Simple and complex stent strategies for bifurcated coronary arterial stenosis involving the side branch origin.

Coronary lesions located in major bifurcations constitute a challenge for the use of stents. Although the occlusion of a side branch covered by a stent is infrequent, the maintenance of a patent, stenosis-free bifurcation may result in a complex procedure. Between September 1994 and April 1998, 70 patients were treated by stent implantation for coronary bifurcation stenosis. The side branch always had a diameter >2 mm. The pairs of treated arteries were: left anterior descending (LAD)/diagonal artery in 32 patients, circumflex/obtuse marginal in 26, right coronary/posterior descending artery in 5, and LAD/circumflex in 7. We applied 2 different techniques of stent implantation: (1) deployment of 1 stent in the parent vessel covering the takeoff of the side branch and subsequent angioplasty of the side branch across the metallic structure (group A, n = 47 patients), and (2) implantation of 1 stent at the ostium of the side branch and complete reconstruction of the entire bifurcation with additional implantation of 1 or 2 stents at the parent vessel (group B, n = 23 patients). There were no significant differences between groups at baseline variables. Procedural success was similar in both groups: 42 (89%) in group A versus 21 (91%) in group B. However, major cardiac events at 18 months follow-up were higher in group B (event-free probability 44% vs 75%, p <0.05). Selected patients with coronary stenosis at major bifurcations can be treated with an acceptable rate of primary and late success. Complex techniques providing radical stent reconstruction of the bifurcation seems to provide no advantages over the simpler stent jail followed by ostial side branch balloon dilation.

Immediate and follow-up findings after stent treatment for severe coarctation of aorta.

Experimental studies have shown that stents implanted at the aorta become incorporated within the aortic wall and can be further expanded in growing animals. Few clinical studies have shown that the stent repair of severe coarctation of aorta provides excellent initial results, and little is known on the follow-up of these patients. We assessed the immediate and follow-up results obtained in a series of 48 patients (mean age 14+/-12 years) with severe coarctation of the aorta who were treated by Palmaz stent implantation; 30 of them (63%) underwent angiographic follow-up studies at a mean of 25+/-11 months after treatment. Quantitative serial analysis of the aortogram (baseline, after treatment, and at follow-up) was performed. Significant relief (mean residual gradient 3+/-4 mm Hg) was always obtained after stent implantation. The isthmus, when hypoplastic (60%), was always expanded with the stent. One associated aneurysm became occluded after the implant. Complications included aortic disruption, stent migration, and decreased or absent femoral pulses. At angiographic follow-up, the stent remained always in place, without recoil. In 22 patients (73%), there were no detectable neointimal proliferation at late angiogram; however, 8 patients (27%) had some degree of intimal thickening (1 to 5 mm), causing mild restenosis in 3 patients treated at early age, and nonsignificant lumen reduction in 5. The serial aortogram analysis revealed a minor but significant increase in nonstented aortic diameters that seemed related to the normal growth of children. No need for stent reexpansion was observed at 2-year follow-up (mean). Two patients (7%) developed late small aneurysm formation at the stented wall; both were occluded by the insertion of coils through the stent orifices. We conclude that stent treatment for severe coarctation of aorta provides excellent immediate and long-term results in young adults and children. However, at early age, restenosis by intimal growth may develop.

In-laboratory removal of femoral sheath following protamine administration in patients having intracoronary stent implantation.

Two hundred twenty-eight patients with successful coronary stent implantation were randomized either to protamine administration and femoral sheath removal (group I, n = 117) or no heparin neutralization and delayed sheath removal (group II, n = 111). The hospital stay after treatment was shorter in patients receiving protamine; therefore, protamine use for neutralizing circulating heparin may be safely administered immediately after stent implantation.

Obliteration of femoral pseudoaneurysm complicating coronary intervention by direct puncture and permanent or removable coil insertion.

We report on percutaneous obliteration of femoral pseudoaneurysm complicating percutaneous coronary interventions in 6 patients. Our findings suggest that permanent or transient direct coil insertion may be an useful alternative in the treatment of pseudoaneurysm in patients who do not respond to mechanical compression.

Angiographic predictors of neointimal thickening after successful coronary wall healing following percutaneous revascularization.

