Laser balloon angioplasty: clinical, angiographic and histologic results.

Laser balloon angioplasty combines conventional coronary angioplasty with laser energy to transiently heat vascular tissue. Laser balloon angioplasty, was performed in 21 patients (aged 56 +/- 13 years), including 10 patients treated urgently after acute failure of conventional angioplasty and 11 patients treated with elective laser balloon angioplasty. Immediately after conventional angioplasty, laser doses (1 to 10 doses of 205 to 380 J each) were delivered during inflation of the laser balloon to a pressure of 4 atm. Seven (70%) of 10 patients with acute failure of conventional angioplasty were successfully treated with laser balloon angioplasty, but 3 (30%) were unsuccessfully treated with the laser procedure and required emergency coronary artery bypass surgery. In all three failures, the 3 mm laser balloon angioplasty catheter was not the optimal size for the vessel. In the 11 patients treated with elective laser balloon angioplasty (reference diameter 2.94 +/- 0.22 mm), the minimal luminal diameter increased from 0.45 +/- 0.25 to 1.85 +/- 0.46 mm after conventional angioplasty and to 2.44 +/- 0.29 mm after laser balloon angioplasty (p less than 0.001). This corresponded to a decrease in diameter stenosis from 84 +/- 9% before to 35 +/- 16% after conventional angioplasty and to 15 +/- 10% after laser balloon angioplasty (p less than 0.001). There were no instances of myocardial infarction, emergency coronary artery bypass surgery or death and no acute complications related to delivery of laser energy in this group. Follow-up coronary angiography was performed 5.5 +/- 1.1 months after laser balloon angioplasty in 18 patients discharged from the hospital after a successful procedure. Ten patients (56%) had angiographic restenosis, defined as recurrent diameter stenosis greater than 50%. Six patients were subsequently treated by directional coronary atherectomy, which revealed intimal proliferation indistinguishable from that in patients with restenosis after conventional angioplasty. In conclusion, laser balloon angioplasty may be effective in sealing severe coronary dissections and reversing abrupt closure associated with failed conventional angioplasty. After uncomplicated conventional angioplasty, laser balloon angioplasty improves immediate luminal dimensions, but restenosis appears to be mediated by intimal hyperplasia, similar to that seen after conventional angioplasty.

Angiographic and clinical outcome of intracoronary stenting: immediate and long-term results from a large single-center experience.

OBJECTIVES: The purpose of this study was to determine the immediate and long-term angiographic and clinical results of coronary stenting. BACKGROUND: Although preliminary trials of endovascular stenting have demonstrated promising results, lack of long-term follow-up has limited the critical evaluation of the role of coronary stenting in the treatment of obstructive coronary artery disease. METHODS: A total of 250 procedures using the Palmaz-Schatz stent, performed in 220 patients between June 1988 and July 1991, were examined. Minimal lumen diameter of the treated segments was measured on angiograms obtained before, after and 6 months after intervention. RESULTS: Stent placement was successful in 246 (98%) of 250 lesions, reducing diameter stenosis from 77% to -2.5%. There were no deaths or Q wave myocardial infarctions. One patient (0.4%) required emergency bypass surgery and one (0.4%) developed subacute thrombosis. Femoral vascular complications occurred in 36 patients (16%). Six-month angiographic follow-up was obtained in 91% of eligible patients. The overall angiographic restenosis rate (stenosis greater than or equal to 50%) was 25%. By univariable analysis, the rate of restenosis was significantly higher for stents in the left anterior descending versus the right coronary artery (44% vs. 12%; p = 0.002); in diabetic patients (56% vs. 20%; p = 0.006), and in vessels with post-stent lumen diameter less than 3.31 mm (34% vs. 16%; p = 0.05). Stenting of the left anterior descending artery was the strongest predictor (p = 0.01) of restenosis in a multivariable model. Total survival was 97% and event-free survival (freedom from death, myocardial infarction or revascularization) was 70% at 36 months. CONCLUSIONS: Palmaz-Schatz stents can be placed successfully with a low incidence of major complications. The angiographic restenosis rate was 25%, and 70% of patients remained free of cardiovascular events at 3 years. Diabetes, small postprocedure lumen diameter and stenting of the left anterior descending artery are associated with higher rates of restenosis.

