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Biomedical subjects

I Sheiban

Publications and source records attributed to I Sheiban.

At least 19 recordsLinked to original sources
PubMed2006

Low testosterone levels are associated with coronary artery disease in male patients with angina.

Historically, high androgen levels have been linked with an increased risk for coronary artery disease (CAD). However, more recent data suggest that low androgen levels are associated with adverse cardiovascular risk factors, including an atherogenic lipid profile, obesity and insulin resistance. The aim of the present study was to evaluate the relationship between plasma sex hormone levels and presence and degree of CAD in patients undergoing coronary angiography and in matched controls. We evaluated 129 consecutive male patients (mean age 58+/-4 years, range 43-72 years) referred for diagnostic coronary angiography because of symptoms suggestive of CAD, but without acute coronary syndromes or prior diagnosis of hypogonadism. Patients were matched with healthy volunteers. Out of 129 patients, 119 had proven CAD; in particular, 32 of them had one, 63 had two and 24 had three vessel disease, respectively. Patients had significantly lower levels of testosterone than controls (9.8+/-6.5 and 13.5+/-5.4 nmol/l, P<0.01) and higher levels of gonadotrophin (12.0+/-1.5 vs 6.6+/-1.9 IU/l and 7.9+/-2.1 vs 4.4+/-1.4, P<0.01 for follicle-stimulating hormone and luteinizing hormone, respectively). Also, both bioavailable testosterone and plasma oestradiol levels were lower in patients as compared to controls (0.84+/-0.45 vs 1.19+/-0.74 nmol/l, P<0.01 and 10.7+/-1.4 vs 13.3+/-3.5 pg/ml, P<0.05). Hormone levels were compared in cases with one, two or three vessel disease showing significant differences associated with increasing severity of coronary disease. An inverse relationship between the degree of CAD and plasma testosterone levels was found (r=-0.52, P<0.01). In conclusion, patients with CAD have lower testosterone and oestradiol levels than healthy controls. These changes are inversely correlated to the degree of CAD, suggesting that low plasma testosterone may be involved with the increased risk of CAD in men.

Adult↗
PubMed2003

Evolving standard in the treatment of coronary artery disease. Drug-eluting stents.

Coronary stent implantation is the predominant method of percutaneous coronary interventions (PCI). This is to be attributed to the ease of use beside the better short and long term clinical outcome as compared to balloon angioplasty. Nevertheless, improvements in operator skill and stent technology together with better use of adjunctive pharmacological therapy have contributed to the improvement in clinical outcome. However, the main limitation of coronary stenting is still represented by in-stent restenosis (ISR) with an estimated rate of 17-32%. Thus, compared to coronary bypass surgery, the major adverse cardiac events following stent implantation are still higher and mainly represented by the need for re-intervention. The advent of drug eluting stents (DES) has led the experts to predict that with DES there will be little or no difference between PCI and coronary bypass surgery in terms of long-term outcome leading to a further expansion of indications. The clinical trial programs of the 2 available DES for clinical use (sirolimus-eluting stent, SES - Cypher and paclitaxol-eluting stent - Taxus) have been able to demonstrate the safety and clinical efficacy of both. Nevertheless, off-label use in patients on high risk for restenosis confirmed these data. At least for SES as was demonstrated by 2 "real world" registries. Thus, the introduction of DES represents a remarkable evolution for new standards in coronary artery disease treatment and offers hope to those patients considered to be "high risk" such as diabetics, patients with ISR, diffuse disease in whom surgery was previously the only therapeutic option. This paper will discuss the main results of the clinical trial programs of the DES (mentioned above) available for clinical use in the present time and analyze technical and procedural aspects which could affect long term outcome.

Adult↗
PubMed2002

Drug-eluting stent: the emerging technique for the prevention of restenosis.

