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T Colman

Publications and source records attributed to T Colman.

At least 19 recordsLinked to original sources
PubMed2001

[Initial results and 6 month clinical follow-up after implantation of a silicon carbide coated coronary stent].

INTRODUCTION AND OBJECTIVES: To present the initial Spanish experience with the Tenax coronary stent, a laser sculpted from high-precision 316L stainless steel coated with hydrogen rich amorphous silicon carbide that reduces thrombogenecity and improves biocompatibility. PATIENTS AND METHODS: From July 1998 to July 1999, 206 patients (62 +/- 5 years) underwent implantation of 231 Tenax stents in 9 centers as the only revascularization procedure. The most frequent clinical indication was unstable angina (66%), and most of the lesions were complex (class B2 and C). The target vessels were the left anterior descending (51%) and right coronary arteries (36%). The ejection fraction was < 0.5 in 19% cases. RESULTS: Revascularization was complete in 70%, elective in 80%, and the implantation was direct in 25% of the cases. The procedure was successful in all the lesions, reducing stenosis from 62 +/- 16 to 16 +/- 10% and increasing the minimal luminal diameter from 0.81 +/- 0.40 to 2.61 +/- 0.59 mm. The TIMI flow was reduced in 30%, but normalized after the stent in all but one case. The incidence of cardiac events was minimal: 1 acute thrombosis (0.5%) resolved by a new angioplasty and 1 non-Q myocardial infarction (0.5%). At the 6-month clinical follow-up 10% of the patients presented complaints of angina greater than class II, and a new angioplasty was carried out in 1.9% of these cases. CONCLUSION: Clinical and angiographic data suggest that the hydrogenated silicon carbide coating of the Tenax coronary stent may indeed play a beneficial role in patient outcome, and should therefore be evaluated by prospective clinical trials.

Angina, Unstable↗
PubMed2001

[Unstable angina in octogenarians: is an invasive approach feasible and effective?].

BACKGROUND AND OBJECTIVE: Octogenarian patients with unstable angina are usually managed more conservatively despite having a worse prognosis. Studies of balloon angioplasty in the elderly have demonstrated a higher incidence of adverse events but the new advances (mainly stenting) have improved the results. We evaluated the efficacy and safety of an invasive approach in octogenarians with unstable angina. PATIENTS AND METHOD: From January 1996 to October 1999, 100 patients at least 80 years old with unstable angina were admitted to our unit and among these, 74 (74%) underwent percutaneous revascularization. We evaluated immediate results, in-hospital events and clinical follow-up. RESULTS: A total of 145 lesions were treated in 74 patients. The stent implantation rate was 79%. The success rate was 92%. Two patients died during hospitalization due to cardiac causes and 1 patient had a non-Q infarction. At follow-up, 24 +/- 12 months (range: 4 -50 months) 14 patients died (19.4%). New revascularization was performed in 10 patients (13.5%), 9 with PTCA and 1 with surgery. The survival rate free of death and infarction in the first year was 89.2%. At the end of follow-up 58 patients were alive (78.4%), 45 asymptomatic and 13 had stable angina, class I or II. CONCLUSIONS: The results of stent implantation in octogenarians were good with a 92% procedural success. Ninety-six percent of patients were free of death and infarction during hospitalization and 78.4% of the patients remained alive, most of them asymptomatic at the end of follow-up.

Age Factors↗
PubMed2000

Evaluation of direct stent implantation without predilatation by intravascular ultrasound.

The present study shows that direct stent implantation without predilatation in selected lesions provides angiographic and ultrasonographic results that could be comparable to those expected with conventional stenting. These results may even safely improve if a balloon-artery ratio of 1.1 to 1.2 is used in combination with implantation pressures of 12 to 16 atm.

Coronary Disease↗
PubMed2000

Stenting the stent: initial results and long-term clinical and angiographic outcome of coronary stenting for patients with in-stent restenosis.

