Percutaneous coronary angioplasty: technique, indications, and results

Identifying High-Risk Patients for Percutaneous Transluminal Angioplasty of Subclavian and Innominate Arteries

We have performed percutaneous transluminal angioplasty for 7 subclavian (4 stenoses, 3 occlusions) and 2 innominate (both stenoses) artery obstructions in 7 patients by percutaneous femoral approach in all, and ipsilateral percutaneous brachial puncture in 2, patients. Initial success was obtained in 4 of the 6 stenoses (2 subclavian and both innominate) but in none of the 3 occlusions. Three of the 4 subclavian stenoses were located proximal to the vertebral artery origin and antegrade vertebral flow without subclavian steal was present in 2 of these lesions. Three patients had complications during the procedure. Two of them developed symptoms and signs of cerebral embolization. Both had shown antegrade vertebral flow and no evidence of subclavian steal in the initial angiogram. The third patient developed angina pectoris. The follow-up period ranged from 4 to 18 months (mean 10.8 months) and no re-stenosis was detected. Angioplasty appears suitable for management of a selected group of patients with nonocclusive lesions in whom subclavian steal phenomenon is evident in the initial diagnostic angiogram. The patients with antegrade vertebral flow are at a high risk of cerebral embolization during angioplasty.

Coronary Angioplasty Using a Low Osmolar Nonionic Contrast Medium

This study was performed to investigate the occurrence of acute angiographic and clinical complications following PTCA using a low osmolar nonionic contrast medium. Five hundred consecutive PTCA procedures were analyzed retrospectively. The incidence of acute in-laboratory complications during PTCA as well as complications occurring during the hospital stay 24 to 48 hours after the procedure were recorded. Occlusion of the dilated artery or a side branch was observed in 19 (3.8%) of the procedures, major dissection in 34 (6.8%), and thrombus in 14 (2.8%). One patient died, 6 (1.2%) required emergency coronary artery bypass grafting (CABG), 4 (0.8%) required an emergency PTCA, and 7 (1.4%) suffered myocardial infarction (MI). Our results show that angiographic findings of thrombus, major dissection and occlusion were serious conditions that related to the clinical complications MI, emergency CABG and re-PTCA. Patients with unstable angina were risk patients for both angiographic and clinical complications. Low rates of intraarterial thrombus formation and coronary artery occlusion indicate good angiographic technique and anticoagulant and antiplatelet medication.

Met-enkephalin levels during PTCA-induced myocardial ischemia

Met-enkephalin (Met-enk) has been demonstrated to modulate myocardial-ischemia mechanisms via the opioid receptors, but no studies are now available on Met-enk levels in the coronary circulation. In this experience Met-enk levels were evaluated in aortic root and in coronary sinus at baseline (T0), during PTCA induced transient ischemia (T1) and during reperfusion (T2). No significant differences were found at any time. Thus, it appears that there is no Met-enk extraction from the coronary circulation during provoked myocardial ischemia and no Met-enk release from the ischemic heart.

Stratification of the risk of thrombosis after intracoronary stenting for threatened or acute closure complicating coronary balloon angioplasty: a Cook registry study

This study was carried out to stratify the risk of stent thrombosis by using three predictors: stent size, poststenting residual dissection, and residual filling defect. In the multicenter clinical trial, 1318 patients had successful deployment of Gianturco-Roubin coronary stent for threatened and acute closure. The 714 (54.2%) patients having none of these risk factors were designated a low-risk group; 484 (36.6%) had one factor and were designated an intermediate-risk group; 120 (9.1%) had two or all three factors and were designated a high-risk group. The incidence of stent thrombosis was 5.6%, 9.4%, and 16.7% in the low-, intermediate-, and high-risk groups; the difference among the three groups was highly significant (p < 0.0001). With these three predictors, the risk of stent thrombosis can be stratified. Avoiding the use of small stents (< 3.0 mm) and achieving optimal angiographic results after stenting for acute or threatened closure are useful strategies in reducing stent thrombosis.

