Early lumen loss after repeat coronary intervention for in-stent restenosis.

The purpose of this study was to compare the effects of balloon angioplasty versus repeat stenting on the early angiographic outcome in patients with in-stent restenosis. The treatment of in-stent restenosis using balloon angioplasty alone often yields excellent early results, but is associated with a high rate of late recurrence. In the SCRIPPS trial, patients with restenosis were treated either with balloon angioplasty alone or placement of additional stents to optimize angiographic results before randomization and exposure of the restenotic segment to gamma radiation or placebo. In patients undergoing repeat catheter based intervention for the treatment of in-stent restenosis, quantitative coronary angiography was used to compare the results of balloon angioplasty alone versus repeat stenting on early lumen loss. After a mean delay time interval of 71 min, the early loss was 0.35 +/- 0.34 mm in the balloon angioplasty alone group compared to 0.01 +/- 0.34 mm in the repeat-stenting group (P = 0.004). The early loss index in the balloon angioplasty alone group (12.8 +/- 12.9%) was significantly greater than in the repeat stenting group (0.7 +/- 12.1%; P = 0.003). Although balloon angioplasty for in-stent restenosis often provides excellent immediate angiographic results, luminal diameters are significantly reduced in the early time period after balloon dilatation. Repeat stenting nearly abolishes this early luminal loss.

Suture-mediated closure of the femoral access site after cardiac catheterization: results of the suture to ambulate aNd discharge (STAND I and STAND II) trials.

Despite advances in other aspects of cardiac catheterization, manual or mechanical compression followed by 4 to 8 hours of bed rest remains the mainstay of postprocedural femoral access site management. Suture-mediated closure may prove to be an effective alternative, offering earlier sheath removal and ambulation, and potentially a reduction in hemorrhagic complications. The Suture To Ambulate aNd Discharge trial (STAND I) evaluated the 6Fr Techstar device in 200 patients undergoing diagnostic procedures, with successful hemostasis achieved in 99% of patients (94% with suture closure only) in a median of 13 minutes, and 1% major complications. STAND II randomized 515 patients undergoing diagnostic or interventional procedures to use of the 8Fr or 10Fr Prostar-Plus device versus traditional compression. Successful suture-mediated hemostasis was achieved in 97.6% of patients (91.2% by the device alone) compared with 98.9% of patients with compression (p = NS). Major complication rates were 2.4% and 1.1%, and met the Blackwelder's test for equivalency (p <0.05). Median time to hemostasis (19 vs 243 minutes, p <0.01) and time to ambulation (3.9 vs 14.8 hours, p <0.01) were significantly shorter for suture-mediated closure. Suture-mediated closure of the arterial puncture site thus affords reliable immediate hemostasis and shortens the time to ambulation without significantly increasing the risk of local complications.

Three-year clinical and angiographic follow-up after intracoronary radiation : results of a randomized clinical trial.

BACKGROUND: Although several early trials indicate treatment of restenosis with radiation therapy is safe and effective, the long-term impact of this new technology has been questioned. The objective of this report is to document angiographic and clinical outcome 3 years after treatment of restenotic stented coronary arteries with catheter-based (192)Ir. METHODS AND RESULTS: A double-blind, randomized trial compared (192)Ir with placebo sources in patients with previous restenosis after coronary angioplasty. Over a 9-month period, 55 patients were enrolled; 26 were randomized to (192)Ir and 29 to placebo. At 3-year follow-up, target-lesion revascularization was significantly lower in the (192)Ir group (15. 4% versus 48.3%; P<0.01). The dichotomous restenosis rate at 3-year follow-up was also significantly lower in (192)Ir patients (33% versus 64%; P<0.05). In a subgroup of patients with 3-year angiographic follow-up not subjected to target-lesion revascularization by the 6-month angiogram, the mean minimal luminal diameter between 6 months and 3 years decreased from 2.49+/-0.81 to 2.12+/-0.73 mm in (192)Ir patients but was unchanged in placebo patients. CONCLUSIONS: The early clinical benefits observed after treatment of coronary restenosis with (192)Ir appear durable at late follow-up. Angiographic restenosis continues to be significantly reduced in (192)Ir-treated patients, but a small amount of late loss was observed between the 6-month and 3-year follow-up time points. No events occurred in the (192)Ir group to suggest major untoward effects of vascular radiotherapy. At 3-year follow-up, vascular radiotherapy continues to be a promising new treatment for restenosis.

