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Biomedical subjects

D P Foley

Publications and source records attributed to D P Foley.

At least 37 records · Page 2Linked to original sources
PubMed2000

Six-month outcome after excimer laser coronary angioplasty for diffuse in-stent restenosis in native coronary arteries.

This study evaluated the intermediate-term follow-up after excimer laser coronary angioplasty (ELCA) and adjunctive percutaneous transluminal coronary angioplasty (PTCA) in patients with diffuse in-stent restenosis (lesion length >10 mm). Clinical and angiographic follow-up were performed at 6 months. Quantitative coronary angiography performed at 3 stages-during stent implantation, before and after ELCA + PTCA, and at follow-up-included measurements of the minimum lumen diameter (MLD) and percent diameter stenosis (DS). Sixteen consecutive patients were included. The (median + range) stent length was 36 mm (range 15 to 105), with a restenotic lesion length of 32 mm (range 10 to 90). After ELCA + PTCA, the MLD increased from 0.60 +/- 0.41 to 2.28 +/- 0.50 mm, whereas the DS decreased from 76 +/- 16% to 22 +/- 8%. Despite adjunctive high-pressure PTCA, the MLD after ELCA + PTCA remained smaller than the MLD after initial stent implantation, (2.28 +/- 0. 50 mm vs 2.67 +/- 0.32 mm, p = 0.014). Adverse events included ELCA-related acute coronary occlusion in 4 patients and a per-procedural intracerebral hematoma in 1. At 6 months, there was recurrence of angina in all patients. Angiographic follow-up was completed in 13 patients (87%), showing a reocclusion in 6 (46%), a >50% DS in 6 (MLD 1.03 +/- 0.87 mm, DS 68 +/- 24%), and a distal de novo lesion in 1. Despite satisfactory acute angiographic results, the recurrence of significant restenosis in all patients suggests that ELCA + PTCA is not a suitable stand-alone therapy for diffuse in-stent restenosis of long stented segments.

Angioplasty, Balloon, Coronary↗
PubMed2000

Carvedilol for prevention of restenosis after directional coronary atherectomy : final results of the European carvedilol atherectomy restenosis (EUROCARE) trial.

BACKGROUND: In addition to its known properties as a competitive, nonselective beta and alpha-1 receptor blocker, carvedilol directly inhibits vascular myocyte migration and proliferation and exerts antioxidant effects that are considerably greater than those of vitamin E or probucol. This provides the basis for an evaluation of carvedilol for the prevention of coronary restenosis. METHODS AND RESULTS: In a prospective, double-blind, randomized, placebo-controlled trial, 25 mg of carvedilol was given twice daily, starting 24 hours before scheduled directional coronary atherectomy and continuing for 5 months after a successful procedure. The primary end point was the minimal luminal diameter as determined during follow-up angiography 26+/-2 weeks after the procedure. Of 406 randomized patients, 377 underwent attempted atherectomy, and in 324 (88.9%), a </=50% diameter stenosis was achieved without the use of a stent. Evaluable follow-up angiography was available in 292 eligible patients (90%). No differences in minimal luminal diameter (1.99+/-0.73 mm versus 2.00+/-0.74 mm), angiographic restenosis rate (23.4% versus 23.9%), target lesion revascularization (16.2 versus 14.5), or event-free survival (79.2% versus 79.7%) between the placebo and carvedilol groups were observed at 7 months. CONCLUSIONS: The maximum recommended daily dose of the antioxidant and beta-blocker carvedilol failed to reduce restenosis after successful atherectomy. These findings are in contrast to those of the Multivitamins and Probucol Trial, which raises doubts regarding the validity of the interpretation that restenosis reduction by probucol was via antioxidant effects. The relationship between antioxidant agents and restenosis remains to be elucidated.

Adrenergic Antagonists↗
PubMed2000

Bile acids in xenogeneic ex-vivo liver perfusion: function of xenoperfused livers and compatibility with human bile salts and porcine livers.