Balloon angioplasty for treatment of in-stent restenosis: feasibility, safety, and efficacy

Sixty patients with 1 or 2 stainless steel intracoronary stents (Cook, Inc.) underwent balloon angioplasty for in-stent restenosis 1.5-13.5 months after stenting. Seventy-five in-stent redilatation procedures were performed. Seventy-three restenotic lesions (97%) were successfully recrossed and dilated, reducing the mean pre-angioplasty intrastent diameter stenosis from 77 +/- 12% to 20 +/- 11% residual. Although one angioplasty (1.3%) was complicated by non-Q-wave infarction, no angioplasty-related death, acute closure, need for additional stenting, emergent coronary bypass surgery, side branch occlusion, or vascular sequelae occurred. Post-procedure heparin was not used in 83% of successful cases. Most patients were discharged the day following redilatation (mean in-hospital stay 1.7 +/- 1.3 days). At 5.4 +/- 3.4 months following in-stent angioplasty, 84% of patients were in Canadian Cardiovascular Society class 0 or I. In conclusion, balloon dilatation in this stent for restenosis appears simple and efficacious in the short term, and may entail less risk than dilatation of unprotected coronary vessels.

Acute angiographic and clinical results of long balloon percutaneous transluminal coronary angioplasty and adjuvant stenting for long narrowings

Historically, long coronary artery stenoses undergoing percutaneous transluminal coronary angioplasty (PTCA) are reported to have reduced procedural and clinical success in comparison with shorter lesions. The efficacy of long balloons (30 or 40 mm) in long lesions was evaluated. Eighty-two patients had 84 PTCA procedures with a primary long balloon. In all, 86 lesions were available for analysis. Data were collected prospectively on standard PTCA procedure forms. Coronary angiograms were reviewed and measured with digital calipers. Hospital charts were examined for complications. PTCA was performed in the left anterior descending artery in 44 cases (51%), the right coronary artery in 29 (34%) and the circumflex artery in 13 (15%). With the use of a modified classification system, 47 lesions (55%) were class C, 24 (28%) were class B2 and 15 (17%) were class B1. Mean lesion length was 22 +/- 11 mm (range 10 to 72), and 38 lesions (44%) were > or = 20 mm. Twelve patients received an intracoronary stent. The long balloon alone produced angiographic success (< 50% residual stenosis) in 77 lesions (90%). Angiographic success was achieved ultimately in all stenoses, using a stent in 7 patients and a short balloon in 2. There were 2 deaths (2%) and 1 Q-wave myocardial infarction (1%). One patient needed coronary artery bypass surgery. Clinical success without death, Q-wave infarction or bypass surgery was achieved in 83 of 86 procedures (97%). In conclusion, the use of long PTCA balloons with adjuvant stenting produced excellent results in these long stenoses. Lesion length was not a precursor of poor angiographic or clinical outcome.

Experience with the Gianturco-Roubin stent for abrupt vessel closure complicating percutaneous transluminal coronary angioplasty

BACKGROUND

Emergency coronary artery bypass grafting (CABG) has previously been the only option in the treatment of refractory abrupt vessel closure complicating percutaneous transluminal coronary angioplasty (PTCA), and has been associated with high rates of morbidity and mortality. Intracoronary stenting now provides an alternative to emergency CABG.

AIM

To assess our initial experience with emergency coronary artery stenting as a new technique.

METHODS

Retrospective case study review with clinical and angiographic follow-up.

RESULTS

The Gianturco-Roubin (GR) stent was deployed in 13 patients in whom PTCA was complicated by abrupt vessel closure refractory to standard balloon techniques. Indications for PTCA were unstable angina (six), stable angina (six) and acute myocardial infarction (MI) (one). The arteries stented included left anterior descending (LAD) artery lesions (eight) and right coronary artery lesions (five). Two patients required urgent CABG, one due to failed stent deployment and one for inadequate control of vessel dissection. In seven of the stented patients the creatine kinase rose to greater than twice the upper limit or normal. Three patients had subacute thrombotic occlusion at seven to 19 days post stent deployment, managed with intravenous thrombolysis or repeat PTCA. At seven months follow-up, 11 patients were free of angina, two patients had Canadian Heart Association class II angina and there were no deaths. Eleven patients had repeat angiography at mean six months post stent. Five patients had evidence of restenosis managed with repeat PTCA in four and CABG in one.