Markers of hemostatic activation in affected coronary arteries during angioplasty.

To characterize the extent of early activation of the hemostatic system following angioplasty, we obtained blood samples from the involved coronary artery of 11 stable angina patients during the procedure and measured sensitive markers of thrombin formation (fibrinopeptide A, prothrombin fragment 1.2, and soluble fibrin) and of platelet activation (beta-thromboglobulin). Levels of hemostatic markers in venous blood obtained from 14 young individuals with low pretest probability for coronary artery disease were not significantly different from levels in venous blood or intracoronary samples obtained prior to angioplasty. Also, there was no translesional (proximal and distal to the lesion) gradient in any of the hemostatic markers before or after angioplasty in samples obtained between 18 and 21 min from the onset of the first balloon inflation. Furthermore, no significant difference was noted between angioplasty and postangioplasty intracoronary concentrations. We conclude that intracoronary hemostatic activation does not occur in the majority of patients during and immediately following coronary angioplasty when high doses of heparin and aspirin are administered.

Acute and long-term outcome of narrowed saphenous venous grafts treated by endoluminal stenting and directional atherectomy.

Angioplasty of the narrowed saphenous vein bypass grafts remains a difficult challenge. Over a 37-month period at this institution, 119 of 176 interventions (68%) on saphenous vein grafts (average age 8.3 years from bypass surgery to graft intervention) were performed using either directional coronary atherectomy (n = 35) or Palmaz-Schatz intracoronary stents (n = 84), representing 37% of all stents and 15% of all atherectomies during the study period, respectively. Of the 57 saphenous vein graft lesions treated with conventional balloon angioplasty during this period, 49 (86%) had 1 or more contraindications to stenting or directional atherectomy (thrombus, total occlusion, reference vessel less than 3 mm in diameter). The acute success rate was 99% for stents (1 failure to dilate) and 94% for directional atherectomy (2 failures to cross the lesion with the atherectomy device). Lumen diameter increased from 0.9 to 3.6 mm (reference vessel 3.6) for stents, and from 0.9 to 3.5 mm (reference 3.8) for atherectomy (for all comparisons, p = not significant), with no major complications (abrupt or subabrupt closure, emergent coronary bypass surgery, death, or Q-wave myocardial infarctions). During the same time period 50 of 57 vein grafts (88%) rejected for stenting or atherectomy were dilated successfully by conventional balloon angioplasty, with 3 patients (5%) requiring emergent coronary bypass surgery. Angiographic follow-up was available for 50 of 64 eligible patients (78%).(ABSTRACT TRUNCATED AT 250 WORDS)

Frequency and outcome of chest pain after two new coronary interventions (atherectomy and stenting).

Between June 1988 and July 1991, 464 new device interventions (Palmaz-Schatz stent or Simpson directional atherectomy) were performed in 410 patients. Chest pain occurred within 72 hours after the procedure in 94 patients (23%). All patients were evaluated with electrocardiograms and cardiac isoenzymes on the day after the procedure, and urgent repeat coronary angiography was performed in 29 chest pain patients (31%). Whereas all 14 patients with abnormal findings on repeat angiography had electrocardiographic changes, 6 of the 20 restudied patients (30%) with electrocardiographic changes had no angiographic explanation for chest pain. Non-Q-wave myocardial infarction occurred in 22 patients (5%) (10 of 35 [29%] with chest pain and electrocardiographic changes, 3 of 44 [7%] with chest pain and no electrocardiographic change, and 9 of 316 [3%] without chest pain). Factors associated with chest pain after new device intervention included a decreased residual percent stenosis (p = 0.05), incomplete revascularization (p = 0.005) and the presence of multivessel disease (p = 0.001). Vessel dissection after stenting but not atherectomy was associated with postprocedure chest pain. Chest pain is common (23%) after new device intervention. Electrocardiographic changes are a sensitive marker of angiographic abnormality and confer a higher risk of non-Q-wave myocardial infarction, but no increase of in-hospital mortality. Determinants of postprocedure chest pain are lower residual percent stenosis, incomplete revascularization and the presence of multivessel disease. Patients with chest pain but no electrocardiographic changes early after successful stent placement or atherectomy need not routinely undergo urgent recatheterization.

