Search PubMed⌕ Search

Biomedical subjects

Rafael Beyar

Publications and source records attributed to Rafael Beyar.

At least 19 recordsLinked to original sources
PubMed2006

Predictive value of white blood cell subtypes for long-term outcome following myocardial infarction.

INTRODUCTION: Elevation of total white blood cells (WBC) count is associated with higher mortality in patients with acute coronary syndromes. However, it is unknown which specific subset of leukocytes best correlates with increased risk of adverse outcome. METHODS AND RESULTS: We prospectively studied the predictive value of WBC subtypes for long-term outcome in 1037 patients with acute myocardial infarction (AMI). Total WBC, neutrophil, monocyte and lymphocyte counts, and high-sensitivity C-reactive protein (CRP) were obtained in each patient. The median duration of follow up was 23 months (range, 6-42 months). Analyzed separately, baseline total WBC (HR 2.2, 95% CI 1.5-3.3; P<0.0001), neutrophil (HR 2.7, 95% CI 1.8-4.1; P<0.0001) and monocyte (HR 1.9, 95% CI 1.3-2.8; P=0.001) counts in the upper quartile, and lymphocyte count in the lower quartile (HR 1.5, 95% CI 1.1-2.3; P=0.03), were all independent predictors of mortality. Comparing nested models, adding other WBC data failed to improve model based on neutrophil count. In contrast, adding neutrophil count to the models based on total WBC (P=0.01), on monocyte count (P<0.0001) or on lymphocyte count (P<0.0001) improved the prediction of the models. Neutrophil count in the upper quartile (>or=9800 microL(-1)) remained a strong independent predictor of mortality after adjustment for left ventricular systolic function and for CRP (HR 2.2, 95% CI 1.6-3.0; P<0.0001). CONCLUSION: Of all WBC subtypes, elevated neutrophil count best correlates with mortality in patients with AMI. Neutrophil count provides additive prognostic information when combined with CRP.

Aged↗
PubMed2006

Ischemic mitral regurgitation and risk of heart failure after myocardial infarction.

BACKGROUND: The development of ischemic mitral regurgitation (MR) after myocardial infarction may impose hemodynamic load during a period of active left ventricular remodeling and promote heart failure (HF). However, few data are available on the relationship between ischemic MR and the long-term risk for HF. METHODS: We prospectively studied 1190 patients admitted for acute myocardial infarction. Mitral regurgitation was assessed by echocardiography and was considered mild, moderate, and severe when the regurgitant jet area occupied less than 20%, 20% to 40%, and greater than 40% of the left atrial area, respectively. The median duration of follow-up was 24 months (range, 6-48 months). RESULTS: Mild and moderate or severe ischemic MR was present in 39.7% and 6.3% of patients, respectively. After adjusting for ejection fraction and clinical variables (age, sex, Killip class, previous infarction, hypertension, diabetes mellitus, anterior infarction, ST-elevation infarction, and coronary revascularization), compared with patients without MR, the hazard ratios for HF were 2.8 (95% confidence interval [CI], 1.8-4.2; P<.001) and 3.6 (95% CI, 2.0-6.4; P<.001) in patients with mild and moderate or severe ischemic MR, respectively. The adjusted hazard ratios for death were 1.2 (95% CI, 0.8-1.8; P = .43) and 2.0 (95% CI, 1.2-3.4; P = .02) in patients with mild and moderate or severe MR, respectively. CONCLUSIONS: There is a graded independent association between the severity of ischemic MR and the development of HF after myocardial infarction. Even mild ischemic MR is associated with an increase in the risk of HF.

Aged↗
PubMed2006

Hyponatremia and long-term mortality in survivors of acute ST-elevation myocardial infarction.

