Tear or dissection after coronary angioplasty. Morphologic correlates of an ischemic complication

SUOH 03 Guidewire for the Management of Coronary Artery Dissection: Insights from a Multicenter Registry

BACKGROUND

In the setting of coronary artery dissection, both spontaneous and iatrogenic, fixing the intimal tear, usually with stent implantation, can be extremely challenging if the distal wire position has been lost. Common complications are mainly related to the inadvertent subintimal tracking of the guidewire while attempting to gain the distal true lumen.

AIMS

To report the registry results of using the SUOH 0.3 guidewire for managing coronary artery dissection in a real-world multicenter setting.

METHODS

The study population in this retrospective, multicenter, international registry included 75 consecutive patients who underwent PCI and required an antegrade wiring of a dissected coronary artery.

RESULTS

Successful use of SUOH 0.3 was achieved in 69 (92%) patients. The use of a microcatheter was associated with a significantly higher rate of TIMI 3 flow at the end of the procedure (no microcatheter: n = 17, 81%; microcatheter: n = 52, 96.3%; p = 0.017). The first recanalization attempt was made with the SUOH 03 guidewire in 48 (64%) cases, and it was successful in 42 (87%). The overall PCI success rate was reported in 72 (96%) patients, with no significant differences among patients with different origins, mechanisms, and locations of dissection.

CONCLUSIONS

In this setting, the SUOH 0.3 guidewire provides high procedural success without additional complex techniques.

Effectiveness of the "new rope coil" composite core Suoh 0.3 guidewire in the management of coronary artery dissections

Coronary artery dissection is a well-known complication of percutaneous coronary interventions. In this setting, coronary artery dissection is caused by mechanical injury of the arterial wall. However, dissection may also occur spontaneously. In both situations, an intimal tear or dissection allows blood entering and separating the layers of the coronary arterial wall. Despite percutaneous approach is still the preferred and the quickest way to restore coronary flow, it remains challenging. One of the main reasons for procedural failure is due to the difficult advancement of a guidewire into the true lumen. In such situation, the ideal wire should have a soft tip, high torque control, and excellent flexibility. Assuming that, the "new rope coil" composite core Suoh 0.3 guidewire, with its unique combination of characteristics, could allow better orientation insight into a dissected coronary artery increasing the chance of procedural success. We collected a case series of nine consecutive patients in which the Suoh 0.3 guidewire was able to gain the true lumen distally to a dissected segment.

Day case discharge of patients treated with drug coated balloon only angioplasty for de novo coronary artery disease: A single center experience

OBJECTIVE

To report our initial experience with drug coated balloon (DCB) only angioplasty and propose a protocol to achieve this safely.

BACKGROUND

There are no articles published in the literature currently regarding the safety of same day discharge in patients treated with DCB-only angioplasty.

METHODS

Retrospective review of all our patients treated with DCB-only angioplasty from September 2017 to April 2018 with identification of potential complications relating to same day discharge.

RESULTS

A total of 100 consecutive patients who underwent elective DCB-only angioplasty for de novo coronary artery disease and were discharged on the same day as the procedure were included. In 99% no cardiac symptoms relating to the procedure requiring urgent hospitalization or urgent investigations were identified. One patient was readmitted the next day requiring stenting of the previously treated lesion. Our 30-day mortality was zero. Some 97 hospital bed days were saved with 100 patients treated.

CONCLUSION

Elective day-case DCB-only angioplasty according to our local protocol is safe and cost-effective and should be considered for the majority of the patients.

Percutaneous Coronary Intervention for Iatrogenic Right Coronary Artery Dissection Post Bentall Procedure: A Case Report and Minireview

Iatrogenic coronary artery dissection is a potentially life-threatening complication of cardiovascular interventions. The optimal management of iatrogenic coronary artery dissection is not clear; however, both conservative management and percutaneous or surgical revascularization have been performed depending on the patient's clinical status and the extent of dissection. We present the first reported case of right coronary artery dissection after Bentall procedure performed for ascending aortic aneurysm. Urgent percutaneous intervention using adjunctive coronary imaging was performed with excellent clinical recovery. In this article, we highlight coronary artery dissection after Bentall procedure as a possible complication, provide an insight into various options in its management, and review published data on iatrogenic coronary artery dissection. We also discuss the challenges in percutaneous treatment of coronary artery dissection with special focus on intracoronary imaging for accurate diagnosis and guidance in the management of this complex lesion.

Spontaneous Resolution of Catheter-Induced Iatrogenic Vein Graft Dissection: First Case Report and Review of Literature

An 86-year-old female patient with a history of bypass surgery was admitted for recurrent dyspnea and chest pain on exertion. She underwent coronary angiography showing high-grade saphenous vein graft stenosis supplying the right coronary. During an attempt to perform percutaneous intervention, saphenous vein graft to the right coronary artery was injured by the guide catheter resulting in dissection with thrombus formation but with normal distal blood flow. The procedure was abandoned since she had normal distal flow and also due to a fear of causing extension of the dissection with further manipulation. The patient was hemodynamically stable and free of chest pain after 30 minutes of observation. The patient was later discharged home on medical treatment. After 1 month, a repeat angiography showed patent saphenous vein graft to the right coronary artery with healed dissection. This is the first case report of spontaneous recovery of iatrogenic saphenous vein graft dissection. This case is followed by the review of literature.

Elutax paclitaxel-eluting balloon followed by bare-metal stent compared with Xience V drug-eluting stent in the treatment of de novo coronary stenosis: a randomized trial

BACKGROUND

Paclitaxel-eluting balloons (PEBs) are a promising alternative to drug-eluting stent (DES) in the treatment of coronary stenoses. The aim of our study was to compare the 9-month restenosis rates of a strategy of predilatation with PEB followed by bare-metal CoCr stent (PEB + BMS group) versus implantation of everolimus DES (DES group).

METHODS

This randomized, single-center study planned to enroll 366 patients with stable angina (183 patients per arm) undergoing percutaneous coronary intervention of a de novo, native coronary artery stenosis ≤ 15 mm in length. Primary end point, in a noninferiority study design, was 9-month binary angiographic restenosis. A frequency-domain optical coherence tomography substudy investigated the percentage of uncovered stent struts per lesion, the percentage of malapposed/uncovered struts per lesion, and the percentage of net volume obstruction at 9-month follow-up among the first consecutive 30 patients enrolled in the PEB + BMS group.

RESULTS

The study was prematurely halted after enrollment of 125 patients, 59 in the PEB + BMS group and 66 in the DES group, because of excess of ischemia-driven target lesion revascularization in the PEB + BMS group. When all the enrolled patients completed their follow-up, IDLTR rates were 14% in the PEB + BMS versus 2% in DES group (P = .001). Binary restenosis, either in-stent or in-segment, was significantly higher in the PEB + BMS compared with DES group (17% vs 3% [P = .01] and 25% vs 4% [P = .009] respectively). Frequency-domain optical coherence tomography demonstrated important neointimal regrowth in the PEB + BMS group, similar to historical BMS data.

