Biomedical subjects
Publications and source records attributed to David P Foley.
There are no significant differences in long-term and event-free survival in patients who undergo stent implantation in different anatomic locations of the left main coronary artery. Predictors of long-term survival are age <65 years, normal left ventricular ejection fraction, and absence of an intra-aortic balloon pump.
OBJECTIVES: In this study, we assess the value of sirolimus eluting stent (SES) implantation in patients with complex in-stent restenosis (ISR). BACKGROUND: The treatment of ISR remains a therapeutic challenge, since many pharmacological and mechanical approaches have shown disappointing results. The SESs have been reported to be effective in de-novo coronary lesions. METHODS: Sixteen patients with severe, recurrent ISR in a native coronary artery (average lesion length 18.4 mm) and objective evidence of ischemia were included. They received one or more 18 mm Bx VELOCITY SESs (Cordis Waterloo, Belgium). Quantitative angiographic and three-dimensional intravascular ultrasound (IVUS) follow-up was performed at four months, and clinical follow-up at nine months. RESULTS: The SES implantation (n = 26) was successful in all 16 patients. Four patients had recurrent restenosis following brachytherapy, and three patients had totally occluded vessels preprocedure. At four months follow-up, one patient had died and three patients had angiographic evidence of restenosis (one in-stent and two in-lesion). In-stent late lumen loss averaged 0.21 mm and the volume obstruction of the stent by IVUS was 1.1%. At nine months clinical follow-up, three patients had experienced four major adverse cardiac events (two deaths and one acute myocardial infarction necessitating repeat target vessel angioplasty). CONCLUSIONS: The SES implantation in patients with severe ISR lesions effectively prevents neointima formation and recurrent restenosis at four months angiographic follow-up.
These studies evaluated the influence of hepatic arterial flow on biliary secretion after cold ischemia. Preparation of livers for transplantation or hepatic support impairs biliary secretion. The earliest indication of cold preservation injury during reperfusion is circulatory function. Arterial flow at this time may be critical for bile secretion. Porcine livers were isolated, maintained at 4 degrees for 2 h and connected in an extracorporeal circuit to an anesthetized normal pig. The extracorporeal livers were perfused either by both the hepatic artery and portal vein (dual) or by the portal vein alone (single). Incremental doses of sodium taurocholate were infused into the portal vein of both the dual and single perfused livers, and the bile secretion was compared. Most endogenous bile acids are lost during hepatic isolation. After supplementation, the biliary secretion of phosphatidyl choline and cholesterol was significantly better in the dual than single vessel-perfused livers; however, no difference was seen in bilirubin output. Single perfused livers were completely unable to increase biliary cholesterol in response to bile acid. The dependence of bile cholesterol secretion on arterial flow indicates the importance of this flow to the detoxification of compounds dependent on phosphatidyl choline transport during early transplantation.
BACKGROUND: In patients with poor left ventricular function and high-risk coronary lesions, prolonged ischemia during percutaneous coronary intervention (PCI) may have major hemodynamic consequences. The Tandemheart is a percutaneous left ventricular assist device intended for short-term circulatory support. METHODS AND RESULTS: The Tandem-heart incorporates 9-17 F. arterial cannulae and a unique 21 F. transseptal cannula and centrifugal bloodpump. Operating at 7500 rpm, the pump withdraws oxygenated blood from the left atrium and delivers up to 4 liters/min to the arterial circulation. As of May 2001, the Tandem-heart was electively employed in three male patients (ages 52, 54 and 56) scheduled for high-risk PCI. The mean time to initial circulatory support was less than 30 minutes. Systemic hemodynamics significantly improved prior to PCI in two patients. Pump flow after one hour ranged from 2.43 to 3.8 liters/min (mean 3.17 liters/min) and duration of support from 23 to 49 hours (mean 33 hours). Procedural success was 100%, with no significant hemolysis or bleeding. Successful weaning was completed in all patients, who have remained free of major cardiac events up to seven months post-PCI. CONCLUSIONS: In this first clinical experience of elective use of Tandem-heart for circulatory support during high-risk PCI, the device was easily inserted and preserved hemodynamic stability, regardless of the intrinsic cardiac function, creating optimism for more widespread use for this and other indications.
