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Acute stent recoil has been observed following balloon deflation in normal and diseased coronary arteries, and the magnitude varies by stent design. We sought to evaluate acute stent recoil in five new stents. Twenty-five stents (four Crown, five Nir Conformer Royale, five Crossflex, five SupraG, and six GFX) were implanted in six Yorkshire pigs. All stents were expanded using a noncompliant balloon (balloon:artery ratio 1.2:1.0). Continuous ultrasound imaging was performed during stepwise balloon inflation and deflation using a 0.018" imaging core. Maximum cross-section areas (CSA) and minimal luminal diameter (MLD) were measured at 12 atm and immediately following balloon deflation. Maximum stent CSA matched expected balloon CSA. Area and diameter recoil were calculated as 1 - (CSAdeflation/CSAmax) and 1 - (MLDdeflation/MLDmax), respectively. Upon deflation, all stents showed recoil from maximal CSA. Area recoil was significantly lower for slotted-tube stents than modular stents (12.6% +/- 1.6% vs. 23.2 +/- 3.5%; P < 0.05). In compliant, nonatherosclerotic porcine coronary arteries, acute stent recoil for the four slotted-tube designs ranged from 8.4% to 18.0% by area. The modular stent tested was associated with significantly greater acute recoil than the slotted-tube stents.

Laser myocardial revascularization is a promising new treatment strategy for patients with severe ischemic heart disease who are not candidates for conventional percutaneous or surgical revascularization. The open chest surgical approach to transmyocardial revascularization has been approved by the FDA for the treatment of angina in inoperable patients, but has had limited use as a stand-alone procedure. More recently, use of fiber-optic catheters has made it possible to use a holmium:yttrium aluminum garnet laser to perform percutaneous catheter-based transmyocardial revascularization. To the extent that many patients have a combination of ischemic sources, some amenable to conventional revascularization and some not, combination or hybrid approaches have been considered. We report herein two patients with class IV angina who underwent laser myocardial revascularization using the Biosense system and complex percutaneous coronary intervention during the same procedure. Areas amenable to conventional percutaneous coronary intervention (PCI) were so treated, and viable but ischemic areas were supplied by totally occluded native vessels and bypass grafts underwent Biosense-guided laser myocardial revascularization (LMR). As the results of more controlled and blinded studies of laser myocardial revascularization become available (if results continue to be promising) and a better understanding of the mechanism of action of this treatment modality is achieved, LMR-PTCA hybrid will be performed in increasing frequency. However, even after establishing LMR efficacy, studies of LMR-PTCA hybrid should be conducted to determine the efficacy of this approach.

The influence of lesion length on early and late outcomes after new device angioplasty has not been well documented. We reviewed the clinical and angiographic outcomes of 2,980 patients (3,902 lesions) undergoing new device angioplasty of native vessels enrolled in the New Approaches to Coronary Interventions (NACI) Registry. Patients were divided into three groups according to the longest lesion length (< 10, 10-20, and > 20 mm) treated. Patients with the longest lesions had more multivessel disease (56.9% vs. 49.0%, P<0.05), right coronary artery disease (52.7% vs. 32.0%, P<0.001), and total occlusions (19.1% vs. 2.5%, P<0.001) than patients with shorter lesions. Longest lesions had the smallest minimal lumen diameter (P<0.001) at baseline and at the end of the procedure. Although in-hospital events were similar, there were differences in clinical outcomes at 1 year due mainly to more target lesion revascularization in the longest lesion group (P<0.01). Multivariate analysis showed that each 1-mm increase in lesion length was associated with an increase relative risk of 1.014 (95% CI, 1.004-1.025) for target lesion revascularization at 1 year. We conclude that despite similar early clinical events, patients undergoing new device angioplasty of longer lesions have more target lesion revascularization at 1 year.

We determined acute outcome in 148 consecutive patients with ST segment elevation myocardial infarction undergoing angioplasty including 72 patients (48.7%) considered ineligible for primary angioplasty trials. Overall, in-hospital mortality for acute infarct angioplasty was 12%, with fivefold higher mortality in the trial-ineligible group (21% vs. 4%, P = 0.003). Thus, primary angioplasty trials continue to exclude nearly 50% of acute infarction patients and reported mortality rates of primary angioplasty trials are likely to be significantly lower than the unselected in-hospital mortality rates. Cathet. Cardiovasc. Intervent. 49:237-243, 2000., (Copyright 2000 Wiley-Liss, Inc.)