CONCLUSION

In the treatment of de novo coronary stenosis, a strategy of predilatation with PEB before BMS implantation was significantly inferior to implantation of an everolimus DES stent in terms of 9-month target lesion revascularization. Frequency-domain optical coherence tomography data confirm the lack of efficacy of this strategy.

Intra-arterial therapy for acute ischemic stroke

Intra-arterial therapy (IAT) for acute ischemic stroke refers to endovascular catheter-based approaches to achieve recanalization using mechanical clot disruption, locally injected thrombolytic agents or both. IAT may be used in addition to intravenous tissue plasminogen activator (tPA) or in patients who do not qualify for tPA, usually because they are outside the approved 3-h timeframe window or have contraindications, such as elevated international normalized ratio or partial thromboplastin time. Recanalization rates correlate with clinical improvement, and with the newest catheters it is possible to achieve recanalization in roughly 80% of patients treated. However, while the catheters are approved by the Food and Drug Administration, there are still no randomized trial data demonstrating the role of current IAT therapy vs either tPA or standard management. IAT is reserved for patients with large artery occlusions in the basilar, distal carotid, or proximal middle cerebral arteries. Imaging the penumbra using magnetic resonance imaging or computed tomographic perfusion is currently the most frequently used way to identify patients who might benefit. However, the imaging and clinical criteria for identifying which patients benefit, and perhaps more importantly those who will do poorly despite IAT, remain unclear.

Coronary artery stents: Part I. Evolution of percutaneous coronary intervention

The subspecialty of interventional cardiology has made significant progress in the management of coronary artery disease over the past three decades with the development of percutaneous coronary transluminal angioplasty, atherectomy, and bare-metal and drug-eluting stents (DES). Bare-metal stents (BMS) maintain vessel lumen diameter by acting as a scaffold and prevent collapse incurred by angioplasty. However, these devices cause neointimal hyperplasia leading to in-stent restenosis and requiring reintervention in more than 20% of patients by 6 mo. DES (sirolimus and paclitaxel) prevent restenosis by inhibiting neointimal hyperplasia. However, DESs also delay endothelialization, causing the stents to remain thrombogenic for an extended, yet unknown, period of time. Late stent thrombosis is associated with a 45% mortality rate. Premature discontinuation of antiplatelet therapy, particularly clopidogrel, is the strongest predictor of stent thrombosis. Sixty percent of patients receive stents for off-label (unapproved) indications, which also increases the frequency of stent thrombosis. Clopidogrel and aspirin are the cornerstone of therapy in the prevention of stent thrombosis in both BMS and DES. Recommendations pertaining to the optimal duration of dual-antiplatelet therapy have been debated. Both the Food and Drug Administration and the American Heart Association/American College of Cardiologists, in association with other major societies, have made recommendations to extend the duration of dual-antiplatelet therapy in patients with DES to 1 yr. The 6-wk duration of dual-antiplatelet therapy in patients with BMS remains unchanged. All patients with coronary stents must remain on life-long aspirin monotherapy. Since the introduction of percutaneous transluminal coronary angioplasty for the treatment of coronary atherosclerosis, the practice of percutaneous coronary intervention has undergone a dramatic transformation from simple balloon dilation catheters to sophisticated mechanical endoprostheses. These advancements have impacted the practice of perioperative medicine. In this series of two articles, in Part I we will review the evolution of percutaneous coronary intervention and discuss the issues associated with percutaneous transluminal coronary angioplasty and coronary stenting; in Part II we will discuss perioperative issues and management strategies of coronary stents during noncardiac surgery.

Dissection properties of the human aortic media: an experimental study

Aortic dissection occurs frequently and is clinically challenging; the underlying mechanics remain unclear. The present study investigates the dissection properties of the media of 15 human abdominal aortas (AAs) by means of direct tension tests (n=8) and peeling tests (n=12). The direct tension test demonstrates the strength of the media in the radial direction, while the peeling test allows a steady-state investigation of the dissection propagation. To explore the development of irreversible microscopic changes during medial dissection, histological images (n=8) from four AAs at different peeling stages are prepared and analyzed. Direct tension tests of coin-shaped medial specimens result in a radial failure stress of 140.1+/-15.9 kPa (mean+/-SD, n=8). Peeling tests of rectangular-shaped medial strips along the circumferential and axial directions provide peeling force/width ratios of 22.9+/-2.9 mN/mm (n=5) and 34.8+/-15.5 mN/mm (n=7); the related dissection energies per reference area are 5.1+/-0.6 mJ/cm(2) and 7.6+/-2.7 mJ/cm(2), respectively. Although student's t-tests indicate that force/width values of both experimental tests are not significantly different (alpha=0.05, p=0.125), the strikingly higher resisting force/width obtained for the axial peeling tests is perhaps indicative of anisotropic dissection properties of the human aortic media. Peeling in the axial direction of the aorta generates a remarkably "rougher" dissection surface with respect to the surface generated by peeling in the circumferential direction. Histological analysis of the stressed specimens reveals that tissue damage spreads over approximately six to seven elastic laminae, which is about 15-18% of the thickness of the abdominal aortic media, which forms a pronounced cohesive zone at the dissection front.

Modeling Plaque Fissuring and Dissection during Balloon Angioplasty Intervention

Balloon angioplasty intervention is traumatic to arterial tissue. Fracture mechanisms such as plaque fissuring and/or dissection occur and constitute major contributions to the lumen enlargement. However, these types of mechanically-based traumatization of arterial tissue are also contributing factors to both acute procedural complications and chronic restenosis of the treatment site. We propose physical and finite element models, which are generally useable to trace fissuring and/or dissection in atherosclerotic plaques during balloon angioplasty interventions. The arterial wall is described as an anisotropic, heterogeneous, highly deformable, nearly incompressible body, whereas tissue failure is captured by a strong discontinuity kinematics and a novel cohesive zone model. The numerical implementation is based on the partition of unity finite element method and the interface element method. The later is used to link together meshes of the different tissue components. The balloon angioplasty-based failure mechanisms are numerically studied in 3D by means of an atherosclerotic-prone human external iliac artery, with a type V lesion. Image-based 3D geometry is generated and tissue-specific material properties are considered. Numerical results show that in a primary phase the plaque fissures at both shoulders of the fibrous cap and stops at the lamina elastica interna. In a secondary phase, local dissections between the intima and the media develop at the fibrous cap location with the smallest thickness. The predicted results indicate that plaque fissuring and dissection cause localized mechanical trauma, but prevent the main portion of the stenosis from high stress, and hence from continuous tissue damage.