BACKGROUND: Hyponatremia, a marker of neurohormonal activation, is a common electrolyte disorder among patients with acute ST-elevation myocardial infarction. The long-term prognostic value of hyponatremia during the acute phase of infarction is not known. METHODS: We studied 978 patients with acute ST-elevation myocardial infarction and without a history of heart failure who survived the index event. During the hospital stay, sodium levels were obtained on admission and at 24, 48, and 72 hours. The median duration of follow-up after hospital discharge was 31 months (range, 9-61 months). RESULTS: Hyponatremia, defined as a mean serum sodium level less than 136 mEq/L, was present during admission in 108 patients (11.0%). In a multivariable Cox proportional hazards model adjusting for other potential clinical predictors of mortality and for left ventricular ejection fraction, hyponatremia during admission remained an independent predictor of postdischarge death (hazard ratio [HR], 2.0; 95% confidence interval [CI], 1.3-3.2; P = .002). Hyponatremia during admission was also independently associated with postdischarge readmission for heart failure (HR, 1.6; 95% CI, 1.1-2.6; P = .04). When serum sodium level was used as a continuous variable, the adjusted HR for death or heart failure was 1.12 for every 1-mEq/L decrease (95% CI, 1.07-1.18; P<.001). CONCLUSION: Hyponatremia in the early phase of ST-elevation myocardial infarction is a predictor of long-term mortality and admission for heart failure after hospital discharge, independent of other clinical predictors of adverse outcome and left ventricular ejection fraction.

Aged↗
PubMed2006

Early inflammation and risk of long-term development of heart failure and mortality in survivors of acute myocardial infarction predictive role of C-reactive protein.

OBJECTIVES: We aimed to study the relationship between C-reactive-protein (CRP), obtained within 12 to 24 h of symptoms onset, and long-term risk of death and heart failure (HF) in survivors of acute myocardial infarction (MI). BACKGROUND: A robust inflammatory response is an integral component of the response to tissue injury during MI. The magnitude of the early inflammatory response to ischemic injury might be an important determinant of long-term outcome. METHODS: We prospectively studied 1,044 patients admitted with acute MI and discharged from hospital in stable condition. RESULTS: During a median follow-up of 23 months (range, 6 to 42 months), 113 patients died and 112 developed HF. In a multivariable Cox regression model adjusting for clinical variables and predischarge ejection fraction, compared with patients in the first CRP quartile, the adjusted hazard ratios (HRs) for death progressively increased with higher quartiles of CRP (second quartile 1.4 [95% confidence interval (CI) 0.6 to 2.9]; third quartile 2.3 [95% CI 1.2 to 4.6]; fourth quartile 3.0 [95% CI 1.5 to 5.7]; for trend, p = 0.0002). Compared with patients in the first CRP quartile, the adjusted HRs for HF were: second quartile, 1.1 (95% CI 0.5 to 2.3); third quartile, 1.9 (95% CI 1.0 to 3.6); and fourth quartile, 2.1 (95% CI 1.2 to 3.9) (for trend, p = 0.005). CONCLUSIONS: C-reactive-protein is a marker of long-term development of HF and mortality in patients with acute MI and provides prognostic information beyond that provided by conventional risk factors and the degree of left ventricular systolic dysfunction.

C-Reactive Protein↗
PubMed2006

Remote-control percutaneous coronary interventions: concept, validation, and first-in-humans pilot clinical trial.

OBJECTIVES: This study was designed to assess the feasibility and safety of a Remote Navigation System (RNS, NaviCath, Haifa, Israel) in which the angioplasty guidewire, the balloon, and the stent are navigated via a computerized system. BACKGROUND: Percutaneous coronary interventions (PCIs) are manually performed under fluoroscopic guidance, requiring lead protection for the operators. A system in which the operator can remotely, safely, and precisely navigate the procedure during PCI would have clear advantages. METHODS: The RNS involves a computer-controlled wire and delivery system navigator. Following preclinical validation, the system was assessed in patients undergoing single-vessel PCI. RESULTS: The study involved 18 patients (age 55.9 years, 16% women). The RNS successfully crossed lesions with the guidewire in 17 patients. The stent was then advanced by the advance/rotate mode and adequately positioned in 15 of 17 cases. Technical malfunction was encountered in three patients in whom the procedure was successfully completed manually. Direct stenting was employed in 10 of 18 patients, pre-dilation in 7 patients, and after-stent balloon dilation in 5 patients. The total fluoroscopy time for 17 RNS patients was compared with the corresponding time of 20 consecutive patients who underwent standard single-lesion PCI. Fluoroscopy time was similar for both procedures, with 8.8 +/- 4.8 min with the RNS versus 9.1 +/- 3.5 min with the standard techniques (p = NS). Clinical success was 100% and technical success 94% for the guidewire and 83% for the overall procedure. CONCLUSIONS: The use of the RNS for guidewire, balloon, and stent manipulation during PCI appears safe and feasible for the treatment of patients with coronary stenosis. The system offers operator radiation safety and may enhance precision of stent placement and balloon dilation strategies.