Stenting is increasingly being used to treat carotid artery disease. However, complications including distal embolization, stent thrombosis, stent collapse from external compression, the need for high-pressure inflation with increased neointimal response, or balloon rupture during stent expansion and stent loss are all potential problems and of concern. To address each of these specific concerns, a new stent was designed, which is self-expandable, made of nitinol, with temperature-dependent superelastic properties, and with high vessel wall surface coverage. Since this device has a number of novel characteristics, we aimed to assess the short- and long-term histopathologic response in pig carotid and iliac arteries. Single stents were deployed in pig carotid and iliac arteries after overstretch balloon injury. Angiograms were performed pre- and poststenting and prior to sacrifice. Intravascular ultrasound was used before implantation to determine vessel size. Vessels were examined histologically at 1 month (n = 6) and 6 months (n = 6) for morphometric analysis, hemorrhage and thrombus, endothelialization, and inflammatory and fibrotic responses. There was a 100% angiographic success rate at implantation. In one case, it was determined histologically that a single stent was implanted in a dissection plane of a pig's left iliac artery and was occluded by organized thrombus, with the true lumen being patent. At 6-month follow-up, this was the only evidence of a single stent occlusion, with flow adjacent to the stent in the true lumen. In the other vessels, the stents showed good vessel wall-stent apposition and the lumens were patent with a concentric and thin neointima. Inflammatory cells were rare and there were no mural thrombi. Coverage of the vessel wall by endothelial-like cells was complete at 1 month. The novel nitinol EndoStent appears to have favorable biocompatibility with minimal thrombus deposition or inflammatory response, and its use is feasible for clinical application in carotid and iliac arteries., (Copyright 1999 Wiley-Liss, Inc.)

A coaxial catheter system for containment of distal embolization is described. Utilizing a novel 0.014" hypotube with a distal elastomeric occlusion balloon, the PercuSurge GuardWire functions as a guidewire while trapping distal embolization resulting from more proximal intervention. The particulate debris is evacuated with a single operator exchange aspiration catheter (Export catheter) prior to deflation of the distal occlusion balloon. This animal study confirmed the feasibility of concept. The system was easily delivered through tortuous coronary anatomy. The GuardWire served as an adequate rail for delivery of dilatation balloons and a multitude of stents. There was no evidence of deep wall damage from low-pressure inflation and apposition of the distal occlusion balloon.

This report describes the treatment by rotational atherectomy of three restenotic ostial diagonal lesions that originated within stented segments of the left anterior descending artery. Excellent results were obtained without complications to stent architecture.

Overnight chronic urokinase infusion was used to successfully treat thrombotic occlusion of a saphenous vein graft. Following removal of the infusion catheter, a 3-cm linear thrombus was observed extending from the graft into the ascending aorta. This mobile thrombus was successfully treated with coumadinization for 9 wk. Potential preventive measures for this complication of indwelling catheters are discussed.

Inadvertent aortosaphenous vein graft-coronary vein anastomosis during coronary bypass surgery is an uncommon complication. We describe a case of aortosaphenous vein side-to-side anastomosis to an obtuse marginal vein resulting in a large arteriovenous fistula and elective closure, using embolization coils delivered percutaneously via the coronary sinus. The clinical findings, interventional procedure, and follow-up are also presented, with a discussion of alternative techniques used previously to treat iatrogenic aortosaphenous vein graft venous fistulae.

Coronary artery bypass surgery remains the standard modality for revascularization of significant left main coronary artery stenoses. Despite major improvement in equipment and operator technique, balloon angioplasty of significant unprotected left main obstruction generally is contraindicated. When catheter intervention is required, Palmaz-Schatz stenting may offer better predictability of the acute result, and possibly improved long-term outcome.

Subclavian artery stenosis is a rare cause of recurrent myocardial ischemia in patients who have undergone left internal mammary-coronary artery bypass grafting. A patient with this syndrome was successfully treated by placement of Palmaz biliary stents in the left subclavian artery. Angiographic and hemodynamic evidence of restricted subclavian flow resolved following stenting, as did the patient's unstable angina syndrome. Endoluminal stenting of the proximal subclavian artery for the treatment of coronary-subclavian steal can be performed safely and provides an alternative to other forms of surgical or percutaneous (PTCA, directional atherectomy) revascularization for treatment of this disorder.

