Biomedical subjects

A E Raizner

Publications and source records attributed to A E Raizner.

At least 37 records · Page 2Linked to original sources

PubMed1995

Differential inhibition of platelet aggregation induced by adenosine diphosphate or a thrombin receptor-activating peptide in patients treated with bolus chimeric 7E3 Fab: implications for inhibition of the internal pool of GPIIb/IIIa receptors.

OBJECTIVES: This study sought to describe in detail the pharmacokinetics and pharmacodynamics of chimeric monoclonal 7E3 Fab (c7E3 Fab) and to compare platelet responses to adenosine diphosphate (ADP) and the 11-amino acid thrombin receptor-activating peptide (TRAP [SFLLRNPNDKY-NH2]) in patients undergoing elective coronary angioplasty. BACKGROUND: Inhibition of platelet aggregation with monoclonal antibody c7E3 Fab directed against glycoprotein (GP) IIb/IIIa has been shown to reduce ischemic complications after angioplasty and is being considered for treatment of other acute ischemic syndromes. METHODS: Patients undergoing elective coronary angioplasty received aspirin (325 mg orally), heparin (12,000 U intravenously) and a bolus of c7E3 Fab (0.25 mg/kg body weight). Surface GPIIb/IIIa receptor blockade and aggregation in response to 20 mumol/liter ADP, 5 micrograms/ml collagen and 7.5 and 15 mumol/liter TRAP were assessed. RESULTS: Surface GPIIb/IIIa receptor blockade by c7E3 Fab was 80% 2 h after injection and decreased to 50% at 24 h. Platelet aggregation in response to 20 mumol/liter ADP was inhibited by 73% at 2 h, and this inhibition decreased to 27% at 24 h. Platelet aggregation in response to 7.5 mumol/liter TRAP was inhibited by 53% at 2 h and 30% at 24 h. In contrast, aggregation in response to 15 mumol/liter TRAP was inhibited only 37% at 2 h and 10% at 24 h (p < 0.001 and p = 0.006, respectively vs. 20 mumol/liter ADP). Addition of exogenous c7E3 Fab to platelet-rich plasma led to more complete inhibition of 7.5 mumol/liter TRAP-induced aggregation. CONCLUSIONS: After c7E3 Fab treatment, inhibition of platelet aggregation depends on the agonist and can be overcome by increased thrombin activity but is restored if additional c7E3 Fab is added to block additional GPIIb/IIIa receptors. This phenomenon may be related to an internal pool of GPIIb/IIIa receptors joining the surface membrane and has implications concerning the duration of therapy with c7E3 Fab for patients with unstable angina or acute myocardial infarction.

Abciximab↗

PubMed1994

Fate of side branches after intracoronary implantation of the Gianturco-Roubin flex-stent for acute or threatened closure after percutaneous transluminal coronary angioplasty.

Side branch occlusion may occur in the course of percutaneous transluminal coronary angioplasty (PTCA), particularly if complicated by site dissection. Concern that the additional placement of a stent may further jeopardize side branches is logical. Consequently, this study analyzed pre-PTCA, post-PTCA, poststent, and 6-month follow-up angiograms of 100 consecutive patients in whom 103 Gianturco-Roubin stents were implanted for acute or threatened closure after PTCA. Side branches were defined as major (> 50% of the stented vessel diameter) and minor (< 50%). Minor branches, often < 1 mm in diameter, were assessed only for patency. One hundred eight major branches, of which 33 were diseased (> 50% stenosis), and 129 minor branches were analyzed. Seven major branches (6%), all of which were diseased before PTCA, and 23 minor branches (18%) were lost after PTCA. Immediately after stent insertion, only 1 additional major and 1 minor branch were lost, whereas 2 of 7 major (29%) and 9 of 23 minor (39%) branches reappeared. At follow-up angiography, 7 major branches (6%) were more stenosed and 6 (6%) were improved compared with the angiogram before PTCA. Only 2 major (2%) and 5 minor (4%) branches remained occluded. Additionally, 2 major and 1 minor branch, which were patent after PTCA and stenting, were occluded at follow-up as a result of total occlusion of the stented segment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1994

Directional atherectomy with the Omnicath: a unique new catheter system.

