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PubMed2000

The place of rotablator for treatment of in-stent restenosis.

In-stent restenosis (ISR) is still a growing problem in interventional cardiology due to the increasing number of stent implantations. Various treatment modalities are available at present. As a non ablative strategy balloon angioplasty is the strategy of choice for focal ISR, while ablative techniques such as directional coronary atherectomy, Excimer laser coronary angioplasty and rotational atherectomy are used preferentially in diffuse restenosis processes. These debulking techniques are optimized by peri-interventional use of intravascular ultrasound and adjunctive balloon angioplasty. Study data comparing different interventional approaches, usually with adjunct balloon angioplasty, have not proven an optimal treatment modality for ISR yet.

Angioplasty, Balloon, Coronary↗
PubMed1995

[The percutaneous treatment of surgical and catheter-angiographic vascular complications].

PURPOSE: Technical innovations of angioplasty have introduced new therapeutic options in the treatment of symptomatic arteriosclerotic disease. Atherectomy devices, aspiration catheters and vascular endoprostheses can be used not only for angioplasty purpose but also for correction of iatrogenic dissections and thromboembolic complications. MATERIAL AND METHODS: 54 patients with vascular complications after surgical (n = 7) and percutaneous (n = 47) interventions were observed in a 5 years period. The complications included acute dissections in 34 cases, acute thrombosis in 4 cases, distal embolism after angioplasty in 14 cases, and two cases with arterial rupture after balloon dilatation. RESULTS: 34 patients with dissections and 18 patients with acute thrombosis were treated. Stent implantation for repair of vessel dissection was successful in 33 of 34 cases. Percutaneous catheter aspiration in combination with local thrombolysis was successful in 4 cases with local thrombosis. Distal emboli after angioplasty were successfully removed using aspiration catheters in 13 of 14 patients. Vessel rupture after angioplasty was closed with prolonged balloon dilatation in two patients avoiding emergency surgery. CONCLUSION: Using newly developed intravascular technologies such as atherectomy, stents, and catheter aspiration, many iatrogenic complications after vascular surgery or vascular interventions can be treated. These technologies should be available in every radiology department performing angioplasty.

Acute Disease↗
PubMed1994

Use of a monoclonal antibody directed against the platelet glycoprotein IIb/IIIa receptor in high-risk coronary angioplasty.

BACKGROUND: Platelets are believed to play a part in the ischemic complications of coronary angioplasty, such as abrupt closure of the coronary vessel during or soon after the procedure. Accordingly, we evaluated the effect of a chimeric monoclonal-antibody Fab fragment (c7E3 Fab) directed against the platelet glycoprotein IIb/IIIa receptor, in patients undergoing angioplasty who were at high risk for ischemic complications. This receptor is the final common pathway for platelet aggregation. METHODS: In a prospective, randomized, double-blind trial, 2099 patients treated at 56 centers received a bolus and an infusion of placebo, a bolus of c7E3 Fab and an infusion of placebo, or a bolus and an infusion of c7E3 Fab. They were scheduled to undergo coronary angioplasty or atherectomy in high-risk clinical situations involving severe unstable angina, evolving acute myocardial infarction, or high-risk coronary morphologic characteristics. The primary study end point consisted of any of the following: death, nonfatal myocardial infarction, unplanned surgical revascularization, unplanned repeat percutaneous procedure, unplanned implantation of a coronary stent, or insertion of an intraaortic balloon pump for refractory ischemia. The numbers of end-point events were tabulated for 30 days after randomization. RESULTS: As compared with placebo, the c7E3 Fab bolus and infusion resulted in a 35 percent reduction in the rate of the primary end point (12.8 vs. 8.3 percent, P = 0.008), whereas a 10 percent reduction was observed with the c7E3 Fab bolus alone (12.8 vs. 11.5 percent, P = 0.43). The reduction in the number of events with the c7E3 Fab bolus and infusion was consistent across the end points of unplanned revascularization procedures and nonfatal myocardial infarction. Bleeding episodes and transfusions were more frequent in the group given the c7E3 Fab bolus and infusion than in the other two groups. CONCLUSIONS: Ischemic complications of coronary angioplasty and atherectomy were reduced with a monoclonal antibody directed against the platelet IIb/IIIa glycoprotein receptor, although the risk of bleeding was increased.

Abciximab↗
PubMed1995

An overview of the results of the EPIC trial.

