Biomedical subjects
Publications and source records attributed to Y Louvard.
Percutaneous revascularization has been used for the treatment of post-coronary bypass graft ischemia. This report illustrates the use of emergency left main coronary artery stenting in protected left main on the first post-operative day for management of perioperative coronary artery bypass graft surgery ischemia.
Stenting of small coronary arteries was long contra-indicated because of a high rate of subacute occlusion. We report a single-center registry including 190 patients stented with 2.5 mm balloons. Procedural success was 98% and subacute occlusion rate was 2.6%. Clinical follow-up showed a 24.5% repeat intervention rate. These results seemed acceptable, warranting stent implantation in small arteries in the case of acute or threatened closure. New stent designs and coatings may contribute to the improvement of outcomes and to the decrease in subacute occlusion and restenosis rates.
Mechanical straightening of a tortuous vessel during angioplasty has been well described. It can be mistaken for thrombus, dissection or spasm. This report presents a case in which straightening of vessel due to stiff guide wire results in accordion effect and flow limitation.
The aims of this study were to assess the feasibility of routine transradial coronary angiography in a standard population of patients with presumed coronary artery disease over a period of time long enough to allow for technical evolution and evaluation of a single operator's learning curve, and to provide data for a randomized comparison versus the femoral approach. Between June 1994 and March 1997, transradial angiography was attempted in 1,000 patients. Approximately 25% of these patients were excluded because of an abnormal Allen test. Except in the case of acute myocardial infarction, there was no selection based on symptoms, age, sex, weight or size in the absence of double internal mammary artery bypass graft operation or simultaneous right heart catheterization. Symptoms and angiographic results were typical of a standard population. The right radial approach was used in 95% of the cases for ease of handling and comfort of a right-handed operator. Radial artery puncture and catheterization success was obtained in 97.6% of the cases; the left coronary artery was selectively catheterized in 100%, right coronary artery in 98%, left ventricle in 96.9%, mammary artery grafts in 100% and saphenous grafts in 97.2%. Average procedure duration was 18 +/- 9 minutes, and decreased progressively with experience and catheter strategies. The optimal catheter selection would seem to be a single catheter, either left Amplatz or Champ, for both coronary arteries. Two coronary complications and 3 transient neurological complications occurred, but no clinically significant vascular complications requiring surgery or transfusion were reported. Transradial angiography seems to be a routine approach that should now be compared with the femoral approach and supersede the brachial approach whenever possible.
We report the case of a patient with severe vascular disease in whom retrograde access to the aortic root was not possible because of aortoiliac and axillary vascular disease. Antegrade coronary angiography was performed through the transseptal approach using standard catheters, although several technical difficulties were encountered.
The limitations (recurrent ischaemia, restenosis, reocclusion) of percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (MI) can be addressed by stenting. The preliminary results of stenting are favourable (Stent PAMI, STENTIM, ZWOLLE trials). We report the results of the ICPS registry including 519 patients directly treated with angioplasty and stenting at the acute phase of myocardial infarction, with a repeat MI rate of 1% and a mortality of 3.7% in the non-shock group.
The aim of this study was to assess the feasibility of the radial artery approach for coronary angiography in a standard population of presumed coronary patients and to continue the assessment for a sufficiently long period of time to perfect the technique, evaluate the learning curve and prepare a randomised comparison with the femoral approach. The radial artery was used for coronary angiography in 800 patients after exclusion of about 25% of patients, mainly because of a negative Allen's maneuver. With the exception of acute myocardial infarction, there was no selection based on symptoms and transradial catheterisation was attempted irrespective of age, sex, weight or height. The representative nature of the study population was confirmed by the results of the procedure (normal: 20%, single vessel disease: 30%, double vessel disease: 26%, triple vessel disease: 18% and left main disease: 5.4%). The right radial artery was used in 94% of cases. Successful radial puncture/catheterisation was obtained in 97% of cases: 100% of left coronary arteries and 99% of right coronary arteries were catheterised, the left ventricle in 98% of cases, the internal mammary arteries in 100%, and venous bypass grafts in 95%. The average duration of the whole procedure was 19 +/- 9 minutes. This decreased regularly with operator experience and judicious choice of catheters. The best choice seemed to be a single catheter for both coronary arteries, either an Amplatz or a Champ catheter. There were two probably avoidable coronary complications and two transient neurological events but no clinically significant vascular complication. The radial artery seemed to be a good approach for routine coronary angiography and may now be compared with the femoral approach. It should help expand the practice of ambulatory coronary angiography.