Omnicath is a directional atherectomy catheter that employs deflecting nontraumatizing wires to anchor the cutting window at the atherectomy site. This anchoring system regulates the depth of cut and provides directional control and distal perfusion. The system continuously removes debris through a suction port from the operative site. To demonstrate the performance of the device, the Omnicath was tested in the external iliac arteries of ten atherosclerotic Hanford miniature swine in which concentric and eccentric lesions were induced. Five animals were sacrificed 3 days after atherectomy; the remaining five animals were sacrificed 6 weeks after the procedure. The acute histology demonstrates depth of cuts varying from partial plaque removal to near full thickness removal of the arterial wall. Histologic sections of the 6 week follow-up group demonstrated minimal healing response. The anchoring wires did not induce either acute injury or neointimal proliferation in the 6 week follow-up period. In conclusion, the Omnicath permits effective and safe atherectomy in this investigative model.

Animals↗

PubMed1994

Is intravascular ultrasound better than quantitative coronary arteriography to assess cardiac allograft arteriopathy?

Optimal methods to detect and quantify allograft arteriopathy have not been established. Both arteriography and intravascular ultrasound have been used to evaluate vessel lumen diameter and area and arterial wall thickness in patients following cardiac transplantation, although due to the anatomically diffuse nature of this disease, neither technique has been accepted as the diagnostic "gold standard". To determine the usefulness of quantitative angiography to detect transplant-related coronary artery disease compared to intravascular ultrasound, 25 patients underwent both procedures following cardiac transplantation (20 < 1 year, 5 > 1 year). Lumen diameter and area measurements of proximal coronary artery segments were compared using both techniques. Overall, lumen diameter and area measurements correlated closely between the two procedures, both for the early and late follow-up patients. However, because of the ability to characterize changes more precisely in coronary vessel shape and wall thickness, intravascular ultrasound offered distinct advantages over routine coronary angiography and is probably the technique of choice to evaluate allograft arteriopathy.

Adult↗

PubMed1994

The crumpled coronary: an enigma of arteriographic pseudopathology and its potential for misinterpretation.

A series of angioplasty cases is presented in which dynamic alterations in coronary artery configuration developed. These changes were suggestive of extensive, complex dissections. Several common features emerged in these cases of which interventional cardiologists should be aware. These features included complex vessel morphology (tortuous segments, anomalous takeoffs, and complex stenoses) and the use of certain types of PTCA hardware (Amplatz guiding catheters and 0.018-inch wires). This phenomenon, termed pseudo narrowing, remains largely unrecognized. Identification of these characteristics and employment of proper management strategies will ensure a good outcome in these situations when they arise.

Aged↗

PubMed1994

Comparison of three porcine restenosis models: the relative importance of hypercholesterolemia, endothelial abrasion, and stenting.

BACKGROUND: Porcine models of post-angioplasty restenosis commonly rely on hypercholesterolemia, endothelial abrasion, and intracoronary stenting to induce neointimal thickening. Although stenting clearly induces marked thickening, the influence of pre-stenting endothelial abrasion, and pre- and post-stenting hypercholesterolemia, on the degree and nature of post-stenting neointimal thickening is not clear. In order to assess this influence, we compared the quantity and quality of neointimal thickening in three stented swine restenosis models. METHODS: Twenty-three Hanford miniature swine completed one of three protocols. Model A animals (n = 9) were fed a cholesterol-raising diet, underwent endothelial abrasion of the left anterior descending (LAD) and circumflex (CFX) coronary arteries after 2 weeks on this diet, had balloon-expandable tantalum coil stents placed in the right coronary artery (RCA), LAD, and CFX after 9 weeks on the diet, and were killed 4 weeks later (total of 13 weeks on diet). Model B animals (n = 7) were also fed the cholesterol-raising diet, underwent stenting after 5 weeks on the diet, and were killed 4 weeks later (total of 9 weeks on diet). Model C animals (n = 7) were fed normal swine food, underwent stenting, and were killed 4 weeks later. Endothelial abrasion was not performed in models B and C. RESULTS: Quantitative angiography revealed no significant differences between models in the change of minimal lumen diameter (mm +/- SD) of stented vessels from post-stenting to pre-sacrifice (LAD: 1.05 +/- 0.74, 0.75 +/- 0.62 and 1.05 +/- 0.34; CFX: 1.00 +/- 0.65, 0.83 +/- 0.51 and 1.17 +/- 0.38; RCA: 0.99 +/- 0.35, 0.20 +/- 0.34, and 0.94 +/- 0.80 for models A, B, and C, respectively; all P = NS). Likewise, morphometric analysis showed no differences in percentage area stenosis (% +/- SD) over the same time (LAD: 55 +/- 15, 44 +/- 24, and 42 +/- 16; CFX: 54 +/- 12, 55 +/- 17, and 40 +/- 15; RCA: 39 +/- 20, 34 +/- 11, and 26 +/- 13 for models A, B, and C, respectively; P = NS). The neointima in each model predominantly consisted of smooth muscle cells and collagen matrix. CONCLUSIONS: The degree and nature of coronary artery neointimal thickening 4 weeks after stenting in normolipemic swine are similar to those in stented swine after 9 weeks on a high-cholesterol diet or 13 weeks on a high-cholesterol diet and early endothelial abrasion. The insertion of an intracoronary stent appears to be the major stimulus to neointimal thickening in these swine models of post-angioplasty restenosis.

