Percutaneous intervention for infrainguinal occlusive disease in women: equivalent outcomes despite increased severity of disease compared with men.

OBJECTIVES: Experience with open surgical bypass suggests similar overall outcomes in women compared with men, but significantly increased risk of wound complications. Percutaneous treatment of lower extremity occlusive disease is therefore an attractive alternative in women, although it is not clear whether there is a difference in outcomes between women and men treated with this technique. We sought to determine the results and predictors of failure in women treated by percutaneous intervention. METHODS: Percutaneous infrainguinal revascularization was performed on 309 women between 2001 and 2006. Procedures, complications, demographics, comorbidities, and follow-up data were entered into a prospective database for review. Patency was assessed primarily by duplex ultrasonography. Outcomes were expressed by Kaplan-Meier curves and compared by log-rank analysis. RESULTS: A total of 447 percutaneous interventions performed in 309 women were analyzed and compared with 553 interventions in men. Mean age in women was 73.2 years; comorbidities included hypertension (HTN) (86%), diabetes melitus (DM) (58%), chronic renal insufficiency (CRI) (15%), hemodialysis (7%), hypercholesterolemia (52%), coronary artery disease (CAD) (42%), and tobacco use (47%). Indications in women included claudication (38.0%), rest pain (18.8%), and tissue loss (43.2%). Overall primary & secondary patency and limb-salvage rates for women were 38% +/- 4%, 66% +/- 3%, and 80% +/- 4% at 24 months. In this patient sample, women were significantly more likely than men to present with limb-threatening ischemia (61.6% vs 47.3%, P < 0.001) and have lesions of TASC C and D severity (71.4% vs 61.7%, P < .005). However, there were no significant differences in primary and secondary patency rates or limb-salvage rates between genders. Furthermore, while women with limb-threat, diabetes, and advanced TASC severity lesions were at increased risk of failure overall, there were no differences between women and men with these characteristics. CONCLUSIONS: Percutaneous infrainguinal revascularization is a very effective modality in women with lower extremity occlusive disease. Although women in this sample were more likely to present with limb-threat than men, patency and limb-salvage rates were equivalent between genders, even in high-risk subsets such as diabetics or those with lesions of increased TASC severity.

Ambient pressure upregulates nitric oxide synthase in a phosphorylated-extracellular regulated kinase- and protein kinase C-dependent manner.

PURPOSE: Using endothelial cell/smooth muscle cell (SMC) cocultures, we have demonstrated that pressurized endothelial cell coculture inhibits SMC proliferation and promotes apoptosis, and that this effect is transferable through pressurized endothelial medium. We now hypothesized that endothelial nitric oxide synthase (eNOS) plays a significant role in mediating these pressure-induced effects. METHODS: Conditioned media from endothelial cells and SMCs exposed to ambient and increased pressure were transferred to recipient SMCs. We counted cells after 5 days of incubation with these media and evaluated eNOS and inducible NOS (iNOS) levels by Western blot. RESULTS: Conditioned media from pressurized endothelial cells significantly decreased recipient SMC counts. This effect was sustained when N-nitro-L-arginine-methyl ester (L-NAME) was added to recipient cells but abolished when L-NAME was added to donor cells. SMCs were then exposed to control and pressurized conditions in monoculture or in coculture with endothelial cells. Pressure and coculture caused similar increase in iNOS levels but had no additive effect in combination. Finally, endothelial cells were exposed to control and pressurized environments. Pressure caused a 24% +/- 1.6% increase in eNOS protein (P = .04, n = 12). This effect was sustained when cells were treated with L-NAME (32% +/- 1.6% increase, P = .02) but abolished when endothelial cells were treated with calphostin C or PD98059 to block protein kinase C (PKC) or extracellular regulated kinase (ERK). Pressure also increased endothelial phosphorylated ERK (p-ERK) by 1.8-fold to 2.6-fold compared with control conditions after exposure of 2, 4, and 6 hours (P = .02, n = 4). This increase was sustained after pretreatment with calphostin C. CONCLUSION: Pressure modulates endothelial cell effects on SMC growth by increasing eNOS in an ERK-dependent and PKC-dependent manner. CLINICAL RELEVANCE: Intimal hyperplasia is the main cause for restenosis that complicates 10% to 30% of all such vascular procedures and 30% to 40% of endovascular procedures. This article provides some novel information about smooth muscle cell/endothelial cell interaction, one of the main regulators of vascular remodeling and intimal hyperplasia. The role of endothelial cell/smooth muscle cell interaction cannot be studied well in vivo because these interactions cannot be distinguished from other factors that coexist in vivo, such as flow dynamics, matrix proteins, inflammatory factors, and interactions with other cells in the vascular wall and in the bloodstream. In this work, we use pressure as a triggering stimulus to alter in vitro endothelial behavior and identify important changes in endothelial regulation of smooth muscle cell biology. The pathways involved in this process and discussed in this article could ultimately be used to manipulate endothelial cell/smooth muscle cell interaction in clinical disease.

Detection of carotid stenosis in African Americans with ischemic heart disease.

