecutive series of patients. BACKGROUND: Although stenting in highly selected patient groups reduces restenosis, the results of stenting in a heterogeneous patient group and the effects of clinical and procedural factors on stent restenosis are currently unclear. METHODS: We analyzed the 6-month angiographic outcome of 500 lesions in 463 consecutive patients undergoing successful CS. Clinical, qualitative and quantitative angiographic variables were correlated with restenosis assessed as both a binary and a continuous variable. RESULTS: Restenosis, defined as the presence of >50% diameter stenosis in the dilated segment, was present in 105 (26%) of the 405 lesions with angiographic follow-up. The mean late lumen loss during the follow-up period was 0.79+/-0.64 mm. Implantation of multiple stents (p < 0.0001) and a high acute gain (p < 0.0002) were independently associated with a higher late lumen loss. In contrast, the use of high inflation pressure (p < 0.02) and Palmaz-Schatz stents (p < 0.005) was independently associated with a lower late lumen loss. When restenosis was defined as a qualitative variable, implantation of multiple stents (p < 0.001), stenosis length (p < 0.01), small reference diameter (p < 0.02) and stent type other than Palmaz-Schatz (p < 0.01) were independent predictors of restenosis. None of the clinical variables tested was associated with restenosis. CONCLUSIONS: Coronary stenting in an unselected patient group is associated with an acceptable restenosis rate. Although some risk factors were identified, the risk of restenosis was not related to most of the variables tested. This suggests that the superiority of CS over balloon angioplasty, in terms of restenosis, might also apply to subgroups of patients that were not included in the recent randomized studies.

Effect of pravastatin on angiographic restenosis after coronary balloon angioplasty. The PREDICT Trial Investigators. Prevention of Restenosis by Elisor after Transluminal Coronary Angioplasty.

OBJECTIVES: This study sought to determine whether pravastatin affects clinical or angiographic restenosis after coronary balloon angioplasty. BACKGROUND: Experimental data and preliminary clinical studies suggest that lipid-lowering drugs might have a beneficial effect on restenosis after coronary angioplasty. METHODS: In a multicenter, randomized, double-blind trial, 695 patients were randomized to receive pravastatin (40 mg/day) or placebo for 6 months after successful balloon angioplasty. All patients received aspirin (100 mg/day). The primary angiographic end point was minimal lumen diameter (MLD) at follow-up, assessed by quantitative coronary angiography. A sample size of 313 patients per group was required to demonstrate a difference of 0.13 mm in MLD between groups (allowing for a two-tailed alpha error of 0.05 and a beta error of 0.20). To allow for incomplete angiographic follow-up (estimated lost to follow-up rate of 10%), 690 randomized patients were required. Secondary end points were angiographic restenosis rate (restenosis assessed as a categoric variable, > 50% stenosis) and clinical events (death, myocardial infarction, target vessel revascularization). RESULTS: At baseline, clinical, demographic, angiographic and lipid variables did not differ significantly between groups. In patients treated with pravastatin, there was a significant reduction in total and low density lipoprotein cholesterol and triglyceride levels and a significant increase in high density lipoprotein cholesterol levels. At follow-up the MLD (mean +/- SD) was 1.47 +/- 0.62 mm in the placebo group and 1.54 +/- 0.66 mm in the pravastatin group (p = 0.21). Similarly, late loss and net gain did not differ significantly between groups. The restenosis rate (recurrence > 50% stenosis) was 43.8% in the placebo group and 39.2% in the pravastatin group (p = 0.26). Clinical restenosis did not differ significantly between groups. CONCLUSIONS: Although pravastatin has documented efficacy in reducing clinical events and angiographic disease progression in patients with coronary atherosclerosis, this study shows that it has no effect on angiographic outcome at the target site 6 months after coronary angioplasty.

A comparison of systematic stenting and conventional balloon angioplasty during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction. STENTIM-2 Investigators.