Angioplasty, Balloon, Coronary↗

PubMed1994

Major clinical events after coronary stenting. The multicenter registry of acute and elective Gianturco-Roubin stent placement. The Gianturco-Roubin Intracoronary Stent Investigator Group.

BACKGROUND: Abrupt vessel closure and early reocclusion remain the principal vascular events underlying early recurrent ischemia complicating elective percutaneous transluminal coronary angioplasty (PTCA). Intracoronary stenting has been used to circumvent emergency bypass surgery after acute vessel closure and as an adjunct for the elective treatment of restenosis. The initial multicenter experience with the Gianturco-Roubin stent is presented, and predictors for early recurrent ischemic events are identified. METHODS AND RESULTS: Data accrued from 639 serial patients undergoing emergency stenting for abrupt closure (n = 415; 65%) or elective deployment for restenosis (n = 224; 35%) from October 1989 through May 1991 were analyzed. The incidence of subsequent ischemic events, including death, nonfatal myocardial infarction, and bypass surgery referral within 90 days of the procedure, was higher after acute deployment (20%) compared with elective stenting (9%; P = .0004). Although mortality within the two cohorts was the same (3%; P = NS), there were significant differences in the incidence of nonfatal myocardial infarction (5% versus 0.5%; P = .002) and bypass surgery (12% versus 6%; P = .02) between the acutely and electively stented patients, respectively. These events were significantly more common when the stent was undersized to the target vessel diameter (stent:artery ratio for event, 0.95 +/- 0.14 versus no event, 1.04 +/- 0.22; P = .0001) or when there was less expansion of the lesion by the deployed device (stent-to-lesion diameter ratio for event, 6.6 +/- 9.2 versus no event, 11.0 +/- 21.4; P = .0001). In a stepwise logistic regression model, acute stenting (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3 to 2.4), multivessel disease (OR, 1.4; CI, 1.1 to 1.8), larger target lesion diameter (OR, 2.1; CI, 1.4 to 3.2), larger target vessel (OR, 2.9; CI, 1.7 to 4.7), and smaller stent size (OR, 6.1; CI, 3.0 to 12.3) were independent predictors of early, recurrent ischemic events. The presence of thrombus was associated with a higher event rate after elective stenting (OR, 2.3; CI, 1.06 to 5.4) but was not associated with a higher early event rate after acute stenting. CONCLUSIONS: Early ischemic events are more common after acute stenting for abrupt or threatened closure than after elective deployment. These events may be avoided with careful attention to morphometric characteristics to avoid undersizing the stent to the target vessel and ensure adequate lesion expansion.

Angioplasty, Balloon, Coronary↗

PubMed1994

Do fish oils prevent restenosis after coronary angioplasty?