Complications of Abdominal and Pelvic Procedures: Computed Tomographic Diagnosis

The postprocedural period is a critical time in which serious complications can manifest. Localization of suspected complications following abdominal and pelvic procedures can be difficult on clinical evaluation alone. For example, abdominal pain after a colonoscopy may vary in etiology and can result from simple colonic spasm to colonic perforation, hemoperitoneum, or even splenic rupture. Vague abdominal pain following a renal biopsy may be due to minimal postprocedural bleeding into and around the kidney or may be due to potentially life-threatening hemorrhage. In such patients, computed tomography can play a crucial role in the rapid identification of complications as well guidance of subsequent patient management. The purpose of this article is to demonstrate the benefit of computed tomography-assisted diagnosis of complications associated with routine procedures performed on or throughout the abdomen and pelvis, including cardiac catheterization, colonoscopy, endoscopy, percutaneous biopsy, and interventional radiology procedures.

Coronary Angioplasty

Percutaneous revascularization is a widely accepted procedure to treat patients with coronary artery disease. Since its first description in the 1970s, significant technological and pharmaceutical advances have occurred and subsequently reduced the complications associated with the procedure. Large, randomized controlled trials have provided additional evidence that percutaneous revascularization improves morbidity and mortality in patients with coronary artery disease. Over the last decade, devices designed to treat patients with more complex coronary artery disease have expanded the available therapeutic options and will likely contribute to a further decline in adverse events. Despite these advances, the management of patients with acute myocardial infarction, in-stent restenosis, and multivessel coronary artery disease remains challenging. The majority of evidence supports an early, aggressive approach in patients with acute ST-elevation and non-ST-elevation myocardial infarction. Ongoing clinical trials should help to further define the role of percutaneous interventions in the optimal management of patients with coronary artery disease.

Angiographic classification of coronary dissections after plain old balloon angioplasty for prediction of regression at follow-up

Coronary dissection after plain old balloon angioplasty often shows regression during follow-up. This study sought to determine whether we can predict such phenomenon angiographically. We analyzed 64 patients with 71 type B-D coronary dissections determined by the National, Heart, Lung, and Blood Institute (NHLBI) criteria. Regression was considered present when minimal lumen diameter increased by more than 0.3 mm during follow-up. Dissections were divided into subgroups using the NHLBI criteria and our classification in which type a and b dissections were characterized by the width of a dissection lumen exceeding one quarter of the reference diameter with the outer edge of the dissection lumen within the boundary of reference in type a and beyond it in type b. In type c and type d dissections, the width of the dissection lumen was within one quarter of the reference with its outer edge within the boundary of reference in type c and beyond it in type d. Type e dissection had a protruding flap or spiral appearance. Regression was recognized in 23.9%. The distribution of dissection types was similar in the groups with and without regression by the NHLBI criteria, but type c dissection had regression more frequently than the other types of coronary dissections (p<0.001) using our classification.

Triage of patients for short term observation after elective coronary angioplasty

OBJECTIVE

To evaluate triage of patients for short term observation after elective percutaneous transluminal coronary angioplasty (PTCA), as appropriate selection of patients for short term observation after angioplasty may facilitate early discharge.

METHODS

1015 consecutive patients scheduled for elective PTCA were prospectively included for short term observation. Patients with unstable angina Braunwald class III were excluded. There were no angiographic exclusion criteria. Patients were discharged from the interventional centre when considered stable during 4 hours of observation after PTCA. It was left to the operator's discretion whether to prolong the observation period. Procedural complications were defined as death, coronary bypass surgery, early repeat PTCA, and myocardial infarction.

OUTCOME MEASURES

The need for prolonged observation (> 4 hours) and the occurrence of complications. Predictors for prolonged observation and the occurrence of complications after the 4 hours observation were assessed by univariate and multivariate analysis.

RESULTS

Two patients died, including one of six patients who underwent emergency bypass surgery. In all, 922 patients (90.8%) were triaged to short term observation and had an uncomplicated three day follow up. Observation was prolonged in 87 patients (8.6%), and 40 patients had a complicated course. Independent predictors of procedural complications were acute closure (odds ratio (OR) 9.7; 95% confidence interval 4.4 to 21.4), side branch occlusion (OR 8.9; 3.4 to 23.7), no angiographic success (OR 5.1; 2.4 to 11.0), female sex (OR 3.1, 1.7 to 5.7), any unplanned stent (OR 2.8, 1.4 to 5.9), and ostial lesion (OR 2.2, 1.0 to 4.7).

CONCLUSIONS

A 4 hour observation period is safe after elective coronary angioplasty. As procedural variables are the strongest predictors of postprocedural complications, the immediate procedural results allow effective triage of patients for short term or prolonged observation in order to anticipate complications.

Favorable impact of stents after emergent coronary artery bypass for failed angioplasty

BACKGROUND

This study was undertaken to determine the impact of the use and availability of coronary stents on outcomes in patients requiring emergent coronary artery bypass graft (CABG) surgery following a failed percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Patients were divided into two groups based on the year of their CABG for a failed PTCA and the availability of stents: group 1, 1992 to 1994, stents not available (n = 34); and group 2, 1995 to 1997, stents available (n = 26).

RESULTS

CABG patients in the group where stents were not available were more likely to have had an abrupt coronary occlusion (26 of 34 versus 3 of 26; p < 0.0001) and less likely to have had a dissection (8 of 34 versus 23 of 26; p < 0.0001) as their indication for emergent CABG. Patients in the stent era had a lower incidence of perioperative myocardial infarction (5 of 26 versus 17 of 34; p < 0.01) and a decreased mortality rate (0 of 26 versus 6 of 34; p < 0.03). In the 9 patients where stents were employed, patency of the lumen was restored in 8 patients and there was only 1 myocardial infarction.

CONCLUSIONS

Stents have had a favorable impact on patients requiring an emergent CABG following a failed PTCA.

Results of coronary stenting after delayed angioplasty of the culprit vessel in patients with recent myocardial infarction

Little information is available concerning the effect of late coronary stenting in patients with recent myocardial infarction, especially long-term results. We retrospectively reviewed our results of 57 stent placements in 52 consecutive patients who received stents at an infarct-related lesion 24 hr to 30 days after an acute myocardial infarctions (median, 14 days). The average age was 67 years; 90% were male. Two patients who suffered from acute stent thrombosis received revascularization again and two early deaths were due to refractory cardiogenic shock before discharge. Mean patient clinical follow-up was 18.3 +/- 6.5 months. There were 1 subacute stent thrombosis, 1 cardiogenic death, and 10 patients (20.8%) in total suffering from angina class II to IV. Angiographic follow-up was performed in 36 patients (80%) at a mean of 7.5 +/- 3.1 months. Of these 36 patients, only 1 (3% of the total population undergoing follow-up angiography) had reocclusion at follow-up, but restenosis existed in 18 patients (50%). We conclude that there is still relatively high incidence of angiographic recurrence that is often silent in long-term follow-up, though the long-term result of late stenting in recent MI is low incidence of reocclusion.