CONCLUSIONS

The GR stent is an effective alternative to urgent CABG in the treatment of refractory abrupt vessel closure complicating PTCA.

Histologic findings in specimens obtained by percutaneous directional coronary atherectomy

Percutaneous directional coronary atherectomy is a second-generation, catheter-based technique for the treatment of coronary artery disease that provides a unique opportunity to study tissue obtained from coronary artery stenoses. We reviewed the histologic findings in 131 coronary atherectomy specimens from 116 patients, including 79 primary lesions and 52 restenosis lesions that developed after a prior coronary intervention. Although atherosclerotic plaque was seen in 95% of cases, an important observation was the finding of deep arterial wall components in the majority of patients, including media in 61% and adventitia in 31%. Despite the relatively common finding of deep wall components, this was not associated with acute clinical complications. Intimal hyperplasia was seen in 64% of cases, including 96% of restenosis lesions. However, intimal hyperplasia was also seen in 45% of primary lesions. The intimal hyperplasia in primary and restenosis lesions was histologically identical and was characterized by cells that showed staining for vimentin and muscle-specific actin, consistent with a myogenous and/or myofibroblastic phenotype. Restenosis was seen in 29 of 94 lesions (31%) with angiographic follow-up an average of 6.3 months after atherectomy. The risk of restenosis was not significantly related to the vessel treated, the nature of the lesion treated (ie, primary v restenosis lesion), or any of the histologic features evaluated. In conclusion, (1) deep arterial wall components are commonly observed in coronary atherectomy specimens without acute complications and (2) intimal hyperplasia is a sensitive, but not specific, marker for restenosis lesions.

Intracoronary stenting for acute and threatened closure complicating percutaneous transluminal coronary angioplasty

BACKGROUND. Acute closure remains a significant limitation of percutaneous transluminal coronary angioplasty (PTCA) and underlies the majority of ischemic complications. This study details the clinical and angiographic characteristics of a series of patients receiving an intracoronary stent device to manage acute and threatened closure and presents the early clinical results. METHODS AND RESULTS. From October 1989 through June 1991, 115 patients undergoing PTCA received intracoronary stents to treat acute or threatened closure in 119 vessels. Sixty-three percent had multivessel coronary disease, 33 (29%) had undergone prior coronary artery bypass grafting (CABG), and 52 (45%) had had previous PTCA. Using the American College of Cardiology/American Heart Association (ACC/AHA) classification, 15% of lesions were class A, 55% were class B, and 30% were class C. Eight patients were referred with severe coronary dissection and unstable angina after PTCA at other institutions. Acute closure was defined as occlusion of the vessel with TIMI (Thrombolysis in Myocardial Infarction) 0 or 1 flow immediately before stent placement. Threatened closure required two or more of the following criteria: 1) a residual stenosis greater than 50%, 2) TIMI grade 2 flow, 3) angiographic dissection comprising extraluminal dye extravasation and/or a length of greater than 15 mm, 4) evidence of clinical ischemia (either typical angina or ECG changes). Twelve vessels (10%) met the criteria for acute closure, and 87 vessels (73%) satisfied the criteria for threatened closure. Twenty vessels (17%) failed to meet two criteria. Stenting produced optimal angiographic results in 111 vessels (93%), with mean diameter stenosis (+/- 1 SD) reduced from 83 +/- 12% before to 18 +/- 29% after stenting. Overall, in-hospital mortality was 1.7% and CABG was required in 4.2%; Q wave myocardial infarction (MI) occurred in 7% and non-Q wave MI in 9%. Stent thrombosis occurred in nine patients (7.6%). For the 108 patients who presented to the catheterization laboratory without evolving MI, Q wave MI occurred in 4% and non-Q wave MI occurred in 7%. Angiographic follow-up has been performed in 81 eligible patients (76%), and 34 patients (41%) had a lesion of greater than or equal to 50%. CONCLUSIONS. This stent may be a useful adjunct to balloon dilatation in acute or threatened closure. Randomized studies comparing this stent with alternative technologies are required.