OBJECTIVES: In a multicenter, randomized trial, systematic stenting using the Wiktor stent was compared to conventional balloon angioplasty with provisional stenting for the treatment of acute myocardial infarction (AMI). BACKGROUND: Primary angioplasty in AMI is limited by in-hospital recurrent ischemia and a high restenosis rate. METHODS: A total of 211 patients with AMI <12 h from symptom onset, with an occluded native coronary artery, were randomly assigned to systematic stenting (n = 101) or balloon angioplasty (n = 110). The primary end point was the binary six-month restenosis rate determined by core laboratory quantitative angiographic analysis. RESULTS: Angiographic success (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3 and residual diameter stenosis <50%) was achieved in 86% of the patients in the stent group and in 82.7% of those in the balloon angioplasty group (p = 0.5). Compared with the 3% cross-over in the stent group, cross-over to stenting was required in 36.4% of patients in the balloon angioplasty group (p = 0.0001). Six-month binary restenosis (> or = 50% residual stenosis) rates were 25.3% in the stent group and 39.6% in the balloon angioplasty group (p = 0.04). At six months, the event-free survival rates were 81.2% in the stent group and 72.7% in the balloon angioplasty group (p = 0.14), and the repeat revascularization rates were 16.8% and 26.4%, respectively (p = 0.1). At one year, the event-free survival rates were 80.2% in the stent group and 71.8% in the balloon angioplasty group (p = 0.16), and the repeat revascularization rates were 17.8% and 28.2%, respectively (p = 0.1). CONCLUSIONS: In the setting of primary angioplasty for AMI, as compared with a strategy of conventional balloon angioplasty, systematic stenting using the Wiktor stent results in lower rates of angiographic restenosis.

Prevention of restenosis future directions.

Restenosis remains the major limitation of percutaneous transluminal coronary angioplasty. Restenosis after balloon angioplasty is due to vascular remodeling and neointimal hyperplasia. In spite of encouraging results in animal models, most of the pharmacological trials of prevention of restenosis in humans have produced negative results. This has prompted interest in the potential role of locally delivered drugs and various balloon catheter systems that are now available to achieve local delivery of therapeutic agents at the site of arterial injury. In 1997, implantation of a coronary stent in conjunction with balloon angioplasty is performed in an increasing number of patients. Randomized studies have shown that coronary stenting may reduce the risk of restenosis. In addition, restenosis after coronary stenting is mainly due to neointimal hyperplasia. Restenosis within coronary stents might thus be much more sensitive to therapies designed to inhibit neointimal hyperplasia than restenosis after balloon angioplasty. Thus, the future prevention of restenosis might well be the combination of a mechanical device that produces the widest possible lumen and prevents vessel constriction with a pharmacologic approach to inhibit the proliferative process. (Trends Cardiovasc Med 1997;7:90-94). © 1997, Elsevier Science Inc.

Percutaneous delivery of the gax gene inhibits vessel stenosis in a rabbit model of balloon angioplasty.

OBJECTIVES: The expression of gax, an anti-proliferative homeobox gene, is rapidly downregulated in vascular smooth muscle cells (VSMCs) following arterial injury. Here we performed percutaneous adenovirus-mediated gene transfer into the iliac arteries of normal rabbits using a channel balloon catheter to assess the effects of gax overexpression on neointima formation, lumen diameter, reendothelialization and functional vasomotion. METHODS: A channel balloon catheter was used to perform both the arterial injury and local gene delivery. In each animal both iliac arteries were randomly assigned to receive either an adenovirus expressing the gax gene (Ad-Gax) or the beta-galactosidase gene (Ad-beta gal). In a second group of animals arteries were randomly assigned to receive either Ad-beta gal or saline. RESULTS: At one month, angiography revealed 36% less luminal narrowing in the Ad-Gax-treated arteries relative to the Ad-beta gal-treated control arteries. Histological analysis revealed that the intimal/medial ratio (I/M) was reduced by 56% in the Ad-Gax group. Endothelium-dependent vasomotion was not affected by the gax gene transfer. In the second group, no statistically significant differences were found between the saline and the Ad-beta gal-treated vessels for any of these parameters. CONCLUSIONS: Percutaneous adenovirus delivery of the gax gene to rabbit iliac arteries following endothelial denudation and vessel wall injury reduces neointimal hyperplasia and luminal stenosis, but does not affect endothelium-dependent vasomotion. This study demonstrates that a VSMC transcription factor can potentially be utilized for the development of a molecular therapy for vascular disorders.