Effect of low-level short-term o-xylene inhalation of benzo[a]pyrene (BaP) metabolism and BaP-DNA adduct formation in rat liver and lung microsomes.

o-Xylene is a commonly used solvent that alters mixed-function oxidase (MFO) activity in an organ- and isozyme-specific pattern following intraperitoneal (ip) administration. Similar MFO alterations have been observed after ip or inhalation exposure to other methyl benzenes. These MFO alterations shifted the metabolism of the carcinogen benzo[a]pyrene (BaP) toward formation of toxication metabolites in lung. The purpose of this study was to determine whether o-xylene inhalation caused similar MFO changes and whether these alterations were reflected in altered BaP metabolism and BaP-DNA adduct formation. o-Xylene (300 ppm, 6 h) decreased the activity of arylhydrocarbon hydroxylase (AHH) in lung. CYP2B1 activity (benzyloxyresorufin O-dealkylase; BROD), which is responsible for metabolism of BaP to relatively nontoxic metabolites, was decreased in lung, as was, to a lesser extent, CYP1A1 (ethoxyresorufin O-dealkylase; EROD), which is responsible for metabolism of BaP to reactive/toxic metabolites. The BROD/EROD ratio, an indirect indicator of the pattern of BaP toxication/detoxication, was decreased in lung, suggesting that BaP metabolism is shifted toward toxication. No MFO alterations were observed in liver. In lung microsomes, o-xylene increased formation of 7,8-BaP-diol, while 9,10-BaP-diol, 3-OH BaP, and 9-OH BaP were decreased. In liver, o-xylene increased 9-OH BaP formation, while 4,5- and 9,10-diols as well as total diols were decreased. The toxication/detoxication ratios for BaP individual and total metabolite groups were increased in lung microsomes and unaltered in liver. The major BaP-DNA adduct, BaP diol epoxide-N2-deoxyguanosine, was increased in lung but decreased in liver microsomes from o-xylene-exposed rats. Four minor BaP-DNA adducts were formed in lung and three in liver, only one of which (liver adduct 3) was decreased. The o-xylene-induced increase in BaP adduct formation in lung and decrease in liver indicate that coexposure to organic solvents such as the methyl benzenes may alter the carcinogenesis of BaP, or other PAHs, in an organ-specific fashion.

Quantitative angiographic analysis of stent restenosis in the Scripps Coronary Radiation to Inhibit Intimal Proliferation Post Stenting (SCRIPPS) Trial.

To identify luminal dimension changes occurring within the stent alone and within the stent + margin segment, we reviewed the quantitative angiographic results obtained from the Scripps Coronary Radiation to Inhibit Proliferation Post Stenting (SCRIPPS) trial, a prospective randomized trial assessing the effect of iridium-192 (Ir-192) on the prevention of stent restenosis. Fifty-five patients were randomly assigned to receive Ir-192 or placebo sources after successful intervention. Procedural and 6-month follow-up cineangiograms were quantitatively reviewed in 52 patients to identify changes within the stent and the stent + margin segment. The percent diameter stenosis was lower within the stent than within the stent + margin segment after the procedure (6 +/- 22% vs 21+/- 15%, p <0.0001) and at follow-up (28 +/- 29% vs 42 +/- 21%, p <0.0001). As a result, a lower restenosis rate was found within the stent than within the stent + margin (25% vs 37%, p <0.0001); isolated stent margin restenosis occurred in 11.5% of lesions. Treatment with Ir-192 reduced restenosis within the stent (8% vs 39%; p = 0.010) and within the stent + margin segment (17% vs 54%; p = 0.010); the reduction in restenosis at the margin only (8.3% vs 14.3%, p = 0.503) was not significant. The lowest relative risk for restenosis resulting from Ir-192 occurred within the stent (0.21; 95% confidence interval [CI] 0.05 to 0.86) compared with the stent + margin segment (0.31; 95% CI 0.12 to 0.81) or the stent margin (0.58; 95% CI 0.12 to 2.91). In the SCRIPPS trial, 32% of restenosis occurred at the stent margins. Treatment with Ir-192 reduced restenosis primarily within the stent rather than the margin. Whether extending the treatment length to fully include the stent margins will further reduce restenosis requires further study.

Utility of standby cardiopulmonary support for elective coronary interventions.

