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Biomedical subjects

C Lotan

Publications and source records attributed to C Lotan.

At least 37 records · Page 2Linked to original sources
PubMed1997

Coronary angiographic characteristics of patients with permanent artificial pacemakers.

BACKGROUND: The cause of severe cardiac conduction disturbances is often uncertain. The aim of this study was to examine a group of patients with permanent pacemakers who underwent coronary arteriography to determine the extent of coronary atherosclerotic disease that might be responsible for the conduction disturbances. METHODS AND RESULTS: Forty-three consecutive patients with a permanent pacemaker and 36 matched control patients were investigated. The coronary angiographic study included measurement of diameter and stenosis severity, qualitative assessment of flow, and classification of pathological anatomy, particularly the blood supply to territories supplying the different segments of the conduction system. Among 43 patients with a permanent pacemaker, 27 had ischemic heart disease (17 after coronary artery bypass graft surgery). The conduction disturbance was infranodal in 28 patients, sinus nodal in 6, AV nodal in 4, and complete AV block of unspecified origin in 5. Patients with permanent pacemakers had a coronary artery pathology compromising blood flow to the septal branches and the right coronary artery (type IV anatomy). This pattern was significantly different from the matched control patients, in whom the most prevalent coronary anatomy was the combination of right coronary artery with distal left anterior descending artery (not involving the septal branches) lesions (P=.007). CONCLUSIONS: Patients with coronary artery disease and severe conduction disturbances that require implantation of permanent pacemakers are more likely to have a specific pathological coronary anatomy that combines a compromised blood flow to the septal branches of the left anterior descending artery with right coronary artery lesions. The location of lesions in the coronary tree rather than severe diffuse atherosclerosis appears to be responsible for the conduction disturbances.

Aged↗
PubMed1997

Changing paradigms in thrombolysis in acute myocardial infarction.

Acute myocardial infarction occurs when a ruptured coronary artery plaque causes sudden thrombotic occlusion of a coronary artery and cessation of coronary artery blood flow. This paper reviews the underlying coronary pathology in progressive coronary atherosclerosis, mechanisms of plaque rupture and arterial occlusion and the time relationship between coronary occlusion and myocardial necrosis. Reperfusion can be achieved by chemical thrombolysis with different thrombolytic agents. Early lysis is achieved best by prehospital administration, a transtelephonic monitor, a mobile intensive care unit, active general practitioner treatment or by warning the emergency room of impending arrival of a patient. Thrombolytic therapy may be unsuccessful and not achieve Grade III TIMI flow in less than 4 h (or even 2 h) due to inadequate or intermittent perfusion or reocclusion. Adjuvant therapy includes aspirin and platelet receptor antagonists. Bleeding is a constant danger. Direct percutaneous transluminal coronary angioplasty (PTCA) may be as effective or better than chemical thrombolysis. Reperfusion protects the myocardium and salvages viable tissue. It also improves mechanical remodelling of the ventricle. Long-term follow-up has shown that quantum leaps of fresh coronary occlusion causes step-wise progression in patient disability and that further early, prompt reperfusion can salvage myocardium and prevent this inexorable progress of the disease.

Fibrinolytic Agents↗
PubMed1997

Atherosclerosis studies by intracoronary ultrasound.

Intravascular ultrasound (IVUS) is a new technique of tomographic visualization of the coronary arteries: its lumen, wall and pathology. Three dimensional (3D) reconstruction shows the tubular structure of the arterial wall and its pathology. IVUS has many advantages over coronary angiography: it has better resolution and shows many hidden lesions. IVUS has helped uncover the underlying mechanisms of percutaneous transluminal coronary angioplasty (PTCA), restenosis, the use and value of other interventional techniques such as directional coronary atherectomy (DCA), rotational atherectomy and stent implantation, and has great value in planning complex interventional procedures. The new American Heart Association (AHA) classification of coronary atherosclerosis pathology can be demonstrated by IVUS. IVUS is sensitive for studies of atheroma regression and progression and shows the coronary artery lesions after cardiac transplantation.