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BACKGROUND: Stenting reduces both acute complications of coronary angioplasty and restenosis rates but increases subacute thrombosis rates and hemorrhagic complications when used with coumadin anticoagulation. METHODS AND RESULTS: To simplify postcoronary stenting treatment and to reduce these drawbacks, we evaluated the 1-month outcome of a prospective registry of 2900 patients in whom successful coronary artery stenting was performed without coumadin anticoagulation. Patients received 100 mg/d aspirin and 250 mg/d ticlopidine for 1 month. Low-molecular-weight heparin (LMWH) treatment was progressively reduced in four consecutive stages, from 1-month treatment to none. Event-free outcome at 1 month was achieved in 2816 patients (97.1%). Major stent-related cardiac events were subacute closure in 51 patients (1.8%), including death in 12 (0.5%), acute myocardial infarction in 17 (0.6%), and coronary artery bypass graft surgery in 9 (0.3%). Stent thrombosis was more frequent with balloon size of < 3.0 mm (< or = 2.5 mm, 10%; 3.0 mm, 2.3%; > or = 3.5 mm, 1.0%; P < .001), bail-out situations (6.67% versus 1.38%, P < .001), and patients with unstable angina or acute myocardial infarction (2.2% versus 1.12%, P = .02). Bleeding complications that required transfusion, surgical repair, or both occurred in 55 patients (1.9%). Bleeding complications were related to female gender (4.0% versus 1.51%, P < .001), duration of LMWH treatment (3.83% in phase II/III versus 0.69% in phase IV/V, P < .001), sheath size (6F, 0.52%; 7F, 1.04%; > or = 8F, 4.23%; P < .001), bail-out situations (4.76% versus 1.67%, P < .01), and saphenous graft stenting (4.38% versus 1.75%, P = .04). CONCLUSIONS: These results suggest that poststenting treatment by ticlopidine/aspirin is an effective alternative to coumadin anticoagulation, achieving low rates of subacute closure and bleeding complications. LMWH treatment does not improve subacute reocclusion rates but increases bleeding complications. Furthermore, as bleeding complications were independently related to sheath size, we suggest that stenting with 6F guiding catheters may prevent local complications. Furthermore, the ticlopidine/aspirin combination allows a low-cost stenting strategy without ultrasound assessment of stent deployment and permits short inhospital stay.
This paper reports experience with a new antithrombotic agent prescribed to reduce the incidence of subacute occlusions during the first month after coronary stenting. Therefore, a powerful association of platelet antiaggregant agents was tested. From December 1992 to October 1994, coronary stenting was successfully achieved in 1,294 patients (1,118 men, average age 60.5 +/- 10 years) who were then treated with the association of ticlopidine 0.25 g/day and aspirin 0.10 g/day for one month. This was covered with anticoagulation with a low molecular weight heparin for a variable period (one month, two weeks, then one week), according to the different phases of the study protocol. In all, 1487 stents were successfully implanted (1,330 Palmaz Schatz; 63 Cook; 80 Wictor; 13 AVE and 1 Strecker) in 1,326 vessels (520 left anterior descending, 208 left circumflex, 475 right coronary, 16 left main coronary arteries and 107 venous grafts) using balloon catheters of 2.5 mm to 5 mm diameter for average 3.45 +/- 0.4 mm). Major complications in the first month included 9 deaths (0.7%), 22 occlusions (1.7%): 14 myocardial infarcts (1%) and 11 aorto-coronary bypass procedures (0.85%). There were 136 local haematomas or false aneurysms (10.5%), 42 of which (3.25%) required blood transfusion or surgical repair. This multicenter trial of a protocol associating platelet antiaggregant agents and low molecular weight heparin for one month showed a low incidence of subocclusion after coronary stenting (1.7 +/= 2.5%) and should enable interventional cardiologists to widen the indications for coronary stenting.