Stent restenosis constitutes a therapeutic challenge affecting an increasing number of patients. Conventional angioplasty and debulking techniques are currently used in these patients. However, the potential role of a second stent implantation in this setting (stenting the stent) remains unknown. Therefore, 65 consecutive patients (12 women, aged 62 +/- 11 years) undergoing stent implantation (42 elective and 23 unplanned) for the treatment of in-stent restenosis (diffuse [> 10 mm] in 39 [60%]) were studied. Angiographic success was obtained in all patients. Three patients developed hospital complications: 1 died from refractory heart failure and 2 suffered non-Q-wave myocardial infarctions. During follow-up (mean 17 +/- 11 months) 1 patient died (noncardiac cause) and only 9 (14%) required target vessel revascularization. Kaplan-Meier event-free survival (freedom from death, myocardial infarction, and target vessel revascularization) at 1 year was 84%. Using Cox analysis, patients with unstable symptoms, a short time to stent restenosis, nonelective stenting, and B2-C lesions tended to have poorer prognosis. After adjustment, nonelective stenting was associated (adjusted RR 2.9, 95% confidence interval [CI] 0.82 to 10.3, p = 0.09) with an adverse clinical outcome. On quantitative angiography (core lab) restenosis was found in 13 of 43 patients (30%) (75% of those eligible). Logistic regression analysis identify restenosis length (adjusted RR 1.43, 95% CI 1.04 to 2.14, p = 0.04), and time to restenosis (adjusted RR 0.67, 95% CI 0.47 to 0.94, p = 0.01) as the only independent predictors of recurrent restenosis. Thus, repeat coronary stenting is a safe and efficacious strategy for the treatment of patients with in-stent restenosis. Both elective and nonelective stenting provide excellent initial results. The long-term clinical and angiographic outcome of these patients is also favorable.

Coronary Angiography↗
PubMed2000

Structural modification of berberine alkaloids in relation to cytotoxic activity in vitro.

The cytotoxicity of two protoberberine alkaloids: berberine and lincangenine, their 8-hydroxy-7,8-dihydro-derivatives and tetrahydroprotoberberine:thaicanine, was evaluated. The cellular responses through the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] (MTT) method were measured in Hela (uterus carcinoma), SVKO3 (ovary carcinoma), Hep-2 (larynx carcinoma), primary culture from mouse embryon, and human fibroblast cells at the concentration: 10-1000 ppm (microg/ml) for 24 h. Berberine showed the highest cytotoxicity among the compounds tested, giving LC50 values for all cell lines at the concentration of 10 ppm. The results indicated that the cytotoxicity was notably decreased by structural changes, i.e. by modulation of the planarity caused by the introduction of hydroxyl group at C-8 and concomitant saturation of double bond between N-C8 in protoberberine molecules. In the case of berberine, the cytotoxic effect changed from 98.8 (berberine) to 39% for 8-hydroxydihydroberberine at the concentration of 100 ppm in Hela cells line. The same effect was observed with lincangenine and 8-OH-lincangenine (cytotoxicities 70 and 25%, respectively, at 1000 ppm in SVKO3 cells). On the other hand, these compounds showed a low selectivity for the different human cancer cell lines tested.

Animals↗
PubMed2000

[Intravascular ultrasonographic evaluation of direct stents, implanted without predilatation. Comparison of results according to lesion types].

INTRODUCTION AND OBJECTIVES: Direct stenting is a safe and feasible technique in selected lesions yielding excellent angiographic results. However, there are no studies providing intravascular ultrasonographic examination after direct stenting. The aim of this study was to evaluate direct stent expansion with ultrasonography and to know whether there are differences in the results based on lesion types. METHODS: Patients with amenable lesions for direct stenting were enrolled; including patients with no occlusion, no calcification, no significant tortuosity or angulation, a length 15 mm and a reference lumen diameter 2.5 mm. Intravascular ultrasonography was performed after stent implantation. The ultrasonographic criteria for optimal expansion were: complete apposition and a minimal intrastent lumen area > 80% of the average reference luminal area and 90% of the distal reference lumen area. RESULTS: We included 40 patients (50 lesions). The final angiographic result was good in all the patients but in one case an additional stent was used due to dissection. The ultrasonographic examination did not show significant differences between type A and B lesions. Optimal expansion was achieved in 14/21 (66%) of type A lesions and 17/29 (58%) of type B lesions (p = 0.5). The balloon/artery ratio was the only factor significantly related to ultrasonographic results. When this ratio was 1.1-1.2 (25 cases), 76% of the stents were optimally expanded and when the ratio was < 1. 1 (25 cases) only in a 48% an optimal result was achieved (p < 0.05). CONCLUSIONS: Direct stenting in selected lesions provides ultrasonographic results comparable to those expected with conventional stenting and these results could be even improved if a balloon artery ratio 1.1-1.2 is used. Taking into consideration the selection criteria the differences observed between lesion types A and B are not significant.