Percutaneous balloon valvuloplasty for severe mitral stenosis during pregnancy: a review of therapeutic options.

A woman presented at 29 weeks' gestation with previously undiagnosed severe mitral stenosis. She did not respond to medical therapy, and underwent successful percutaneous balloon mitral valvuloplasty with complete resolution of her symptoms. The remainder of her pregnancy was uncomplicated, and she delivered a healthy infant at 40 weeks' gestation. Percutaneous balloon valvuloplasty offers an innovative alternative to standard surgical therapy if medical management is unsuccessful.

Giant right coronary artery aneurysm with fistulous connection to the coronary sinus: diagnosis and management.

This report describes the case of a giant aneurysmal right coronary artery connecting to the coronary sinus near its opening into the right atrium in a 70-year-old woman who presented with a recent onset of congestive heart failure. By coincidence, a secundum atrial septal defect was also present. The diagnosis and surgical management of this uncommon pathology are described.

Distortion of Palmaz-Schatz stent geometry following side-branch balloon dilation through the stent in a rabbit model.

The compromise of side-branches following coronary angioplasty of the parent vessel remains a limitation of the procedure. Reports of dilation through a Palmaz-Schatz stent to salvage a compromised side-branch covered by the stent have been made. We examined the distortion of stent geometry which occurs following this procedure in a rabbit model. Palmaz-Schatz stents were placed at the aortoiliac bifurcation in 7 rabbits and the contralateral iliac artery was dilated through the stent. Despite good angiographic results, varied degrees of stent distortion were noted on gross pathologic analysis. Most distortion occurred when the arteries were dilated through the ends of the struts or through the "diamonds," and least distortion occurred during dilation through the mid-artriculation site. While good stent depolyment is thought to be necessary for improved outcomes, the distortion of stents after balloon dilation through the stent, despite good angiographic results, may have negative implications for both short- and long-term outcomes.

Laser balloon angioplasty: potential clinical applications.

Coronary laser balloon angioplasty (LBA) is a new technique which permits application of heat (generated by the laser source) and pressure (by balloon inflation) to thermally weld tissue during coronary angioplasty (PTCA). The goal of LBA is to achieve a large, smooth arterial lumen, by thermal welding of dissection flaps, elimination of elastic recoil, elimination of vasospasm, reduction in platelet activation, desiccation of thrombus, and inhibition of smooth muscle cell proliferation (Table 1). The LBA system consists of a 50 watt continuous wave Nd:YAG laser with a wavelength of 1060 nm, and a modified coronary balloon angioplasty catheter with a 4.3 French shaft and a PET balloon measuring 20 mm in length and 2.5, 3.0 and 3.5 mm in diameter. For clinical use, laser doses ranging from 250 to 450 joules each are delivered over 20 seconds, to achieve adventitial tissue temperatures of 90 to 110 degrees C. The LBA technique is quite similar to that of conventional PTCA. The LBA catheter is usually positioned over a 0.014" guidewire through an 8 French guiding catheter. Once the laser balloon is in position, the balloon is inflated to a pressure of 4 atmospheres and the programmed laser dose is delivered over 20 seconds, followed by continued balloon inflation for an additional 20 to 40 seconds while the temperature of the arterial wall returns to normal. Conventional PTCA is virtually never necessary to improve lumen appearance and dimensions after LBA. LBA has been shown to be effective in the management of acute failure of PTCA, due to abrupt closure or severe dissection with impaired flow ("impending closure").(ABSTRACT TRUNCATED AT 250 WORDS)

Complete heart block complicating retrograde left ventricular catheterization: case report and review.

Complete heart block (CHB) following retrograde left ventricular catheterization is uncommon. We report a case of transient CHB in a patient with severe aortic stenosis and bifascicular block on the baseline surface electrocardiogram during retrograde left ventricular catheterization. The block resolved spontaneously without sequelae. A review of the literature using MedLine was performed and recommendations for temporary and permanent pacing are outlined.

Persistent thallium-201 defect: can clinical, electrocardiographic and exercise hemodynamic variables predict defect normalization with reinjection?