Elective intracoronary Micro-Stent II implantation without quantitative coronary angiography or intravascular ultrasound guidance and without subsequent anticoagulation: short- and long-term results

Intracoronary stenting has been shown to reduce acute closure and restenosis rate in patients treated with coronary angioplasty. The use of high inflation pressures and intravascular ultrasound guidance allowed the substitution of anticoagulants with antiplatelet agents but increased the cost. The aim of this study was to investigate the effectiveness, safety, and long-term outcome of the elective implantation of a relatively new type of stent (Micro-Stent II), without the use of quantitative coronary angiography or intravascular ultrasound guidance and without subsequent anticoagulation. The study included 361 patients who underwent elective microstent implantation. Stent expansion was performed at 8 atm followed by higher inflation pressure at 14-20 atm. Heparin was given intraarterially only once immediately after the arterial sheath insertion. Ticlopidine was started at least 48 hours before the procedure and continued for 1 month while aspirin was continued indefinitely. All patients were followed up for 12.9 +/- 3.6 months. Short term outcome (first month): Stent implantation was successfully achieved in 361 of 366 patients (98.6%). Seven patients (1.9%) were excluded from the study and received anticoagulants because of a suboptimal result. In total, 423 stents were implanted. There was no subacute thrombosis, but acute vessel closure occurred in one patient (0.3%). Non-Q wave myocardial infarction occurred in six patients (1.7%), Q wave myocardial infarction occurred in one patient (0.3%), and only one death (0.3%) of nonischemic origin was reported. No major peripheral vascular complications were observed. Late results: Q or non-Q wave infarction occurred in 13 patients (3.6%), 26 patients (7.2%) underwent a repeat angioplasty, eight patients (2.2%) underwent coronary artery bypass grafting, and four patients (1.1%) died. Overall, 284 patients (78.7%) were free of symptoms, while 77 (21.3%) had recurrent coronary ischemia. In conclusion, Micro-Stent II implantation without quantitative coronary angiography or intravascular ultrasound guidance and without anticoagulation was found to be effective, safe, and with good long-term outcome.

Comparison of slow oscillating versus fast balloon inflation strategies for coronary angioplasty

Previous studies suggest that slow and/or oscillating balloon inflation during coronary angioplasty may decrease the incidence of coronary dissection and improve clinical outcomes. To compare the effect of slow oscillating versus conventional fast inflation techniques on the incidence of severe coronary dissection during angioplasty, 622 patients were randomized to slow oscillating inflation versus fast inflation. Angiographic outcomes of the procedures and in-hospital clinical events were recorded. The primary end point of severe (type C, D, E, F) dissection occurred in 7.7% of patients undergoing slow oscillation and 6.6% of patients undergoing fast inflation (p = 0.87). Major complications (death, urgent coronary artery bypass graft surgery, stroke, abrupt closure, or Q-wave myocardial infarction) occurred in 4.7% of patients undergoing slow oscillation and 3.5% of patients undergoing fast inflation (p = 0.45). The 2 inflation strategies did not differ in the pressure at which the balloon achieved full expansion, angiographic success rate, residual stenosis, and incidence of all minor and/or major complications. We conclude that there is no benefit of slow oscillating inflation over routine fast inflation in angioplasty. Slow oscillating inflation did not dilate lesions at lower pressures, decrease the incidence of dissection or severe dissection, or reduce the incidence of adverse clinical outcomes.

Comparison of immediate and in-hospital results of conventional balloon and perfusion balloon angioplasty using intracoronary ultrasound

Angiographic studies have demonstrated that perfusion balloon percutaneous transluminal coronary angioplasty (PTCA) may result in modestly improved luminal gains and fewer major dissections than conventional balloon PTCA. However, intracoronary ultrasound (ICUS), which is more sensitive than angiography in evaluating the incidence, extent, and severity of dissection, was not used. We randomized 48 patients with 54 coronary stenoses to conventional or perfusion balloon PTCA. Four 2-minute inflations were permitted with conventional balloon PTCA. Two 10-minute inflations were allowed with perfusion balloon PTCA. Quantitative coronary angiography and ICUS were performed before and after treatment. In-hospital clinical events were recorded. Conventional and perfusion balloon PTCA achieved similar improvements in lumen diameter (1.25+/-0.51 vs 1.28+/-0.51 mm) and reductions in percent stenosis (-45+/-21% vs -44+/-15%) by quantitative coronary angiography. Comparable gains in lumen diameter (0.62+/-0.39 vs 0.50+/-0.38 mm) and lumen area (2.70+/-1.96 vs 2.05+/-1.52 mm2) were observed on ICUS. Angiography demonstrated similar rates of any dissection (36% vs 21%) and major dissection (12% vs 7%). ICUS identified a similar incidence of any dissection (60% vs 76%) and type II dissection (52% vs 62%). The relative dissection area was also similar (9.2+/-5.6% vs 7.8+/-5.8%). One conventional balloon patient experienced postprocedural chest pain. No patient in either group died, or had myocardial infarction, abrupt closure, or urgent revascularization.

Long-term follow-up study of coronary reconstruction with multiple stents

BACKGROUND

Conventional balloon angioplasty of very long de novo coronary lesions or very long coronary dissection caused by angioplasty is associated with low success and high complication rates. Multiple intracoronary stents have been used to treat both conditions, although long-term efficacy has not been defined.

METHODS AND RESULTS

Between June 1993 and December 1995, 47 consecutive patients underwent native coronary angioplasty and stenting with 4 or more stents covering at least 2 consecutive diseased coronary segments. Preangioplasty and poststenting diameter stenoses were 81% +/- 13% and 21% +/- 12%, respectively. Reference vessel diameters were 3.53 +/- 0.55 mm proximal to the stents and 2. 95 +/- 0.62 mm distal to the stents. Average lesion length was 63 +/- 20 mm. The number of stents used was 4.5 +/- 1 per vessel (from 4 to 7). Gianturco Roubin I stents were used in all patients. Coronary Palmaz-Schatz stents were used as supplementary stents in 3 patients. Angiographic success was 100%. In-hospital outcomes include 1 death, 1 coronary bypass surgery, no Q-wave myocardial infarction, and 7 non-Q-wave myocardial infarctions. Long-term follow-up at 430 +/- 199 days was completed in all patients. Thirty-five (76%) patients were asymptomatic, 8 (17%) had class 1 or 2 angina, 1 had a myocardial infarction, 13 (28%) underwent repeat angioplasty, 2 patients had subsequent elective bypass surgery, and 3 died during follow-up.

CONCLUSIONS

Multiple intracoronary stents for very long lesions or dissection can be performed with acceptable immediate and long-term outcomes.

Predictive factors of restenosis after coronary stent placement

OBJECTIVES

The objective of this study was to identify clinical, lesional and procedural factors that can predict restenosis after coronary stent placement.

BACKGROUND

Coronary stent placement reduces the restenosis rate compared with that after percutaneous transluminal coronary angioplasty (PTCA). However, restenosis remains an unresolved issue, and identification of its predictive factors may allow further insight into the underlying process.

METHODS

All patients with successful coronary stent placement were eligible for this study unless they had had a major adverse cardiac event during the 1st 30 days after the procedure. Of the 1,349 eligible patients (1,753 lesions), follow-up angiography at 6 months was performed in 80.4% (1,084 patients, 1,399 lesions). Demographic, clinical, lesional and procedural data were prospectively recorded and analyzed for any predictive power for the occurrence of late restenosis after stenting. Restenosis was evaluated by using three outcomes at follow-up: binary restenosis as a diameter stenosis > or =50%, late lumen loss as lumen diameter reduction and target lesion revascularization (TLR) as any repeat PTCA or coronary artery bypass surgery involving the stented lesion.