Percutaneous coronary interventions (PCI) have surpassed coronary artery bypass grafting as the most common means for treating coronary artery disease, because of materials improvement, the use of stent and pharmacotherapy. However, despite the variety of mechanical techniques such as dilatation, debulking or conventional stent implantation, the incidence of restenosis on short and mid-term follow-up is still representing an important limitation to PCI. Restenosis is mainly due to elastic recoil, negative vessel remodelling and neointimal proliferation, as a response to vessel injury induced by angioplasty devices. The use of conventional stents has provided an efficient method to avoid elastic recoil and negative vessel remodelling, thus partially reducing restenosis as compared to conventional balloon dilatation. However, neointimal proliferation (biological vessel response to injury caused by stent implantation) is not affected by stenting technique. Thus, the extensive use of coronary stent, even in complex lesions, have produced again a "new" disease: the in-stent restenosis especially in some patients' subset (diabetics) or in some lesion subset (bifurcations, long lesions, small vessels, total occlusions, diffuse disease). Therefore, the main target of today's interventional cardiologists is to resolve this problem. The combination between mechanical control of elastic recoil and negative remodelling (stent) and the control of neointimal proliferation - biological response to vessel injury - (antiproliferative drugs) is the emerging approach against restenosis. This emerging approach consists in using the stent as drug carrier to the target site. Local delivery of antiproliferative or immunosuppressive agents using a drug-coated stent is supposed to inhibit in stent restenosis. The first antiproliferative agents being used successfully in clinical trials are sirolimus and paclitaxel and, so far, the data available of these trials demonstrated a marked reduction of restenosis using sirolimus- and paclitaxel-coated stents as compared to conventional stents. However, many questions are still to be answered and several other clinical trials with drug-eluting stents are ongoing, evaluating safety and efficacy of sirolimus and paclitaxel in a larger number of patients and in different subset of coronary lesions type and morphology. Based on the very impressive results available at the present time, we can expect, in the very near future, remarkable changes in our clinical practice and the beginning of a new "era" of interventional cardiology.

Angiogenesis Inhibitors↗
PubMed2001

Emergency stenting to treat neurological complications occurring after carotid endarterectomy.

OBJECTIVES: The purpose of this study was to assess the efficacy of emergency stent implantation for the treatment of perioperative stroke after carotid endarterectomy (CEA). BACKGROUND: Carotid endarterectomy has been proven safe and effective in reducing the risk of stroke in symptomatic and asymptomatic patients with >60% carotid artery stenosis. However, perioperative stroke has been reported in 1.5% to 9% of CEA cases. The management of such a complication is challenging. Recently, percutaneous transluminal carotid angioplasty with stent deployment has emerged as a valuable and alternative strategy for the treatment of carotid artery disease. METHODS: Between April 1998 and February 2000, 18 of the 995 patients (1.8%) who had CEA in our institution experienced perioperative major or minor neurological complications. Of these, 13 patients underwent emergency carotid angiogram and eventual stent implantation, whereas the remaining five had surgery re-exploration. RESULTS: Carotid angiogram was performed within 20+/-10 min and revealed vessel flow-limiting dissection (five cases) or thrombosis (eight cases). Percutaneous transluminal carotid angioplasty with direct stenting (self-expandable stent) was performed in all 13 cases. Angiographic success was 100%. Complete remission of neurological symptoms occurred in 11 of the 13 patients treated by stent implantation and in one of the five patients treated by surgical re-exploration (p = 0.024). CONCLUSIONS: Stent implantation seems to be a safe and effective strategy in the treatment of perioperative stroke complicating CEA, especially when carotid dissection represents the main anatomic problem.

Aged↗
PubMed2001

Time course and determinants of left ventricular function recovery after primary angioplasty in patients with acute myocardial infarction.