Animals↗
PubMed1997

Initial experience with long coronary stents: the changing practice of coronary angioplasty.

The initial experience with the use of long coronary stents (> 30 mm in length) was analyzed retrospectively. Sixty-seven stents were deployed in 58 narrowings in 57 patients (34 AVE Microstents, 16 Nir stents, four Gianturco-Roubin II stents, and 13 Wallstents). Stents were implanted in 22 patients with unstable angina, 34 patients with stable angina, and one patient during direct angioplasty for acute myocardial infarction. Eighteen additional short stents were implanted to cover the entire length of the lesions so that an average of one and a half stents were deployed per patient. The length of the narrowings before stenting was 40 +/- 20 mm and the length of the stented segments was 45 +/- 20 mm. Stents were deployed for "bailout" in 23 narrowings, to improve suboptimal results of balloon angioplasty in 18 narrowings, and electively in 17 narrowings. Twenty of the 67 long stents were deployed in saphenous vein grafts. The success rate of stent implantation was 100%. One patient had a rupture of a saphenous vein graft after deployment of two long stents, with tamponade treated by emergency surgery. One patient had chest pain 18 hours after stent deployment; by the time he arrived at the catheterization laboratory the pain had subsided and the angiogram revealed a patent artery with normal flow. There were no other major complications during the hospital course and 1-month follow-up. We conclude that long coronary stents can be deployed successfully in native coronary arteries and vein grafts. They are useful for elective implantation and extremely helpful in bailout situations. The immediate results are excellent, but long-term outcome is awaited.

Aged↗
PubMed1997

Angiographic deterioration of target coronary artery narrowing as a result of percutaneous balloon angioplasty.

We evaluated the long-term angiographic outcome of balloon angioplasty by comparing original and follow-up target coronary narrowing. Rather than using restenosis to determine outcome, as in most angioplasty studies, we took an unusual approach and analyzed outcome in terms that are commonly used in progression and regression studies after medical interventions. Quantitative angiographic measurements were undertaken in 315 narrowings with an initial diameter stenosis <90% before and after angioplasty and at follow-up. Angiographic deterioration (>10% increase in follow-up diameter stenosis) was identified in 44 (14%) narrowings. Angiographic deterioration was not influenced by age, sex, risk factors, lipid profile, or the indication for angioplasty. Deterioration was also not predicted by the severity, length, or the location of the narrowing. The deteriorating narrowings had a higher recoil after dilatation compared with narrowings with angiographic improvement (21% +/- 31% vs 12% +/- 17%, p = 0.006); the residual stenosis after angioplasty was therefore higher. The late loss was also significantly increased compared with narrowings with angiographic improvement (65% +/- 26% vs 8% +/- 24%, p < 0.001). We conclude that the incidence of angiographic deterioration of coronary disease as a result of restenosis is uncommon but not negligible. Interventional cardiologists should resist the temptation to dilate mild, silent coronary narrowings because the procedure might have an unfavorable angiographic (and probably clinical) effect.

Angioplasty, Balloon, Coronary↗
PubMed1997

A multicenter study of recombinant human erythropoietin (epoetin alpha) in the management of anemia in cancer patients receiving chemotherapy.

Current evidence suggests that epoetin alpha administration is well tolerated and effective in the management of anemia of cancer and cancer chemotherapy. An open-label, multinational, non-comparative study was conducted in 215 cancer patients with anemia secondary to chemotherapy with platinum- or non-platinum-based combinations. Epoetin alpha was administered s.c. (150 IU/kg three times/week) for a planned period of 16 weeks. The response rate of epoetin alpha, defined as an increase in hemoglobin level of 2 g/dl or more from baseline, was 67%. The rate of response was not related to the chemotherapy regimen administered (platinum or non-platinum based). The percentage of patients transfused and the transfusion rate during epoetin alpha treatment were reduced. Transfusional need was eliminated in 64 (75%) of the 85 patients transfused before the study start, after 1 month of therapy. Quality of life, assessed using a visual analog scale, improved markedly in patients who experienced a hematological response. These patients also experienced a statistically significant (p < 0.0001) improvement in mean WHO performance score. These findings indicate that epoetin alpha is a well tolerated and effective agent which increases hemoglobin concentration and reduces transfusion requirements in anemic cancer patients receiving chemotherapy.