BACKGROUND: After treatment with intracoronary brachytherapy, enlargement of lumen (negative late loss) at follow-up has been demonstrated. The aim of the study is to analyze the sensitivity and specificity of quantitative coronary angiography (QCA) parameters to detect a positive vessel remodeling after intracoronary -radiation as compared to intravascular ultrasound (IVUS). METHODS: Twenty-seven patients (27 vessels) treated with balloon angioplasty followed by catheter-based intracoronary -radiation with a (90)Strontium/(90)Yttrium source were assessed by both QCA and three-dimensional IVUS with electrocardiogram-gated pullback. Irradiated segments were analyzed over the total treatment length and in subsegment lengths of 5 mm. RESULTS: Change in minimum luminal diameter (MLD) was not a predictor for the positive remodeling in either total irradiated segments or 5 mm subsegments, with a 54.3% ROC curve area [95% confidence interval (CI), 30-79%], sensitivity of 39% and specificity of 44% (p = not significant) in the total irradiated segments and a 55.9% ROC curve area (95% CI, 46-66%), sensitivity of 55% and specificity of 54% (p = not significant) in the 5 mm subsegments. Changes in mean and maximal lumen diameter were not significant parameters to detect positive vessel remodeling. When only central subsegments were analyzed, change in MLD was a significant predictor, with a 63.3% ROC curve area (95% CI, 52-75%), sensitivity of 55% and specificity of 64% (p = 0.029). CONCLUSION: Lumen enlargement detected by QCA does not reliably indicate a positive vessel remodeling after intracoronary radiation. IVUS analysis may be necessary to investigate the mechanism of restenosis after balloon angioplasty followed by catheter-based radiation.
BACKGROUND: Early results of sirolimus-eluting stent implantation showed a nearly complete abolition of neointimal hyperplasia. The question remains, however, whether the early promising results will still be evident at long-term follow-up. The objective of our study was to evaluate the efficiency of sirolimus-eluting stent implantation for up to 2 years of follow-up. METHODS AND RESULTS: Fifteen patients with de novo coronary artery disease were treated with 18-mm sirolimus-eluting Bx-Velocity stents (Cordis) loaded with 140 microg sirolimus/cm2 metal surface area in a slow release formulation. Quantitative angiography (QCA) and intravascular ultrasound (IVUS) were performed according to standard protocol. Sirolimus-eluting stent implantation was successful in all 15 patients. During the in-hospital course, 1 patient died of cerebral hemorrhage after periprocedural administration of abciximab, and 1 patient underwent repeat stenting after 2 hours because of edge dissection that led to acute occlusion. Through 6 months and up to 2 years of follow-up, no additional events occurred. QCA analysis revealed no significant change in stent minimal lumen diameter or percent diameter stenosis, and 3-dimensional IVUS showed no significant deterioration in lumen volume. In 2 patients, additional stenting was performed because of significant lesion progression remote from the sirolimus-eluting stent. CONCLUSION: Sirolimus-eluting stents showed persistent inhibition of neointimal hyperplasia for up to 2 years of follow-up.
OBJECTIVES: We sought to assess the relationship between completeness of revascularization and adverse events at one year in the ARTS (Arterial Revascularization Therapies Study) trial. BACKGROUND: There is uncertainty to what extent degree of completeness of revascularization, using up-to-date techniques, influences medium-term outcome. METHODS: After consensus between surgeon and cardiologist regarding the potential for equivalence in the completeness of revascularization, 1,205 patients with multivessel disease were randomly assigned to either bypass surgery or stent implantation. All baseline and procedural angiograms and surgical case-record forms were centrally assessed for completeness of revascularization. RESULTS: Of 1,205 patients randomized, 1,172 underwent the assigned treatment. Complete data for review were available in 1,143 patients (97.5%). Complete revascularization was achieved in 84.1% of the surgically treated patients and 70.5% of the angioplasty patients (p < 0.001). After one year, the stented angioplasty patients with incomplete revascularization showed a significantly lower event-free survival than stented patients with complete revascularization (i.e., freedom from death, myocardial infarction, cerebrovascular accident and repeat revascularization) (69.4% vs. 76.6%; p < 0.05). This difference was due to a higher incidence of subsequent bypass procedures (10.0% vs. 2.0%; p < 0.05). Conversely, at one year, bypass surgery patients with incomplete revascularization showed only a marginally lower event-free survival rate than those with complete revascularization (87.8% vs. 89.9%). CONCLUSIONS: Complete revascularization was more frequently accomplished by bypass surgery than by stent implantation. One year after bypass, there was no significant difference in event-free survival between surgically treated patients with complete revascularization and those with incomplete revascularization, but patients randomized to stenting with incomplete revascularization had a greater need for subsequent bypass surgery.