The Evaluation of 7E3 for the Prevention of Ischaemic Complications (EPIC) trial assessed the use of abciximab in the treatment of patients at high risk undergoing percutaneous revascularization procedures. Abciximab (c7E3) is a chimeric monoclonal antibody targeted to block the glycoprotein IIb/IIIa receptor on the surface of the platelet; this receptor is believed to be the final common pathway of platelet aggregation. Administered at the time of angioplasty or directional coronary atherectomy, abciximab had a beneficial effect in the population studied, which included patients considered to be at high risk from complications of the procedure, based on the presence of acute or recent myocardial infarction, severe unstable angina or adverse coronary morphological characteristics. Abciximab reduced the risk of the primary endpoint at 30 days (death, myocardial infarction, repeat angioplasty or bypass surgery for recurrent ischaemia, balloon pump or stent insertion for ischaemia) by 35%: from 12.8% in the placebo group to 8.3% in patients treated with abciximab bolus and infusion. This trend was observed as a whole and in each component of the primary endpoint. At 6 months follow-up, the effect of the treatment was modestly enhanced beyond 30 days. A variety of substudies have documented substantial evidence of treatment benefit in patients with acute myocardial infarction and unstable angina. Non-fatal infarction, observed as beyond that normally expected in other studies with directional coronary atherectomy, was not above normal in patients treated with abciximab, and there was evidence of a treatment benefit in the elderly, although more information would be helpful in patients over the age of 70. The substantial site-to-site variability indicates that standardization of percutaneous revascularization could enhance the benefit of abciximab, while reducing bleeding complications.

Abciximab↗
PubMed2006

Expression of endothelin-converting enzyme, endothelin-1 and endothelin receptors at the site of percutaneous coronary intervention in humans.

OBJECTIVE: The repair process at the site of injury after percutaneous coronary intervention (PCI) is dominated by neointimal formation composed mainly of smooth muscle cells (SMC). Endothelin-1 (ET-1) is a powerful vasoconstrictor and SMC mitogen. Endothelin-converting enzyme (ECE) is the final key enzyme of endothelin processing. The effects of ET-1 are mediated by binding to endothelin type A (ETA) and endothelin type B (ETB) receptors. The ligand/receptor/ligand-producing system (ET system) could be involved in the pathogenesis of neointimal formation in humans. METHODS: Fifteen post-PCI sites obtained at autopsy and eight atherectomy specimens obtained from restenotic sites were investigated using immunohistochemical single and double staining techniques. Frozen sections were stained with antibodies against ECE, ET-1, ETA and ETB receptors, SMC, macrophages and endothelial cells. RESULTS: At the early stage, less than 3 months after PCI, neointimal SMC were positive for ECE, ET-1, ETA and ETB receptors. The expression of ECE, ET-1, ETA and ETB receptors in these neointimal SMC decreased markedly from 6 months onwards. The ECE, ET-1, ETA and ETB receptor-positive cell areas were significantly (P < 0.005) greater in the first 3 months after PCI compared with 6 months or more after PCI. Atherectomy specimens also showed similar positivity. CONCLUSIONS: These observations strongly suggest that the expression of ECE, ET-1, ETA and ETB receptors is enhanced in neointimal SMC at early stages after PCI injury in human coronary arteries. The increased expression of the ET system may contribute to SMC proliferation/migration and vasoconstriction in human post-PCI coronary lesions.

Aged↗
PubMed2003

Histopathology of coronary in-stent restenosis following gamma brachytherapy.

The histopathology of in-stent restenosis (ISR) following gamma brachytherapy is described. Such histology has not been reported previously. An 82 year old man presented with recurrent ISR three months after gamma brachytherapy to an area of ISR within a native circumflex vessel. The recurrent ISR was treated with directional coronary atherectomy; the histopathology of this directional coronary atherectomy specimen is discussed. These histopathological examinations showed abundant extracellular matrix material. Surprisingly, there was a relatively small cellular (myofibroblastic) component, with an absence of endothelial cells and little evidence of active proliferation. ISR after gamma brachytherapy may be a pathologically distinct entity.

Aged↗
PubMed1996

Clinically stable angina pectoris is not necessarily associated with histologically stable atherosclerotic plaques.