Adult↗
PubMed2006

Carotid artery stenting in surgical high-risk patients.

Recent studies have shown that carotid artery angioplasty and stenting may offer a viable alternative for symptomatic and asymptomatic patients with carotid artery stenosis, especially in high-risk patients. We report the results of a prospective single-center registry designed to evaluate the feasibility and safety of carotid artery angioplasty and stenting with and without distal protection devices in high-risk patients. A total of 116 consecutive patients underwent 126 procedures and 127 stents were deployed successfully in 130 lesions. The majority of patients (63%) had restenosis after a prior carotid endarterectomy; 31% were considered to be ineligible for carotid endarterectomy by both the vascular surgeons and the interventional cardiologist and 9% were considered ineligible for surgery due to hostile neck anatomy. Periprocedural and follow-up evaluation included a thorough independent clinical and neurological assessment. Distal embolic protection devices were used in 44% of all cases. Procedural success was achieved in 122 procedures (97%). The overall rate of in-hospital major adverse cerebrovascular events (death, stroke, and myocardial infarction) was 2.6%. Event rates in patients with prior carotid endarterectomy were comparable to patients with de novo lesions with 5.2% vs. 2.4% death/stroke at 30 days and 8.3% and 6.6% stroke/death rates at 1 year, respectively. When distal protection devices were used, death/stroke rates were 0% as compared to 4.5% when distal protection was not used (P = NS). However, minor embolic phenomena were observed in both primary and secondary lesions independent of the use of distal protection. These results support the use of carotid artery angioplasty and stenting in high-risk patients with significant primary or secondary carotid artery stenosis. In both types of lesions, acceptable results justify its use as a valid revascularization method. While clinical embolic events occur in a minority of patients in both lesion types, they are not entirely prevented by distal protection.

Aged↗
PubMed2006

Preprocedural C-reactive protein levels predict myocardial necrosis after successful coronary stenting in patients with stable angina.

BACKGROUND: Myocardial necrosis as assessed by cardiac troponin elevation occurs frequently after coronary stenting and is associated with adverse clinical outcome. Mechanical factors have been implicated in this complication and the role of systemic inflammation is not known. METHODS: We prospectively studied 208 patients with chronic stable angina who underwent elective coronary stenting. All patients had normal troponin levels before the procedure. Blood samples for high-sensitivity C-reactive protein (CRP) were obtained before the procedure and analyzed using a high-sensitivity kit. Cardiac troponin T (cTnT) was obtained 24 hours after the procedure. RESULTS: Postprocedural cTnT elevations were observed in 46 (22%) patients. There were 11 (16%), 14 (20%), and 21 (30%) patients with elevated postprocedural cTnT in the first, second, and third CRP tertile, respectively (P for trend = .045). In a multivariate logistic regression model, adjusting for all the significant univariate predictors and for statin therapy, CRP remained a significant independent predictor of postprocedural cTnT elevation with an odds ratio of 2.6 in patients in the third CRP tertile compared with patients in the first CRP tertile (95% CI 1.1-6.0, P = .02). Patients in the third CRP tertile also had higher cTnT elevations compared with patients in the first and second CRP tertile (P = .03). CONCLUSIONS: Elevated baseline CRP levels are associated with higher risk of postprocedural troponin elevations in patients with stable angina undergoing uncomplicated coronary stenting. These results underscore the role of systemic inflammation in the pathogenesis of periprocedural myocardial injury.

Angina Pectoris↗
PubMed2006

Contrast enhanced multi-detector computed tomography coronary angiography versus conventional invasive quantitative coronary angiography in acute coronary syndrome patients-correlation and bias.