BACKGROUND: The omega-3 polyunsaturated fatty acids derived from fish oils have been shown to modulate many factors believed to affect the pathogenesis of atherosclerosis. Because certain features of restenosis following angioplasty mimic some of the early changes of atherogenesis, some researchers have suggested that fish oil might prevent restenosis following angioplasty. We report the effects of omega-3 fatty acids on the rate of restenosis following percutaneous intraluminal coronary angioplasty (PTCA). METHODS AND RESULTS: From August 1989 through September 1992, 551 patients were randomized to start receiving a daily dietary supplement of ten 1.0-g capsules containing 80.6% ethyl esters of omega-3 fatty acids providing 4.1 g eicosapentaenoic acid (EPA) and 2.8 g docosahexaenoic acid (DHA) for 6 months or an equal amount of an ethyl ester of corn oil. Four hundred seventy subjects who were well matched for risk factors completed successful angioplasty of one or multiple lesions in native coronary vessels and constituted the study cohort, of whom 447 were evaluable at 6 months after PTCA. The criteria for restenosis were that the quantitative coronary angiography at 6 months show a > 30% increase in narrowing at the stenosis site or loss of at least half of the gain achieved at the time of PTCA and final restenosis with < 50% luminal diameter remaining. In 93% of the patients, the end point was determined by angiography and in all except 1% of these by quantitative coronary angiography. Compliance with the fish oil supplement was good as judged by incorporation of EPA and DHA in plasma and red blood cell phospholipids. The restenosis rate among analyzable patients was 46% for corn oil and 52% for fish oil (P = .37). The addition of 200 mg alpha-tocopherol for all subjects during the study had no effect on restenosis rates. CONCLUSIONS: This was the largest of such trials to date, and a supplement of 8 g/d of omega-3 fatty acids failed to prevent the usual high rate of restenosis after PTCA. No adverse effects were attributable to this large daily supplement of omega-3 fatty acids.

Adult↗

PubMed1994

Percutaneous transluminal in vivo gene transfer by recombinant adenovirus in normal porcine coronary arteries, atherosclerotic arteries, and two models of coronary restenosis.

BACKGROUND: Gene therapy has been proposed as a possible solution to the problem of restenosis after coronary angioplasty. The current study was undertaken to assess conventional methods of gene transfer and to develop percutaneous techniques for introducing genes directly into the coronary arteries of large mammals. Since the anticipated targets of gene therapy against restenosis include atherosclerotic and previously instrumented arteries, we also evaluated gene transfer in atherosclerotic coronary arteries and in two porcine models of restenosis: one using intracoronary stents and a second using balloon overstretch angioplasty. METHODS AND RESULTS: The conventional method of using perforated balloon catheters to deliver Lipofectin-DNA complexes directly into the coronary arteries of intact animals was applied to 18 porcine coronary arteries including normal arteries, hypercholesterolemic arteries, and those simulating restenosis. The results of this study were consistent with previously published results indicating that only low levels of luciferase gene expression could be obtained by Lipofectin-mediated gene transfer. We therefore undertook a second, parallel study to evaluate percutaneous transluminal in vivo gene transfer using a replication-deficient adenoviral vector. A comparison of the two studies revealed that the mean level of reporter gene expression in the cohort undergoing adenoviral infection was 100-fold higher than in the cohort undergoing Lipofection. Analysis of luciferase activity over time in normal arteries revealed that recombinant gene expression was half-maximal after 1 day, peaked within 1 week, was still half-maximal at 2 weeks, and declined to low levels by 4 weeks. Histochemical analysis of coronary arteries treated with a second adenovirus expressing a nuclear-localized beta-galactosidase gene demonstrated gene transfer to a limited number of cells in the media and adventitia. Immunohistochemical analysis of Ad5-infused arteries using a monoclonal antibody directed against CD44 identified a periadventitial infiltrate composed of leukocytes. CONCLUSIONS: The recombinant adenoviral vectors proved to be far more effective than Lipofectin at delivering foreign genes directly into the coronary arteries of living mammals. Furthermore, the influences of hypercholesterolemia and arterial injury appeared to have little effect on the levels of gene expression obtained using either method. The results demonstrate that low-level recombinant gene expression, the major obstacle impeding gene therapy for the prevention of restenosis, can potentially be overcome by using adenoviral vectors to mediate coronary gene transfer in vivo. The duration of gene expression provided by these vectors and their effective deployment in atherosclerotic, balloon-overstretched, and stented coronary arteries suggest that recombinant adenovirus may have potential for evaluating gene therapy in the clinically informative porcine models of coronary restenosis.

Adenoviridae↗

PubMed1994

Amiprilose hydrochloride inhibits porcine aortic smooth muscle cell proliferation in vitro.