BACKGROUND: In recent years, hepatic support systems using xenogeneic cells have been developed to support patients in fulminant hepatic failure. The extent to which xenogeneic hepatocytes metabolize and excrete human organic anions is unclear. In these studies we examined the ability of the ex vivo porcine liver to clear human bile acids during extracorporeal liver perfusion (ELP). METHODS: Four patients with fulminant hepatic failure underwent extracorporeal liver perfusion with 9 porcine livers. The venovenous circuit was designed as previously described (NEJM,1994,331:234) as were the immunologic features (Transplantation 1994,58:1162). Bile from the porcine liver and serum samples were collected hourly during perfusion. Three bile acids (glycocholic, glycodeoxycholic, taurodeoxycholic acid) were selected as markers for human bile and three (glycohyocholic, glycohyodeoxycholic, and glyco-3alpha-hydroxy-6-oxo-5beta-cholanoic acid) for markers of pig bile. Bile acids from both serum and bile were processed and analyzed through high performance liquid chromatography. The Students' t test was used for statistical analysis. RESULTS: The mean duration of perfusions was 4.1+/-1.5 hr. The mean total bile acid clearance from serum (243+/-44 micromol/h) was similar to the total bile acid biliary excretion (286+/-84 micromol/hr, P = 0.06). After 1 hr of perfusion, bile samples demonstrated a predominance of pig bile salts (65%). After 3 hr of perfusion, human bile acids made up 85% of total biliary bile acids. Pig bile acids appeared in patients' sera after 1 hr of perfusion, and after 3 hr, 35% of serum bile salts were pig-specific. CONCLUSIONS: Porcine livers perfused with human blood can clear the serum of potentially toxic human bile acids and excrete them into bile. Simultaneously, the percentage of pig-specific bile acids in patient serum increases during xenogeneic perfusion for unknown reasons. The relative hepatic uptake of bile acid from serum is similar to bile acid excretion in bile. Further development of systems using porcine livers or hepatocytes is warranted.

Animals↗
PubMed2000

Three-dimensional intravascular ultrasonic volumetric quantification of stent recoil and neointimal formation of two new generation tubular stents.

Currently, several different designs of coronary stents are available. However, only a few of the new generation stents have been investigated in large randomized trials. Mechanical behavior of first-generation stents (Palmaz-Schatz, Gianturco-Roubin) may not be applied to the new designs. We investigated the chronic mechanical behavior (recoil) of 2 stents recently approved by the Food and Drug Administration (MULTILINK and NIR). Forty-eight patients with single-stent implantation (23 MULTILINK and 25 NIR) were assessed by means of volumetric 3-dimensional intravascular ultrasound analysis after the procedure and at 6-month follow-up. In addition, volumetric assessment of neointimal formation was performed. No significant chronic stent recoil was detected in both groups (delta MULTILINK stent volume: +5.6+/-41 mm3 [p = NS] and delta NIR stent volume + 2.1+/-26 mm3 [p = NS]). A similar degree of neointimal formation at 6 months was observed between the 2 stents (MULTILINK 46+/-31.9 mm3 vs NIR 39.9+/-27.6 mm3, p = NS). In conclusion, these 2 second-generation tubular stents did not show chronic recoil and appeared to promote similar proliferative response after implantation in human coronary arteries.

Cell Division↗
PubMed2000

Coronary bifurcation stenting using dedicated bifurcation stents.

We report three cases of successful implantation of three different stents specially designed for bifurcation lesions, guided by intracoronary ultrasound. The BARD and AVE are true bifurcated stents for side-branch access and the NIR-Side Royal is a single modified NIR stent with an aperture to allow provisional bifurcation stenting. These designs introduce a new era in percutaneous management of coronary bifurcation lesions. Cathet. Cardiovasc. Intervent. 49:105-111, 2000.

Adult↗
PubMed2000

Acute changes of global and regional left ventricular function immediately after direct myocardial revascularization.