This study was undertaken to characterize, by intracoronary ultrasound technique, the neointimal thickening at follow-up of treated coronary segments after successful arterial wall repair and to compare the findings with serial angiographic studies. We selected for study 81 patients with single-vessel coronary disease successfully treated by percutaneous revascularization who were angiographically and ultrasonically reevaluated at a mean follow-up time of 22 +/- 21 months; 23 had been treated by balloon angioplasty, 27 by directional atherectomy, and 31 by elective Palmaz-Schatz stent implantation. The late maximal neointimal thickness varied between 0.1 and 1.5 mm (mean 0.65 +/- 0.31 mm), and the neointimal area ranged between 0.97 and 14.9 mm2 (mean 5.19 +/- 3.14 mm2). The neointimal repair was thinner in patients who obtained a better acute angiographic result immediately after treatment and in stented (3.4 +/- 1.8 mm2) versus dilated (7.8 +/- 4.1 mm2) or resected (5 +/- 1.6 mm2, p < 0.001) segments. On the contrary, the repaired neointimal layer was thicker in those patients who angiographically exhibited less late luminal loss or even expansion and in those evaluated after a longer time since treatment. The acute gain and the time influence resulted in independent predictors of the degree of neointimal thickness. These findings suggest that two reparative mechanisms of the coronary wall may operate in close relation.

[Primary stent treatment in the acute phase of myocardial infaction]. / Tratamiento primario con stent en la fase aguda del infarto de miocardio.

INTRODUCTION: Although direct balloon angioplasty has emerged as an alternative to thrombolytic therapy in patients with acute myocardial infarction, reocclusion and restenosis rates are limiting factors. We postulated that these limitations could be partly overcome by primary stenting of the responsible lesion. MATERIAL AND METHODS: Since January/94 we have studied 59 patients with acute myocardial infarction who were treated in the early phase (3.1 +/- 2 hours since the onset of symptoms) by elective Palmaz-Schatz stent implantation. No adjunctive thrombolytic therapy was associated. Two patients were in cardiogenic shock and were treated under percutaneous cardiopulmonary support. At cardiac catheterization a left ventriculography and coronary angiograms were obtained. Then, mechanical recanalization of the responsible lesion was performed. If the angiographic anatomy was considered suitable, a stent was implanted at the lesion. RESULTS: The infarct related artery was the left anterior descending in 29 patients, the circumflex in 14 and the right coronary artery in 16. At baseline conditions, 40 patients had a totally occluded artery and 19 showed a TIMI-grande 1 antegrade flow. One patient had an early clinical recurrence 4 days later, which required an additional divided Palmaz-Schatz stent at the distal portion of the lesion, in order to seal a residual dissection. All remaining patients had a favourable clinical course without major complications. Immediately after treatment the minimal lumen diameter was 3.2 +/- 0.4 mm and no residual stenosis was detectable at the treated segment. Six-month angiographic reevaluation was performed in all 29 (49%) eligible patients. Restenosis (> 50% stenosis) was detected in 6 out of the 29 evaluated patients (21%). CONCLUSIONS: Primary stent implantation in selected patients with an evolving myocardial infarction provides good initial and 6-month results.

Reduction of thrombotic and hemorrhagic complications after stent implantation.

This study compared two consecutive antithrombotic strategies after Palmaz-Schatz stent implantation and involved 918 patients. Patients treated between May 1991 and May 1994 (group 1; n = 379) received aspirin, dipyridamole, and intravenous unfractionated heparin until oral anticoagulation was effective, between June 1994 and August 1995, 539 patients (group 2) were treated for 1 month with subcutaneous low-molecular-weight heparin (Fragmin), ticlopidine, and aspirin. There were no differences between the groups in terms of sex, clinical condition, vessel diameter, and severity and location of stenosis. Patients in group 1 were younger than those in group 2 (4% were > 70 years old compared with 12%, respectively; p < 0.01). Group 1 patients had more frequent unplanned stenting (48% vs 18%, respectively; p < 0.01) and fewer endoprostheses in the same artery than those in group 2 (1.1 +/- 0.5 vs 1.2 +/- 0.5, respectively; p < 0.01). Among group 2 patients, there was a significant reduction in thrombotic and hemorrhagic complications compared with group 1 patients. No subacute thrombosis occurred in patients in group 2 in contrast with a 5.8% incidence in patients in group 1 (p < 0.01). In addition, a lower incidence of groin and systemic bleeding was observed in patients in group 2 compared with patients in group 1 (2.6% vs 15%, respectively; p < 0.01). The association of low-molecular-weight heparin and antiplatelets provides a simpler antithrombotic strategy in patients treated with intracoronary stents and reduces the incidence of stent thrombosis and hemorrhagic complications. Our findings suggest that this antithrombotic regimen may prevent or completely avoid stent thrombosis.

[Directional coronary atherectomy in ostial lesions of the anterior descending coronary artery]. / Aterectomía coronaria dirigida en lesiones ostiales de la descendente anterior.