Neointimal thickening after balloon denudation is enhanced by aldosterone and inhibited by spironolactone, and aldosterone antagonist.

OBJECTIVE: The aim was to examine the effects of aldosterone and of an aldosterone antagonist, spironolactone, on neointimal thickening in a rabbit model of balloon injury. METHODS: Eighteen rabbits underwent aortic and iliac balloon injury and were randomised to subcutaneous infusion of aldosterone (70 micrograms.kg-1.d-1) or vehicle solution for 28 d. Eighteen other rabbits were randomised to receive daily subcutaneous injections of spironolactone (50 mg.kg-1.d-1) or of vehicle for 7 d before injury and for 28 d after the procedure. All animals were then killed just after measurement of plasma renin activity and of arterial pressure. Vessels were fixed and five cross sections were analysed per rabbit (three aortic; two from iliac artery). Mean values of neointimal area and of the neointimal area/medial area ratio were calculated. RESULTS: Aldosterone treatment was associated with a decrease in renin activity and a non-significant increase in mean arterial pressure. Aldosterone significantly augmented the neointimal thickening in the iliac artery [0.42(SEM 0.07) v 0.24(0.03) mm2, P < 0.05] but not in the aorta [0.63(0.08) v 0.59(0.12) mm2, NS]. Spironolactone significantly inhibited intimal thickening, both in the iliac artery [0.09(0.02) v 0.29(0.01) mm2, P < 0.001] and in the aorta [0.31(0.03) v 0.59(0.06) mm2, P < 0.001]. Spironolactone administration was associated with an increase in renin activity and a decrease in mean arterial blood pressure. CONCLUSIONS: Aldosterone administration enhances neointimal thickening after injury and spironolactone, an aldosterone antagonist, is a potent inhibitor of neointimal thickening in the same model. This suggests a role for aldosterone in the pathophysiology of neointimal proliferation after balloon injury and for aldosterone antagonists in its prevention.

L-arginine and L-NAME have no effects on the reendothelialization process after arterial balloon injury.

OBJECTIVE: Growth regulatory properties of nitric oxide (NO) in cultured endothelial cells is controversial. The aim of our study was to investigate the effect of L-arginine, the endogenous NO precursor, and L-NAME, an inhibitor of NO synthase on the reendothelialization process after angioplasty. METHODS: Fifty-five New Zealand White rabbits underwent denudation of the left iliac artery. After injury the rabbits were randomized in three groups: L-arginine 2.25% (L-arginine, n = 19); NG-nitro-L-arginine methyl ester 15 mg/kg/day (L-NAME, n = 19); and placebo (controls, n = 17). Treatment was solubilized in drinking water. Reendothelialization was evaluated at 4 weeks by macroscopic evaluation of Evans blue staining and endothelial-specific immunostaining (CD-31) on cross sections. Intimal hyperplasia was evaluated by morphometric analysis. RESULTS: Despite a significant increase in plasma arginine (P = 0.001) and a reduction in intimal hyperplasia (P = 0.003) with L-arginine, neither agent had a significant effect on reendothelialization at 4 weeks (controls = 36 +/- 4%, L-arginine = 43 +/- 3%, L-NAME = 33 +/- 4%; NS). CONCLUSION: These results suggest that, in spite of previously demonstrated effects on neointimal hyperplasia, the NO pathway does not influence the regrowth of macrovascular endothelial cells in vivo.

Circulatory support devices: fundamental aspects and clinical management of bleeding and thrombosis.