RESULTS

Multivariate analysis demonstrated that diabetes mellitus, placement of multiple stents and minimal lumen diameter (MLD) immediately after stenting were the strongest predictors of restenosis. Diabetes increased the risk of binary restenosis with an odds ratio (OR) [95% confidence interval] of 1.86 [1.56 to 2.16] and the risk of TLR with an OR of 1.45 [1.11 to 1.80]. Multiple stents increased the risk of binary restenosis with an OR of 1.81 [1.55 to 2.06] and that of TLR with an OR of 1.94 [1.66 to 2.22]. An MLD <3 mm at the end of the procedure augmented the risk of binary restenosis with an OR of 1.81 [1.55 to 2.06] and that of TLR with an OR of 2.05 [1.77 to 2.34]. Classification and regression tree analysis demonstrated that the incidence of restenosis may be as low as 16% for a lesion without any of these risk factors and as high as 59% for a lesion with a combination of these risk factors.

CONCLUSIONS

Diabetes, multiple stents and smaller final MLD are strong predictors of restenosis after coronary stent placement. Achieving an optimal result with a minimal number of stents during the procedure may significantly reduce this risk even in patients with adverse clinical characteristics such as diabetes.

Pharmacologic prevention of acute ischemic complications of coronary angioplasty

The risk of acute coronary occlusion following percutaneous transluminal coronary angioplasty (PTCA) has remained high despite the traditional use of heparin and aspirin. Interest has focused on newer strategies for preventing intracoronary thrombus formation, which is an important mechanism of abrupt vessel closure. Pretreatment with thrombolytic agents has failed vigorous testing in double-blind trials. Retrospective and observational studies have indicated that pretreatment with intravenous heparin is of benefit in patients with unstable symptoms, but prolonged infusion after angioplasty increases bleeding complications without improving outcomes. Subcutaneous heparin may be safer, but has not proved more effective. Oral dipyridamole has shown no advantage over aspirin, although there is evidence to suggest a benefit when given intravenously. Direct thrombin inhibitors (such as hirudin and hirulog) are associated with fewer early complications compared with heparin, but have yielded no apparent long-term benefit. The use of the antiplatelet drug ticlopidine is increasing, although long-term data are lacking. A great deal of recent interest has focused on newer antiplatelet agents, particularly the glycoprotein IIB/IIIa receptor inhibitor c7E3 Fab. In a large-scale trial, c7E3 significantly reduced the 30-day rate of mortality and cardiac events, and these benefits were maintained at 6 mo. This drug, unlike other antiplatelet agents, inhibits the final common pathway of platelet aggregation, which influences not only acute closure but has lasting effects for at least 6 mo. This may reflect a reduction in restenosis, although this remains to be proven. This article gives a brief overview of the pharmacologic agents available for the prophylaxis and treatment of acute ischemic complications of PTCA.

A hypothesis regarding vascular acoustic emission accompanying arterial injury induced by balloon angioplasty

Stress-induced structural damage is often accompanied by sound release. This behavior is known as acoustic emission (AE). We hypothesize that vascular injury such as that produced by balloon angioplasty is associated with AE. Postmortem human peripheral arterial specimens were randomly partitioned into test (n = 10) and control segments (n = 10). Test segments were inserted into a pressurization circuit and subjected to two consecutive hydrostatic pressurizations. Amplitude, frequency, and energy content of the AE signals released during pressurization were quantified. Test and matched control segments subsequently underwent identical histological processing. Pressure-induced tissue trauma was estimated via computerized histomorphometric analysis of the resulting slides (n = 100). Vascular acoustic emission (VAE) signals exhibited an amplitude range of +/- 5.0 mu bars and were observed to occur during periods of increasing intraluminal pressure. The VAE signal power within the monitored bandwidth was concentrated below 350 Hz. More than 25 times as much VAE energy was released during the first pressurization as during the second: 1,855 +/- 513.8 mJ vs. 73 +/- 44.9 mJ (mean +/- SEM, p < 0.006). Estimates of circumferential intimal wall stress at AE onset averaged 170 kPa, slightly below reported values of arterial tissue rupture strength. Histomorphometric estimates of tissue trauma was greater for the test than their matched control segments (p < 0.0001). These preliminary data suggest that detectable acoustic energy is released by vascular tissue subjected to therapeutic stress levels. Histological analysis suggest that the underlying source of sound energy may be related to tissue trauma, independent of histological preparation artifacts. From this preliminary work, we conclude that VAE may be a fundamental property accompanying vascular tissue trauma, which may have applications to improving balloon angioplasty outcomes.

One-week and six-month angiographic controls of stent implantation after occlusive and nonocclusive dissection during primary balloon angioplasty for acute myocardial infarction

We prospectively assessed in 124 consecutive patients by means of 1-week and 6-month follow-up angiograms the rate of reocclusion and restenosis of coronary stenting with Palmaz-Schatz stents after occlusive and nonocclusive dissection during primary balloon angioplasty for acute myocardial infarction (AMI). Patients were further evaluated clinically at 1 year. Stenting was performed on large (>3.2 mm) coronary arteries for suboptimal results (47%), occlusive (8%), or nonocclusive dissections (45%) after balloon angioplasty. Stents were delivered using the bare stent technique and high pressure inflations (>12 atm). All patients received ticlopidine 250 mg (500 mg if weight was >80 kg) and aspirin 100 mg for 1 month. No patient received warfarin. At 1 week, 6 patients died of cardiogenic shock and 2 of right ventricular infarction. One subacute occlusion occurred at day 14. At 6 months, in 95 patients, the angiographic restenosis rate (>50% diameter stenosis) was 19%. One-year clinical follow-up, available in 55 patients, indicated cardiac death in 5, and repeat revascularization in 3. Thus, coronary stenting on large (>3.2 mm) coronary arteries after occlusive and nonocclusive dissection during primary balloon angioplasty for AMI using bare Palmaz-Schatz stents, high pressures, ticlopidine, and aspirin is safe. Our reocclusion and restenosis rates are similar to those of trials on elective stenting in stable patients.

