Cass A. Pinkerton

A comparison of directional atherectomy with coronary angioplasty in patients with coronary artery disease

BACKGROUND Directional coronary atherectomy is a new technique of coronary revascularization by which atherosclerotic plaque is excised and retrieved from target lesions. With respect to the rate of restenosis and clinical outcomes, it is not known how this procedure compares with balloon angioplasty, which relies on dilation of the plaque and vessel wall. We compared the rate of restenosis after angioplasty with that after atherectomy. METHODS At 35 sites in the United States and Europe, 1012 patients were randomly assigned to either atherectomy (512 patients) or angioplasty (500 patients). The patients underwent coronary angiography at base line and again after six months; the paired angiograms were quantitatively assessed at one laboratory by investigators unaware of the treatment assignments. RESULTS Stenosis was reduced to 50 percent or less more often with atherectomy than with angioplasty (89 percent vs. 80 percent; P < 0.001), and there was a greater immediate increase in vessel caliber (1.05 vs. 0.86 mm, P < 0.001). This was accompanied by a higher rate of early complications (11 percent vs. 5 percent, P < 0.001) and higher in-hospital costs (

Multicenter investigation of coronary stenting to treat acute or threatened closure after percutaneous transluminal coronary angioplasty : clinical and angiographic outcomes

11,904 vs

A multicenter, randomized trial of coronary angioplasty versus directional atherectomy for patients with saphenous vein bypass graft lesions

10,637; P = 0.006). At six months, the rate of restenosis was 50 percent for atherectomy and 57 percent for angioplasty (P = 0.06). However, the probability of death or myocardial infarction within six months was higher in the atherectomy group (8.6 percent vs. 4.6 percent, P = 0.007). CONCLUSIONS Removing coronary artery plaque with atherectomy led to a larger luminal diameter and a small reduction in angiographic restenosis, the latter being confined largely to the proximal left anterior descending coronary artery. However, atherectomy led to a higher rate of early complications, increased cost, and no apparent clinical benefit after six months of follow-up.

Coronary arterial thrombolysis with combined infusion of recombinant tissue-type plasminogen activator and urokinase in patients with acute myocardial infarction.

OBJECTIVES This study reports on the initial experience with the Gianturco-Roubin flexible coronary stent. The immediate and 6-month efficacy of the device and the incidence of the complications of death, myocardial infarction, emergency coronary artery bypass surgery and recurrent ischemic events are presented. BACKGROUND Abrupt or threatened vessel closure after coronary angioplasty is associated with increased risk of myocardial infarction, emergency coronary artery bypass graft surgery and in-hospital death. When dissection or prolapse of dilated plaque into the lumen is unresponsive to additional or prolonged balloon catheter inflation, coronary stenting offers a nonsurgical mechanical means to rapidly restore stable vessel geometry and adequate coronary blood flow. METHODS From September 1988 through June 1991, 518 patients underwent attempted coronary stenting with the 20-mm long Gianturco-Roubin coronary stent for acute or threatened vessel closure after angioplasty. In 494 patients, one or more stents were deployed. Thirty-two percent of patients received stents for acute closure and 69% for threatened closure. RESULTS Successful deployment was achieved in 95.4% of patients. Overall, stenting resulted in an immediate angiographic improvement in the diameter stenosis from 63 +/- 25% before stenting to 15 +/- 14% after stenting. Emergency coronary artery bypass graft surgery was required in 4.3% (21 of 493 patients). The incidence of in-hospital myocardial infarction (Q wave and non-Q wave) was 5.5% (27 of 493 patients). At 6 months, myocardial infarction was infrequent, occurring in 1.6% (8 of 493 patients). The incidence of in-hospital death was 2.2% (11 of 493 patients). Late death occurred in 7 patients (1.4%) and 34 patients (6.9%) required later bypass graft surgery. Complications included blood loss, primarily from the arterial access site, and subacute thrombosis of the stented vessel in 43 patients (8.7%). CONCLUSIONS The early multicenter experience suggests that this stent is a useful adjunct to coronary angioplasty to prevent or minimize complications associated with flow-limiting coronary artery dissections previously correctable only by surgery. Although this study was not randomized, it demonstrated a high technical success rate and encouraging results with respect to the low incidence of emergency coronary artery bypass graft surgery and myocardial infarction.

Intravascular ultrasound: a histological study of vessels during life. The new 'gold standard' for vascular imaging.