OBJECTIVES: We sought to evaluate the importance of time in relation to treatment, time course and determinants of recovery of left ventricular (LV) function in patients with acute myocardial infarction (AMI) undergoing primary percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND: Myocardial salvage has been shown to be dependent on the time elapsed from the onset of AMI to reperfusion. METHODS: Left ventricular function was evaluated at hospital admission, after angioplasty, at 24 h and 6 months by both echocardiography and angiography and at 1, 7, 30, 90 and 180 days by echocardiography in 101 consecutive patients. RESULTS: Patients were allocated to three groups according to interval between symptom onset and angioplasty: <2 h (group A), 2 to 4 h (group B) and >4 h (group C). Patients in groups A and B showed a progressive improvement of LV function between day 7 and day 90, which became statistically significant at day 30 (p < 0.01). No LV function changes were noted in group C patients. Thrombolysis In Myocardial Infarction (TIMI) flow grade <3 at 24 h was not associated with any significant change in LV volume and function during the six-month follow-up period. Restenosis, when associated with TIMI flow grade 3 in the infarct-related vessel, did not influence LV function. Flow grade <3 of the infarct-related artery was not associated with any improvement of cardiac events independently from the time to treatment at the initial procedure. CONCLUSIONS: Patients undergoing primary PTCA for AMI have a good recovery of LV function if TIMI flow grade 3 is restored within 4 h. Coronary angioplasty limits further remodeling of the LV in patients treated after 4 h.

Angioplasty, Balloon, Coronary↗
PubMed2001

Influence of treatment delay on long-term left ventricular function in patients with acute myocardial infarction successfully treated with primary angioplasty.

BACKGROUND: Myocardial salvage has been shown to be dependent on the time elapsed from the onset of acute myocardial infarction (AMI) to reperfusion. The aim of this study was to evaluate the importance of time to reperfusion for left ventricular function recovery after primary angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) for AMI. METHODS: Ninety-five patients undergoing long-term successful PTCA for AMI were studied. Echocardiography was performed before and 3, 7, 30, 90, and 180 days after PTCA. End-diastolic volume index (EDVI) and end-systolic volume index (ESVI), ejection fraction, and left ventricular wall motion score index (WMSI) were evaluated. RESULTS: Patients were divided into group A, 23 patients reperfused within 2 hours; group B, 32 patients reperfused between 2 and 4 hours; group C, 22 patients reperfused between 4 and 6 hours; and group D, 18 patients reperfused between 6 and 12 hours. Both EDVI and ESVI were reduced in groups A and B at 90 days. Groups C and D did not show any changes of EDVI and ESVI at any stage throughout the study. Ejection fraction improved only in groups A and B at 30, 90, and 180 days. At study entry, WMSI was similar in all groups. After 7 days, in group A and in group B, WMSI was improved, no changes were observed in group C, and a mild deterioration was observed in group D at 3 and 7 days. Subsequent evaluations showed progressive improvement of WMSI in all groups. CONCLUSIONS: Myocardial salvage is achieved only in patients revascularized within 4 hours from AMI onset. However, revascularization after 6 hours may be worthwhile by preventing ventricular remodeling.

Adult↗
PubMed2000

Acute electrophysiologic effect of estradiol 17beta in menopausal women.

Sixteen postmenopausal women underwent electrophysiologic study before and 20 minutes after the administration of sublingual estradiol 17beta or placebo. Estradiol 17beta significantly affected electrophysiologic parameters, thereby suggesting its role in the development of palpitations in women.

Administration, Sublingual↗
PubMed2000

Immediate and long-term results of "T" stenting for bifurcation coronary lesions.

The technique of "T" stenting, which incorporates wiring both the branches of a bifurcation lesion, dilating a balloon in the main branch during stent deployment in the side branch followed by deployment of stent in the main branch, provides excellent immediate results in terms of technical and procedural success. However, further innovations are mandated to optimize the long-term outcome, which with a restenosis rate of 63%, can be described as not encouraging.

Angioplasty, Balloon, Coronary↗
PubMed2000

Detrimental effects of acute heparin administration on ischemic threshold in patients with coronary artery disease.