Effects of nonionic versus ionic contrast media on complications of percutaneous transluminal coronary angioplasty

To evaluate the effect of contrast agents on percutaneous transluminal coronary angioplasty (PTCA) complications, 913 patients undergoing 1,058 separate PTCA procedures were prospectively randomized to receive either nonionic iopamidol (Isovue-370) [n = 507 PTCA procedures] or ionic contrast media, meglumine sodium diatrizoate (Renografin-76) [n = 551 PTCA procedures]. Angioplasty operators, technicians, nurses and patients were blinded to the agent used. All patients were pretreated with 0.6 mg of atropine sulfate intravenously before any contrast injections. Hypotension (mean arterial pressure less than 65 mm Hg associated with contrast injections) occurred during 8.5% of PTCA procedures in which the patients were receiving iopamidol and during 9.5% of the procedures in which the patients were given diatrizoate (difference not significant). Bradycardia (heart rate of less than 40 beats/min associated with contrast injections) developed during 5.7% of procedures when patients were given iopamidol and during 5.1% of procedures when patients were given diatrizoate (difference not significant). The need for additional atropine or temporary pacing during the procedure was similar for patients given iopamidol and diatrizoate. The overall incidence of ventricular tachycardia or fibrillation, or both, during the procedure occurred less frequently when iopamidol was used compared with diatrizoate (1 vs 2.5%, p = 0.045). These serious ventricular arrhythmias were attributable to contrast injections in 0.6% of the PTCA procedures when iopamidol was given and in 2.0% of the cases in which diatrizoate was the contrast agent (p = 0.09). Only 1 patient had an allergic reaction to the contrast agent, and this was in a patient who received iopamidol.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous supra-aortic angioplasty in a high risk coronary patient

We have performed percutaneous angioplasty of the innominate and carotid arterial stenoses in a high risk patient with proximal disease involving the vessels arising from the aortic arch and seriously limiting blood flow to all four cerebral vessels. The patient also had severe left main and triple vessel coronary artery disease. The role of supra-aortic angioplasty in this clinical setting is discussed.

Effect of pretreatment with aspirin versus aspirin plus dipyridamole on frequency and type of acute complications of percutaneous transluminal coronary angioplasty

It is unknown whether the addition of dipyridamole to aspirin as pretreatment for patients undergoing percutaneous transluminal coronary angioplasty (PTCA) decreases acute complications. In this study 232 patients were prospectively randomized to receive either aspirin 325 mg orally 3 times daily (group 1, n = 115) or aspirin 325 mg orally 3 times daily plus dipyridamole 75 mg orally 3 times daily (group 2, n = 117) before elective PTCA. All clinical, angiographic and PTCA-related variables were similar between groups. Angiographic success rate was 93% in both groups. Clinical success was achieved in 107 patients (92%) in group 1 and in 101 patients (88%) in group 2 (difference not significant). Q-wave myocardial infarction occurred in 2 patients (1.7%) in group 1 and 5 patients (4.3%) in group 2 (difference not significant). Emergency coronary artery bypass grafting was required in 3 patients (2.6%) in group 1 and 7 patients (6.1%) in group 2 (difference not significant). There was 1 in-hospital death (in group 2). In this study, the addition of dipyridamole to aspirin as pretreatment of patients undergoing PTCA did not significantly reduce acute complications compared to aspirin alone.

CO2-laser radiation damage of the arterial wall

This study describes the effects of CO2 laser radiation on the histology of the normal rabbit arterial wall, using models that simulate laser angioplasty and anastomosis. Rabbit arteries were exposed to laser treatments similar to those used clinically; 40, 0.5 sec pulses of 40-60 mW, CO2 continuous wavelength laser, or a 1/2-circumferential laser anastomosis with a 60-80 mW continuous pulse. Aneurysms developed in 8 of 22 femoral, 1 of 22 carotid, and no controls at 12 week. There were small breaks in the internal elastic lamina with atrophy, loss of muscularis, "packing" of the elastica, thinning of the muscularis at the damage site, and enlargement of the arterial diameter. Aneurysms developed in one femoral and no carotid anastomosed artery. Laser anastomoses demonstrated more muscle damage and loss, with extensive scarring and a wider area of elastic loss than the controls. The intima was reestablished with focal reduplication of the internal elastic lamina. There were no histologic differences between the arteries which developed aneurysms and those which did not in either series. These results suggest that low power laser damage of the arterial wall consists mainly of destruction of the muscularis propria, with minimal damage to the elastica.