Adolescent↗
PubMed1997

The Radial Artery: An Applicable Approach to Complex Coronary Angioplasty.

The purpose of this study was to assess the clinical value of the transradial approach (TRA) in coronary angioplasty. During the 18Ðmonth period from June 1994 to December 1995, 250 patients (mean age 61 +/- 11) underwent coronary angioplasty using the transradial approach. In 7 (2.8%) radial puncture was unsuccessful and in 6 (2.4%) additional femoral access was needed to complete the procedure. Ninety patients (36%) had angioplasty of two or three vessels and 49.5% had type B2 or C lesions. Sixty-five patients (22%) had additional procedures: stent implantations in 50 (16%) and rotational ablation in 15 (6%). Angiographic success was 97% and there were no deaths. Major procedural complications included: Q-wave myocardial infarction in 2 (0.8%), non-Q-wave myocardial infarction in 5 (2.0%), urgent coronary artery bypass grafting in 2 (0.8%) and CVA in 2 (0.8%). Local vascular complication included: compartment syndrome necessitating fasciotomy in 1 patient (0.4%), mild hematoma in 6 (2.4%) and a small pseudo-aneurysm treated by local compression in 4 (1.6%). Radial pulse was palpated in 93% before discharge and in 3% adequate flow could be heard with Doppler. No patient suffered from ischemia of the hand. Complex coronary angioplasty can be performed safely using the TRA with few vascular complications.

Journal Article↗
PubMed1996

Experience with the AVE Micro stent in native coronary arteries.

Experience with implantation of 62 AVE Micro stents is described. Stents were quickly and successfully deployed in 62 of 63 attempts (98.4%), in tortuous coronary vessels, through proximally deployed stents, and under conditions of hemodynamic instability. It is therefore a very attractive choice to treat difficult anatomy during urgent situations.

Aged↗
PubMed1996

"Congenital" coronary arteriovenous malformations: are they truly congenital?

We report a patient with ischemic chest pain due to obstructive coronary artery disease. The patient underwent a second cardiac catheterization 2 years later that revealed progression of the coronary disease and the appearance of a new arteriovenous malformation. Unless a prior angiogram was available, this malformation would have been classified as congenital. This case report raises the question of whether all congenital arteriovenous malformations are truly congenital.

Aged↗
PubMed1996

Importance of delaying balloon angioplasty in patients with unstable angina pectoris.

Angioplasty in patients with unstable coronary artery disease is associated with higher complication rates compared with patients with stable disease. In this report we describe our results from a group of patients with unstable disease (unstable angina pectoris and postmyocardial infarction) where a strategy of delaying angioplasty for > 5 days after admission was undertaken. Included are 2069 consecutive patients: 1197 treated for stable angina pectoris and 872 treated during admission for unstable angina or myocardial infarction. There was no difference between the two groups in angioplasty success (92.1% stable, 92.3% unstable), failure to dilate without complication (6.4% stable, 6.1% unstable), or in the rate of major complications: death (0.5% stable, 1.1% unstable), Q-wave myocardial infarction (0.9% stable, 1.1% unstable), and emergency coronary artery bypass (0.6% stable, 0.3% unstable). The duration of hospitalization following angioplasty was longer in the unstable group (5.6 +/- 8.1 days vs. 4.2 +/- 4.1 days; p < 0.001) because of longer duration of heparin infusion. There was no difference between groups in minor complications such as groin hematoma and pseudoaneurysm, renal failure, or infections. It was concluded that delaying angioplasty in unstable patients for > 5 days after admission is a safe and effective therapeutic strategy for this group of patients. The need for prolonged heparin infusion after angioplasty is increased in unstable patients and thus the duration of hospitalization after the procedure is longer.