Coronary Disease↗
PubMed1999

Randomized comparison of coronary stent implantation and balloon angioplasty in the treatment of de novo coronary artery lesions (START): a four-year follow-up.

OBJECTIVE: The purpose of this study was to test the hypothesis that stent implantation in de novo coronary artery lesions would result in lower restenosis rates and better long-term clinical outcomes than balloon angioplasty. BACKGROUND: Placement of an intracoronary stent, as compared with balloon angioplasty, has proven to reduce the rate of restenosis. However, the long-term clinical benefit of stenting over angioplasty has not been assessed in large randomized trials. METHODS: We randomly assigned 452 patients with either stable (129 patients) or unstable (323 patients) angina pectoris to elective stent implantation (229 patients) or standard balloon angioplasty (223 patients). Coronary angiography was performed at baseline, immediately after the procedure and six months later. End points were the rate of restenosis at six months and a composite of death, myocardial infarction (MI) and target vessel revascularization over four years of follow-up. RESULTS: Procedural success rate was achieved in 84% and 95% (balloon angioplasty vs. stent, respectively). The increase in the minimal luminal diameter was greater in the stent group both after the intervention (2.02 +/- 0.6 mm vs. 1.43 +/- 0.6 mm in the angioplasty group; p < 0.0001), and at six-month follow-up (1.98 +/- 0.7 mm vs. 1.63 +/- 0.7 mm; p < 0.001). The corresponding restenosis rates were 22% and 37%, respectively (p < 0.002). After four years, no differences in mortality (2.7% vs. 2.4%) and nonfatal MI (2.2% vs. 2.8%) were found between the stent and the angioplasty groups, respectively. However, the requirement for further revascularization procedures of the target lesions was significantly reduced in the stent group (12% vs. 25% in the angioplasty group; relative risk 0.49, 95% confidence interval 0.32 to 0.75, p = 0.0006); most of the repeat procedures (84%) were carried out within six months of entry into the study. CONCLUSIONS: Patients who received an intracoronary stent showed a lower rate of restenosis than those treated with conventional balloon angioplasty. The benefit of stenting was maintained four years after implantation, as manifested by a significant reduction in the need for repeat revascularization.

Aged↗
PubMed1999

[A direct stent without predilatation. Our experience in 300 lesions].

INTRODUCTION: The stent alone technique, direct stenting without predilatation, aims to reduce cost and procedural time. Other potential benefits are the avoidance of abrupt vessel closure after balloon angioplasty and lessening of the restenosis rate due to the reduced arterial injury. We present our experience with this therapeutic approach in a long series of patients. PATIENTS AND METHODS: 230 patients referred to our unit were included with 300 non-occlusive stenotic lesions without excessive tortuosity, calcification, length or angulation and with a reference vessel diameter > or = 2.5 mm. In these patients stent implantation without predilatation was attempted. The immediate angiographic results and procedural related complications were evaluated. RESULTS: The stent alone technique succeeded in 256 (85%) among the 300 lesions treated. In 43 (14.3%) lesions predilatation was required and in one case the stent could not be positioned. A new dilatation after deployment was required due to suboptimal stent expansion in 27/256 (10.5%) lesions. Stent embolization occurred in 5 patients, 4 stents were retrieved and there were no clinical sequelae. The best results were obtained in non-subtotal and non-bifurcated lesions type A or B1 without moderate calcification, tortuosity or angulation. CONCLUSIONS: Direct stenting is feasible in a large number of patients with a high success rate after an appropriate selection. The most optimal lesions to be treated with this technique are < or = 90% stenotic non-bifurcated lesions type A or B1 without moderate calcification, tortuosity or angulation.

Aged↗
PubMed1998

[Symptomatic ischemia in a patient with a single right coronary artery without lesions].

Coronary artery anomalies are not a frequent finding, and a single right coronary artery is extremely rare. This anomaly has been included among the potentially serious ones because its association with infarction and sudden death has been reported. We present the case of a female patient who complained of chest pain, showed a positive exercise treadmill test and had a single right coronary artery in the angiography with no stenotic lesions. The pathophysiology and the clinical implications are discussed.

Angina Pectoris↗
PubMed1998

Polymorphism of the platelet glycoprotein IIIa gene in patients with coronary stenosis.