Thrombolysis is the most widely used method of coronary reperfusion in the acute phase of myocardial infarction. The indications of angioplasty after thrombolysis have been subject of considerable controversy over the last few years. Three randomised trials (TIMI 2, TAMI, ECSG) have shown that it is not desirable to perform systematic immediate angioplasty after intravenous thrombolysis with rt-PA. Angioplasty may be carried out as a "salvage" procedure in cases of failure of thrombolysis. The validity of this approach was confirmed recently by the "RESCUE" trial in anterior myocardial infarction. The practical application of its results is confronted by logistical problems inherent to the practice of angioplasty in the acute phase of myocardial infarction and to the inadequacy of non-invasive methods for the detection of coronary reperfusion after thrombolysis. Angioplasty may also be necessary in cases of left ventricular failure or cardiogenic shock. The efficacy of a rapid angioplasty in cases of recurrence of ischaemia after thrombolysis has been proved in reducing mortality and preserving left ventricular function. The results of TIMI IIB and SWIFT trials show that secondary angioplasty, several days after thrombolysis, is only usually indicated in patients with residual clinical ischaemia or positive stress tests. This attitude should however be modulated in the light of the "open artery" theory and the limitations of methods of evaluating myocardial viability. The present strategies will no doubt be modified with the introduction of new thrombolytic and/or antithrombotic agents and the use of coronary stents.
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The objective of this study was to relate the number of ventricular arrhythmias (VA) to the normalization time of the ST segment during thrombolysis for acute myocardial infarction. The 24 h Holter recordings, begun on start of intravenous thrombolytic therapy, and the 12-lead electrocardiograms of 41 patients with a patent infarct-related artery according to coronary angiography were analysed. The mean time from onset of chest pain to angiography was 30.5 +/- 3.1 h, < or = 24 h in 59%. The normalization time of the ST segment, assessed by the time of decrease of ST segment elevation from start of Holter recording to normal or steady state was < or = 60 min in 13 patients (group 1), 60 to 180 min in 15 patients (group 2) and > 180 min in 13 patients (group 3). The incidence of VA was similar in all groups, except for ventricular tachycardias (VT) > 15 beats (group 1:69%, group 2:13%, group 3:15%, P = 0.002). The frequency of accelerated idioventricular rhythms (AIVR), early AIVR (< or = 6 h) and of VT was significantly higher in group 1 than in group 3 with a 8-, 30- and 6-fold increase, respectively (back transformed mean). We conclude that the number of VAs is related to the normalization time of the ST segment during reperfusion. This may suggest that faster reflow is more arrhythmogenic.
The object of this study was to analyse ventricular arrhythmias occurring during intravenous thrombolysis for acute myocardial infarction with respect to ST segment changes on 24 hour Holter ECG monitoring initiated at the same time as thrombolytic therapy and on repeated 12 lead electrocardiogrammes. Forty-one patients in whom the infarct-related artery was patent at coronary angiography carried out 30.5 +/- 3.1 hours (< or = 24 hours in 59% of cases) after the onset of chest pain were included. The time to normalisation of the ST segment was defined as the interval between maximum ST elevation to a steady state and helped identify rapid (< or = 60 minutes, n = 13) from intermediate (60-180 minutes, n = 15) and slow (> 180 minutes, n = 13) reperfusion. The incidence of ventricular arrhythmias was the same in all three groups, except for prolonged ventricular tachycardias (> 15 complexes): 69%, 13% and 15% respectively (p = 0.002). The number of arrhythmias was greater when the ST segment changes were rapid than when they were intermediate or slow. This was true for ventricular extrasystoles (p < 0.05), accelerated idioventricular rhythms (p < 0.05), early (< or = 6 hours from onset of thrombolysis) accelerated idioventricular rhythms (p < 0.01) and ventricular tachycardias (p < 0.05). Therefore, the number of ventricular arrhythmias seems to be related to the speed of ST segment change, suggesting that more sudden reperfusion is more arrhythmogenic.