Direct myocardial revascularization (DMR) has been proposed to treat patients with severe coronary artery disease who are not amenable for classical revascularization techniques such as percutaneous coronary intervention (PCI) or bypass surgery (CABG). Although recent reports suggest its benefit in alleviating patients' complaints in the long term, there is still a paucity of data on the immediate impact on regional and global myocardial functioning following this treatment. In this overview we discuss our own experience and provide a summary of other data currently available.

Coronary Disease↗
PubMed2000

Further insights into coronary debulking: the EUROCARE trial of directional atherectomy and the PACT trial of pullback atherectomy.

Although the principle of reducing plaque load in the coronary artery remains very appealing, clinical benefit from debulking devices has not been demonstrated unequivocally. Other approaches to prevent restenosis had been the application of various pharmacological agents. Unfortunately, the majority of clinical studies have not reproduced the promising results observed in the experimental laboratories. New frontiers in improving atherectomy devices and in optimizing concomitant medical treatment are currently being explored. We report on the EUROCARE trial investigating the possible benefit of carvedilol after coronary atherectomy, and the Pullback Atherectomy (PAC) pilot trial using a novel atherectomy device.

Adrenergic beta-Antagonists↗
PubMed1999

Biliary secretion of extracorporeal porcine livers with single and dual vessel perfusion.

BACKGROUND: Hepatic support systems that provide detoxification without biliary secretion (i.e., isolated hepatocyte systems) are sufficient to improve encephalopathy and bridge patients to transplantation. However, biliary secretion may be critical when hepatic support attempts to restore function and regeneration of the host liver. The purpose of these studies was to optimize the support liver secretory response to bile acid by either single-vessel (portal vein; PV) or dual-vessel (hepatic artery [HA] + PV) perfusions during extracorporeal porcine liver perfusion. METHODS: Extracorporeal porcine liver perfusion of anesthetized pigs was developed using support porcine livers perfused through the PV (n=4) alone and through the HA + PV (n=4) via a venovenous circuit. Support livers were provoked with taurocholate (TC) to enhance bile aqueous and hydrophobic outputs. RESULTS: After cold preservation and reperfusion, both PV and HA + PV livers had initial 1-hr bile aqueous outputs < 15% of in vivo flow, with cholesterol (C) and phospholipid (PC) outputs <25% of in vivo flow. Bile flow was significantly greater for recovered HA + PV livers (3.0+/-0.01 ml/15 min) than PV livers (1.9+/-0.01 ml/15 min). Despite this, PC output was significantly greater for PV than HA + PV livers. The C/PC ratio of PV livers was twice that of HA + PV livers. TC infusion (48 micromol/kg/15 min) of HA + PV livers demonstrated significantly greater increments in bile flow, PC output, and C output than PV livers. CONCLUSION: In the unstimulated state, porcine support livers with dual-vessel perfusion generated greater aqueous and C outputs despite diminished PC output than in those with single-vessel perfusion. TC stimulation increased bile flow, PC output, and C output in dual-perfused livers more than in PV livers. HA + PV perfusion of support livers is the preferred technique for removing hydrophobic compounds that require PC transport for excretion or exist in the aqueous phase.

Animals↗
PubMed1999

Stenting with a true bifurcated stent: acute and mid-term follow-up results.

Percutaneous therapy of coronary bifurcated lesions is associated with greater risk of acute complications and late restenosis. Numerous innovative techniques using various stent types have been proposed. We report the first clinical use of a truly bifurcated stent (Bard XT Carina). The implantation procedure, favorable medium-term angiographic and 1-year clinical follow-up of the first human use in a 43-year-old female are illustrated with angiography and intravascular ultrasound. As a single prosthesis that effectively covers the bifurcation, this stent presents appealing alternative for the treatment of coronary bifurcation lesions when compared to methods that involve multiple-stent implantation. Cathet. Cardiovasc. Intervent. 47:361-369, 1999.