Based on genetic variability, structural differences in the glycoprotein IIb/IIIa platelet receptor for adhesive proteins result in individual differences in the thrombogenicity of platelets. Recent studies suggest a controversial association between a genetic polymorphism of the glycoprotein IIIa gene (PlA2) and the risk of coronary artery disease. In our study, the prevalence of the PlA2 allele in a group of patients undergoing percutaneous coronary revascularization was 37%, a value significantly higher than in controls [13%, odds ratio (OR) = 3.93, 95% CI, 1.84 to 8.53] suggesting a significant association between this polymorphism and documented coronary stenosis, which is strongest among <60 years old patients (OR = 12.30, 95% CI, 2.98 to 70.93). This polymorphism represents an inherited risk factor for severe cardiovascular disease due to coronary occlusion.

Aged↗
PubMed1998

[Wiktor coronary stent for elective placement with an antiaggregation regimen. WINE study. WINE Group Study].

INTRODUCTION AND OBJECTIVES: The main problems associated with coronary stent implantation are subacute thrombosis and vascular and hemorrhagic complications due to the intensive anticoagulant regime. We studied the complications and the six-month restenosis rate after the elective implantation of a Wiktor stent in patients treated only with antiplatelet drugs. PATIENTS AND METHODS: The WINE study is an open, observational, multicenter study that included 368 patients (380 lesions) from 11 Spanish hospitals. All patients were treated with aspirin (125-325 mg/day) and ticlopidine (250 mg/12 h for 4 weeks). After hospitalization, a clinical control and clinical and angiographic controls were performed at one and six months respectively. RESULTS: 27 patients were excluded after the procedure because of failed delivery of the stent (5 cases), suboptimal angiographic result (15 cases) or lack of adherence to the antithrombotic regime (7 cases). Among the 341 patients with an adequate result most lesions (76.2%) were type B, including 39.1% type B2 and 8.5% type C. Subacute stent occlusion occurred in two patients (0.6%). Seven patients (2.1%) had vascular complications related to the arterial puncture. No major hemorrhagic complications needing transfusion were found. At six months 64 patients (19.8%) showed angiographic restenosis. CONCLUSIONS: When the angiographic result after Wiktor stent placement is adequate, the therapy with aspirin and ticlopidine is associated with a very low stent thrombosis rate as well as with a low rate of vascular complications and 6 month angiographic restenosis.

Adult↗
PubMed1997

[Blood coagulation, genetics and post-angioplasty restenosis].

Throughout the last few decades, different factors have been related to coronary stenosis which is clinically evidenced by coronary heart disease, the leading cause of death in developed countries. Different experimental models have contributed towards defining some of these factors, and to an understanding of the physiopathology of the atherosclerotic lesion. The genetic basis related to individual responses to the same event is currently being established. As endothelial injury reparative mechanisms are fundamental in atherosclerosis pathogeny, patients who experiment restenosis after undergoing revascularization procedures are useful human models in the study of these processes. We review from the literature the genetic factors related to thrombus formation, which may be associated with restenosis after percutaneous transluminal coronary angioplasty, in order to define the most suitable anticoagulant therapy for each patient. We refer to the recently characterized gene for the platelet receptors and its relationship with fibrinogenous, factor Xa, PAI-I, and the involvement of apolipoprotein (a) in the coagulation process.

Angioplasty, Balloon, Coronary↗
PubMed1995

Balloon mitral commissurotomy in patients with previous annuloplasty. Our experience.

Balloon mitral commissurotomy is an alternative to surgical commissurotomy in the treatment of mitral stenosis and different studies have shown its usefulness for restenosis following surgical commissurotomy. We describe our experience in balloon mitral commissurotomy in five patients with previous commissurotomy and annuloplasty. Among 360 balloon commissurotomies performed in our hospital up to December 1993, 29 procedures were performed on patients with restenosis after surgical commissurotomy, five of whom also had an annuloplasty (flexible ring in four and rigid in one). The balloon commissurotomy was performed without complications using the Inoue single balloon technique. Mitral valve area increased from 0.9 +/- 0.1 cm2 to 1.0 +/- 0.1 cm2 by pressure half-time, and from 1.0 +/- 0.2 cm2 to 1.3 +/- 0.1 cm2 by Gorlin formula. Two patients in functional class III underwent mitral valve replacement, 32 and 11 months later; the other three patients were in class II 38, 10 and 7 months later. The presence of a mitral ring should not constitute a contraindication to balloon commissurotomy. However, the haemodynamic results are not favourable in our patients, probably due to the practical absence of commissural fusion and the ring's restrictive effect on valvular stretching.

Adult↗