INTRODUCTION AND OBJECTIVES: Coronary stenoses at ostial level, when treated by balloon angioplasty, show a primary success rate much lower than those located in other parts of the coronary tree. Balloon dilation of lesions located at the left anterior descending ostium is associated with a high degree of restenosis, elastic recoil and the possibility of retrograde dissection to the left main coronary artery. Simpson atherectomy may be considered a percutaneous alternative in this particular location, since this technique produces fewer incidents of elastic recoil than balloon dilation. The purpose of the present study is to evaluate directional atherectomy in the treatment of patients with symptoms deriving from severe to stenosis at the origin of the left anterior descending artery. MATERIAL AND METHODS: From a total number of 302 patients treated by Simpson atherectomy, we have analyzed 45 with severe stenosis at the left anterior descending ostium (less than 3 mm from its origin). The mean age was 54 +/- 12 years. Eighty two percent of the patients were male. The clinical condition was stable in unstable in 34; eleven had had a previous myocardial infarction. Six had multivessel coronary disease, all of them underwent combined balloon angioplasty of other segments. The treated lesion was native in 41 patients and previously dilated by balloon (restenosis) in 4. Two patients needed balloon predilation with 2 and 2.5 mm to facilitate the pass of the atherocatheter. The size of the Simpson atherocatheter was mainly 7F (78%). The weight of the resected arteriosclerotic material was 11 +/- 7 mg. RESULTS: Primary success (residual stenosis < 40% without major complications) was obtained in 42 out of 45 patients (93%); 3 patients (7%) had major complications (1 death, 1 emergency surgery, and 1 non-Q wave myocardial infarction). A follow-up angiography study was available in 31 patients 7 +/- 8 months later. Restenosis was evidenced in 12 (39%). CONCLUSIONS: Simpson atherectomy for left anterior descending artery ostial lesions is an effective transluminal alternative in selected patients providing a high rate of primary success (93%) and an acceptable restenosis rate (39%).

Follow-up patency of side branches covered by intracoronary Palmaz-Schatz stent.

To assess the risk of late side branch occlusion after Palmaz-Schatz stent deployment, we analyzed the angiographic evolution of 62 patients treated by successful stent implantation who had a total of 85 side branches starting from the stented segment. Side branches were considered minor (n = 39) when the diameter was < 1 mm and intermediate (n = 46) when the vessel had > or = 1 mm diameter. One angiographic follow-up study was available in all patients at 8 +/- 5 months. Eight minor branches presented some degree of stenosis at origin before stent deployment (4 totally occluded). After stent deployment, 32 (82%) of 39 remained unchanged and 3 became occluded. Late progression at origin occurred in 4 of 34 (3 occluded). Before stent deployment, 48% of the intermediate branches had some compromise degree at their starting point (1 totally occluded). Eight of 45 intermediate branches became occluded after stent implantation. Late progression at origin happened in 5 of 32 branches (2 occluded). Some degree of follow-up stenosis regression at the origin was observed in 22 (26%) of 85 arteries. Neither clinical nor angiographic factors could be identified as predictors of late side branch occlusion or stenosis progression at its origin. Later occlusion or progression at origin of a side branch covered by a Palmaz-Schatz stent seems to be an uncommon occurrence (7% and 12% respectively) that cannot be predicted by angiographic or clinical factors. On the contrary, regression at follow-up of a side branch-origin stenosis can also come about.

Serial angiographic observations after successful directional coronary atherectomy.

This study focuses on the early and late angiographic evolution observed in 82 patients with coronary artery disease who were successfully treated by directional coronary atherectomy (DCA) without adjunctive balloon angioplasty. Qualitative inspections and quantitative measurements were obtained from a selected angled-view projection in the following conditions: (1) before treatment; (2) immediately after treatment; (3) the day after atherectomy; (4) 1 month after; and (5) 6 months after. The appearance of the treated segment 24 hours after the procedure did not differ in 79 patients from that observed immediately after DCA; silent total occlusion occurred in two patients, and one had an aneurysm at the site of resection (all three patients were excluded from the analysis). At the 1-month study restenosis developed in 3 (3.6%) patients; the remaining 76 had identical appearances, with no evidence of renarrowing of the lumen. However, from 1 to 6 months after the procedure restenosis developed in 35 of the remaining 76 (46%) patients, and 41 patients were free of restenosis and symptoms. These findings, which show that early elastic recoil does not occur after successful DCA, are different from the changes observed after balloon angioplasty. At the 1-month observation restenosis is an infrequent but possible phenomenon (3.8%). From this point the healing of the arterial wall leads to no or mild renarrowing (late success); an exaggerated proliferative response produces restenosis.

Factors determining late success after mitral balloon valvulotomy.