OBJECTIVE: To investigate the extent of plaque inflammation in culprit lesions of patients with chronic stable angina. DESIGN: Retrospective study. SETTING: Amsterdam reference centre. SUBJECTS: 89 consecutive patients who underwent directional coronary atherectomy, 58 of whom met the following inclusion criteria: chronic stable angina (Canadian Cardiovascular Society classification 1-3 (group 1, n = 28)); unstable angina (Braunwald class II (group 2, n = 18)); unstable angina (Braunwald class III (group 3, n = 12)). INTERVENTIONS: Directional atherectomy in patients with angina pectoris. MAIN OUTCOME MEASURES: Tissue areas of culprit lesions occupied by inflammatory cells and smooth muscle cells related to clinically defined ischaemic syndrome. RESULTS: Areas (% of total surface area (mean (SEM)) rich in smooth muscle cells were larger in patients with chronic stable angina (group 1, 51.2 (20.9)) than in those with unstable angina (group 2, 42.1 (20.5); group 3, 29.5 (19.4)) (1 v 2 and 2 v 3, NS; 1 v 3, P < 0.004). Macrophage rich areas were significantly smaller in patients with stable angina (group 1, 21.8 (11.9)) than in those with unstable angina (group 2, 31.5 (14.6); group 3, 46.4 (16.7)) (1 v 2, P < 0.02; 2 v 3, P < 0.02; 1 v 3, P < 0.001). Mean numbers of T cells per mm2 were as follows: group 1, 17 (9.4); group 2, 25 (15.9); group 3, 41 (30.6) (1 v 2, P 0.04; 2 v 3, P 0.07; 1 v 3, P < 0.001). Areas with HLA-DR positive cells showed the same pattern as macrophages and T cells and were smaller in stable (29.9 (12.4)) than in unstable angina (group 2, 40.4 (17.6); group 3, 52.4 (12.0)) (1 v 2, P < 0.02; 2 v 3, P < 0.05; 1 v 3, P < 0.001). CONCLUSION: The inverse relation between the extent of inflammatory activity in plaque tissues of culprit lesions and the clinical stability of the ischaemic syndrome supports the concept that reduction of inflammation favours plaque stabilisation. At the same time, the considerable overlap between groups indicates that patients with clinically stable angina do not all have histologically stable plaques.

Angina Pectoris↗
PubMed1998

Recent activation of the plaque immune response in coronary lesions underlying acute coronary syndromes.

OBJECTIVE: To discriminate between chronic inflammation and acute activation of the plaque immune response in culprit lesions of patients with acute coronary syndromes. DESIGN: Retrospective study. SETTING: Tertiary referral centre. SUBJECTS: 71 patients having coronary atherectomy were classified according to their ischaemic syndrome: stable angina (n = 23); stabilised unstable angina (n = 18); refractory unstable angina (n = 11); and acute myocardial infarction (n = 19). MAIN OUTCOME MEASURES: Immunohistochemical measurement of interleukin 2 receptor (IL-2R) (CD25) positive cells expressed as a percentage of the total amount of (CD3 positive) T lymphocytes in frozen sections of atherectomy specimens. RESULTS: The number of lesions containing IL-2R (CD25) positive T cells increased with severity of the ischaemic coronary syndrome (stable angina, 52%; stabilised unstable angina, 77.8%; refractory unstable angina, 90.9%; acute myocardial infarction, 89.4%). The percentage of activated T cells (CD25/CD3 ratios x100) increased in lesions associated with refractory unstable angina (7.8%) and acute myocardial infarction (18.5%), compared with those in lesions associated with either chronic stable angina (2.2%) or stabilised unstable angina (3.3%). CONCLUSIONS: An increase in the percentage of IL-2R positive T lymphocytes in culprit lesions of patients with acute coronary syndromes indicates recent activation and amplification of the immune response within plaques. This may result in a burst of inflammatory products with tissue degrading and vasoactive properties and, hence, could initiate or accelerate the onset of an acute coronary event.

Angina Pectoris↗
PubMed1998

Histological patterns of atherosclerotic plaques in unstable angina patients vary according to clinical presentation.