The introduction of balloon valvuloplasty and new devices for coronary intervention has increased the incidence and changed the site and clinical presentation of cardiac perforation. We reviewed all cases of cardiac perforation that occurred during 11,845 consecutive catheterization procedures during a 6-yr period (1986-91). Fourteen cardiac perforations (overall incidence 0.12%) occurred as a result of the following procedures: mitral valvuloplasty 7 of 150 (4.7%), aortic valvuloplasty 4 of 260 (1.5%), pericardiocentesis 1 of 90 (1.1%), temporary pacer 1 of 1,660 (0.06%), and diagnostic left heart catheterization 1 of 6,965 (0.01%). Perforation was recognized in the catheterization laboratory in 11 patients, within 1 hr of leaving the laboratory in two patients, and 15 hr later in one patient. Hemodynamic evidence of tamponade developed in 13 patients and was confirmed by fluoroscopy (immobile heart borders) or echocardiography. Pericardiocentesis is definitive therapy in nearly half of the cases; the remaining patients require pericardiocentesis plus surgical repair of the perforation.

Restenosis rates following Palmaz-Schatz stenting vary between 13 and 36%. To determine whether the nearly three-fold interseries difference in restenosis rates reflects systematic factors (demographic and procedural variables such as post-treatment lumen diameter) rather than random variation, we pooled 486 lesions treated with the Palmaz-Schatz coronary stent in the U.S. Multicenter Registry (n = 259) with the single-center Beth Israel Hospital experience (n = 227) and analyzed the combined series using a continuous geometric model of restenosis. A greater proportion of lesions (66 vs. 50%; P < 0.001) in the Multicenter cohort represented restenosis after a prior intervention. The Multicenter experience also showed a smaller minimum lumen diameter following stent placement (2.61 vs. 3.43 mm; P < 0.001), higher post-stent percent stenosis (16 vs. -2%; P < 0.001), and less acute gain (1.79 vs. 2.67 mm; P < 0.001) than lesions treated in the Beth Israel cohort. At 6-month follow-up, the angiographic restenosis rate (> or = 50% diameter stenosis) was significantly higher in the Multicenter group (35 vs. 27%; P = 0.05), despite the development of less absolute late loss (0.96 vs. 1.32 mm; P < 0.001). Multivariable modeling, however, showed that the only independent predictors of restenosis were a post-procedure lumen diameter < 2.80 mm (odds ratio = 1.57; P = 0.04), diabetes mellitus (odds ratio = 3.55; P < 0.001), and prior restenosis (odds ratio = 1.84; P = 0.008).(ABSTRACT TRUNCATED AT 250 WORDS)

Abrupt closure of the dilated segment occurs in approximately 4 to 7% of cases following conventional percutaneous coronary angioplasty. Additional balloon angioplasty reverses roughly 40% of these closures, to yield an overall 1.6 to 3.4% rate of emergent surgery. The impact of new devices on the incidence and reversal rate of abrupt closure has not been examined. Abrupt closure occurred in 80 (4.2%) of 1,919 consecutive coronary angioplasties performed in our single center, 389 (20%) of which were performed using newer interventions (208 Palmaz-Schatz stents, 170 directional coronary atherectomies, and 11 elective laser balloon angioplasties). Abrupt closure was less frequent following newer coronary interventions (1.8%) compared to standard balloon angioplasty (4.9%, P < 0.01), possibly reflecting case selection. When abrupt closure did occur, percutaneous rescue was successful in 53 (66%) patients, including 42 (53%) who were rescued using standard or perfusion balloon angioplasty, and 11 (13%) who were rescued using laser balloon balloon angioplasty after failure of additional angioplasty attempts. Medical therapy alone was used in 8 (10%), while emergent coronary bypass surgery was performed in 18 (23%), yielding an overall emergent surgery rate of 0.9%. Q-wave myocardial infarction was significantly less frequent (0.2%) following percutaneous rescue, compared to either medical therapy (25%) or emergent surgery (33%, P < 0.001). In our catheterization laboratory, use of these 3 new coronary interventional devices coincides with a trend towards a lower incidence of abrupt closure, a higher percutaneous rescue rate with reduced incidence of myocardial infarction, and a lower emergent bypass surgery rate.