OBJECTIVES: We sought to investigate the clinical benefit of additional stent implantation after achieving an optimal result of balloon angioplasty (BA) in long coronary lesions (>20 mm). BACKGROUND: Long coronary lesions are associated with increased early complications and late restenosis after BA. Stenting improves the early outcome, but stent restenosis is also related to both lesion length and stent length. METHODS: A total of 437 patients with a single native lesion 20 to 50 mm in length were included and underwent BA, using long balloons matched to lesion length and vessel diameter (balloon/artery ratio 1.1) to achieve a diameter stenosis (DS) <30% by on-line quantitative coronary angiography (QCA). "Bail-out stenting" was performed for flow-limiting dissections or >50% DS. Patients in whom an optimal BA result was achieved were randomized to additional stenting (using NIR stents) or no stenting. The primary end point was freedom from major adverse cardiac events (MACE) at nine months, and core laboratory QCA was performed on serial angiograms. RESULTS: Bailout stenting was necessary in 149 patients (34%) and was associated with a significantly increased risk of peri-procedural infarction (p < 0.02). Among the 288 randomized patients, the mean lesion length was 27+/-9 mm, and the vessel diameter was 2.78+/-0.52 mm. The procedural success rate was 90% for the 143 patients assigned to BA alone (control group), as compared with 93% in the 145 patients assigned to additional stenting (stent group), which resulted in a superior early minimal lumen diameter (0.54 mm, p < 0.001) and led to reduced angiographic restenosis (27% vs. 42%, p = 0.022). Freedom from MACE at nine months was 77% in both groups. CONCLUSIONS: A strategy of provisional stenting for long coronary lesions led to bailout stenting in one-third of patients, with a threefold increase in peri-procedural infarction. Additional stenting yielded a lower angiographic restenosis rate, but no reduction in MACE at nine months.
OBJECTIVE: This study was designed to determine whether antisense oligodeoxynucleotides (ODN) directed against the nuclear proto-oncogene c-myc could inhibit restenosis when given by local delivery immediately after coronary stent implantation. BACKGROUND: Failure of conventional pharmacologic therapies to reduce the incidence of coronary restenosis after percutaneous revascularization techniques has prompted interest in the use of agents that target intracellular central regulatory mechanisms. METHODS: Eighty-five patients were randomly assigned to receive either 10 mg of phosphorothioate-modified 15-mer antisense ODN or saline vehicle by intracoronary local delivery after coronary stent implantation. The primary end point was percent neointimal volume obstruction measured by computerized analysis of electrocardiogram-gated intravascular ultrasound (IVUS) at six-month follow-up. Secondary end points included clinical outcome and quantitative coronary angiography analysis. RESULTS: Analysis of follow-up IVUS data was performed on 77 patients. In-stent volume obstruction was similar between groups (44 +/- 16% and 46 +/- 14%, placebo vs. ODN; p = 0.57; 95% confidence interval: -1.13 to 0.85). Minimum luminal diameter increased from 0.84 +/- 0.36 and 0.90 +/- 0.45 (p = 0.55) to 2.70 +/- 0.37 and 2.80 +/- 0.37 (p = 0.28) after stent implantation, which decreased to 1.50 +/- 0.61 and 1.50 +/- 0.53 (p = 0.98) by six months, yielding similar loss indexes (placebo vs. ODN, respectively). There were no differences in angiographic restenosis rates (38.5 and 34.2%; p = 0.81; placebo vs. ODN) or clinical outcome. CONCLUSIONS: Treatment with 10 mg of phosphorothioate-modified ODN directed against c-myc does not reduce neointimal volume obstruction or the angiographic restenosis rate in this patient population.