BACKGROUND: Unstable angina is a heterogeneous clinical syndrome. The diverse clinical presentations of unstable angina may reflect different pathogenic mechanisms within the plaque. OBJECTIVE: To investigate the cellular constituents of culprit coronary atheromatous plaques in patients with stable angina pectoris and patients with diverse clinical presentations of unstable angina. METHODS: 48 patients who underwent coronary atherectomy for management of ischaemic heart disease: 23 had stable angina and 25 had unstable angina. Of the latter, 11 patients were classified as Braunwald's IIB and 14 as Braunwald's IIIB unstable angina. The presence of thrombus, cholesterol clefts, and smooth muscle cell proliferation was assessed in atherectomy samples using standard histological techniques. Monoclonal antibodies were used to identify smooth muscle cells and macrophages within atherosclerotic plaque fragments. RESULTS: Fresh thrombus was more frequently found in patients with Braunwald's IIIB unstable angina (64%) than in patients with stable angina (22%) or IIB unstable angina (27%) (p < 0.0006). A pattern of smooth muscle cell proliferation ("accelerated progression pattern") was observed which was also associated with coronary thrombus. This pattern was present in 30% of patients with stable angina, 64% of patients with IIIB unstable angina, and in all patients (100%) with IIB unstable angina. Atherosclerotic plaques with thrombus, cholesterol clefts, and macrophages were more common in patients with unstable angina than in stable angina patients. CONCLUSION: The presence of a specific smooth muscle cell proliferation (accelerated progression) pattern in patients with unstable angina, particularly in those with Braunwald's IIB unstable angina, suggests that episodic plaque disruption and subsequent healing may be an important mechanism underlying angina symptoms in these patients.

Adult↗
PubMed1995

Late reobstruction in iliac arterial stents: percutaneous treatment.

PURPOSE: To retrospectively analyze in a nonrandomized fashion the efficacy of percutaneous reintervention in obstructed iliac stents. MATERIALS AND METHODS: In 21 symptomatic patients with iliac lesions, 26 reinterventions (16 for stent occlusion and 10 for stent stenosis) were performed. Restenoses were treated with balloon dilation and either atherectomy or stent placement. Reocclusions were treated with atherectomy or aspiration thrombectomy and then recanalization with balloon dilation and selective stent placement. RESULTS: Balloon angioplasty for stent stenosis was effective in all but one patient. Recanalization was successful in 14 of 16 patients with stent occlusion. The mean period of patency after reintervention was 18 months +/- 15. Cumulative stent stenosis patency after reintervention was 87% after 1 year. Stent occlusion patency was 57%. Recurrent stent obstruction occurred in eight of 24 (33%) patients with successful primary interventions. CONCLUSION: Percutaneous reintervention for both stent stenosis and occlusion is feasible with a moderate complication rate and may be attempted before surgery.

Angioplasty, Balloon↗
PubMed2001

Elevated levels of oxidized low density lipoprotein show a positive relationship with the severity of acute coronary syndromes.

BACKGROUND: There is accumulating data that acute coronary syndromes relate to recent onset activation of inflammation affecting atherosclerotic plaques. Increased blood levels of oxidized low density lipoprotein (ox-LDL) could play a role in these circumstances. METHODS AND RESULTS: Ox-LDL levels were measured in 135 patients with acute myocardial infarction (AMI; n=45), unstable angina pectoris (UAP; n=45), and stable angina pectoris (SAP; n=45) and in 46 control subjects using a sandwich ELISA method. In addition, 33 atherectomy specimens obtained from a different cohort of patients with SAP (n=10) and UAP (n=23) were studied immunohistochemically for ox-LDL. In AMI patients, ox-LDL levels were significantly higher than in patients with UAP (P<0.0005) or SAP (P<0.0001) or in controls (P<0.0001) (AMI, 1.95+/-1.42 ng/5 microgram LDL protein; UAP, 1.19+/-0.74 ng/5 microgram LDL protein; SAP, 0.89+/-0.48 ng/5 microgram LDL protein; control, 0.58+/-0.23 ng/5 microgram LDL protein). Serum levels of total, HDL, and LDL cholesterol did not differ among these patient groups. In the atherectomy specimens, the surface area containing ox-LDL-positive macrophages was significantly higher in patients with UAP than in those with SAP (P<0.0001). CONCLUSIONS: This study demonstrates that ox-LDL levels show a significant positive correlation with the severity of acute coronary syndromes and that the more severe lesions also contain a significantly higher percentage of ox-LDL-positive macrophages. These observations suggest that increased levels of ox-LDL relate to plaque instability in human coronary atherosclerotic lesions.

Angina Pectoris↗
PubMed1993

Vascular complications after balloon and new device angioplasty.