Aged↗
PubMed1996

The outcome of patients with acute myocardial infarction ineligible for thrombolytic therapy. Israeli Thrombolytic Survey Group.

PURPOSE: The aim of this study was to determine the proportion of patients with acute myocardial infarction (AMI) excluded from thrombolytic therapy on a national basis and to evaluate the prognosis of these patients by reasons of ineligibility and according to the alternative therapies that they received during hospitalization. PATIENTS AND METHODS: During a national survey, 1,014 consecutive patients with AMI were hospitalized in all the 25 coronary care units operating in Israel. RESULTS: Three hundred and eighty-three patients (38%) were treated with a thrombolytic agent and included in the GUSTO study. Ineligible patients for GUSTO were treated: (1) without any reperfusion therapy (n = 449), (2) by mechanical revascularization (n = 97), or (3) given 1.5 million units of streptokinase (n = 85) outside of the GUSTO protocol. The inhospital and 1-year post-discharge mortality rates were 6% and 2% in patients included in the GUSTO study; 6% and 5% in those mechanically reperfused; 15% and 10% in those treated with thromoblysis despite ineligibility for the GUSTO trial, and 15% and 13% among patients not treated with any reperfusion therapy. CONCLUSIONS: Ineligibility for thrombolysis among patients with AMI remains high. Patients ineligible for thrombolysis according to the GUSTO criteria, but nevertheless treated with a thrombolytic agent were exposed to an increased risk.

Actuarial Analysis↗
PubMed1996

Coronary Stenting in Vessels with Marked Proximal Tortuosity Using a Sport Wire: Advantages and Pitfalls.

In this report two patients are described in whom successful deployment of a coronary stent was achieved in a very tortuous coronary artery. Deployment was performed using a special extra-support wire that straightened the proximal segment of the artery and provided the support for stent advancement. The mechanical straightening of the artery induced marked narrowing that did not respond to intracoronary nitroglycerin but disappeared after withdrawal of the wire.

Journal Article↗
PubMed1996

Improved outcome of coronary stenting by utilizing a modified treatment protocol.

Coronary stents improve patient outcome, are easy to deploy and are now being utilized very frequently after coronary angioplasty. New protocols have been suggested to overcome the main limitations of stenting, namely subacute stent thrombosis, local vascular complications, and the length of hospitalization. In this report we describe our current results with coronary stenting in 100 patients: we modified our standard protocol and used high pressure noncompliant balloons to expand the stent, added ticlopidine to some of the patients to inhibit platelet activity, and used the transradial approach in some patients to reduce the risk of vascular complications. These results were compared to those obtained in our initial group of 50 patients in whom we used a standard implantation protocol. Subacute thrombosis occurred in one patient in the current group of patients compared to five patients in our early experience (P = 0.026). There was no change in local vascular complications. This preliminary report shows that subacute thrombosis can almost be eliminated by the new stent implantation protocols. Less aggressive anticoagulation and radial artery catheterization can decrease vascular complications.

Aged↗
PubMed1996

Urgent rotational ablation of a partially protected, totally occluded left main coronary artery.

Coronary artery by-pass surgery (CABG) is considered the treatment of choice for patients with significant stenosis of the left main coronary artery. However, with reduction of the flow post-CABG, the left main may become totally occluded. This may become important once graft failure occurs. This case describes a patient who had by-pass surgery for critical left main stenosis and was re-admitted four months later with graft failure and total occlusion of his left main, necessitating urgent rotational ablation of this partially protected, totally occluded left main coronary artery. This case raises the question of "prophylactic" left main angioplasty soon after surgery for critical left main stenosis, in order to eliminate the need for redo operation once graft failure occurs.

Atherectomy, Coronary↗
PubMed1995

Influence of coronary angioplasty on the progression of coronary atherosclerosis.