The purpose of this study was to compare measurements by MetriCath to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). The MetriCath system consists of a low-pressure (200 mm Hg) balloon catheter connected to a pressure transducer and infusion pump linked to a computer that records pressure-volume curves. Cross-sectional area of blood vessels is obtained directly from the unrestrained and in-stent pressure-volume measurements. We compared stent cross-sectional area measurements by MetriCath, IVUS, and QCA in a porcine stented coronary artery model. Comparison of area measurements in 14 stents showed no significant differences between the three methods (P = 0.66). On average, values differed 0.37 +/- 0.60 mm(2) between MetriCath and QCA, 0.13 +/- 0.55 mm(2) between MetriCath and IVUS, and 0.22 +/- 0.80 mm(2) between IVUS and QCA. This corresponds to 6.2% +/- 10%, 3.0% +/- 9.0%, and 3.1% +/- 12.9% relative difference from the average of two corresponding measurements. Linear regression analysis showed excellent correlation between measurements (r = 0.99 for all comparisons). The differences in in-stent area measurements between MetriCath and both QCA and IVUS were small. Considering the ease and rapidity of obtaining MetriCath results, this technique may form an alternative to the others in evaluating stent expansion. Based on these findings, clinical evaluation seems warranted.
BACKGROUND: Cold preservation produces hepatic injury that is difficult to assess during early reperfusion. The value of reperfusion plasma choline phospholipid in predicting subsequent organ function is documented in these studies. MATERIALS AND METHODS: Livers of female Yorkshire pigs were prepared for transplantation. After 2 h of cold ischemia the reperfusion plasma was evaluated for choline phospholipid and cholesterol. These values were correlated with bile secretion, hepatic hemodynamics, oxygen uptake, and plasma sorbitol dehydrogenase levels. RESULTS: The isolated porcine liver demonstrates a rapid efflux of choline phospholipids into plasma during early reperfusion after cold preservation. After this initial efflux no subsequent plasma increment occurred. These choline-phospholipid increments were isolated in plasma higher density (d > 1.063) lipoproteins and were not accompanied by equivalent increases in cholesterol. Neither biliary reflux nor lecithin cholesterol acyl transferase abnormalities contributed appreciably to the phospholipid increments in reperfusion plasma. Livers with the largest efflux of choline phospholipids had the most impaired circulatory and bile secretory function at 4 h of reperfusion. CONCLUSION: The immediate increase of choline phospholipids, particularly lysophosphatidylcholine, in reperfusion plasma after cold ischemia provides an index of the injury occurring during this interval and correlates with early organ function.
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BACKGROUND: Coronary stents have been used with increasing frequency and in increasingly complex coronary lesions for the treatment of symptomatic coronary artery disease. A new stainless steel coronary stent, the R Stent, has been designed to provide maximum flexibility for tracking and high radial strength post-deployment. AIMS: To assess the safety and feasibility of the R Stent in patients with coronary artery disease. Specific objectives were to assess the R Stent's deployment success, angiographic and procedural success (< 20% residual stenosis and TIMI 3 flow), safety (absence of complications), 30-day and six-month clinical follow-up. METHODS: Between April 1998 and January 1999, stent deployment was attempted in 36 lesions in 30 patients with stable (43%) or unstable (57%) angina pectoris and 29/36 of the lesions were anatomically complex. Treated lesions were in the LAD (n = 15), RCA (n = 13) or LCX (n = 8). RESULTS: Stent deployment was achieved in 97% with one crossing failure in a patient with a long, calcified, proximal LAD lesion. After the procedure, patients were scheduled for one- and six-month clinical follow-up. One patient experienced a non-Q-wave myocardial infarction in hospital. At one month, there were no additional complications. Only one patient experienced recurrence of angina (CCS class 2) within the 30 days. At six-month follow-up, one sudden death had occurred. Three (10%) patients had anginal complaints, one of them received target lesion repeat PTCA. All other patients (87%) were event- and angina-free. CONCLUSION: This first clinical experience with the R Stent shows acceptable feasibility and safety with good long-term clinical results.