The authors report the case of a 69 year old man with a large left ventricular thrombosis complicating anterior myocardial infarction occurring three years previously for which anticoagulant therapy had to be withdrawn. The discussion is based around the large size of the thrombus, its complete regression with anticoagulant therapy (heparin and coumarin-derivative) and also around the detection of spontaneous echo contrast in the left ventricle by transoesophageal echocardiography. This case underlines the probable risk of withdrawing anticoagulant therapy in patients with severe left ventricular dysfunction and left ventricular spontaneous contrast.
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Reperfusion arrhythmias were described from the first trials of intracoronary thrombolysis for myocardial infarction. The prevalence of ventricular fibrillation during intravenous thrombolysis is low (< 7%) and comparable to that observed with classical treatment. Holter recording shows that ventricular tachycardia and accelerated idioventricular rhythms occur in over 80% of cases. These arrhythmias are generally well tolerated and do not require specific therapy. A bradycardia-hypotension syndrome is observed in about a quarter of reperfused patients, nearly always in inferior wall infarction. It normally resolves spontaneously or after atropine or vascular filling. Reperfusion is associated with a clearcut increase in the number of episodes of arrhythmia. Some arrhythmias such as sustained ventricular tachycardia, early accelerated idioventricular rhythms (occurring in the first 6 hours) or the bradycardia-hypotension syndrome may be considered as non-invasive criteria of reperfusion. More severe ischemia and sudden reperfusion favour the arrhythmogenicity of reperfusion in the animal. Recent data suggest that this may be the case in the clinical context. In some uncontrolled studies, lidocaine, betablockers and aspirin did not affect the prevalence of the arrhythmias. Preliminary trials indicate that flunarizine and captopril may reduce the incidence of reperfusion arrhythmias in man. Ventricular arrhythmias and myocardial stunning could be the result of sa single phenomenon (the extent of the ischemic lesions or reperfusion lesions). Studies currently under way should clarify the relationship between the incidence of arrhythmias, the severity of stunning and myocardial recovery. Protocols evaluating therapeutic interventions on the reperfusate should include Holter monitoring.
Ventricular arrhythmias during thrombolysis for acute myocardial infarction and their relation to coronary artery patency were examined. Twenty-four-hour Holter monitoring was begun 3.1 +/- 0.2 hours after onset of pain in 40 patients (age 54 +/- 1.6 years; anterior infarction 42.5%) treated with streptokinase (42.5%) or recombinant tissue-type plasminogen activator (57.5%) (delay from pain 3.3 +/- 0.2 hours). A Marquette 8000 computer was used for Holter analysis. The infarct-related artery was considered as patent (72.5%) or non-patent (27.5%) according to coronary angiography (delay from pain 26.7 +/- 2.5 hours; 60% less than 24 hours). Ventricular arrhythmias were present in all patients. Tolerance was good (1 cardioversion for ventricular fibrillation). The incidence of accelerated idioventricular rhythm was not different between patients with a patent and nonpatent artery (90 vs 82%), nor for ventricular tachycardia (VT) (83 vs 73%). Coronary artery patency was associated with a 14-, 13- and 32-fold increase of ventricular premature complexes, VT and accelerated idioventricular rhythms, respectively. The increased incidence of sustained VT (patent 38%; nonpatent 0%; p less than 0.05) and early (before the first 6 hours) accelerated idioventricular rhythm (patent 76%; nonpatent 18%; p less than 0.01) associated with artery patency suggests that these arrhythmias may be noninvasive diagnostic criteria for reperfusion (sensitivity 38 vs 76%, and specificity 100 vs 82%). A positive correlation was found between the frequency of ventricular premature complexes and VT, and peak creatine kinase.