BACKGROUND: Despite their potential advantages, new coronary angioplasty devices may be associated with more frequent vascular complications than noted after standard balloon angioplasty, theoretically due to the larger sheaths and prolonged periods of anticoagulation required by some of these devices. This study sought to identify the incidence, predictors, and clinical outcome of vascular complications after new device angioplasty. METHODS AND RESULTS: The clinical course of 1413 patients was reviewed after balloon or new device angioplasty. Vascular complications were defined as formation of a pseudoaneurysm, arteriovenous fistula, retroperitoneal hematoma, or groin hematoma associated with a > 15-point hematocrit drop or the need for surgical repair. Stepwise logistic regression was used to identify independent predictors for vascular complications. Vascular complications developed after 84 (5.9%) procedures; they occurred more frequently after intracoronary stenting (14.0%) and extraction atherectomy (12.5%) than after balloon angioplasty (3.2%) (odds ratios, 4.86; P < .001, and 4.26, P < .05, respectively). Independent predictors of vascular complications included the use of intraprocedural thrombolytic agents (P < .01), intracoronary stenting (P < .005), or extraction atherectomy (P < .05); high maximum creatinine level (P < .005); low nadir platelet count (P < .001); longer periods of excess anticoagulation (P < .05); and the need for repeat coronary angioplasty (P < .005). Vascular complications were not related to the size of the arterial sheath used. CONCLUSIONS: Vascular complications developed more frequently after new device angioplasty than after balloon angioplasty, with the risk for vascular complications directly related to the degree of periprocedural anticoagulation.

Aneurysm, False↗
PubMed1993

Smooth muscle cell abundance and fibroblast growth factors in coronary lesions of patients with nonfatal unstable angina. A clue to the mechanism of transformation from the stable to the unstable clinical state.

BACKGROUND: The mechanisms responsible for the transformation of stable angina to unstable angina, a major cause of morbidity and mortality, are commonly believed to be plaque rupture and thrombosis. We determined whether additional mechanisms are operative by analyzing the histopathology and immuno-histopathology of coronary plaques retrieved by directional atherectomy of patients with unstable angina in whom no intraluminal thrombus was demonstrated by angiography. METHODS AND RESULTS: The histological findings of atherectomy specimens from 34 patients with unstable angina were compared with those of 24 patients with postangioplasty restenosis, whose lesions are known to be composed of smooth muscle cells (SMCs), and 10 patients with stable angina, whose lesions contain relatively few SMCs. We also studied the expression of acidic and basic fibroblast growth factors (aFGF and bFGF), whose role in the vascular response to injury has been established. Specimens from unstable angina resembled those from postangioplasty restenosis in regard to SMC abundance (scale, 0 to 3; 1.4 +/- 0.9 versus 1.7 +/- 0.9; P = NS), and both differed from those of stable angina. Thrombus and/or hemorrhage occurred in only 34% of patients with unstable angina (compared with 8% of restenosis patients and in none of stable angina patients). Active lesions (defined as lesions (defined as lesions containing one or more of the following: thrombus, hemorrhage, abundant and disorganized SMCs in the presence of loose connective tissue, or inflammatory infiltrate) were observed in 56% of the unstable angina patients and in 50% of the restenosis patients but in none of the stable angina patients. The expression of aFGF and bFGF was detected in 80% to 100% of unstable angina (n = 11) and restenosis (n = 10) specimens but in only 1 of 5 stable angina specimens. CONCLUSIONS: Microscopic evidence of thrombosis and plaque rupture occurred in only one third of unstable angina patients, selected because they had no angiographic evidence of intracoronary thrombus. Moreover, their lesions resembled those of restenosis patients in regard to SMC abundance, lesion activity, and the expression of aFGF and bFGF. Our findings therefore suggest that an alternative mechanism to plaque rupture and thrombus formation may be operative in the precipitation of unstable angina; namely, in a subset of patients, SMC proliferation may lead to gradual plaque expansion and thereby to lumenal narrowing and unstable angina. Our data also suggest a role for aFGF and bFGF in this process.

Adult↗
PubMed1995

Identification of 92-kD gelatinase in human coronary atherosclerotic lesions. Association of active enzyme synthesis with unstable angina.