Mitral balloon valvulotomy (MBV) has proved to be an effective method in the treatment of patients with mitral stenosis. Although several factors determining an optimal immediate result have been described, there is little information regarding long-term follow-up, as well as factors influencing late success after MBV. This study analyzes 350 patients (mean age 46 +/- 12 years) treated by MBV who were clinically followed up between 6 months and 6 years. At least 1 echo-Doppler follow-up study was obtained in 298 patients 28 +/- 14 months after MBV; hemodynamic reevaluations were performed in 66 patients after 23 +/- months. Late success was considered if the patient was in functional class I to II and free of major events (death, restenosis and valve surgery). Restenosis was defined as a 50% loss of initial gain with regard to valve area by echocardiography, which was confirmed hemodynamically. After a mean follow-up of 38 +/- 15 months, 296 patients (84%) remained in functional class I to II, without surgery or the need for an increase in medical treatment. The 5-year Kaplan-Meier survival rate was 94 +/- 1%, whereas restenosis, valve surgery and major event-free probability were 90 +/- 3%, 91 +/- 2% and 85 +/- 2%, respectively. Multivariate study (Cox regression model) identified the presence of sinus rhythm (p < 0.001) and the absence of calcium at fluoroscopy (p < 0.003) as the only independent factors of late success.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracoronary ultrasound assessment of directional coronary atherectomy: immediate and follow-up findings.

OBJECTIVES: This study was conducted to assess the relations among intracoronary ultrasound, angiographic and histologic data obtained from patients with coronary artery disease successfully treated by directional coronary atherectomy. In addition, it was designed to elucidate whether some aspects of intravascular ultrasound or pathologic findings could predict a propensity to restenosis. BACKGROUND: Intracoronary ultrasound is a useful technique in guiding and assessing atherectomy. However, there is little information about the characterization of the different types of coronary plaques and the changes observed in them after resection. Furthermore, the follow-up ultrasound appearance of previously treated lesions remains undepicted. METHODS: Fifty-two patients (54 +/- 10 years old) were studied. All were successfully treated by atherectomy with the aid of intracoronary ultrasound guidance. Qualitative and quantitative ultrasound and angiographic variables were derived before and after resection. Quantitative histologic morphometric information was also obtained from the specimens. In 22 patients, a follow-up echoangiographic reevaluation was performed 6 +/- 4 months later. RESULTS: Echogenic plaques had a higher collagen and calcium content, whereas echolucent plaques had an increased level of fibrin, nuclei and lipids. Ultrasound plaque reduction after atherectomy was greater in echolucent (76 +/- 21%) than in echogenic plaques (60 +/- 18%; p < 0.05). That reduction correlated with the weight of the resected material (r = 0.62; p < 0.01). At follow-up study, 13 of 22 patients had angiographic and ultrasound evidence of restenosis. Most recurrent lesions had a stenotic three-layer appearance. The incidence of restenosis of primary lesions treated with atherectomy was higher in echolucent (100%) than in echogenic (33%) plaques. Similarly, a higher proportion of nuclear content in the resected material was observed in patients who developed restenosis (2.1 +/- 0.7%) than in patients who had late success after atherectomy (1.2 +/- 0.6%). CONCLUSIONS: Our findings suggest that echolucent plaques are easier to resect than are echogenic plaques but frequently develop restenosis. In contrast, the resection of echogenic plaques, although often incomplete, is associated with better long-term results.

Peripheral stent recovery after failed intracoronary delivery.

The Palmaz-Schatz stent can be successfully deployed in most patients. However, in a small percentage of instances a systemic embolism of the stent has been reported. In the present article we describe an easy and fast method of stent capture when detachment from the balloon has happened (pulling back the stent-loaded balloon into the guiding catheter or femoral sheath). In this situation we propose the use of the coronary guide-wire "as a guide" to capture coaxially the lost stent. This method allows for continuing the procedure without removal of the femoral sheath.

[Follow-up study after percutaneous mitral valvuloplasty. The COR-PAL experience]. / Estudio de seguimiento tras valvuloplastia mitral percutánea. Experiencia COR-PAL.

Mitral balloon valvulotomy has proven to be an effective method for the treatment of patients with mitral stenosis. Although several factors determining an optimal immediate result have been described, there is few information regarding the longterm follow-up as well as factors influencing late success after the procedure. In this article, we analyzed our series of 311 patients treated by mitral balloon valvulotomy who were clinically followed between 3 months and 5 years (mean 23 +/- 11 months). At least, one echo-Doppler follow-up study was obtained in 260 patients, 20 +/- 10 months after. Hemodynamic re-evaluations were performed in 63 patients after 20 +/- 11 months. Late success was defined as the patient being in functional class I-II and free of major events (death, restenosis or valve surgery). Restenosis was defined as the loss of 50% of initial gain in terms of valve area, confirmed always hemodynamically. Major events during follow-up period occurred in 19 patients (10 deaths, 8 restenosis and 11 mitral valve surgery). We performed a multivariate study using the Cox-regression model. In the analysis, all variables with or near statistic significance in the univariate analysis (Mantel-Haezel) were included. The only significant independent predictors of late success were the presence of sinus rhythm (p < 0.04) and the absence of calcium at the valve (p < 0.001). In conclusion, the best results 5 years after mitral balloon valvulotomy are observed in patients with non calcified valve and sinus rhythm.