The effect of amiprilose hydrochloride, a synthetic monosaccharide, on smooth muscle cell proliferation was studied in vitro. Using porcine aortic smooth muscle cell cultures, amiprilose significantly inhibited cell proliferation in a dose-dependent fashion at concentrations of 0.5-1.0 mg/ml. This antiproliferative effect was reversible upon removing amiprilose by cell washing and adding fresh media. Pretreating cells with amiprilose before serum stimulation did not affect subsequent growth. Inhibition of proliferation occurred when amiprilose was added up to 48 hours after serum stimulation. As such, amiprilose deserves further investigation as a potential therapeutic agent in preventing restenosis after angioplasty.

Animals↗

PubMed1994

Lipofectin-mediated versus adenovirus-mediated gene transfer in vitro and in vivo: comparison of canine and porcine model systems.

BACKGROUND: Restenosis after coronary angioplasty might be prevented by locally delivered gene therapy in conjunction with percutaneous transluminal coronary angioplasty (PTCA), since this approach should provide a sustained source of therapeutic protein within the dilated lesion. However, the potential application of gene therapy is limited by the technical barrier of efficiently transferring genes to vascular cells. METHODS: We used cultured coronary smooth muscle cells of human, porcine, and canine origin to evaluate three methods of gene transfer: recombinant adenovirus, liposomal complexes (Lipofectin), and Lipofectin supplemented with hemagglutinin. We then compared Lipofectin- and adenovirus-mediated direct gene transfer in canine and porcine coronary arteries. RESULTS: The lipofection of cultured smooth muscle cells was enhanced by adding hemagglutinin, yielding luciferase levels that were 631-fold (human), ninefold (porcine), and sevenfold (canine) higher than with Lipofectin alone. However, the recombinant adenovirus directed even higher levels of gene expression, yielding luciferase levels that were 113,000-fold (human), 450-fold (porcine), and 230-fold (canine) higher than with Lipofectin alone. After percutaneous transluminal local delivery to intact canine coronary arteries, the adenovirus produced 55 times more luciferase than did Lipofectin. In living porcine coronary arteries, adenovirus produced 95 times more luciferase than did Lipofectin. CONCLUSION: Recombinant adenovirus produces far more recombinant protein than does Lipofectin after percutaneous transluminal direct gene transfer to canine and porcine coronary arteries. Adenoviral vectors may therefore prove useful in evaluating the potential of gene therapy in large animal models of coronary restenosis.

Adenoviridae↗

PubMed1994

Coronary restenosis and gene therapy.

Restenosis continues to limit the efficacy of coronary angioplasty, despite the various mechanical and pharmaceutical interventions that have been employed. The migration, proliferation, and extracellular matrix production by vascular smooth muscle cells are processes integral to restenosis, and sustained local delivery of drugs at high concentration should curtail these vascular responses to balloon angioplasty. Our laboratory and others are exploring the potential of using somatic cell gene therapy to provide such treatment and thereby prevent restenosis. However, conventional methods of gene transfer fail to produce physiologic levels of recombinant protein in vivo. This obstacle might be overcome by using adenoviral vectors to mediate efficient direct gene transfer. Herein we summarize these developments and focus upon our laboratory's progress towards evaluating adenovirus-mediated gene therapy in porcine coronary arteries. Recombinant adenoviruses directing the expression of the beta-galactosidase and luciferase reporter genes were evaluated in cultured coronary vascular smooth muscle cells in vitro and in porcine coronary arteries in vivo. Following percutaneous transluminal gene transfer in vivo, recombinant adenoviruses were shown to produce 70- to 240-fold more reporter protein than that produced by Lipofectin-DNA complexes. Furthermore, the high levels of adenovirus-mediated gene expression were shown to persist for at least 14 days following catheterization. Additional histologic studies will be required to determine the cellular distribution of gene expression and to elucidate potential interactions between adenovirus and the host's immune system, but recombinant adenovirus appears to be a promising vector for evaluating gene therapy against coronary restenosis.

Adenoviridae↗

PubMed1993

Coronary artery spasm culminating in thrombosis following ergonovine stimulation.