BACKGROUND: Recent studies have indicated that heparin administration might decrease endothelial nitric oxide production. The aim of this study was to investigate the effect of heparin on ischemic threshold. METHODS: Eighteen patients with a positive exercise test and proven coronary artery disease were submitted to a randomized, placebo-controlled trial using i.v. 0.9% NaCl as placebo and i.v. heparin (5,000 IU bolus + 1,000 IU/h). After both saline and heparin bolus, the infusion was started and, after 10 min, the exercise test was performed. Blood samples for nitric oxide metabolites and free fatty acid determinations were taken before, at peak exercise, and at ECG recovery. RESULTS: As compared to placebo, heparin significantly decreased time to 1 mm ST segment depression (241 +/- 160 vs 303 +/- 175 s, p = 0.003) and prolonged recovery (573 +/- 177 vs 441 +/- 195 s, p = 0.003), while exercise duration was similar. Accordingly, rate-pressure product at 1 mm ST segment depression was lower after heparin, while it was similar at peak exercise. No significant differences were found for plasma nitric oxide metabolite levels. Conversely, free fatty acid levels were higher after heparin throughout the study in all patients. The increase in free fatty acids was not correlated with the difference in rate-pressure product at 1 mm ST segment depression between placebo and heparin (r = 0.34, p = NS). CONCLUSIONS: In patients with stable coronary artery disease, heparin significantly decreased exercise ischemic threshold. The lower rate-pressure product at 1 mm ST segment depression during heparin, compared to placebo, suggests an impairment of coronary blood flow, which does not seem to be mediated by decreased nitric oxide production/release. The increased free fatty acid release, on the other hand, might contribute to the detrimental effect of heparin on exercise-induced ischemia, but the lack of a correlation with changes in ischemic threshold suggests that other, still unknown, factors are involved.

Aged↗
PubMed2000

Predictors of long-term clinical outcome in patients undergoing multiple vessel stenting for coronary artery disease.

BACKGROUND: Coronary artery stenting reduces the restenosis rate compared to coronary angioplasty alone. With the increased number of procedures completed with stent placement there has been a parallel increase in the number of procedures performed in patients with multivessel disease and therefore a rise in the number of patients receiving multiple stents. The clinical outcome and the predictors of the outcome of patients receiving multiple stents are not known. METHODS: To evaluate the clinical outcome of patients with multivessel coronary artery disease undergoing multiple stenting we studied 133 consecutive patients who had received > 1 stent in at least two vessels. A total of 375 coronary stents (2.8 stent per patient) were implanted in elective procedure situations. Clinical follow-up was complete in 100%. RESULTS: During follow-up 2 patients (1.5%) died (1 cardiac death), 4 patients (3%) had acute myocardial infarction, 96 patients (72.1%) remained angina-free, and 31 patients (23.3 %) had recurrence of angina. Repeat revascularization procedure was performed in 45 patients (33.8%); 43 patients (32.3%) underwent coronary angioplasty; 2 patients (1.5%) underwent coronary artery bypass grafting. The female gender and the presence of diabetes were significant (p < 0.05) predictors for coronary angioplasty or coronary artery bypass grafting procedures during follow-up. Recurrence of angina was also significantly (p < 0.05) associated with unstable angina at the time of the first procedure as well as diabetes and the female gender. Diabetes, the female gender and unstable angina were highly predictive factors of major adverse cardiac events during follow-up. CONCLUSIONS: Multiple vessel stenting in patients with multivessel coronary artery disease is associated with an acceptable immediate and long-term clinical outcome and could be considered as an alternative therapeutic option in these patients. Predictors of an adverse long-term outcome are the female gender and the presence of diabetes mellitus.

Angioplasty, Balloon, Coronary↗
PubMed1999

Prevention of distal embolization during saphenous vein graft lesion angioplasty. Experience with a new temporary occlusion and aspiration system.