BACKGROUND: Previous studies that compared multi-detector computed tomography (MDCT) non-invasive coronary angiography with conventional coronary angiography, did not assessed the ability of MDCT to detect stenotic lesions correctly in acute coronary syndromes (ACS) patients. The aim of the present study was to assess prospectively the correlation and bias between 16-slice MDCT coronary angiography and quantitative coronary angiography analysis (QCA) in these patients. METHODS: Patients underwent electrocardiogram-gated, 16-slice MDCT coronary angiography and routine invasive percutaneous coronary angiography with quantitative coronary angiography (QCA) analysis blinded to MDCT results. The correlation and the bias between the results of MDCT and QCA were assessed in segments observed by both modalities in vessels > or = 2 mm in diameter. RESULTS: 59 patients (81% male, age 56 +/- 11 years), admitted due to ACS, underwent MDCT and invasive coronary angiography. 544 segments were analyzed. The correlations between MDCT and QCA observed for the left anterior descending coronary artery (LAD), the left circumflex coronary artery (Cx), the right coronary artery (RCA) and for all analyzed segments were 0.74 (P < 0.0001), 0.54 (P < 0.009), 0.72 (P < 0.0001) and 0.70 (P < 0.0001), respectively. By Bland-Altman analysis, a small overestimation of the lesion severity with MDCT of 4.8% for the LAD, 5.9% for the Cx, and 3.3% for the RCA was observed. CONCLUSIONS: In ACS patients, MDCT contrast-enhanced coronary angiography provides good quantification of the luminal diameter as compared to coronary angiography, and it is characterized by a small overestimation bias.

Angina, Unstable↗
PubMed2006

Rescue percutaneous coronary intervention after failed thrombolysis: results from the Acute Coronary Syndrome Israel Surveys (ACSIS).

BACKGROUND: The benefit of rescue percutaneous coronary intervention (PCI) in acute myocardial infarction patients, who fail to show signs of reperfusion after full dose thrombolysis, is still an unresolved issue. AIM: To assess the outcomes of patients who underwent rescue PCI after full-dose thrombolytic therapy and compare them to patients treated only with thrombolysis in the Acute Coronary Syndrome Israel Surveys (ACSIS). METHODS: ACSIS is a biannual survey on acute myocardial infarction performed in all 26 intensive cardiac care units in Israel during a two-month period. 2,018 patients were admitted with acute myocardial infarction during the two-month period in the 2000 and 2002 surveys, and 796 of them were treated with thrombolytic therapy. RESULTS: Rescue PCI was performed in 99 patients who failed to show signs of reperfusion. The control group consisted of patients with unsuccessful thrombolysis and no further intervention. Patients who underwent rescue PCI had a numerically higher incidence of anterior wall myocardial infarction, diabetes, higher Killip class on admission and cardiogenic shock. Furthermore, almost half of these patients had reduced left ventricular function (P = 0.03). During hospitalization, there was a significantly higher prevalence of recurrent ischemic events and major bleeding complications in patients who underwent rescue PCI. In-hospital, 30-day and one-year mortality rates were similar between the two groups. By multivariate analyses, Killip class 3-4 (OR: 2.62, CI = 0.95-6.58, P = 0.05) and streptokinase treatment (OR: 0.623, CI = 0.4-0.97, P = 0.05) were independent predictors of rescue PCI. Rescue angioplasty was associated with 15% risk-reduction (CI = 0.45-1.97, P = 0.05) in 30-day mortality and recurrent emergent hospitalization. CONCLUSIONS: Patients who underwent rescue PCI had similar short- and long-term mortality rates compared to patients treated with thrombolysis alone, despite differences in baseline characteristics. Rescue angioplasty was associated with a 15% risk reduction in mortality at 30-days, at the cost of higher rate of recurrent ischemic events and bleeding complications. Therefore, rescue angioplasty may be an equalizer in severely ill patients who receive thrombolytic therapy and fail to show signs of reperfusion.

Angioplasty, Balloon, Coronary↗
PubMed2006

The eccentric lumenology.

Coronary angiography has a poor predictive value for the detection of eccentric plaque morphology. Many reports have demonstrated discordance between the angiographic classification and the intravascular ultrasound (IVUS) classification. Although eccentricity is usually considered a dichotomous character, more than two-thirds of all coronary stenosis have some degree of eccentricity. The American College of Cardiology/American Heart Association (ACC/AHA) Task force included lesion eccentricity as a risk factor for moderate procedural success (60-85%) and moderate complications (type B). Although lesion eccentricity has been implicated as a risk factor for reduced short-term procedural results, current available data does not support the adverse impact of eccentricity on procedural success or restenosis. The present article reviews the incidence and the various clinical scenarios known to be associated with the eccentric lumenogram and the impact of coronary artery remodeling contributing to misinterpretation of disease eccentricity. Various therapeutic modalities with reference to eccentric lesions are also considered.