Abciximab↗
PubMed1999

Spontaneous dissections of all three coronary arteries in a 33-week-pregnant woman.

The clinical course and angiographic follow-up of a woman with spontaneous coronary dissections in all three coronary arteries during the third trimester of pregnancy is described. Mother and child survived and subsequent clinical course was uneventful. At 6-month follow-up, dissections in the right and circumflex coronary artery had healed completely. At the site of the dissection in the LAD, an aneurysm had formed. This is to our knowledge the first report of antepartum and antemortem diagnosis of pregnancy related coronary dissections in all three coronary arteries. Cathet. Cardiovasc. Intervent. 48:207-210, 1999.

Adult↗
PubMed1999

A randomized placebo-controlled trial of fluvastatin for prevention of restenosis after successful coronary balloon angioplasty; final results of the fluvastatin angiographic restenosis (FLARE) trial.

BACKGROUND: The 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors competitively inhibit biosynthesis of mevalonate, a precursor of non-sterol compounds involved in cell proliferation. Experimental evidence suggests that fluvastatin may, independent of any lipid lowering action, exert a greater direct inhibitory effect on proliferating vascular myocytes than other statins. The FLARE (Fluvastatin Angioplasty Restenosis) Trial was conceived to evaluate the ability of fluvastatin 40 mg twice daily to reduce restenosis after successful coronary balloon angioplasty (PTCA). METHODS: Patients were randomized to either placebo or fluvastatin 40 mg twice daily beginning 2-4 weeks prior to planned PTCA and continuing after a successful PTCA (without the use of a stent), to follow-up angiography at 26+/-2 weeks. Clinical follow-up was completed at 40 weeks. The primary end-point was angiographic restenosis, measured by quantitative coronary angiography at a core laboratory, as the loss in minimal luminal diameter during follow-up. Clinical end-points were death, myocardial infarction, coronary artery bypass graft surgery or re-intervention, up to 40 weeks after PTCA. RESULTS: Of 1054 patients randomized, 526 were allocated to fluvastatin and 528 to placebo. Among these, 409 in the fluvastatin group and 427 in the placebo group were included in the intention-to-treat analysis, having undergone a successful PTCA after a minimum of 2 weeks of pre-treatment. At the time of PTCA, fluvastatin had reduced LDL cholesterol by 37% and this was maintained at 33% at 26 weeks. There was no difference in the primary end-point between the treatment groups (fluvastatin 0.23+/-0.49 mm vs placebo 0.23+/-0.52 mm, P=0.95) or in the angiographic restenosis rate (fluvastatin 28%, placebo 31%, chi-square P=0.42), or in the incidence of the composite clinical end-point at 40 weeks (22.4% vs 23.3%; logrank P=0.74). However, a significantly lower incidence of total death and myocardial infarction was observed in six patients (1.4%) in the fluvastatin group and 17 (4.0%) in the placebo group (log rank P=0.025). CONCLUSION: Treatment with fluvastatin 80 mg daily did not affect the process of restenosis and is therefore not indicated for this purpose. However, the observed reduction in mortality and myocardial infarction 40 weeks after PTCA in the fluvastatin treated group has not been previously reported with statin therapy. Accordingly, a priori investigation of this finding is indicated and a new clinical trial with this intention is already underway.

Angioplasty, Balloon, Coronary↗
PubMed1999

Long term outcome after coronary stent implantation: a 10 year single centre experience of 1000 patients.