At our institution, elective coronary interventions are performed without formal surgical backup. Instead, a policy of "standby cardiopulmonary support" (CPS), and "next-available operating room" is used. Standby CPS requires a perfusionist dedicated to the catheterization laboratory with immediate access to CPS apparatus. Between January 1989 and June 1994 we performed 2,850 elective coronary interventions. Eleven patients (0.4%) required emergency CPS. None of these patients fell into a high-risk category for PTCA (i.e., sole circulation, ejection fraction <20%, unprotected left main). Eight of these (73%) had completion of their coronary intervention while on CPS in the catheterization laboratory. Three patients were sustained on CPS until an operating room became available. All patients required blood transfusions and sustained non-Q-wave myocardial infarctions. Two late in-hospital deaths occurred. Nine patients (82%) were successfully discharged. Standby CPS provides hemodynamic support for patients who sustain a potentially catastrophic event during coronary intervention. Our data suggest that this modality should not be limited to high-risk patients.

Two-year follow-up after catheter-based radiotherapy to inhibit coronary restenosis.

BACKGROUND: Although early trials indicate the treatment of restenosis with radiation therapy is safe and effective, the long-term impact of this new technology has been questioned. The possibility of late untoward consequences, such as aneurysm formation, perforation, and accelerated vascular disease, is of significant concern. Furthermore, it is not known whether the beneficial effects of radiation therapy will be durable or whether radiation will only delay restenosis. METHODS AND RESULTS: A double-blind, randomized trial was undertaken to compare 192Ir with placebo sources in patients with previous restenosis after coronary angioplasty. Patients were randomly assigned to receive a 0.76-mm (0. 03-in) ribbon containing sealed sources of either 192Ir or placebo. All patients underwent repeat coronary angiography at 6 months. All living patients were contacted 24 months after their index study procedure. Patients were assessed with respect to the need for target-lesion revascularization or nontarget-lesion revascularization, occurrence of myocardial infarction, or death. Over a 9-month period, 55 patients were enrolled; 26 were randomized to 192Ir and 29 to placebo. Follow-up was obtained in 100% of living patients at a minimum of 24 months. Target-lesion revascularization was significantly lower in the 192Ir group (15.4% versus 44.8%; P<0. 01). Nontarget-lesion revascularization was similar in 192Ir and placebo patients (19.2% versus 20.7%; P=NS). There were 2 deaths in each group. The composite end point of death, myocardial infarction, or target-lesion revascularization was significantly lower in 192Ir-treated versus placebo-treated patients (23.1% versus 51.7%; P=0.03). No patient in the 192Ir group sustained a target-lesion revascularization later than 10 months. CONCLUSIONS: At 2-year clinical follow-up, treatment with 192Ir demonstrates significant clinical benefit. Although further follow-up (including late angiography) will be necessary, no clinical events have occurred to date in the 192Ir group to suggest major untoward effects of vascular radiotherapy. At the intermediate follow-up time point, vascular radiotherapy continues to be a promising new treatment for restenosis.

A subgroup analysis of the Scripps Coronary Radiation to Inhibit Proliferation Poststenting Trial.

INTRODUCTION: In the Scripps Coronary Radiation to Inhibit Proliferation Poststenting (SCRIPPS) Trial, 192Ir significantly reduced angiographic, ultrasonographic, and clinical endpoints of restenosis. The objective of this analysis was to quantitate the impact of patient, lesion and technical characteristics on late angiographic outcome. METHODS: Patients with restenotic, stented coronary lesions were randomized to receive either 192Ir or placebo sources. Late luminal loss and loss index were calculated for several patient subgroups, including patients with diabetes, in-stent restenosis, multiple previous percutaneous transluminal coronary angioplasty (PTCA) procedures, longer lesion lengths, saphenous vein grafts, small vessel diameters, and minimum dose exposures < 8.00 Gy. Two-factor analysis of variance was used to test for an interaction between patient characteristics and treatment effect. RESULTS: In the treated group, late loss was particularly low in patients with diabetes (0.19 mm), in-stent restenosis (0.17 mm), reference vessel diameters < 3.0 mm (0.07 mm), and patients who received a minimum radiation dose to the entire adventitial border of at least 8.00 Gy. The loss index in each of these subgroups was similarly low at -0.02, 0.03, -0.02, and 0.03, respectively. By 2-factor analysis of variance, a significant interaction between subgroup characteristic and treatment effect (late loss) was found in patients with in-stent restenosis (p = 0.035), and patients receiving a minimum dose of 8.00 Gy to the adventitial border (p = 0.009). CONCLUSION: In this pilot study, patient characteristics associated with a more aggressive proliferative response to injury appeared to confer an enhanced response to radiotherapy. Furthermore, a dose threshold response to 192Ir was found with an enhanced response occurring when the entire circumference of the adventitial border was exposed to at least 8.00 Gy.