Angioplasty, Balloon, Coronary↗
PubMed2006

Calcium handling in embryonic stem cell-derived cardiac myocytes: of mice and men.

Excitation-contraction (EC) coupling is fundamental to the function of cardiac myocytes (CMs). In mature myocytes plasma membrane (PM) L-type Ca(2+) channels function in close juxtaposition to ryanodine receptors (RyR) on the sarcoplasmic reticulum (SR) membrane. Action potentials (APs) cause the opening of PM L-type Ca(2+) channels, which in turn provide trigger Ca(2+) for a larger RyR-mediated SR Ca(2+) release. In contrast, developing myocytes have a less well-developed SR. This incomplete development is observed in early stage and mid-maturation stages of murine embryonic stem cell-derived cardiac myocytes (ESC-CMs). Despite the absence of a well-developed t-tubule system, murine ESC-CMs use internal Ca(2+) stores for EC coupling. Direct measures of Ca(2+) handling, including pharmacological studies and investigation of genetically modified mouse ESC-CMs, established an important contribution of RyR-mediated internal Ca(2+) store to cell function. Similarly, early-stage human ESC-CMs use internal Ca(2+) store and partially share Ca(2+) handling characteristics with murine ESC-CMs. For example, elementary Ca(2+) release events are present in both murine and human ESC-CMs, and it is likely that Ca(2+) handling contributes to automatic rhythm generation in these cells. However, in human ESC-CMs, a unique voltage-gated Na(+) channel window current is critical for spontaneous, rhythmic depolarization. The advent of the murine and human ES cardiomyocyte differentiating systems has provided initial insights into the early steps of development of excitability and electromechanical coupling in the mammalian heart, including patterns of gene expression, myofibrillogenesis, ion channel development and function, and Ca(2+) handling. Here we discuss the information gained from these models to describe the nexus of voltage-gated channel currents and Ca(2+) handling on rhythmic activity.

Animals↗
PubMed2006

Effects of synchronized cardiac assist device on cardiac energetics.

A novel physiological cardiac assist device (PCAD), the LEV RAM assist device, which is synchronized with the failing heart ejection, was developed to improve the failing heart systolic and diastolic functions and cardiac energetics. The PCAD uses a single short cannula, which is inserted into the beating left ventricle (LV) by means of a specially designed device. Blood is ejected from the PCAD into the LV after the opening of the aortic valve and augments the cardiac stroke work. The same amount of blood is withdrawn from the LV into the PCAD, through the same cannula, during the diastole. The study aims to test the effects of the PCAD on cardiac energetics and coronary blood flow. Adult normal sheep were anesthetized and the heart was exposed by left thoracotomy. Pressures transducers (Millar Instruments, Inc., Houston, TX) were inserted into the LV and aorta. LV volume was measured by sonocrystals (Sonometrics Corp., London, Ontario, Canada) and impedance catheter (CD Lycom, Argonstrat 116 Zoetermeer, 2718 SP The Netherlands). Flowmeters (transonic) measured the cardiac output (CO) and the coronary arteries (left anterior descending (LAD) and circumflex) flows. A thin cannula was inserted into the coronary sinus and the oxygen content of the LV and the coronary sinus were determined (AVOXimeter-1000). Pressure-volume loops, myocardial energetics, and coronary flow were measured. The displaced PCAD volume was 11 mL. Four different levels of assist were studied by changing the frequency of the assist: (1) assist beat after three successive regular beats [1:4], (2) assist every third beat [1:3], (3) alternate assist and normal beat [1:2], and (4) continuous assist [1:1]. Cardiac output (CO) and stroke volume (SV) increased proportionally with increasing frequency of assist. Systolic mechanical efficiency of the PCAD was above 90%. Simultaneously, the PCAD decreased the end-diastolic volume (EDV; diastolic unloading). The PCAD increased coronary flow and decreased cardiac arterial-venous O(2) difference. We conclude that the PCAD efficiently augments CO and stroke work, decreases preload, and decreases the coronary arterial-venous O(2) difference; all these may expedite cardiac reverse remodeling, and promote recovery of function and eventual easy explanation of the device.

Animals↗
PubMed2006

16-MDCT coronary angiography versus invasive coronary angiography in acute chest pain syndrome: a blinded prospective study.