BACKGROUND: Coronary stents have been used with increasing frequency and in increasingly complex coronary disease. A new 316 LVM stainless steel coronary stent, the R Stent, has been designed to provide maximum flexibility for tracking and high radial strength post-deployment. PURPOSE: To assess the clinical feasibility of the R Stent in a tertiary referral population of patients with coronary heart disease. Specific objectives are to assess the R Stent's deployment success, angiographic and procedural success (<20% residual stenosis and >TIMI 2 flow), safety (absence of complications), and 30-day clinical success (angiographic/procedural success plus no major adverse coronary events). METHODS: Between April and November 1998, stent deployment was attempted in 27 patients with stable (46%) or unstable (54%) angina pectoris who qualified for percutaneous transluminal coronary angioplasty. Eighty per cent of patients had a pre-existing history of myocardial infarction, coronary bypass surgery or percutaneous transluminal coronary angioplasty, and several of the lesions were anatomically complex (totally occluded, n 32; thrombus present, n 32; heavily calcified, n 33; ostial, n 31; >20 mm long, n 39; angulation >45 degrees, n 37). Lesions in aortocoronary saphenous vein grafts were excluded. Adjunctive medical management included intraprocedural aspirin and heparin and post-procedural aspirin and ticlopidine. After deployment, patients were followed up in the hospital and at 30 days post procedure. RESULTS: Stent deployment was achieved in 32 of 33 attempts (26 of 27 patients). There was one deployment failure in a long, calcified ostial and proximal left coronary lesion. In the 26 successful deployments, TIMI 3 flow was achieved. One other patient experienced a painless increase in creatine kinase to 375 (CK-MB of 59) at 12 h without ECG changes. At 30 days, there were no deaths, no myocardial infarctions, no subacute thromboses, no repeat interventions, no bypass surgeries and no bleeding complications. Only the patient with post-procedural CK-MB elevation experience recurrence of CCS class 2 angina within the 30 days. CONCLUSION: The R Stent is a promising new device for the treatment of complex coronary heart disease. A larger, more broadly-based study is warranted.
BACKGROUND: Implantation of short balloon-expandable stents provides superior clinical and angiographic outcome compared with balloon angioplasty in selected patients. The purpose of the Wellstent study was to evaluate the safety and efficacy of the self-expanding Wallstent combined with aspirin and ticlopidine in patients with stable or unstable angina related to a native coronary lesion up to 45 mm in length. METHODS: 105 patients (111 lesions) with stable (57%) or unstable (43%) angina were included in this prospective multicentre evaluation. Angiography before and after Wallstent implantation and at 6-month follow-up was analysed at the core lab using the CAAS 2 system. The primary end-point was incidence of major adverse cardiac events (MACE) at 30 days. Secondary end-points were angiographic outcome at 6 months and MACE at 6 months and 1 year. RESULTS: Acute procedural success (successful stent implantation with residual stenosis <20%) was achieved in 99%. Mean reference diameter was 3.18 +/- 0.66 mm, minimal luminal diameter was 1.00 +/- 0.50 mm pre- and 2.84 +/- 0.47 mm poststent (diameter stenosis 16 +/- 6%). The mean hospital stay was 2.2 days. At 30 days, 95% of patients were free of MACE. At 6 month and 1 year clinical follow-up, 75% and 71% of patients, respectively, remained free of MACE, the majority of which (19 of 30) were re-interventions at re-angiography. In 90% of eligible patients, MLD at follow-up was 1.65 +/- 0.75 mm (late loss 1.20 +/- 0.66 mm, loss index 0.66), diameter stenosis 42 +/- 15%, with a restenosis rate of 32%. Longer stents were associated with greater luminal loss (P = 0.001) and less-favourable clinical outcome. CONCLUSIONS: Wallstent implantation, combined with aspirin and ticlopidine, achieved excellent acute and 30 day clinical results in a heterogenous high-risk patient group. Clinical outcome at 6 months and 1 year remained good, and most adverse events were re-PTCA during follow-up angiography. The loss index of 0.66 and restenosis rate of 32%, related in part to the use of longer stents, emphasizes the continuing need for effective anti-proliferative therapy.
Reperfusion of support livers after cold preservation produces hemodynamic instability (i.e., postreperfusion syndrome) in the recipient during both orthotopic liver transplantation and extracorporeal liver perfusion. We evaluated the effect of the normal porcine cold-preserved support liver on healthy recipient hemodynamics and in situ liver function during extracorporeal liver perfusion. Support livers were harvested from Yorkshire pigs and reperfused in an extracorporeal circuit with a healthy, anesthetized recipient pig. Correlation analyses were performed between support liver variables of function (oxygen consumption, bile flow, and biliary phospholipid and cholesterol output) and both recipient hemodynamic stability (heart rate, blood pressure, urine output, and vasopressor use) and hepatic function (bile flow and biliary phospholipid secretion). The data indicate that optimally functioning support livers are associated with improved recipient hemodynamic stability manifested by decreased recipient heart rate and vasopressor use and increased recipient urine output. Support livers exhibiting poor biliary secretory function (i.e., bile flow and phospholipid output) were associated with similarly diminished recipient liver biliary secretory function. These data indicate that the functional condition of the support liver after harvest and cold preservation may influence both recipient hemodynamic parameters and the endogenous function of the recipient liver.