Circulatory support devices are increasingly being used to overcome cardiac or respiratory failure. Long-term devices are used either as a 'bridge to transplant' to support patients who are unable to wait any longer for a heart transplant, or, more recently, as 'destination therapy' for older patients suffering from end-stage heart failure and who have contraindications to heart transplantation. Short-term support devices for high-risk percutaneous coronary intervention, or as a 'bridge for decision' for patients suffering from refractory cardiogenic shock, have also been developed. The clinical benefit of such assist devices has been demonstrated in several important studies, but, unfortunately, thrombotic and bleeding complications are two major clinical issues in patients requiring these devices. Overcoming these issues is of major importance to allow the safe and broad use of these devices, and to consider them as true alternatives to heart transplantation. The present review focuses on thrombotic and bleeding complications, and describes how the risk of thrombosis and bleeding may vary according to the clinical indication, but also according to the type of device. We describe the current knowledge of the mechanisms underlying the occurrence of these complications, provide some guidance for choosing the most appropriate anticoagulation regimen to prevent their occurrence for each type of device and indication, and provide some recommendations for the management of patients when the complication occurs.

Autologous Mesenchymal Stem Cells Show More Benefit on Systolic Function Compared to Bone Marrow Mononuclear Cells in a Porcine Model of Chronic Myocardial Infarction.

Cardiac cell therapy is a strategy to treat patients with chronic myocardial infarction (MI). No consensus exists regarding the optimal cell type. First, a comparison between autologous bone marrow-derived mononuclear cells (BMMNC) and mesenchymal stem cells (MSC) on therapeutic efficacy after MI was performed. Next, the effect of repetitive, NOGA-guided transendocardial injection was determined via a crossover design. Nineteen pigs were allocated in three groups: (1) placebo (at 4 and 8 weeks), (2) MSC (followed by placebo at 8 weeks), or (3) BMMNC (followed by MSC at 8 weeks) delivery including a priming strategy to enhance MSC effect. At 4 weeks, ejection fraction (EF) was significantly improved after MSC injection and not by BMMNC injection. After 8 weeks, no difference was observed in EF between cell-treated groups demonstrating the positive systolic effect of MSC. This study showed that MSC rather than BMMNC injection improves systolic function in chronic MI.

Effects of poloxamer 407 on transfection time and percutaneous adenovirus-mediated gene transfer in native and stented vessels.

UNLABELLED: Reduction in transfection time and the ability to perform gene transfer in conjunction with endovascular stent implantation constitute two important challenges for percutaneous adenovirus-mediated gene transfer to vessel walls. Studies have suggested that the use of biocompatible polyol poloxamer 407 could be useful. We first evaluated the use of poloxamer 407 for percutaneous gene transfer in nonstented rabbit iliac arteries. A 200-microl mixture of Ad-RSVbetagal or Ad-CMVLuc in either phosphate-buffered saline (PBS) or 20% poloxamer was delivered. After 3 days, gene transfection was evaluated by X-Gal staining or measurement of luciferase activity. Poloxamer use resulted in a 3- to 15-fold increase in the percentage of transfected cells (X-Gal, p = 0.001) and a 16-fold increase in protein product (luciferase activity, p = 0.03), and allowed a decrease in transfection time from 30 to 5 min with minimal reduction in transfection efficiency. We then evaluated the feasibility of percutaneous gene transfer, using Ad-RSVbetagal diluted in pure PBS or 20% poloxamer, in conjunction with stent implantation. Gene delivery was performed either immediately before (pre-) or after (post-) stent implantation. When adenoviruses were diluted in PBS, gene transfer had a low efficiency (prestent, 0.3%; poststent, 0.2%; NS). With poloxamer, the efficacy was much higher (p = 0.0001) and similar "pre" (2.2%) or "post" (1.7%) stent delivery (NS). CONCLUSIONS: (1) The use of poloxamer, rather than PBS, as a vehicle increases the efficacy of percutaneous adenovirus-mediated gene transfer and reduces transfection time; (2) gene transfer performed during stent implantation with poloxamer is feasible and achieves a significant level of gene expression. Thus percutaneous gene delivery is applicable to conventional stents and could present an attractive method by which to achieve local biological effects in a stent environment.