A 53-yr-old active man with angina but no angiographically significant obstructive coronary artery disease developed refractory spasm following ergonovine provocation. This resulted in thrombus formation and myocardial infarction. As such, this is the first case in which thrombosis developed at the site of intense coronary artery spasm induced by ergonovine, all of which were documented angiographically. Despite the notable safety of this test, this case re-emphasizes the potential of ergonovine to produce intractable myocardial ischemia and infarction.

Cardiac Catheterization↗

PubMed1993

Randomized placebo-controlled trial of amlodipine in vasospastic angina. Amlodipine Study 160 Group.

OBJECTIVES: This study was designed to assess the efficacy and safety of amlodipine, a long-acting calcium channel blocker, in patients with vasospastic angina. BACKGROUND: Previous studies have established the value of short-acting calcium channel blockers in the treatment of coronary spasm. METHODS: Fifty-two patients with well documented vasospastic angina were entered into the present study. After a single-blind placebo run-in period, patients were randomized (in a double-blind protocol) to receive either amlodipine (10 mg) or placebo every morning for 4 weeks. Twenty-four patients received amlodipine and 28 received placebo. All patients were given diaries in which to record both the frequency, severity, duration and circumstances of anginal episodes and their intake of sublingual nitroglycerin tablets. RESULTS: The rate of anginal episodes decreased significantly (p = 0.009) with amlodipine treatment compared with placebo and the intake of nitroglycerin tablets showed a similar trend. Peripheral edema was the only adverse event seen more frequently in amlodipine-treated patients. No patient was withdrawn from the double-blind phase of the study because of an adverse event. Patients who completed the double-blind phase as responders to amlodipine or as nonresponders to placebo were offered the option of receiving amlodipine in a long-term, open label extension phase. During the extension, the daily dose of amlodipine was adjusted to 5 or 15 mg if needed and the rate of both anginal episodes and nitroglycerin tablet consumption showed statistically significant decreases between baseline and final assessment. CONCLUSION: This study suggests that amlodipine given once daily is efficacious and safe in the treatment of vasospastic angina.

Adult↗

PubMed1993

Multicenter investigation of coronary stenting to treat acute or threatened closure after percutaneous transluminal coronary angioplasty: clinical and angiographic outcomes.

OBJECTIVES: This study reports on the initial experience with the Gianturco-Roubin flexible coronary stent. The immediate and 6-month efficacy of the device and the incidence of the complications of death, myocardial infarction, emergency coronary artery bypass surgery and recurrent ischemic events are presented. BACKGROUND: Abrupt or threatened vessel closure after coronary angioplasty is associated with increased risk of myocardial infarction, emergency coronary artery bypass graft surgery and in-hospital death. When dissection or prolapse of dilated plaque into the lumen is unresponsive to additional or prolonged balloon catheter inflation, coronary stenting offers a nonsurgical mechanical means to rapidly restore stable vessel geometry and adequate coronary blood flow. METHODS: From September 1988 through June 1991, 518 patients underwent attempted coronary stenting with the 20-mm long Gianturco-Roubin coronary stent for acute or threatened vessel closure after angioplasty. In 494 patients, one or more stents were deployed. Thirty-two percent of patients received stents for acute closure and 69% for threatened closure. RESULTS: Successful deployment was achieved in 95.4% of patients. Overall, stenting resulted in an immediate angiographic improvement in the diameter stenosis from 63 +/- 25% before stenting to 15 +/- 14% after stenting. Emergency coronary artery bypass graft surgery was required in 4.3% (21 of 493 patients). The incidence of in-hospital myocardial infarction (Q wave and non-Q wave) was 5.5% (27 of 493 patients). At 6 months, myocardial infarction was infrequent, occurring in 1.6% (8 of 493 patients). The incidence of in-hospital death was 2.2% (11 of 493 patients). Late death occurred in 7 patients (1.4%) and 34 patients (6.9%) required later bypass graft surgery. Complications included blood loss, primarily from the arterial access site, and subacute thrombosis of the stented vessel in 43 patients (8.7%). CONCLUSIONS: The early multicenter experience suggests that this stent is a useful adjunct to coronary angioplasty to prevent or minimize complications associated with flow-limiting coronary artery dissections previously correctable only by surgery. Although this study was not randomized, it demonstrated a high technical success rate and encouraging results with respect to the low incidence of emergency coronary artery bypass graft surgery and myocardial infarction.