Angioscopy variables predictive of early angiographic outcome after excimer laser-assisted coronary angioplasty

This study attempted to determine whether anatomic findings at angioscopy were associated with adverse early angiographic outcomes following excimer laser-assisted coronary angioplasty. Predictive factors of either coronary abrupt vessel closure or early (< or =24 hours) restenosis after percutaneous coronary angioplasty, including clinical and angiographic variables, have been widely evaluated. The role of angioscopic findings may contribute to identification of patients at risk for early poor outcome. Thirty-seven patients with severe lesions, including 23 total occlusions which underwent successful percutaneous transluminal coronary angioplasty (PTCA) with laser irradiation and adjunctive balloon dilatation (n = 35), or stand alone laser (n = 2), had concomitant angioscopic imaging of the target vessel. All patients had a 24-hour angiographic follow up. Early unfavorable outcome (n = 15) was defined as abrupt vessel closure or restenosis (> or = 50% stenosis) at 24 hours. By multivariate logistic regression analysis, immediate post-PTCA residual percent stenosis was associated with a poor outcome (restenosis: 33 +/- 22% vs no restenosis: 21 +/- 14%, p = 0.05). Angioscopic red thrombus aspect was the most significant correlate for early closure or restenosis (7 of 15 patients with unfavorable outcome vs 2 of 22 patients with favorable outcome, odds ratio, 22.9; p < 0.01) and was associated with a significantly higher early minimal lumen diameter loss (1 +/- 0.8 mm in the presence of a red thrombus vs 0.3 +/- 0.5 mm without thrombus, p < 0.005). Red thrombus appearance is associated with an unfavorable early angiographic outcome in patients who undergo laser-assisted coronary angioplasty.

Coronary stent placement in patients with acute myocardial infarction: comparison of clinical and angiographic outcome after randomization to antiplatelet or anticoagulant therapy

OBJECTIVES

The Intracoronary Stenting and Antithrombotic Regimen (ISAR) trial is a randomized comparison of combined antiplatelet with anticoagulant therapy after coronary Palmaz-Schatz stent placement. The objective of this study was to compare early and late clinical and angiographic outcome in a subgroup of patients with stent placement for acute myocardial infarction.

BACKGROUND

Stenting has become a treatment option for acute myocardial infarction, but it is not known which antithrombotic regimen is more adequate after stent implantation.

METHODS

One hundred twenty-three patients with successful stenting after acute myocardial infarction were randomized to receive aspirin plus ticlopidine (n = 61) or intense anticoagulant therapy (n = 62). Six-month repeat angiography was performed in 101 (86.3%) eligible patients.

RESULTS

During the first 30 days after stenting, patients with antiplatelet therapy had a significantly lower clinical event rate (3.3% vs. 21.0%, p = 0.005) and stent vessel occlusion rate (0% vs. 9.7%, p = 0.03) and a trend to fewer cardiac events (1.6% vs. 9.7%, p = 0.12). After 6 months, the survival rate free of recurrent myocardial infarction was higher in patients with antiplatelet therapy (100% vs. 90.3%, p = 0.03), and the rate of stent vessel occlusion was lower (1.6% vs. 14.5%, p = 0.02). Both groups had comparable restenosis rates (26.5% vs. 26.9%, p = 0.87).

CONCLUSIONS

This study demonstrates that combined antiplatelet therapy after stent placement in patients with acute myocardial infarction is associated with an overall better clinical and angiographic outcome than anticoagulant therapy.

Short- and long-term clinical effects of primary directional coronary atherectomy for acute myocardial infarction

We performed primary directional coronary atherectomy (DCA) without antecedent thrombolytic therapy in 21 of 67 patients with acute myocardial infarction within 24 hr of onset between June 1993-March 1994. Reperfusion with primary DCA was successful in 18 patients (85.7%, group D). Results were compared with those of primary balloon angioplasty patients treated between June 1992-May 1993 (group P). Minimum lumen diameter (MLD) values both immediately after reperfusion and in predischarge angiograms were significantly larger in group D than in group P, but were similar in late follow-up angiograms. Although a larger MLD in group D than in group P contributed to the prevention of reocclusion of the coronary artery before discharge in DCA patients, a high rate of restenosis at late follow-up canceled the beneficial effects of primary DCA.

Primary stent implantation without coumadin in acute myocardial infarction

OBJECTIVES

We tested the feasibility and efficacy of primary stent implantation without Coumadin in 74 patients within 8 h of the onset of acute myocardial infarction.

BACKGROUND

Although stent implantation in patients with effort angina provides better short- and long-term outcomes than balloon angioplasty, it is not clear whether primary stent implantation is applicable or effective in acute myocardial infarction.

METHODS

Primary sent implantation was attempted when 1) the lesion was not located distally in the main coronary branches, 2) the coronary artery did not show any severe calcification or excessive bending proximal to the lesion on fluoroscopy, and 3) the arterial diameter was > or = 2.5 mm. The results (group S) were compared with those of primary balloon angioplasty (group P). Poststenting regimens contained ticlopidine and aspirin without Coumadin. Poststenting inflation was performed with > or = 12 atm.

RESULTS

Stent implantation was successful in 72 patients. Stent thrombosis was noted in only one patient who was not given ticlopidine, aspirin or Coumadin. The rates of restenosis and frequency of major clinical events during the hospital period in groups S and P were 0% versus 13.2% (p = 0.007) and 2.8% versus 18.6% (p = 0.009), respectively. Kaplan-Meier analysis demonstrated that cumulative 90-day clinical event-free rates in groups P and S were 98.1 +/- 16.0% versus 79.4 +/- 43.7% (p = 0.0068), and that 180-day rates were 86.5 +/- 38.4% versus 64.2 +/- 49.7% (p = 0.014).

CONCLUSIONS

Primary stent implantation can improve clinical outcomes of patients with acute myocardial infarction when the stent is dilated adequately and antiplatelet drugs are used.

Elective implantation of intracoronary stents without intravascular ultrasound guidance or subsequent warfarin

Two hundred forty-three stents (203 Palmaz-Schatz, 40 Glanturco-Roubin) were electively Implanted in 188 lesions in 168 patients (mean age 58 +/- 10 years, 77% males) using angiographic but not ultrasound guidance. Patients were treated subsequently with aspirin and observed in hospital for up to 7 days. Those with acute myocardial infarction, radiolucent defects in coronary arteries suggestive of thrombus, and results that were not optimal after stent implantation were anticoagulated with warfarin and not Included in the study. Two had subacute stent thrombosis and two patients non-Q-wave myocardial infarction in-hospital. At follow-up (median 149 days) none had had subacute stent thrombosis, one suffered non-Q-wave myocardial infarction, none had died, and none had developed major complications at the vascular access site. Fourteen (8%) had undergone further revascularisation procedures. This initial experience suggests that aspirin is sufficient to prevent subacute stent thrombosis after elective high pressure assisted coronary stent implantation without intravascular ultrasound guidance if the angiographic appearance after stent deployment is optimal.