BACKGROUND Directional coronary atherectomy and percutaneous transluminal coronary angioplasty have both been used in symptomatic patients with coronary saphenous vein bypass graft stenoses. The relative merits of plaque excision and removal versus balloon dilatation remain uncertain. We compared outcomes after directional coronary atherectomy or angioplasty in patients with de novo bypass graft stenoses. METHODS AND RESULTS Fifty-four North American and European sites randomized 305 patients with de novo vein graft lesions to atherectomy (n = 149) or angioplasty (n = 156). Quantitative coronary angiography at a core laboratory assessed initial and 6-month results. Initial angiographic success was greater with atherectomy (89.2% versus 79.0%), as was initial luminal gain (1.45 versus 1.12 mm, P < .001). Distal embolization was increased with atherectomy (P = .012), and a trend was shown toward more non-Q-wave myocardial infarction (P = .09). Although the 6-month net minimum luminal diameter gain was 0.68 mm for atherectomy and 0.50 mm for angioplasty, the restenosis rates were similar, 45.6% for atherectomy and 50.5% for angioplasty (P = .491). At 6 months, there was a trend toward decreased repeated target-vessel interventions for atherectomy (P = .092); in addition, 13.2% of patients treated with atherectomy versus 22.4% of the angioplasty patients (P = .041) required repeated percutaneous intervention of the initial target lesion. CONCLUSIONS Atherectomy of de novo vein graft lesions was associated with improved initial angiographic success and luminal diameter but also with increased distal embolization. There was no difference in 6-month restenosis rates, although primary atherectomy patients tended to require fewer target-vessel revascularization procedures.

Status of the myocardium and infarct-related coronary artery in 19 necropsy patients with acute recanalization using pharmacologic (streptokinase, r-tissue plasminogen activator), mechanical (percutaneous transluminal coronary angioplasty) or combined types of reperfusion therapy.

To determine whether tissue-type plasminogen activator (t-PA) and urokinase (UK) act synergistically to achieve coronary thrombolysis, incremental doses of both drugs were infused intravenously over 60 min. In 146 consecutive patients treated 3.0 +/- 1.0 hr from symptom onset, coronary angiography was performed 90 min after the start of the infusion and at 7 days. The groups of patients treated by different dose regimen were as follows: group I, 14 patients treated with t-PA 25 mg and UK 0.5 million U; group II, 20 patients given t-PA 25 mg and UK 1.0 million U; group III, 24 patients given t-PA 1.0 mg/kg and UK 0.5 million U; group IV, 33 patients treated with t-PA 1.0 mg/kg and UK 1.0 million U; and group V, 55 patients given t-PA 1.0 mg/kg and UK 2.0 million U. In groups I and II, patency of the infarct-related vessel at 90 min was only 36% and 42%, respectively. With 1 mg/kg t-PA and increasing doses of UK (groups III to V), patency ranged from 72% to 75% (overall 73%). Repeat catheterization at 7 days demonstrated reocclusion in groups III to V in 10 of 110 (9%). The patency and reocclusion rates in groups III to V were not significantly different from those in our previous study of 386 patients treated with t-PA alone (150 mg over 6 to 8 hr). In that study the patency rate of the infarct-related vessel at 90 min was 75% (p = .66) and reocclusion occurred in 15% (p = .11).(ABSTRACT TRUNCATED AT 250 WORDS)

Suture-mediated closure of the femoral access site after cardiac catheterization: results of the suture to ambulate aNd discharge (STAND I and STAND ii) trials

uring the last several years, dramatic developD ments have taken place in the area of cardiac imaging techniques. From an era of imaging by silhouettes (chest roentgenography, fluoroscopy, angiocardiography, angiography), we have emerged into an era of imaging by tomographic scanning (echocardiography, radionuclide and computed tomography, magnetic resonance).l-3 Two-dimensional intravascular echocardiography is one of these exciting new techniques capable of providing cross-sectional tomographic images of coronary arteries. Although visualization of the major epicardial coronary arteries by transthoracic or transesophageal echocardiography has been possible for nearly 15 years,4-17 intravascular ultrasound has, for the first time, allowed visualization of the coronary lumen and various normal and abnormal layers of the coronary arteries. In essence, intravascular echocardiographic imaging represents a histological study of the coronary artery during life. The usual three-layer structure (intima, media, adventitia) of muscular arteries such as the coronary artery system is acoustically distinctive, which permits ultrasound imaging. The relative echo lucency of the media compared with the intimal and adventitial layers permits visualization of this multilayer architecture first described in vitro by Meyer et a118 in 1988 and in vivo by Yock et a119 in 1989. The bright inner (luminal) lining of the ultrasound image in the normal coronary artery is caused principally by the internal elastic membrane separating the intima from the media.20-22 The intimal layer in the normal coronary artery is probably not thick enough to generate a distinct ultrasonic layer.3 Further refinement in the interpretation of images from the internal and external elastic membranes as well as the luminal surface of vessels is under way. Several in vitro and in vivo studies of arterial vessels (with and without histology) have confirmed the ultrasonic appearance of these arterial structures and have validated measurements of layer thickness and luminal cross-sectional area.23-35 Attention is now focusing on the clinical applications of intravascular echocardiography. At least three major areas of diagnostic and therapeutic use of intravascular

Relation of stenosis morphology and clinical presentation to the procedural results of directional coronary atherectomy.