Coronary arteriovenous fistulae are rare, but can be of hemodynamic significance. We report a circumflex-coronary sinus fistula in an elderly man which was associated with a loud continuous murmur and congestive heart failure. Noninvasive evaluation, including transesophageal echocardiography and magnetic resonance imaging, suggested the diagnosis. Angiographic diagnosis of concomitant atherosclerotic coronary disease may be difficult, and can require postoperative study.

Of 13,203 transfemoral diagnostic and therapeutic cardiac catheterization procedures performed between January 1, 1980 and December 31, 1990, 73 (0.55%) were complicated by pseudoaneurysm (PA) formation, and 15 (0.11%) by arteriovenous fistulas (AVF). The rate of PA increased progressively from 0.44% (1980-1987), to 0.59% (1987-1989), to 0.92% (1990), with no corresponding change in the incidence of AVF. The rising incidence of PA complicating transfemoral cardiac catheterization was associated closely with the use of larger diameter catheters and aggressive antiocoagulation during coronary interventions, but findings during surgical repair suggested that puncture of the superficial femoral (SFA), rather than the common femoral artery (CFA), was an important avoidable cause of some PA and AVF. A technique for fluoroscopic localization of the puncture site to avoid inadvertent SFA puncture and the associated increased risk of complication is proposed.

Coronary-subclavian steal syndrome is a rare cause of angina pectoris after bypass grafting using the internal mammary artery. We report the 11th case in the literature and review the pathophysiology and treatment of this disorder. We also review appropriate screening for this possibly increasing, yet preventable disorder.

Distal microvascular spasm is a somewhat uncommon occurrence following PTCA and often does not respond well to nitroglycerin. We report several patients who developed distal microvascular spasm that was refractory to intracoronary nitroglycerin but responded promptly to intracoronary verapamil.

During the initial perioperative period (1 mo to 1 yr) after saphenous vein coronary grafting, early stenosis and occlusion occurs in 5-8% of grafts due to intimal hyperplasia. We report a patient who developed ostial stenosis within 4 mo of bypass surgery at the aortotomy site of two vein grafts. Balloon angioplasty of the elastic stenoses did not provide significant luminal enlargement, but successful treatment of the lesions was obtained using directional atherectomy. Histological examination demonstrated intimal hyperplasia. Directional atherectomy may be an excellent technique for treatment of elastic ostial vein graft stenoses in lieu of conventional balloon dilatation.

The New Approaches to Coronary Intervention (NACI) Registry was developed to collect in-depth data about patients whose coronary artery lesions are being treated with new interventional techniques such as atherectomy, stents, and laser devices. The NACI Registry database distinguishes among several possible "modes" for device use, such as preparatory, planned definitive, and bailout use. Common definitions are used for data collection across all devices, and device-specific forms are used to record procedural details. NACI's unique modular form design facilitates thorough data collection, even for the most complex treatment scenarios. The database structure allows for data analysis at the patient, procedure, lesion, and device levels, as required to perform in-depth analyses of the immediate and long-term success of new devices. Once adequate knowledge of basic device performance has been collected, the Registry structure can also allow expeditious planning and performance of randomized trials comparing a new device to conventional PTCA.

Intraaortic balloon counterpulsation is helpful for controlling myocardial ischemia and providing hemodynamic support, but its applicability is limited by lower extremity ischemic complications in a significant percentage of patients. We developed a new sheathless technique for percutaneous intraaortic balloon catheter insertion which reduces the effective catheter diameter. A pilot study using this new technique resulted in a 10% rate of limb ischemia, without compromise of balloon function. We conclude that this technique may be useful in reducing the incidence of limb ischemia associated with intraaortic balloon counterpulsation.

A case is described in which the left main coronary artery arises from the posterior sinus of Valsalva in an otherwise normal heart. This coronary anomaly did not result in any functional obstruction or myocardial ischemia but represents only the third such anomaly described in the English language literature.