BACKGROUND: Repeat coronary artery bypass graft surgery (CABG) is associated with a high morbidity and mortality, rendering percutaneous treatment of saphenous vein graft (SVG) lesions an attractive alternative. However, percutaneous interventions of degenerated SVGs carries high risk of distal embolization. METHODS AND RESULTS: This study reports our initial experience with the PercuSurge GuardWire, a new device developed to prevent embolization during treatment of degenerated SVG. This device consists of a 190-cm-long, hollow 0.014-in guidewire with a central lumen connected to a distal occlusion balloon. A dedicated inflation device (the MicroSeal Adapter) was used to inflate the distal balloon and maintain complete lumen occlusion during balloon dilatation and stent implantation. A monorail aspiration catheter, connected to a vacuum syringe, was used to evacuate atherosclerotic and thrombotic debris. Angioplasty with stent implantation was performed in 15 degenerated SVGs (18 lesions). Procedural success was achieved in all patients with normal postprocedure flow (Thrombolysis in Myocardial Infarction grade 3). No distal embolization was observed. There were no major in-hospital adverse clinical events, including Q-wave or non-Q-wave myocardial infarction, emergency CABG, or death. All patients were asymptomatic at discharge. CONCLUSIONS: This preliminary series supports the feasible use of the PercuSurge GuardWire for retrieval of plaque debris and prevention of embolization in degenerated SVGs. The good tolerance of temporary occlusions without angiographic or clinical evidence of distal embolization represents encouraging early findings.

Aged↗
PubMed1999

Successful treatment of a bifurcation lesion with the Carina Bard stent: A case report.

In the last years new techniques and user-friendly stents have improved the results of stent implantation in coronary bifurcational lesions but difficulties in stent deployment and incomplete coverage of the bifurcation remain a problem. We describe the case of a proximal lesion of the anterior descending artery involving a large diagonal branch treated with the Carina Bard bifurcate stent, a new device that allows the complete immediate coverage of a bifurcational lesion with a single stent. Cathet. Cardiovasc. Intervent. 48:89-92, 1999.

Coronary Angiography↗
PubMed1999

Administration of protamine after coronary stent deployment.

BACKGROUND: Prompt reversal of anticoagulation by protamine administration could be an important therapeutic option to treat serious procedural complications such as vessel rupture or major bleeding from the puncture site during coronary stent implantation. However, this therapeutic option is rarely used because of the possible risk of stent thrombosis. METHODS: We retrospectively analyzed the incidence of acute and subacute stent thrombosis and vascular complications in 90 patients who received protamine (protamine group) and 1763 patients who did not receive protamine (control group) after successful coronary stent implantation. The 2 groups were matched for clinical, angiographic, and procedure characteristics. RESULTS: No patients in the protamine group had adverse effects such as hypotension or vascular collapse during protamine administration. Acute stent thrombosis did not occur in any protamine group patient but did occur in 12 patients in the control group (0.7%) (P =.47). Subacute stent thrombosis occurred in 2 patients in the protamine group (2.1%) and in 15 in the control group (0.8%) (P =.20). By logistic regression analysis, protamine was not a determinant of stent thrombosis. CONCLUSIONS: Reversal of anticoagulation by protamine after stent implantation does not predispose to stent thrombosis. This result has important clinical consequences because it allows the use of protamine in the treatment of coronary perforation and serious bleeding complications that may occur during coronary stent deployment.

Aged↗
PubMed1999

Comparison of stress/rest myocardial perfusion tomography, dipyridamole and dobutamine stress echocardiography for the detection of coronary disease in hypertensive patients with chest pain and positive exercise test.