In acute myocardial infarction, myocardial salvage is dependent on rapid restoration of blood flow. Pharmacologic (streptokinase, recombinant tissue-type plasminogen activator), mechanical (percutaneous transluminal coronary angioplasty, guide wire perforation) or combined forms of reperfusion therapy can accomplish this goal, but their effects on infarcted myocardium and vessel occlusion site have not been compared at necropsy. The heart of 19 necropsy patients who had received various forms of acute reperfusion therapy was studied: 14 had pharmacologic or combined forms of reperfusion therapy (13 streptokinase and 1 tissue-type plasminogen activator, including 4 with combined balloon angioplasty) and 5 had had purely mechanical (balloon angioplasty) reperfusion therapy. Reperfusion was initially clinically successful in all 19 patients with the average time from onset of symptoms to reperfusion being 3.7 hours. Necropsy observations separated the 19 patients into distinct subgroups based on changes in the myocardium and infarct-related coronary arteries. Of the 19 patients, 14 (74%) had hemorrhagic myocardial infarction and they all received pharmacologic or combined forms of reperfusion therapy. The remaining five patients (26%) had nonhemorrhagic (anemic) infarction and were treated with balloon angioplasty therapy alone. Increased luminal cross-sectional area was present in 8 of 9 patients with acute balloon angioplasty but severe coronary atherosclerotic plaque remained in 9 of 10 patients without acute balloon angioplasty. Severe hemorrhage surrounded angioplasty sites in all four patients who also received streptokinase or tissue-type plasminogen activator. Severe bleeding at the angioplasty site compromised the dilated coronary lumen in one patient. No patient with angioplasty alone had intraplaque bleeding. Thus, acute coronary balloon angioplasty reperfusion therapy alone appears to avoid the potentially adverse effects of myocardial and intraplaque hemorrhage while simultaneously increasing luminal cross-sectional area at the site of acute occlusion.

Restenosis 1 to 24 months after clinically successful coronary balloon angioplasty: A necropsy study of 20 patients

Despite advances in other aspects of cardiac catheterization, manual or mechanical compression followed by 4 to 8 hours of bed rest remains the mainstay of postprocedural femoral access site management. Suture-mediated closure may prove to be an effective alternative, offering earlier sheath removal and ambulation, and potentially a reduction in hemorrhagic complications. The Suture To Ambulate aNd Discharge trial (STAND I) evaluated the 6Fr Techstar device in 200 patients undergoing diagnostic procedures, with successful hemostasis achieved in 99% of patients (94% with suture closure only) in a median of 13 minutes, and 1% major complications. STAND II randomized 515 patients undergoing diagnostic or interventional procedures to use of the 8Fr or 10Fr Prostar-Plus device versus traditional compression. Successful suture-mediated hemostasis was achieved in 97.6% of patients (91.2% by the device alone) compared with 98.9% of patients with compression (p = NS). Major complication rates were 2.4% and 1.1%, and met the Blackwelders test for equivalency (p <0.05). Median time to hemostasis (19 vs 243 minutes, p <0.01) and time to ambulation (3.9 vs 14.8 hours, p <0.01) were significantly shorter for suture-mediated closure. Suture-mediated closure of the arterial puncture site thus affords reliable immediate hemostasis and shortens the time to ambulation without significantly increasing the risk of local complications.

Morphologic evidence of accelerated left main coronary artery stenosis: a late complication of percutaneous transluminal balloon angioplasty of the proximal left anterior descending coronary artery

BackgroundDirectional coronary atherectomy has recently become available to treat coronary stenoses. This study was performed to determine the relation of patient characteristics and stenosis morphology to procedural outcome with directional coronary atherectomy to gain insight into which patients might be best treated with this device. Methods and ResultsFour hundred stenoses from 378 patients consecutively treated at six major referral institutions were analyzed. Angiographic data were assessed at a central angiographic laboratory using standardized morphological criteria and computer-assisted quantitative dimensional analyses. Procedural success was achieved in 87.8% of stenoses, and major ischemic complications (death, myocardial infarction, and emergency bypass surgery) occurred in 6.3% of patients. Lesion success and complications were closely correlated with recognized modified American College of Cardiology/American Heart Association Task Force lesion morphological criteria. Observed for type A stenoses were 93% success and 3% complication rates; for type Bi stenoses, 88% success and 6% complication rates; and for type B2 stenoses, 75% success and 13% complication rates, respectively. There were too few type C stenoses treated to analyze. Furthermore, multivariate testing demonstrated stenosis angulation (multivariate p < 0.001), proximal tortuosity (p < 0.001), decreased preatherectomy minimum lumen dimension (p =0.032), and calcification (p =0.041) to correlate independently with adverse outcome and complex, probably thrombus-associated stenoses to have a favorable outcome (p =0.055). Operator experience (p =0.020) and a history of restenosis (p =0.022) also favorably influenced outcome. ConclusionsThe procedural outcome of directional coronary atherectomy is highly associated with coronary stenosis morphology. Furthermore, after appropriate stratification for morphology and clinical presentation, overall atherectomy procedural outcome may be similar to that achieved with coronary angioplasty. However, specific subsets of patients may have relatively better outcome with either atherectomy or balloon angioplasty.