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

Intimal tear or dissection is an important descriptor of ischemic complications after coronary angioplasty, but only the minority of patients will develop an acute ischemic event. To identify additional factors that may predict the development of an ischemic event when arterial disruption occurs during otherwise uncomplicated angioplasty, the records of 1,346 patients prospectively identified as having tear or dissection without immediate vessel closure were examined. Ischemic complications, defined as ischemic chest pain, myocardial infarction, the need for coronary bypass surgery, or death, occurred in 120 patients (9%). Significant multivariate correlates of an ischemic complication were the presence of unstable angina or a totally occluded vessel before angioplasty and diameter stenosis of greater than 30% after angioplasty. Detailed geometric and videodensitometric analysis of the postdilatation angiograms of a subset of 96 consecutive patients was carried out. Ischemic complications occurred in 11 patients (11%). Multivariate analysis revealed that the independent correlates of complications, in decreasing order of importance, were the length of the tear or dissection (p = 0.001), diameter stenosis after angioplasty (p = 0.001), cross-sectional area after dilatation measured by videodensitometric methods (p = 0.013), and the presence of extraluminal contrast (p = 0.044). When tear or dissection occurs during otherwise uncomplicated coronary angioplasty, patients at risk of developing delayed ischemic complications can be identified and may benefit from measures designed to minimize this risk. By controlling for the geometric or mechanical factors that result in tear or dissection, it has been possible to identify factors not previously thought associated with ischemic complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Histopathologic phenomena at the site of percutaneous transluminal coronary angioplasty: the problem of restenosis

Seventeen postangioplasty cases were morphologically studied at postmortem. Four of the eleven, early and intermediate cases (few hours to 1 month from angioplasty to death), revealed intraluminal thrombi, although in only two cases were those thrombi occlusive. Almost all of the nine early cases (eight of nine) exhibited intimal disruptions. Except for two of these cases in which circumferential and/or longitudinal dissections were present, the remainder of the intimal cracks were superficial and of limited extent. Limited dissection between intima and media is not considered a serious or detrimental local event. The early cases showed an aneurysmal dilatation of the plaque-free segment of the arterial wall in eccentric plaques. This finding was interpreted as the result of uneven distribution of the dilating force (circumferential stress) on the aterial wall. Late cases (survival over 1 month) revealed characteristic medial and intimal lesions indicative of the initial dilatation injury. It is hypothesized that intrinsic arterial wall changes (medial disruption) at the plaque-free segment and the resulting altered arterial geometry at the site of dilatation have a significant hemodynamic effect on the vascular conduit and may enhance and sustain the myoproliferative intimal response.

Intra-arterial stenting in the atherosclerotic rabbit

The major problem associated with percutaneous transluminal coronary angioplasty is recurrence of the stenotic lesion. Balloon catheter-mounted intracoronary stent devices may reduce restenosis by improving luminal morphology and flow characteristics. This study assessed the effects of a stainless steel wire, interdigitating coil stent on restenosis in the atherosclerotic rabbit model. Fifteen cholesterol-fed rabbits with preexisting iliac arterial lesions induced by balloon deendothelialization were instrumented in one iliac artery with a 2.0-mm diameter stent after balloon dilatation; the contralateral iliac lesion was treated by dilatation only to serve as a control. The animals were given heparin with aspirin (60 mg) and aspirin every 3rd day until death. Arteriography was repeated 4 weeks after stenting, just before death. Tissue sections from stented and control arterial segments were analyzed morphometrically. Stented arteries had a significantly larger luminal diameter at restudy, whether measured by arteriography (1.38 +/- 0.19 vs. 0.94 +/- 0.35 mm, p less than 0.01) or from tissue sections (1.26 +/- 0.18 vs. 0.81 +/- 0.30 mm, p = 0.0001). Wall thickness of the stented segment was slightly, but significantly, less than the control segment (436 +/- 143 vs. 532 +/- 221 microns, p less than 0.05). Scanning electron microscopy of five stented atherosclerotic rabbit aortas revealed regeneration of a nonthrombogenic, confluent, flow-directed endothelium by 4 weeks after placement. Intra-arterial stenting may be of benefit in the prevention of restenosis by the preservation of a larger functional lumen and by a decrease in the neointimal hyperplastic response to arterial injury.