OBJECTIVES: Although different noninvasive tests have been proposed for detecting coronary artery disease (CAD) in patients with hypertension and chest pain symptoms, the relative performance of the available techniques has not been systematically assessed. BACKGROUND: Patients with hypertension frequently complain of chest pain and exhibit ischemic-like ST segment changes on the exercise electrocardiogram (ECG). However, the specificity of such changes for predicting significant CAD is very low, because these patients often exhibit a normal coronary angiogram. METHODS: In 101 patients with hypertension, chest pain and positive exercise ECG, we performed stress/rest myocardial single photon emission computed tomography with 99mTc-MIBI, dipyridamole and dobutamine stress echocardiography and coronary angiography. All patients had normal global ventricular function and 57 had left ventricular hypertrophy. All were kept on ACE inhibitors during the study period. RESULTS: No patients had significant side effects during perfusion scintigraphy. Dose-limiting side effects were observed in five patients with dipyridamole and in seven patients with dobutamine. Only 56% of study patients exhibited significant CAD. Sensitivity, specificity, accuracy, positive and negative predictive values were, respectively, 98%, 36%, 71%, 67% and 94% for perfusion scintigraphy, 61%, 91%, 74%, 90% and 64% for dipyridamole and 88%, 80%, 84%, 85% and 83% for dobutamine stress echocardiography. CONCLUSIONS: This study shows that stress echo in patients with hypertension yields a satisfactory diagnostic accuracy for identifying significant epicardial CAD. Our results indicate that dobutamine might be superior to dipyridamole. The low specificity of myocardial scintigraphy probably relates to the fact that this method traces perfusion abnormalities, not necessarily caused by epicardial CAD, possibly due to microvascular disease and not causing obvious wall motion abnormalities.

Aged↗
PubMed1999

Direct coronary stenting without predilation.

OBJECTIVES: Coronary stenting is the primary therapeutic option for percutaneous treatment of many coronary lesions, after the risk of subacute stent thrombosis and bleeding complications has been reduced by improved antithrombotic regimens and high pressure stent expansion. BACKGROUND: Direct stent implantation (without predilation) has been considered a promising new technique that may reduce the procedure time, radiation exposure time and cost. METHODS: After having reviewed all cases of stent implantation from February to June 1998 (n = 585), 185 (32%) of these patients were retrospectively considered candidates for direct stent implantation without predilation, according to prespecified criteria (i.e., absence of severe coronary calcifications and/or tortuosity of the lesion or the segment proximal to the lesion). By operator preference, direct coronary stent implantation was actually attempted in 123 (21%) of the 585 patients (100 men, 60 +/- 10 years old) on 123 lesions. The impact of direct stenting in terms of cost, procedure time, radiation exposure time and amount of contrast dye used was assessed by comparing the two groups of patients who underwent single-vessel stenting without (n = 69) and with (n = 46) predilation. RESULTS: Direct stenting was successful in 118 patients (96%). No acute or subacute complications occurred in these patients. Procedure time, radiation exposure time and cost were significantly lower in the group of patients who had single-vessel direct versus conventional stenting (45 +/- 31 vs. 64 +/- 46 min, 12 +/- 9 vs. 16 +/- 10 min and 1,305 +/- 363 vs. 2,210 +/- 803 Euro, respectively; p < 0.05 for all). CONCLUSIONS: Direct stenting without predilation in selected lesions seems to be a safe and successful procedure that provides a way to contain cost and to shorten radiation exposure time.

Angioplasty, Balloon, Coronary↗
PubMed1999

Intraoperative stenting of the internal carotid artery after unsuccessful eversion endarterectomy.

Stenting of the internal carotid artery (ICA) has been shown to be feasible in atherosclerotic lesions, in restenosis after carotid endarterectomy, and in spontaneous carotid dissections. To correct an intimal flap that detached distal occlusion of the ICA after eversion carotid endarterectomy, as shown with intraoperative completion angiography, we successfully used stenting of the ica with a self-expandable stainless steel stent placed during surgery through the common carotid artery.

Carotid Artery, Internal↗
PubMed1999

[Myocardial infarct with ST segment depression: an absolute contraindication to thrombolytic therapy?].

The benefit of thrombolytic reperfusion has been demonstrated widely in patients who present with ST segment elevation and develop myocardial infarction. Instead, the role of thrombolytic therapy in patients who present with ST segment depression and develop myocardial infarction is still unresolved. The purpose of this paper is to review the literature on the subject and give rise to reconsideration of thrombolytic therapy in this subgroup of patients who are usually excluded from receiving thrombolytic agents because of the absence of indications and the presence of contraindications.

Angioplasty, Balloon, Coronary↗