Angiographic and procedural outcome after coronary angioplasty in high-risk subsets using a decremental diameter (tapered) balloon catheter. Tapered Balloon Registry Investigators

The angiographic and clinical outcomes of 115 patients (129 lesions) treated at 11 clinical centers using a decremental diameter (tapered) balloon catheter were evaluated. The presence of marked tapering of the reference vessel, lesion location involving a bifurcation or anastomosis of a saphenous vein graft, or total coronary occlusion where estimation of the distal vessel size was difficult were indications for this device. The tapered balloon was used as the initial dilatation device in 62 patients (73 narrowings), and as a secondary device in 53 patients (56 narrowings). Lesions selected for tapered balloon angioplasty were generally complex (95% had > or = 1 and 60% had > or = 2 adverse morphologic features). Vessel diameters were larger in the proximal reference segments (3.07 +/- 0.52 mm) than in distal ones (2.48 +/- 0.45 mm) (p<0.001). After tapered balloon angioplasty, the minimal lumen diameter increased from 0.85 +/- 0.34 mm to 2.13 +/- 0.50 mm (p<0.001), and the percent diameter stenosis decreased from 69 +/- 12% to 24 +/- 12% (p<0.001). Coronary dissections occurred in 20% of lesions; they were severe in 4% (National Heart, Lung, and Blood Institute grade C to F). Abrupt closure occurred in 4.3% of patients (2.6% immediate; 1.7% delayed). Procedural success was obtained in 110 patients (96%); major complications (in-hospital death, myocardial infarction, or emergency coronary bypass surgery) occurred in 3 patients (2.7%). Coronary angioplasty using the tapered balloon catheter appears to be a safe and effective technique for the treatment of complex lesion subsets, particularly those involving coronary arteries with marked segmental tapering.

Oscillating balloon angioplasty: does pressure oscillation reach the balloon?

Oscillating pressure inflations may minimize trauma to the coronary artery during coronary angioplasty. We measured in vitro diameters of polyolepin copolymer compliant angioplasty balloons (as a surrogate for pressure) during pressure oscillation at the inflator to determine if pressure oscillations at the inflator were conducted to the balloon. Balloon diameter oscillation increased as cycle length and inflator pressure amplitude increased. Currently practiced oscillating inflation (cycle length 2-3 sec, amplitude 2-3 atm) did not effectively transmit oscillation to the balloon. Clinically feasible optimal balloon oscillation was achieved at a cycle length of 6 sec and pressure amplitude of about 3 atm.

Abrupt closure: the CAVEAT I experience. Coronary Angioplasty Versus Excisional Atherectomy Trial

OBJECTIVES

This study sought to assess the incidence and consequences of abrupt closure in a series of patients undergoing directional coronary atherectomy versus percutaneous coronary angioplasty.

BACKGROUND

Abrupt closure with coronary angioplasty has been associated with adverse outcome. The results from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) I, a randomized trial of coronary angioplasty versus directional coronary atherectomy, were analyzed.

METHOD

This multicenter trial enrolled 1,012 patients from 1991 to 1992. All records from patients with abrupt closure, which was coded as a discrete complication, were reviewed.

RESULTS

Abrupt closure occurred in 60 patients (5.9%) and was associated with a significantly longer hospital stay (median 8 vs. 3 days). Severe proximal target vessel tortuosity was more common in patients with abrupt closure (20.3% vs. 11.6%, p = 0.046), as was preexistent coronary artery thrombus (30.5% vs. 18.3%, p = 0.02). Abrupt closure was associated with a marked increase in subsequent complications (myocardial infarction 46.7% vs. 2.1%, emergency bypass surgery 38.3% vs. 0.32%, death 33% vs. 0%) and occurred more frequently in the directional coronary atherectomy group (8.0% vs. 3.8%, p = 0.005). In the coronary angioplasty group, the occlusion usually occurred at the target lesion (91%), presumably related to the effects of barotrauma. In the directional coronary atherectomy group, the site of the occlusion was the target lesion in only 58% (p = 0.045). The remaining occlusions related to problems with the technique (guide catheter or nose cone trauma), reflecting the fact that directional coronary atherectomy is a more complex procedure.

CONCLUSIONS

Abrupt closure remains the principal determinant of adverse outcome after percutaneous procedures for the treatment of coronary artery disease. Although abrupt closure is more common with directional atherectomy than angioplasty, the sequelae are similar.

Initial experience with an intracoronary flow support device providing localized drug infusion: the Scimed Dispatch catheter

Two cases are presented illustrating the use of a new intracoronary infusion catheter providing flow support using a unique spiral coil design. Good clinical outcomes were obtained employing 4-hr inflations with localized infusion of urokinase at the site of dissection and extensive clot formation, respectively. This low-profile catheter-mounted device may provide an alternative to stent placement in cases of acute dissection complicated by thrombus formation.

Effects of balloon compliance on angiographic and clinical outcomes after PTCA

Eighty patients underwent percutaneous transluminal coronary angioplasty (PTCA) for 109 lesions. Comparison was done between two groups based on balloon compliance. The groups were comparable in their baseline characteristics. The mean inflation pressure used with compliant balloons was significantly higher; other procedural variables were not different. The occurrence rates of intimal tears and coronary dissections were not significantly different. The rates of side branch occlusions, myocardial infarction, redo PTCA or coronary stenting and death were low and similar, and likewise unaffected by balloon material. We conclude that the occurrence of adverse outcomes after PTCA is unrelated to balloon material compliance.

Bailout coronary stenting with 6F guiding catheters for failed balloon angioplasty

Between July 1992 and February 1994, we attempted bailout Palmaz-Schatz stent implantation through a 6F guiding catheter after 52 failed coronary balloon angioplasty procedures to reverse (14 [27%] cases) or prevent (38 [73%] cases) abrupt vessel closure. The stents or half-stents were manually crimped onto a monorail balloon catheter for delivery. Thirty-nine (75%) procedures involved a single stent, and 13 (25%) involved two or three stents. Technical success was achieved in 50 (96%) procedures, and clinical success without major complications was obtained in 45 (87%) cases. Target vessel occlusion was documented angiographically or suggested clinically in 2 (4%) cases. Two (4%) patients underwent semielective bypass surgery, and in 4 (8%) patients a non-Q-wave and in 1 (2%) a Q-wave myocardial infarction developed. There were no deaths. Major bleeding occurred in 2 patients: 1 had an important groin hematoma that was treated with local surgery followed by coronary bypass surgery, and one had macroscopic hematuria that required interruption of anticoagulation therapy on day 4. Three (6%) femoral pseudoaneurysms were diagnosed by ultrasound and could be obliterated by external compression alone. Bailout coronary stent implantation through 6F guiding catheters after failed balloon angioplasty is technically reliable, safe, and cost-efficient. As a consequence, use of 6F guiding catheters is a good option for a large majority of routine balloon angioplasty procedures.

Clinical and lesion morphologic determinants of coronary angioplasty success and complications: current experience

OBJECTIVES

This study evaluated the validity of the American College of Cardiology/American Heart Association ABC lesion classification scheme and its modifications.

BACKGROUND

With the continued refinement in angioplasty technique and equipment evolution, the lesion morphologic determinants of immediate angioplasty outcome have changed significantly. Hence, the validity of the classification scheme has been questioned.

METHODS

We assessed the lesion morphologic determinants of immediate angioplasty outcome in 729 consecutive patients who underwent coronary angioplasty of 994 vessels and 1,248 lesions.