Influence of balloon size on initial success, acute complications, and restenosis after percutaneous transluminal coronary angioplasty. A prospective randomized study

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) is strongly associated with incomplete initial dilatation. To determine if oversized PTCA balloons would reduce the restenosis rate without increasing the risk of arterial dissection and acute complications, we prospectively randomized 336 patients to receive either smaller or larger balloons. Thirty-four percent of patients had multivessel disease and 18% had multisite dilatation. One hundred sixty-nine patients were randomized to PTCA with a larger balloon and 167 to PTCA with a smaller balloon. Balloon:artery diameter ratios were 1.13 +/- 0.14 in the larger group and 0.93 +/- 0.12 in the smaller group (p less than 0.001). The trial was halted as clinically important differences in acute complications emerged. Emergency bypass graft surgery, usually for the treatment of arterial dissection, was required in 7.1% of patients in the larger balloon group and 3.6% of patients in the smaller balloon group (p = 0.15). Myocardial infarction (Q wave and non-Q wave) complicated 7.7% of procedures in which large balloons were assigned and 3.0% of procedures in which small balloons were assigned (p = 0.056). There were no deaths in either group. The incidence of bypass surgery was 1.7% when the balloon:artery ratio was less than 0.9, 3.1% when the ratio was 0.9-1.1, and 7.8% when it was greater than 1.1. Stepwise logistic regression analysis demonstrated that larger balloon assignment, multiple lesion dilatation, and multivessel coronary artery disease were independent predictors of emergency surgery. Angiographic restudy rates were 50% in the larger group and 60% in the smaller group (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal coronary angioplasty in dextrocardia: case report

Percutaneous transluminal coronary angioplasty (PTCA) is described in a patient with dextrocardia. Selective cannulation of the right anterior descending coronary artery (morphologic left anterior descending coronary artery) was achieved with modification of standard guiding catheters "preformed" for the normal, levo-position heart. This report demonstrates the feasibility of PTCA in patients with cardiac malposition who survive into adulthood and develop coronary atherosclerosis.

Repeat coronary angioplasty: correlates of a second restenosis

To identify the correlates of a second restenosis after repeat percutaneous coronary angioplasty, the records of 384 patients with single vessel disease who underwent repeat angioplasty for restenosis complicating a first elective angioplasty were examined. A second restenosis occurred in 47 (31%) of 151 patients having angiographic follow-up. Univariate correlates of a second restenosis were an interval between the first and second angioplasty less than 5 months (41 versus 20% of patients had restenosis, p less than 0.01), male gender (35 versus 12%, p less than 0.05), lesions length greater than or equal to 15 mm before the second angioplasty (62 versus 28%, p less than 0.05), diameter stenosis greater than 90% before the second angioplasty (67 versus 29%, p less than 0.05), final gradient greater than 20 mm Hg after the second angioplasty (52 versus 28%, p less than 0.05) and an additional site requiring dilation at the time of the second angioplasty (50 versus 29%, p = 0.10). Multivariate predictors of a second restenosis were an interval of less than 5 months between the first and the second angioplasty (p = 0.001), male gender (p = 0.001), lesion length greater than or equal to 15 mm before the second angioplasty (p = 0.001) and the need to have an additional site dilated at the time of the second angioplasty (p = 0.002). Patients at increased risk of restenosis after the second angioplasty can be identified and may serve as a useful population for intervention studies.