This study examines the effect of coronary angioplasty on the progression and appearance of new disease in sites of the coronary tree that were not dilated by the balloon. We examined 355 pairs of coronary angiograms from 252 patients. The study consisted of consecutive patients who were referred for catheterization > 1 month after successful angioplasty. Progression/regression and the appearance of new narrowings at sites not dilated by angioplasty were determined. The life-table method was used to determine outcome, and any event (progression, regression, and new narrowing) was analyzed according to the time of occurrence. The angioplasty artery was compared with the non-angioplasty artery and the effect of restenosis was determined by comparing arteries with and without restenosis. Progression/regression rates were not significantly different in angioplasty and non-angioplasty arteries. More new narrowings were identified in the angioplasty artery (p < 0.01). With regard to narrowings located in the angioplasty artery, progression was more common, regression less common, and the appearance of new narrowings more common in arteries with restenosis than in non-angioplasty arteries or arteries without restenosis. We believe that mechanical trauma to the artery during angioplasty could accelerate disease progression and the appearance of new narrowings in angioplasty arteries, whereas normalization of flow rate and pattern, especially in arteries without restenosis, attenuates the rate of progression and the appearance of new narrowings in these arteries. The final outcome depends on the balance between these factors.

Angioplasty, Balloon, Coronary↗
PubMed1995

Transradial approach for coronary angiography and angioplasty.

The transradial approach has currently been advocated as an alternative catheterization method for coronary angiography and angioplasty, due to the recent miniaturization of angioplasty equipment. The purpose of this study was to assess the practical clinical applicability of this method. From June to November 1994, 100 patients underwent coronary angiography and angioplasty with the transradial approach. Their mean age was 66.6 +/- 11.2 years, and 79 were men. In 4, radial puncture was not successful, and in 3, femoral access was necessary to complete the procedure. Coronary angioplasty was performed in 63 patients (76 lesions) with angiographic success (per lesion) of 96%. In 5 patients, a stent was successfully implanted. All patients were ambulatory on the day after the angioplasty procedure. In 98% of the patients, the introducer was taken out 1 to 4 hours after the procedure by local compression using a special custom-made device. No patient required blood transfusion. Major complications occurred in 2 patients; both had a cerebrovascular accident (1 probably not procedure-related), and both recovered. A radial pulse was palpated in 91 of the patients before discharge, and in 6 others, adequate flow could be heard with Doppler. In 2 patients, radial flow was restored within several weeks. None of the patients suffered from ischemia of the hand. Two patients had a small pseudoaneurysm successfully treated by local compression. Thus, coronary angioplasty can be performed safely using the transradial approach with relatively few vascular complications and with better patient comfort. However, the procedure is more time-consuming initially compared with the transfemoral approach due to a learning curve regarding equipment selection and catheter manipulation.

Adult↗
PubMed1995

One-stage coronary angiography and angioplasty.

The combination of diagnostic angiography and angioplasty as a single procedure is becoming common practice in many institutions, but the feasibility and safety of this strategy have not been reported. This report describes 2,069 patients who underwent coronary angioplasty over a 3-year period at an institution where combined angiography and angioplasty is the norm. All patients were prepared before angiography for potential immediate angioplasty. In 1,719 patients, angioplasty was performed immediately after the diagnostic angiogram, while separate procedures were performed in 350 patients. Of those 350 patients, 254 were referred for angioplasty after diagnostic angiography at other hospitals. One thousand one hundred ninety-seven patients were admitted electively for treatment of stable angina pectoris, and 872 underwent procedures during hospitalization for unstable angina or acute myocardial infarction. One thousand nine hundred seven patients (92.2%) had successful angioplasties; in 130 patients (6.3%) the lesion could not be dilated, but no complication occurred, and in 32 patients (1.5%) angioplasty ended with a major complication (0.8% death, 1.0% Q-wave myocardial infarction, 0.5% emergency coronary artery bypass surgery). There was no difference between the combined and staged groups with regard to success, major and minor complication rates or in length of hospitalization after angioplasty. We conclude that routine combined strategy for angiography and angioplasty is feasible, safe, easier for the patient, and more cost-effective than 2 separate procedures.

Angina Pectoris↗