Inhibition of rat lung mixed-function oxidase activity following repeated low-level toluene inhalation: possible role of toluene metabolites.

Toluene is a commonly used solvent that has been shown to alter mixed-function oxidase (MFO) activity, in an organ- and isozyme-specific pattern, following intraperitoneal administration. The purpose of this study was to determine whether similar changes occurred following repeated, low-level inhalation exposure, and to investigate the role of toluene metabolites in these alterations. Exposure to 375 ppm toluene, 6 h/d for up to 5 d, resulted in significant inhibition of the activity of pulmonary arylhydrocarbon hydroxylase (AHH), cytochrome P-4502B1 (CYP2B1), and CYP4B1, but not CYP1A1. After exposure to lower toluene levels (125 ppm, 6 h/d, 3 d), the activities of lung AHH, CYP2B1, and CYP4B1 were also significantly decreased, but in a dose-related manner. MFO activity was not consistently altered in liver. Control pulmonary or liver microsomes were incubated with various concentrations (0.01-10 mM) of toluene or its metabolites and CYP2B1, CYP1A1, and/or CYP4B1 activities were subsequently determined. Benzaldehyde produced a significant dose-related inhibition in the activity of all three lung P-450s examined (IC50 10(-3) M). Toluene was found to be a more potent inhibitor of lung CYP2B1 and CYP1A1 (IC50, 10(-4) M) than benzaldehyde, but neither toluene nor benzyl alcohol was an effective inhibitor of lung CYP4B1. Toluene and its metabolites were weaker inhibitors of CYP1A1 than of CYP2B1. For CYP2B1 and CYP1A1, the order of inhibitory potency was toluene > benzaldehyde > benzyl alcohol and suggests that both the parent molecule and its metabolites may act in concert to inhibit catalytic activity of these cytochromes. The MFO inhibition seen after repeated low-level toluene inhalation exposure could result in altered metabolic profiles of other xenobiotics in an organ-specific fashion.

Efficacy of coronary stenting versus balloon angioplasty in small coronary arteries. Stent Restenosis Study (STRESS) Investigators.

OBJECTIVES: The goal of this study was to compare the efficacy of elective stent implantation and balloon angioplasty for new lesions in small coronary arteries. BACKGROUND: Palmaz-Schatz stents have been designed and approved by the Food and Drug Administration for use in coronary arteries with diameters > or = 3.0 mm. The efficacy of elective stent placement in smaller vessels has not been determined. METHODS: By quantitative coronary angiography, 331 patients in the Stent Restenosis Study (STRESS) I-II were determined to have a reference vessel < 3.0 mm in diameter. Of these, 163 patients were randomly assigned to stenting (mean diameter 2.69 +/- 0.21 mm), and 168 patients were assigned to angioplasty (mean diameter 2.64 +/- 0.24 mm). The primary end point was restenosis, defined as > or = 50% diameter stenosis at 6-month follow-up angiography. Clinical event rates at 1 year were assessed. RESULTS: Baseline clinical and angiographic characteristics were similar in the two groups. Procedural success was achieved in 100% of patients assigned to stenting and in 92% of patients assigned to angioplasty (p < 0.001). Abrupt closure within 30 days occurred in 3.6% of patients in both groups. Compared with angioplasty, stenting conferred a significantly larger postprocedural lumen diameter (2.26 vs. 1.80 mm, p < 0.001) and a larger lumen at 6 months (1.54 vs. 1.27 mm, p < 0.001). Restenosis (> or = 50% diameter stenosis at follow-up) occurred in 34% of patients assigned to stenting and in 55% of patients assigned to angioplasty (p < 0.001). At 1 year, event-free survival was achieved in 78% of the stent group and in 67% of the angioplasty group (p = 0.019). CONCLUSIONS: These findings suggest that elective stent placement provides superior angiographic and clinical outcomes than balloon angioplasty in vessels slightly smaller than 3 mm.