OBJECTIVE: The purpose of our study was to prospectively evaluate the usefulness of CT coronary angiography versus invasive coronary angiography for the detection of clinically significant coronary artery disease in patients hospitalized for acute chest pain syndrome. SUBJECTS AND METHODS: Sixty-six consecutive patients (52 men and 14 women; average age, 57 +/- 11 [SD] years) who were hospitalized for acute chest pain syndrome underwent CT coronary angiography and invasive coronary angiography within an average time interval of 4 days. ECG-gated CT coronary angiography was performed with a 16-MDCT scanner (0.42-sec rotation time, 16 x 0.75 mm detector collimation). Beta-blockers were not administered routinely, and thus the average heart rate was 71 +/- 11 beats per minute. CT coronary angiographic images were evaluated concurrently by two radiologists, who were blinded to invasive coronary angiography results, for stenoses having a diameter of 50% or more, using a 15-segment classification, including all segments 2 mm or more in diameter. The consensus interpretation was compared with results of invasive coronary angiography. RESULTS: CT coronary angiography was technically successful in 59 patients (89%). After exclusion of 20 (3.1%) of 649 coronary segments, which were classified as nonevaluable by CT coronary angiography, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT coronary angiography for identifying significant coronary artery disease in the remaining 629 coronary segments were 80% (68/85), 89% (482/544), 52% (68/130), 97% (482/499), and 87% (550/629), respectively. The overall accuracy for the main vessels (left main, left anterior descending, left circumflex, and right coronary arteries) was 93%, 88%, 86%, and 86%, respectively. CONCLUSION: CT coronary angiography using a 16-MDCT scanner enables accurate noninvasive detection of significant coronary artery disease in patients hospitalized for acute chest pain syndrome. Furthermore, relative high sensitivity and specificity of CT coronary angiography can be achieved without pharmacologic manipulation of patient heart rates.

Acute Disease↗
PubMed2006

Glycoprotein IIb/IIIa inhibitors during rescue percutaneous coronary intervention in acute myocardial infarction.

Although percutaneous coronary intervention (PCI) following full-dose thrombolytic therapy (rescue angioplasty) is a common procedure, there is ample controversy regarding the usefulness of the procedure. Moreover, few data are available concerning the safety and efficacy of concomitant treatment with glycoprotein (GP) IIb/IIIa inhibitors in these patients. The aim of the present study was to compare the clinical outcomes of patients who underwent rescue PCI with stents and were treated with GP IIb/IIIa inhibitors. A total of 59 consecutive patients underwent rescue PCI at our institution during the study period, 29 patients (49.2%) were treated concomitantly with a GP IIb/IIIa inhibitor and 30 patients (50.8%) were not. Baseline clinical characteristics were similar between the two groups. In-hospital outcomes regarding death, reinfarction and the need for urgent target vessel revascularization was significantly lower in patients treated with GP IIb/IIIa inhibitors compared to those who were not treated (3.4% vs. 26.7%; p = 0.01, respectively). However, GP IIb/IIIa inhibitor administration was not an independent predictor of better outcomes by multivariate analysis. There was a higher rate of major bleeding complications in patients who received GP IIb/IIIa inhibitors, though it did not achieve statistical significance (6.9% vs. 0%; p = 0.14, respectively). The composite endpoint of major, minor bleeding and vascular complications was similar in both groups (24.1% vs. 16.7%; p = 0.48). In conclusion, the administration of GP IIb/IIIa inhibitors in patients undergoing rescue PCI after failed thrombolysis with stents was safe and may have a beneficial effect on 30-day event-free survival rates, without a significant increase in bleeding or vascular complications. These results warrant further investigation.

Abciximab↗
PubMed2006

[Percutaneous carotid artery stenting in high-risk patients].