OBJECTIVE: To describe the long term clinical outcome (up to 11 years) after coronary stenting. DESIGN: A single centre observational study encompassing 1000 consecutive patients with a first stent implantation (1560 stents) between 1986 and 1996, who were followed for at least one year with a median follow up of 29 months (range 12-132 months). RESULTS: Up to July 1997 the cumulative incidence of the major adverse cardiac events (MACE) of death, non-fatal acute myocardial infarction, coronary artery bypass grafting, and repeat percutaneous transluminal coronary angioplasty was 8.2%, 12.8%, 13.1%, and 22.4%, respectively. Survival at one, three, and five years was 95%, 91%, and 86%, respectively. Comparison of MACE incidence during the "anticoagulant era" and the "ticlopidine era" revealed significantly improved event free survival with ticlopidine (27% v 13%; p < 0.005). Multivariable analyses showed that ejection fraction < 50% (relative risk (RR) 4. 1), multivessel disease (RR 3.0), diabetes (RR 2.9), implantation in saphenous vein graft (RR 2.1), indication for unstable angina (RR 1. 9), and female sex (RR 1.7) were independent predictors of increased mortality after stenting. Independent predictors of any MACE were multivessel stenting (RR 2.0), implantation in saphenous bypass graft (RR 1.6), diabetes (RR 1.5), anticoagulant treatment (versus ticlopidine and aspirin) (RR 1.5), bailout stenting (RR 1.5), multivessel disease (RR 1.4), and multiple stent implantation (RR 1. 5). CONCLUSIONS: Long term survival and infarct free survival was good, particularly in non-diabetic men with single vessel disease and good ventricular function, who had a single stent implanted in a native coronary artery. A dramatic improvement was observed in event free survival, both early and late, with the replacement of anticoagulation by ticlopidine. This, of course, cannot be separated from improved stent implantation techniques between 1986 and 1995. Ultimately, almost 40% of the patients experienced an adverse cardiac event (mainly repeat intervention) in the long term. New advances in restenosis treatments and in secondary prevention must be directed at this aspect of patient management after stenting.

Adult↗
PubMed1999

Endotoxin fails to stimulate inositol triphosphate production in macrophages.

UNLABELLED: Inositol Triphosphate (IP3) production is an early cell signaling event which leads to mobilization of intracellular calcium (Ca++). We examined whether bacterial endotoxin (lipopolysaccharide, LPS) stimulates IP3 production in macrophages pretreated with LPS (tolerant) or not. METHODS: RAW 264.7 macrophages were cultured at 5 x 10(6) cells in RPMI supplemented with 10% FCS. LPS tolerance was induced by pretreating macrophages (Tol) for 19 h with 10 ng/ml of LPS. Non-tolerant (Non-Tol) macrophages received no LPS pretreatment. Macrophages were next washed, repleted with fresh media, and stimulated with 100 ng/ml LPS. Paired cultures were stimulated with 1 microM platelet activating factor (PAF), a known stimulant of IP3 production. Following 1, 10, and 15-min stimulation intervals, IP3 was extracted with trichloroacetic acid and measured by receptor displacement assay. RESULTS: LPS did not stimulate IP3 production in either Non-Tol or Tol macrophages. In contrast, PAF stimulated significant increases in IP3 levels within 1 min in both Non-Tol (9.5 +/- 3.0 pmol/ml) and Tol (9.5 +/- 2.4 pmol/ml) macrophages. Non-Tol IP3 levels returned to baseline by 10 min, while Tol IP3 levels remained significantly elevated (8.2 +/- 1.7 pmol/ml). CONCLUSIONS: Unlike PAF, bacterial LPS fails to stimulate IP3 production in macrophages. Furthermore, IP3 production could not be elicited in cultured macrophages repetitively stimulated with LPS.

Cell Line↗
PubMed1998

Coronary wallstents show significant late, postprocedural expansion despite implantation with adjunct high-pressure balloon inflations.