The evolution of antithrombotic therapy in coronary stenting.

A rare but important side effect associated with the use of coronary stents is the development of subacute thrombotic occlusion within the first week after implantation. Recent studies have indicated that the incidence of subacute thrombosis can be reduced with a combination regimen consisting of aspirin and ticlopidine instead of the standard regimen of aspirin and warfarin. The evolution in our understanding of the factors causing subacute stent thrombosis, coupled with the development of new implantation procedures, has permitted the development of a new treatment strategy with less aggressive anticoagulation therapy, fewer side effects, and, it is hoped, lower costs.

Acute and long-term outcome after Palmaz-Schatz stenting: analysis from the New Approaches to Coronary Intervention (NACI) registry.

The randomized Stent Restenosis Study (STRESS) and Belgium Netherlands Stent (Benestent) trials established that elective use of Palmaz-Schatz stents (PSSs) in native coronary arteries with de novo lesions is associated with increased procedural success and reduced restenosis. However there are other clinical indications for which stents are commonly used (unplanned use, vein grafts, restenosis lesions) that are not addressed in these studies. From 1990-1992, 688 lesions in 628 patients were treated with PSSs in the New Approaches to Coronary Intervention (NACI) registry. Angiographic core laboratory readings were available for 543 patients (595 lesions, of which 106 were stented for unplanned indications, 239 were in saphenous vein bypass grafts, and 296 were previously treated). The cohort of patients in whom stents were placed for unplanned indications had more women, current smokers, and had a higher incidence of recent myocardial infarction (MI). Patients who underwent stenting of saphenous vein grafts were older, had a higher incidence of diabetes mellitus, unstable angina, prior MI, and congestive heart failure. Lesion success was similar in all cohorts (98%), but procedural success was significantly higher for planned stenting (96% vs 87%; p < 0.01). Predictors of adverse events in-hospital were presence of a significant left main stenosis and stenting for unplanned indication. The incidence of target lesion revascularization by 30 days was significantly higher for patients undergoing unplanned stenting due to a higher risk for stent thrombosis. Recent MI, stenting in native lesion, and small postprocedural minimum lumen diameter independently predicted target lesion revascularization at 30 days. Independent predictors of death, Q-wave myocardial infarction, or target lesion revascularization at 1 year included severe concomitant disease, high risk for surgery, left main disease, stenting in the left main coronary artery, and low postprocedure minimum lumen diameter.

Catheter-based radiotherapy to inhibit restenosis after coronary stenting.

BACKGROUND: In animal models of coronary restenosis, intracoronary radiotherapy has been shown to reduce the intimal hyperplasia that is a part of restenosis. We studied the safety and efficacy of catheter-based intracoronary gamma radiation plus stenting to reduce coronary restenosis in patients with previous restenosis. METHODS: Patients with restenosis underwent coronary stenting, as required, and balloon dilation and were then randomly assigned to receive catheter-based irradiation with iridium-192 or placebo. Clinical follow-up was performed, with quantitative coronary angiographic and intravascular ultrasonographic measurements at six months. RESULTS: Fifty-five patients were enrolled; 26 were assigned to the iridium-192 group and 29 to the placebo group. Angiographic studies were performed in 53 patients (96 percent) at a mean (+/-SD) of 6.7+/-2.2 months. The mean minimal luminal diameter at follow-up was larger in the iridium-192 group than in the placebo group (2.43+/-0.78 mm vs. 1.85+/-0.89 mm, P=0.02). Late luminal loss was significantly lower in the iridium-192 group than in the placebo group (0.38+/-1.06 mm vs. 1.03+/-0.97 mm, P=0.03). Angiographically identified restenosis (stenosis of 50 percent or more of the luminal diameter at follow-up) occurred in 17 percent of the patients in the iridium-192 group, as compared with 54 percent of those in the placebo group (P= 0.01). There were no apparent complications of the treatment. CONCLUSIONS: In this preliminary, short-term study of patients with previous coronary restenosis, coronary stenting followed by catheter-based intracoronary radiotherapy substantially reduced the rate of subsequent restenosis.

Effects of p-chlorotoluene (PCT) on rat lung and liver benzo[a]pyrene metabolism and microsomal membrane structure and function.