UNLABELLED: Recent studies have shown that percutaneous carotid artery angioplasty and stenting can be safely performed in patients with carotid artery stenosis, especially those considered to be at high-risk for surgery. AIM: We evaluated the safety and feasibility of carotid artery angioplasty and stenting, with and without distal protection devices in patients at high-risk for surgical endarterectomy. METHODS: A total of 169 consecutive patients underwent 185 procedures and 189 stents were deployed successfully in 195 lesions. The majority of patients (51%) had restenosis after a prior carotid endarterectomy, 40% were considered to be ineligible for carotid endarterectomy by both the vascular surgeons and the interventional cardiologist and 7% were considered ineligible for surgery due to hostile neck anatomy. RESULTS: Distal embolic protection devices were used in 52% of all cases. Procedural success was achieved in 181 of 185 procedures (98%). The overall rate of in-hospital major adverse cerebrovascular events (death, major stroke, and myocardial infarction) was 2.4%. In-hospital event rates in patients with prior carotid endarterectomy were comparable to patients with de novo lesions with 3.3% vs. 1.1% death/ stroke at 30 days, and 3.3% and 3.3% stroke/death rates at 30 days, respectively. When distal protection devices were used death/stroke rates were 0% as compared to 4.7% when distal protection was not used (p = NS). However, minor embolic phenomena were observed in both primary and secondary lesions independent of the use of distal protection. CONCLUSIONS: These results support the use of carotid artery angioplasty and stenting in high-risk patients with significant primary or secondary carotid artery stenosis. In both types of lesions, acceptable results justify its use as a valid revascularization method. While clinical embolic events occur in a minority of patients in both lesion types, they are not entirely prevented by distal protection devices.

Aged↗
PubMed2006

Five-year clinical follow up after intracoronary radiation for the prevention of in-stent restenosis.

Intracoronary radiation therapy (IRT), utilizing both gamma- and beta-emitting radiation sources, is considered to be a safe and effective treatment for in-stent restenosis (ISR). Although no longer in clinical use, a significant number of patients were treated in the past with IRT, and their long-term outcomes have not been well documented. The aim of the present analysis was to document the long-term outcomes of all patients who underwent IRT at our institution for the prevention of recurrence of ISR. Data were collected from 132 patients (148 irradiated lesions) treated with IRT at our institution between March 1999 and January 2004. Clinical and angiographic data were collected over a 5-year period. Patients were divided into 2 groups: those with failed IRT (n = 65), defined as a procedure that resulted in a major adverse cardiac event: death, myocardial infarction, target lesion revascularization, target vessel revascularization or coronary artery bypass graft surgery at any time during the follow-up period, and patients with successful IRT (n = 67). Both groups were identical regarding baseline clinical and angiographic characteristics, with the exception of a higher percentage of multivessel disease and diffuse restenosis in patients who failed IRT (p = 0.01). At 1-year follow up, slightly less than half (43%) of those patients in the failure group experienced a major adverse cardiac event. During the long-term follow up period, half of all patients who underwent IRT at our institution experienced a major adverse cardiac event, 61 patients (46%) either died or underwent a revascularization procedure, 16 patients (24%) had a myocardial infarction or died, and 55 patients (42%) required repeat coronary revascularization. The average time to develop a major adverse cardiac event was 14.6 +/- 15 months. Therefore, during long-term follow up following IRT for the prevention of ISR, half of all patients developed a major cardiovascular event, mainly due to the need for repeat revascularization procedures.

Aged↗
PubMed2005

Endoluminal hydrogel films made of alginate and polyethylene glycol: physical characteristics and drug-eluting properties.

Drug-eluting stents signify a major achievement in reducing the incidence of coronary restenosis after percutaneous transluminal coronary angioplasty. However, where drug-eluting stents have been unsuccessful, endoluminal gel-paving strategies offer renewed optimism, mainly in a variety of vascular procedures requiring catheter-based sustained, localized delivery of therapeutic drugs, and biological factors. Despite promising results in animals, endoluminal paving has met with very limited clinical success because of the technical difficulties and stringent safety demands. The current study presents an alternative to gel paving using 40-mum-thick biodegradable polymeric films for deployment onto the artery wall during balloon angioplasty and stenting. The films are made from a durable yet compliant network of alginate and polyethylene glycol (PEG), and are securely held affixed to the vessel wall by the expanded stent struts. The alginate-based films are characterized by measuring their strength, elasticity, degree of swelling, degradability in water and saline, and drug release properties. The combination of alginate and PEG afforded the films sufficient strength and compliance for endoluminal deployment using an in vitro organ culture system. In characterizing the film degradability, it was discovered that the ionic concentration of the buffered saline was the main determinant in regulating the degradation kinetics and the release kinetics of the drug molecule Paclitaxel. These results suggest that the use of alginate-based, PEG-containing polymeric films for endoluminal coverage offers an alternative solution to conventional drug-eluting stents, with the added advantage of uniform endoluminal coverage of the treated segment and homogeneous endoluminal application of the active substance.

Alginates↗