Adult↗

PubMed1993

Amiprilose in the prevention of restenosis after coronary intervention in a swine model.

BACKGROUND: Amiprilose hydrochloride is a synthetic carbohydrate with anti-inflammatory and antiproliferative properties. This study tested the potential benefit of amiprilose in preventing coronary artery restenosis in a swine model. METHODS: The swine restenosis model was prepared using Hanford miniature swine made atherosclerotic with coronary abrasion, high-fat and high-cholesterol feeding, and intracoronary stenting. Eighteen animals were randomized to receive amiprilose, 100 mg/kg body weight orally twice per day (n = 9), or no amiprilose (n = 9) beginning 5 days before stenting and continuing through 4 weeks until sacrifice. Presacrifice quantitative coronary angiography and postsacrifice histologic examination revealed the degree of intimal proliferation. RESULTS: Coronary angiography revealed no difference in percentage-diameter stenosis between the amiprilose and control groups (left anterior descending artery [LAD], 46% +/- 10% vs 44% +/- 17%; circumflex artery [CFX], 43% +/- 21% vs 42% +/- 15%; right coronary artery [RCA], 37% +/- 11% vs 34% +/- 9%; P = not significant [NS]), respectively, or in change in lumen diameter from poststenting to presacrifice (LAD, -1.0 +/- 0.4 mm vs -1.1 +/- 0.7 mm; CFX, -1.2 +/- 0.8 mm vs -1.0 +/- 0.7 mm; RCA, -1.1 +/- 0.4 mm vs -1.0 +/- 0.4 mm; P = NS). Morphometric histologic analysis likewise showed no difference in percentage-area stenosis (LAD, 55% +/- 14% vs 55% +/- 15%; CFX, 53% +/- 15% vs 54% +/- 12%; RCA, 39% +/- 17% vs 39% +/- 20%; P = NS) or in maximal intimal thickness. CONCLUSION: Amiprilose hydrochloride did not prevent coronary intimal proliferation in this swine model of restenosis.

Angioplasty, Balloon, Coronary↗

PubMed1993

Enalapril in the prevention of restenosis following intracoronary intervention in a swine model.

BACKGROUND: Restenosis following percutaneous transluminal coronary angioplasty continues to be a major limitation of the procedure. To test whether an angiotensin-converting enzyme inhibitor may reduce restenosis, this study utilized an atherosclerotic, stented, Hanford miniature swine model of restenosis. METHODS: Each animal first was started on an atherogenic diet and had balloon abrasion of the left anterior descending and right coronary arteries. Four months later, balloon-mounted coil stents were placed into the abraded coronary arteries of each animal. Twenty-four animals then were randomly assigned to one of two groups: enalapril, and control. The enalapril group received 50 mg orally twice daily starting 1 week before intracoronary stenting. RESULTS: Follow-up 2 months later revealed angiographic stenosis in the control group of 30% +/- 13%/25% +/- 10% (left anterior descending/right coronary artery) versus 37% +/- 9%/20% +/- 11% in the enalapril group (P = not significant). The change in minimal lumen diameter from immediately after stenting to follow-up was not significantly different between control and enalapril groups. Area stenosis and maximal intimal thickness obtained by morphometric analysis were also compared, and the mean percentage area stenosis for the control group was 39 +/- 12%/31% +/- 16% and for enalapril 36% +/- 14%/35% +/- 19%. The maximal intimal thickness in the control group was 573 microns +/- 204 microns/605 microns +/- 266 microns and in the enalapril group 530 microns +/- 220 microns/424 microns +/- 237 microns. There was no statistical difference. CONCLUSIONS: Enalapril fails to reduce restenosis in this animal model.

Angioplasty, Balloon, Coronary↗

PubMed1993

Papillary fibroelastoma. A right atrial presentation.

Papillary fibroelastoma is a rare cardiac tumor arising most frequently from valvular endocardium. These tumors are clinically important because of their tendency to embolize. Emphasis is therefore placed on early detection and surgical excision. We describe a case of a papillary fibroelastoma arising from the right atrium. To our knowledge, only 2 such cases have been reported in the English literature. Our case illustrates the discovery of a rare, but potentially fatal cardiac tumor, successfully removed by surgery.

Aged↗