Treatment of rats with p-chlorotoluene (PCT, 1 g/kg, ip) resulted in peak PCT blood and lung concentrations at 4 h, which declined to very low levels at 12 h. The concentration of PCT in the liver attained its highest value at 1 h and also declined to low levels at 12 h. In the dose-response study, PCT significantly decreased hepatic and pulmonary AHH activities at 0.5 g/kg, 1 h. Maximum inhibition was attained at 1 g/kg, 1 h, and further increase in the dose did not enhance the enzyme inhibition in the time-course investigation, PCT (1 g/kg) maximally inhibited hepatic and pulmonary aryl hydrocarbon hydroxylase (AHH) activities at 1 h and the decrease in enzyme activity was sustained through 12 h. Administration of PCT (1 g/kg, 1 h) also markedly decreased pulmonary cytochrome P-450 content, while hepatic cytochrome P-450 content was only slightly reduced. The partial decrease in cytochrome P-450 content indicated altered levels of the P-450 isozymes, which may have profound effects on the metabolic disposition of benzo[a]pyrene [BaP]. BaP is regioselectively metabolized by two major isoforms of P-450 to toxic dihydrodiols and nontoxic phenol derivatives and there is a balance between these two metabolite groups. PCT (1 g/kg, 1 h) significantly inhibited the phenolic 3-OH BaP formation in both lung (52%) and liver (56%). The formations of BaP 7,8-dihydrodiol (146%) and 9,10-dihydrodiol (90%) were significantly elevated in the lung. The toxication to detoxication ratios were significantly elevated in both organs. Total quinone formation was markedly enhanced in the liver. Since PCT inhibited phenolic metabolite formation and increased dihydrodiol production, the activities of the isozymes that are responsible for their formations were determined. PCT (1 g/kg, 1 h) significantly inhibited cytochrome P-4502B1 in the lung (50%) and 2B1/2B2 in the liver (40%), while cytochrome P-4501A activity was not altered in either lung or liver. PCT increased phospholipid (PL) levels (45%) and conjugated diene (CD) formation (58%) in lung but not in liver, while membrane fluidity was increased [phospholipid/cholesterol (PL/CL) ratio; diphenylhexatriene (DPH) and trimethylammonium DPH (TMA-DPH) fluorescence polarization] in both organs. There was no apparent relationship between these membrane changes and alterations in MFO activity. Taken together the results suggest that PCT is capable of nonselectively inactivating the hepatic and pulmonary isozymes of P-450 that are responsible for the detoxication of BaP. The observed shift in the metabolism of BaP toward potentially more toxic metabolites suggests that concurrent exposure to BaP and PCT may result in greater toxicity, compared to exposure to BaP alone.

Effect of combined anticoagulation and low-dose aspirin treatment on upper gastrointestinal bleeding.

Multiple studies link the use of nonsteroidal antiinflammatory drugs (NSAIDs) with severe upper gastrointestinal bleeding (UGIB); the incidence of such bleeding is 2-4%. One common regimen to assure patency after intracoronary stent placement requires an anticoagulant (warfarin) combined with aspirin as an antiplatelet agent. However, a 13-fold increase in the risk of UGIB occurs with long-term use of oral anticoagulants and NSAIDs. We retrospectively assessed the rate of UGIB in 138 patients who had received coronary stents (group I, receiving heparin followed by warfarin in combination with aspirin) and 109 angioplasty patients without stents (group II, receiving aspirin alone) between 1990 and 1994. UGIB was identified by hematemesis or melena, which led to gastrointestinal consultation. Patients were analyzed for multiple risk factors. UGIB occurred in 28 of 138 group I patients (20%; 95% CI 13.3-26.7%) and 0 of 109 group II patients (P < 0.0001). Esophagogastroduodenoscopy (EGD) findings on the 28 patients with UGIB included 13 patients with esophagitis or gastritis, 7 patients with gastric or duodenal ulcers, and 8 patients with no identifiable source of bleeding. UGIB occurred within a mean of 2.5 days of initiation of combination therapy. Of patients with UGIB, 10 required blood transfusion (mean number of units = 5.3). Previous history of peptic ulcer disease, smoking, and use of antiulcer medication did not significantly differ between the two groups. The concurrent use of anticoagulant and aspirin in patients with coronary stents creates a significant potential for UGIB and should be used only with extreme caution.

Hail stentors! How the hail do I stop the warfarin?