This study was designed to assess the contribution of clinical, electrocardiographic and exercise hemodynamic variables to the prediction of normalization on resting reinjection scintigraphy of persistent thallium-201 (201Tl) myocardial perfusion defects seen with exercise and 2- to 4-hour delayed (redistribution) imaging. To evaluate this contribution, we studied 159 consecutive patients with persistent 201Tl myocardial perfusion defects on routine exercise and 2- to 4-hour-delayed scintigrams at the University of Rochester Medical Center who were classified as having moderate or greater ischemic normalization (group 1, n = 76) or minimal to no ischemic normalization (group 2, n = 83) by reinjection scintigraphy. Multiple logistic regression analysis with backward elimination was used to model the effects of clinical, electrocardiographic and exercise hemodynamic data on the odds ratio of a normalized defect. No difference was observed in the two groups with regard to gender, angina on exertion, rate-pressure product, exercise duration, resting or exertional ischemic ST changes on electrocardiogram, presence of Q waves or left ventricular hypertrophy on baseline electrocardiogram, or total number of stress thallium defects (2.8 +/- 1.5 segments). No single variable or combination of variables discriminated between groups 1 and 2 by logistic regression analysis. We conclude that defect normalization seen on resting 201Tl myocardial perfusion scintigraphy is prevalent in patients with persistent defects on routine exercise and delayed myocardial perfusion scintigraphy, and was not predictable from available clinical, electrocardiographic and exercise hemodynamic variables.

Tolerance of normal rabbit femoral arteries to single high dose external beam irradiation.

PURPOSE: We gave high single doses of external radiation to normal vessels to produce vascular injury and establish the dose tolerance in an animal model. We also performed immunohistochemical staining for macrophages and smooth muscle cells to assess qualitative changes in their populations. METHODS: Following direct bilateral inguinal cutdown in New Zealand white rabbits, single doses of 15, 20 and 30 Gy were delivered to one vessel. At predetermined time intervals following treatment, the animals underwent angiography and were sacrificed. Both systems were harvested and analyzed, and their luminal and medial areas compared. RESULTS: No statistically significant differences were found between any treatment vessel and its contralateral control at any time point. In addition, no alterations in subintimal or medial content of macrophages or smooth muscle cells were observed. CONCLUSIONS: Our data suggest that single radiation doses as high as 30 Gy appear to be well tolerated in the normal, uninjured rabbit vessel over a 6-month follow-up. However, the use of a diseased vessel model and longer follow-up times need to be studied to provide a better clinical understanding of the basic radiobiology of this technique.

Intracoronary verapamil for the treatment of distal microvascular coronary artery spasm following PTCA.

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.

Changing incidence and management of abrupt closure following coronary intervention in the new device era.

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.

Evolution in the practice of primary angioplasty: effect of adjunctive coronary stenting and glycoprotein IIb/IIIa inhibitors on long-term outcomes.

Primary angioplasty strategies have evolved dramatically, including increasing adjunctive use of stents and glycoprotein (GP) IIb/IIIa inhibitors. The purpose of this study was to examine the specific effects of these adjunctive therapies on long-term outcomes after primary angioplasty. From 1996 to 1998, 257 unselected, consecutive patients underwent primary PTCI at our institution. In-hospital mortality was 5.4% (2.9% for patients without cardiogenic shock). The remaining 243 patients were followed for 2.0 +/- 0.7 years. Adjunctive stenting was associated with increased late mortality (8.7% vs. 2.3%, P = 0.02). GP IIb/IIIa inhibitors were associated with reduced late mortality among patients receiving stents (6.9% vs. 21.4%, P = 0.07), but not in those patients treated with balloon angioplasty alone (2.9% vs. 0%, P > 0.20). Coronary stenting remained a significant predictor of late mortality (hazard ratio 5.6, 95% CI 1.5-21.2) after adjustment for other established risk factors. In this unselected series, adjunctive coronary stenting was associated with higher late mortality among hospital discharge survivors. Concomitant GP IIb/IIIa inhibitors partially corrected for this increase. These results are limited by the small sample size and retrospective design of this study. Additional long-term studies are required to test these findings and evaluate for possible mechanisms.