Adjunct high-pressure balloon inflations following the delivery of oversized self-expandable Wallstents may affect their implied late, postprocedural self-expansion. Consequently, we examined 15 "Magic" Wallstents, which were implanted following a strategy of stent oversizing and subsequent adjunct high-pressure balloon inflations (16 +/- 2 atm; all > or = 12 atm). The excellent radiographic visibility of this stent permitted reliable quantitative coronary angiographic measurement of both lumen and stent dimensions (before and after stenting, and at follow-up). At follow-up, extent and distribution of in-stent neointimal proliferation were evaluated with volumetric intravascular ultrasound. Between postintervention and follow-up examination, mean stent diameter increased from 3.7 +/- 0.4 to 4.2 +/- 0.4 mm (p <0.0001); there was no significant difference in late stent expansion between proximal, mid-, and distal stent subsegments. Late stent expansion showed a significant (reverse) relation to maximum balloon size (r = -0.56, p <0.04), but not with follow-up lumen size or late lumen loss. On average, 52 +/- 18% of the stent was filled with neointimal ingrowth; neointimal volume/cm stent length was 64 +/- 22 mm3. Both late stent expansion (r = 0.36, p <0.02) and maximum balloon pressure (r = 0.41, p <0.001) were related to neointimal volume/cm stent but not to follow-up lumen size. Thus, despite high-pressure implantation, Wallstents showed significant late self-expansion, which resulted in larger stent dimensions at follow-up that assisted in accommodating in-stent neointimal proliferation. Conversely, late stent expansion had a significant relation to the extent of in-stent neointimal ingrowth. Beneficial and disadvantageous effects of the late stent expansion appear to be balanced, because a relation to late lumen loss or follow-up lumen dimensions was not found to be present.

Aged↗
PubMed1998

Laparoscopic surgery and the systemic immune response.

OBJECTIVE: The authors review studies relating to the immune responses evoked by laparoscopic surgery. SUMMARY BACKGROUND DATA: Laparoscopic surgery has gained rapid acceptance based on clinical grounds. Patients benefit from faster recovery, decreased pain, and quicker return to normal activities. Only more recently have attempts been made to identify the metabolic and immune responses that may underlie this clinical success. The immune responses to laparoscopy are now being evaluated in relation to the present knowledge of immune responses to traditional laparotomy and surgery in general. METHODS: A review of the published literature of the immune and metabolic responses to laparoscopy was performed. Laparoscopic surgery is compared with the traditional laparotomy on the basis of local and systemic immune responses and patterns of tumor growth. The impact of pneumoperitoneum and insufflation gases on the immune response is also reviewed. CONCLUSIONS: The systemic immune responses for surgery in general may not apply to laparoscopic surgery. The body's response to laparoscopy is one of lesser immune activation as opposed to immunosuppression.

Carbon Dioxide↗
PubMed1997

Variations of remodeling in response to left main atherosclerosis assessed with intravascular ultrasound in vivo.

Histopathologic studies have demonstrated that vessels enlarge to compensate for an increase in plaque burden; this has been confirmed in vivo using intravascular ultrasound (IVUS). The initial studies suggested a biphasic course of lesion formation with (1) preservation of lumen dimensions up to a plaque burden of approximately 40%, and (2) luminal narrowing as plaque burden further increases. In this study, we used IVUS and angiography to assess the extent of left main (LM) atherosclerosis in 107 patients undergoing catheter-based procedures of the left anterior descending or left circumflex coronary arteries. Using IVUS, atherosclerotic plaques were found in all LM arteries, but only 26 (24%) had varying degrees of luminal narrowing on the angiogram. Nevertheless, there was an inverse relation (r = -0.62, p <0.0001) between the minimal lumen area and the plaque burden (i.e., plaque + media divided by total vessel area) that was not restricted to plaque burden values >40% (or >30%), but persisted at plaque burden values of 20% to 40%. In addition, LM arteries with a plaque burden <40% had a similar total vessel area as did LM arteries with a plaque burden > or =40% (22.9 +/- 6.1 vs 21.8 +/- 4.8 mm2, p = 0.30). These data suggest that lumen dimensions may not be preserved even if plaque occupies no more than 20% to 40% of the total vessel area. Thus, there is more variation in remodeling response during earlier stages of plaque accumulation within the LM artery than is commonly suggested.

Adult↗