To evaluate angiographic success, frequency of branch vessel loss and salvage, and long-term outcome, we studied the early and late outcomes of 56 consecutive patients who underwent PTCA of bifurcation lesions, which involved the left anterior descending or left circumflex coronary artery, with stenoses greater than 70% in both the parent and an involved branch vessel. In 35 patients (63%), the PTCA strategy was attempted dilation of both the main vessel and the involved branch vessels using predominantly a double-wire, sequential balloon technique; in 21 (27%) the PTCA attempt was confined to the main vessel alone. Transient angiographic occlusion of the branch vessel occurred in 32% of patients in whom dilation of both vessels was attempted, and in 38% in whom the main vessel alone was dilated (p = NS); 91% of the occluded branch vessels were the salvaged when sequential angioplasty of both vessels had been initially planned, compared to only 38% when the initial strategy had been dilation of the main vessel alone (p less than .05). Predischarge exercise testing showed residual ischemia in 6% of patients who had both vessels successfully dilated, versus 37% in those in whom dilatation was confined to the main vessels (p less than .01). Clinical restenosis, defined as late (greater than 6 weeks) recurrence of angina or a positive exercise test, occurred in 42% of patients who had both vessels successfully dilated. Thus although bifurcation lesion angioplasty frequently results in transient branch vessel loss, these branches can usually be salvaged using a double-wire technique but tend to have a higher late restenosis than conventional single vessel PTCA.

We report an unusual anomaly of the right coronary artery consisting of proximal branching of the artery and subsequent interweaving of the branches, referred to as a "woven" coronary artery. Implications and differential diagnosis are discussed.

Up to 90% of coronary bypass operations in some centers now include at least one IMA graft. In parallel with the increased use of IMA grafts, our catheterization laboratory records for 1986-7-8 demonstrate a progressive increase in IMA angiography, both absolutely (11, 28, 48 cases/yr) and as a percent of restudy procedures performed after prior bypass (14, 25, 43%). Unfortunately, these records also show that cannulation of the right and left IMAs may involve substantial technical hurdles, resulting in a mean time of 19 +/- 19 min from catheter insertion to selective IMA angiography. Based on this experience, we review a standard technique for IMA angiography using preformed catheters, and describe alternative methods (including use of PTCA guidewires with or without super-selective catheters, and non-selective angiography utilizing a specially designed balloon occlusion catheter).

Of 84 consecutive patients referred for coronary angioplasty, an exchange length (260 cm) guide wire was used in 17 (20%) to allow serial passage of different sized dilatation catheters. Exchanges were performed for the following reasons: 1) inability to cross the stenotic segment with a full-sized dilatation catheter, with exchange for a smaller catheter to permit initial dilatation followed by a second exchange to reintroduce the full-sized balloon catheter; 2) premeditated initial use of a low-profile balloon catheter in severe stenosis, with subsequent exchange to a full-sized balloon catheter; 3) inability to achieve a satisfactory reduction of the transstenotic gradient or angiographic stenosis with the initial dilation catheter, requiring subsequent passage of a larger balloon catheter into the partially dilated segment. Eighteen of 19 attempted exchanges and 18 of 19 angioplasty procedures were completed successfully. The use of exchange guide wires permits multiple recrossings of a dilated segment, allows safe serial passage of different sized balloon catheters, and obviates the need for renegotiating difficult proximal coronary anatomy. The exchange guide wire techique can be applied safely and effectively to coronary angioplasty and provides an additional option in the successful completion of movable guide wire angioplasty procedures.

A formal analysis of the error associated with the use of radiographic diameter measurements in estimating the luminal area of an elliptically-shaped coronary cross-section was performed. When two views are available, the maximum potential error was found to decrease rapidly as the angle between the views increased to 90 degrees, but this error was small (less than 25%) for orthogonal views only for mild degrees of ellipticity (major/minor axis ratio less than 2). Since, for each successive doubling of the number of radiographic views, a stepwise reduction in the potential error by an approximate factor of only one-half was found, a large number of views is required to eliminate the potential error associated with diameter assessment of highly elliptical lumena.

A 39-year-old woman with symptomatic mitral stenosis underwent percutaneous mitral valvuloplasty at the end of her first trimester of pregnancy. Balloon dilatation utilizing a double 18-20 mm balloon technique resulted in improvement in mean mitral gradient (16 to 7 mmHg) and in calculated mitral valve area (1.4 to 2.4 cm2), without significant complications and with an estimated radiation exposure to the fetus of less than 0.2 rads. The procedure resulted in disappearance of symptoms of congestive heart failure and allowed for discontinuation of diuretics. The subsequent course of gestation was uncomplicated and a normal baby boy was delivered in the 36th wk. We conclude that percutaneous mitral valvuloplasty may produce successful palliation of symptoms in patients with mitral stenosis during pregnancy.