OBJECTIVES: This study was conducted to define the frequency of internal carotid stenosis in African American patients with ischemic heart disease (IHD). METHODS: We recruited 101 African American patients with IHD from a university medical center for carotid duplex examination. RESULTS: The frequency of >30%, >50%, and >70% stenosis was 21%, 11%, and 5%, respectively. Age >60 years (21% vs 3%, P < .01) and diabetes mellitus (22% vs 5%, P < .01) were predictors of unilateral stenosis of >50% and remained significant on multivariate testing. CONCLUSION: African American patients with established IHD have higher rates of extracranial carotid stenosis than community dwelling African American subjects and comparable rates with other populations.

Pressure alters endothelial effects upon vascular smooth muscle cells by decreasing smooth muscle cell proliferation and increasing smooth muscle cell apoptosis.

BACKGROUND: Although de-endothelialization after vascular intervention is associated with intimal hyperplasia, endothelial cells (ECs) increase smooth muscle cell (SMC) numbers in conventional cocultures. In previously published work, SMCs cocultured with ECs in a chronic high-pressure environment exhibited significantly decreased cell counts compared to monocultured SMCs in the same high pressure. This finding contrasted with SMCs cocultured with ECs in ambient pressure, which exhibited significantly higher cell counts than the monocultured SMCs in ambient pressure. We now hypothesize that extracellular pressure decreases SMC number during coculture with ECs by decreasing SMC proliferation through nuclear protein regulation and by increasing SMC apoptosis. Furthermore, this effect depends on the EC response to pressure. METHODS: Rat aortic SMCs were cultured independently (SMC/0) or cocultured with EC (SMC/EC) under either atmospheric or increased pressure (130-135 mmHg over ambient, SMC/0-P and SMC/EC-P) for 5 days. We assessed SMC proliferative potential by determining c-myc expression (by protein analysis), apoptosis (by cell counting, staining with acridine orange or TUNEL technique), and topoisomerase IIalpha levels. Parallel studies measured the effects of conditioned media from monocultured EC and SMC exposed for 5 days to control or increased pressure on recipient SMC growing in conventional culture. RESULTS: In high-pressure conditions, SMC/EC-P exhibited 42% less c-myc expression than SMC/0s (P = .00028). Significantly increased apoptotic activity (22 +/- 1.8%) in SMC/EC-Ps compared to SMC/0s was coupled with significantly lower topoisomerase IIalpha levels. Interestingly, pressure (SMC/0-P) and EC coculture (SMC/EC) each separately raised myocyte apoptotic activity to 15 +/- 1.3% and 17 +/- 2.0%, respectively. Conditioned media from pressurized ECs caused a 20% decrease in cell counts in target SMC compared to conditioned media from ECs in atmospheric pressure. Media from pressurized SMCs did not affect target SMCs. CONCLUSIONS: In a model designed to study SMC/EC interactions in a dynamic environment, EC exposure to pressure alters the growth characteristics and apoptotic activity of SMCs via a secreted factor. Extracellular pressure may alter EC regulation of SMC behavior and regulate intimal hyperplasia.

Chronic high pressure potentiates the antiproliferative effect and abolishes contractile phenotypic changes caused by endothelial cells in cocultured smooth muscle cells.

UNLABELLED: High in vitro pressures have been reported to alter smooth muscle cell (SMC) and endothelial cell (EC) phenotype, while endothelial cells (ECs) can influence the proliferation, phenotype, and contractile features of smooth muscle cells (SMC) in coculture systems. However, little is known about the in vitro effects of pressure on EC/SMC cocultures. We therefore sought to compare SMC proliferation in independent and EC coculture under ambient and high pressure, and identify changes in the contractile phenotype of SMCs by measuring levels of the L-type Ca(2+) channel a(1) subunit (dihydropyridine-DHP receptor) which is critical for Ca(2+) transients, differentiation and contractility in SMC. METHODS: Rat aortic SMCs in independent culture (SMC/0) and coculture with ECs (SMC/EC) were maintained in 5% CO(2) under either atmospheric or high pressure (130 mmHg). SMC were counted at 0, 1, 3, and 5 days and compared to initial cell counts of day 0 before the exposure to experimental conditions. DHP receptor levels were quantitated by Western blotting (three similar studies). RESULTS: ECs suppressed SMC proliferation on day 1 of coculture in both atmospheric and high pressure (20% inhibition vs independent culture, P < or = 0.05). By day 3, cocultured SMC under atmospheric pressure displayed no EC-mediated inhibition, and at day 5, atmospheric cocultured SMCs revealed statistically significant enhanced proliferation as compared with SMCs in independent cultures. However, cocultured SMCs exposed to 130 mmHg pressure displayed sustained sensitivity to EC growth inhibition at both days 3 and 5 of the experiment. Coculture decreased SMC DHP-receptor levels under atmospheric pressure. However, this effect was abolished in cocultures exposed to high pressure. CONCLUSIONS: High pressure substantially alters the regulatory influence of EC on SMC proliferation and contractile potential. This pressure/coculture model should increase our understanding of cellular interaction in hypertensive vasculopathy.