Interest in coronary stenting has exploded since the publication of several large, randomized trials, and (due to the rapidity of patient recruitment into non-randomized trials) volumes of data are quickly abandoning "old standards" of patient selection, operative technique, and postoperative anticoagulation management. In this editorial, suggestions are offered to help clinicians take the leap from outdated Food and Drug Administration-guided regulations to off-label use and withholding of anticoagulation.

Low-level m-Xylene inhalation alters pulmonary and hepatic cytochrome P-450 activity in the rat.

m-Xylene is a commonly used industrial solvent that has been shown to alter mixed-function oxidase (MFO) activity, in an organ- and isozyme-specific pattern, following intraperitoneal administration of the solvent. The purpose of this work was to determine whether similar alterations occurred in cytochromes P-450 (CYP) following m-xylene inhalation, the primary route of occupational exposure. A single 6-h exposure to m-xylene resulted in the inhibition of aryl hydrocarbon hydroxylase (AHH) activity in the lung while the activity of AHH was unchanged in the liver. CYP 2B1 activity, which is responsible for the metabolism of benzo[a]pyrene (BaP) to relatively nontoxic metabolites, was decreased in lung but not in liver. The activity of CYP 1A1, responsible for the metabolism of BaP to reactive/toxic products, was not altered in lung or liver. The CYP 2B1/1A1 ratio is an indirect indicator of the pattern of BaP toxication/detoxication. This ratio was decreased in lung, suggesting that BaP metabolism is shifted toward toxication. CYP 1A2 and CYP 4B1 activity was decreased in the lung while remaining unchanged in the liver. CYP 2E1 activity was also inhibited in lung while its activity was increased in the liver. This organ-specific inhibition of pulmonary cytochromes P-450 may be due to the lower MFO activity in the lung compared to liver. Alteration of the cytochromes P450 by m-xylene could result in a change in the metabolic profiles of xenobiotics in coexposure or subsequent exposure scenarios in increased or decreased toxicity in an organ-specific fashion.

High-speed rotational atherectomy of tortuous coronary arteries with guidewire-associated pseudostenosis.

A series of high-speed rotational atherectomy cases is discussed in which pseudostenosis was noted following initial guidewire placement. The results and technical considerations when using the Rotablator in the setting of guidewire-induced pseudostenosis are discussed.

Immediate results and late outcomes after stent implantation in saphenous vein graft lesions: the multicenter U.S. Palmaz-Schatz stent experience. The Palmaz-Schatz Stent Study Group.

OBJECTIVES: This study reports the multicenter registry experience evaluating the safety and efficacy of the Palmaz-Schatz stent in the treatment of saphenous vein graft disease. BACKGROUND: Saphenous vein graft angioplasty is associated with frequent periprocedural complications and a high frequency of restenosis. Stent implantation has been shown to reduce restenosis, with improved long-term outcomes in the treatment of native coronary artery disease. Preliminary experience with stent placement in the treatment of saphenous vein graft lesions has been favorable. METHODS: Twenty U.S. investigator sites enrolled a total of 589 symptomatic patients (624 lesions) for treatment of focal vein graft stenoses between January 1990 and April 1992. Follow-up angiography was performed at 6 months, and the clinical course of all study patients was prospectively collected at regular intervals for up to 12 months. RESULTS: Stent delivery was successful in 98.8% of cases, and the procedural success rate was 97.1%. The lesion diameter stenosis decreased from 82 +/- 12% (mean +/- SD) before to 6.6 +/- 10.2% after treatment. Major in-hospital complications occurred in 17 patients (2.9%); stent thrombosis was found in 8 (1.4%); and major vascular or bleeding complications were noted in 83 (14.3%). Six-month angiographic follow-up revealed an overall restenosis rate (> or = 50% diameter stenosis) of 29.7%. Multivariate logistic regression analysis indicated that 1) restenotic lesions, 2) smaller reference vessel size, 3) history of diabetes mellitus, and 4) higher percent poststent diameter stenosis were independent predictors of restenosis. The 12-month actuarial event-free survival was 76.3%. CONCLUSIONS: Stent implantation in patients with focal saphenous vein graft lesions can be achieved with a high rate of procedural success, acceptable major complications, reduced angiographic restenosis and favorable late clinical outcome compared with historical balloon angioplasty control series. The rigorous anticoagulation regimen after stent placement results in more frequent vascular and other bleeding complications. Future randomized studies comparing standard balloon angioplasty with stent implantation are warranted to properly assess the full impact of stent placement in the treatment of saphenous vein graft lesions.