RESULTS

Angioplasty success was achieved in 91% of lesions, and abrupt closure occurred in 3%. Success was achieved in 96%, 93% and 80% of type A, B and C lesions, respectively (A vs. B, p = NS; B vs. C, p < 0.001; A vs. C, p < 0.001; A vs. B1, p = NS; A vs. B2, p = 0.03; B1 vs. B2, p = 0.02; B2 vs. C, p < 0.001; C1 vs. C2, p = NS). Abrupt closure occurred in 2.1%, 2.6% and 5% of type A, B and C lesions, respectively (A vs. B, B vs. C, A vs. C and A vs. B1, all p = NS; B1 vs. B2, p = 0.01; B2 vs. C1, p = NS; C1 vs. C2, p = 0.04). Type B characteristics had a success rate ranging from 74% to 95% and an abrupt closure rate ranging from 2.2% to 14%. Type C characteristics had a success rate ranging from 57% to 88% and an abrupt closure rate ranging from 0% to 16%. Longer lesions, calcified lesions, diameter stenosis of 80% to 99% and presence of thrombus were predictive of a lower success rate. Longer lesions, angulated lesions, diameter stenosis of 80% to 99% and calcified lesions were predictive of an abrupt closure.

CONCLUSIONS

The previously proposed classification schemes are outdated and need to be changed for application in current angioplasty practice. Analyzing specific lesion morphologic characteristics rather than applying a simple lesion classification score when evaluating angioplasty outcome may be more useful because it provides a more precise profile of the lesion and allows better patient stratification and selection.

Coronary dissection resulting from angioplasty with slow oscillating vs. rapid inflation and slow vs. rapid deflation

To determine if slow inflation or slow deflation (compared to standard rapid inflation/deflation) would minimize coronary arterial dissection, we randomized 162 lesions from 136 patients undergoing coronary angioplasty with polyolefin copolymer balloons to slow oscillating (1 atmosphere/20 sec) vs. rapid (over 30 sec) inflation and slow (over 15 sec) vs. rapid deflation. The incidence of any dissection was nearly identical in the four inflation/deflation groups. The incidence of severe dissection, however, was significantly higher for the slow inflation/slow deflation group compared to the other three groups (38% vs. 15%, P = .024). For angioplasty performed with polyolefin copolymer balloons, slow deflation combined with slow oscillating inflation is associated with more frequent severe dissections.

Intracoronary stenting in the treatment of acute or threatened closure in angiographically small coronary arteries (< 3.0 mm) complicating percutaneous transluminal coronary angioplasty

The effect of the Flex-Stent on immediate and long-term angiographic and clinical results for acute and threatened closure was evaluated in 42 consecutive patients with coronary arterial segments < 3.0 mm in diameter after percutaneous transluminal coronary angioplasty (PTCA). Forty-two consecutive patients were treated with Flex-Stent (2.0 or 2.5 mm) for acute or threatened closure complicating PTCA. Ten patients (24%) had acute closure and 32 (76%) had threatened closure with a residual luminal stenosis of > 50%. Successful stent deployment was achieved in 40 patients (95%) with a primary clinical success rate of 90% (freedom from myocardial infarction, coronary artery surgery, and death). In-hospital complications occurred in 5 patients (some patients fell into more than one category): 3 (7.1%) had coronary bypass surgery, 1 (2.4%) had acute stent thrombosis, 1 (2.4%) had subacute stent thrombosis, 2 (4.8%) had myocardial infarction, and 1 (2.4%) had dextran allergy. There was no hospital death. Clinical follow-up was complete at a mean of 14.8 +/- 7.6 months, and recurrence of angina was noted in 20 of 38 eligible patients (53%). Angiographic restenosis was found in 19 of 29 patients (66%) (76.3% of eligible patients) on follow-up angiography (mean 5.9 +/- 4.6 months). Fourteen patients (74%) underwent successful repeat PTCA at the stented site, 4 of 38 patients (11%) had bypass surgery. Intracoronary stenting in the treatment of acute or threatened closure in arteries < 3.0 mm is effective in improving the acute clinical outcome and is a viable nonsurgical alternative for this subset of patients.

Development of a new technique for reducing pressure pulse generation during 308-nm excimer laser coronary angioplasty

Despite expectations that excimer laser ablation would result in a low incidence of coronary dissection, studies have documented a 15-20% incidence of dissection (including a 4-6% incidence of clinically significant dissection) during excimer interventions. This investigation sought to determine if pressure pulses produced by the exposure of fluid phase media (blood and contrast) to 308-nm excimer radiation might contribute to untoward outcomes. Pressure pulses generated in these media were quantitated to be > 100 atm. In vitro ablation of porcine aorta in the presence of blood or contrast resulted in tissue dissection, while ablation in pure crystalloid did not. Next, a "flush and bathe" technique designed to replace all blood and contrast with crystalloid was applied to a pilot population of 57 consecutive patients. There were no rhythm disturbances or laser-related clinically significant dissections in this group, and the clinical success rate was 95%. In summary, this report quantitates a potential etiology for excimer dissection and suggests that replacement of blood and contrast with crystalloid might improve procedural and clinical success rates.

Discrimination of intravascular lumen and dissections in single intravascular ultrasound images using subtraction, conventional averaging and saline flush

With current 30-MHz intravascular ultrasound systems, flowing blood may cause considerable backscatter which in real-time images is characterized by dynamic speckle. However, in a single intravascular ultrasound image (still-frame) the discrimination between arterial lumen and wall may be difficult due to the frozen intraluminal speckle, particularly in the presence of dissections. We compared subtraction, averaging and saline flush as methods to improve the discrimination between arterial lumen and wall in a single image. The real-time images served as gold standard. In 22 patients who underwent peripheral balloon angioplasty, ultrasound images obtained from 84 sites were examined. The sensitivity and specificity of detecting dissections were in the subtraction image 85% and 100%, in the averaged image 57% and 96%, and in the saline flush image 58% and 86%, respectively. Subtraction is a promising method to outline the irregular lumen in a single image.

The impact of balloon material and lesion characteristics on the incidence of angiographic and clinical complications of coronary angioplasty

To assess the importance of balloon material used for percutaneous transluminal coronary angioplasty (PTCA), we compared the complication rates observed with low complaint plastomer (PM 300), intermediately compliant polyethylene (PE 600), and highly compliant polyolefin copolymer (POC) balloons. In a total of 1,650 procedures, one of these balloon materials was used to dilate 2,040 lesions. The dissection rate tended to be slightly lower with the use of more compliant balloon material. The total clinical complication rate (death, emergency coronary surgery, myocardial infarction, need for bail-out stenting or for prolonged heparin treatment, abrupt out-of-laboratory vessel closure) was 8.1%, 7.4%, and 4.2% in the procedures exclusively performed with PM 300 (N = 653), PE 600 (N = 543) and POC (N = 454) balloons, respectively (P = 0.03). In multivariate analysis, the use of less compliant balloon material emerged as an independent correlate of clinical complications (P = 0.007). However, the predictive power of the lesion complexity (B2, C versus A, B1) was four times stronger. In contrast to current concerns, the use of compliant balloon material seems at least as safe as the use of less compliant material.