BACKGROUND: Acute coronary ischemia is usually initiated by rupture of atherosclerotic plaque, leading to intracoronary thrombosis and clinical sequelae. The proximate cause of plaque rupture is unknown. Accordingly, we investigated the potential role of the 92-kD gelatinase member of the matrix metalloproteinase family in acute coronary ischemia. METHODS AND RESULTS: Coronary atherectomy specimens from patients with atherosclerosis and an acute ischemic syndrome consistent with recent plaque rupture (unstable angina) (n = 12) were immunostained for the presence of 92-kD gelatinase; the results were compared with those obtained by identical study of atherectomy specimens from patients with atherosclerosis and angina but without acute ischemia (stable angina) (n = 12). Positive immunostaining for 92-kD gelatinase was present in 83% of specimens from both unstable and stable angina patients. However, intracellular localization of enzyme (indicating active synthesis) was documented in 10 of 10 positively stained specimens from patients with unstable angina compared with 3 of 10 positively stained specimens from patients with stable angina. Macrophages and smooth muscle cells were the major sources of 92-kD gelatinase in all specimens examined by immunostaining of adjacent sections. CONCLUSIONS: 92-kD gelatinase is commonly expressed in coronary arterial atherosclerotic lesions. Active synthesis of 92-kD gelatinase by macrophages and smooth muscle cells in atherosclerotic lesions may play a pathogenic role in the development of acute coronary ischemia.

Angina Pectoris↗
PubMed1996

Significance of mild transient release of creatine kinase-MB fraction after percutaneous coronary interventions.

BACKGROUND: The clinical significance of minor elevations in creatine kinase-myocardial band isoenzyme (CK-MB) after coronary interventions has not been systematically evaluated. METHODS AND RESULTS: We examined 4484 patients who underwent successful percutaneous transluminal coronary angioplasty or directional coronary atherectomy and whose peak CK levels did not exceed twice the upper limit of laboratory normal. Group 1 (3776 patients) had no CK or MB elevation after the procedure (ie, CK < or = 180 IU/L, with MB fraction < or = 4%). Group 2 (450 patients) had a peak CK level between 100 and 180 IU/L, with MB fraction > 4%, and group 3 (258 patients) had a peak CK level between 181 and 360 IU/L, with MB fraction > 4%. The strongest correlate of postprocedure CK-MB elevation was the performance of directional coronary atherectomy (odds ratio, 4.1; P < .0001), followed by the development of > or = 1 in-1ab minor procedural complication (odds ratio, 2.6; P < .0001). Clinical follow-up was available in 4461 patients (99.5%), with a mean duration of 36 +/- 22 months. Survival analysis, adjusted with Cox proportional hazards regression model, showed that the groups with elevated CK-MB had a significantly higher incidence of cardiac death (risk ratio, 1.3; P = .04) and myocardial infarction (risk ratio, 1.3; P = .03). Major ischemic complications (death, myocardial infarction, and coronary revascularization) occurred more frequently in the groups with increased CK-MB (groups 1 versus 2 versus 3, 37.3% versus 43.3% versus 48.9%; P = .01). CONCLUSIONS: This study shows that minor elevations of CK-MB after successful coronary interventions identify a population with a worse long-term prognosis compared with patients with no enzyme elevations and appear to have an adverse effect on long-term prognosis. Future studies of percutaneous coronary revascularization should include routine measurements of biochemical cardiac markers as important predictors of long-term prognosis.

Angioplasty, Balloon, Coronary↗
PubMed1997

Contemporary percutaneous treatment of unprotected left main coronary stenoses: initial results from a multicenter registry analysis 1994-1996.

BACKGROUND: Coronary artery bypass surgery (CABG) has been considered the therapy of choice for patients with unprotected left main (ULMT) coronary stenoses. Selected single-center reports suggest that the results of percutaneous intervention may now approach those of CABG. METHODS AND RESULTS: To assess the results of percutaneous ULMT treatment from a wide variety of experienced interventional centers, we requested data on consecutive patients treated after January 1, 1994, from 25 centers. One hundred seven patients were identified who were treated either electively (n=91) or for acute myocardial infarction (n=16). Of patients treated electively, 25% were considered inoperable, and 27% were considered high risk for bypass surgery. Primary treatment included stents (50%), directional atherectomy (24%), and balloon angioplasty (20%). Follow-up was 98.8% complete at 15+/-8 months. Results varied considerably, depending on presentation and treatment. For patients with acute myocardial infarction, technical success was achieved in 75%, and survival to hospital discharge was 31%. For elective patients, technical success was achieved in 98.9%, and in-hospital survival was strongly correlated with left ventricular ejection fraction (P=.003). Longer-term event (death, infarction, or bypass surgery) -free survival was correlated with ejection fraction (P<.001) and was inversely related to presentation with progressive or rest angina (P<.001). Surgical candidates with ejection fractions > or = 40% had an in-hospital survival of 98% and a 9-month event-free survival of 86+/-5%, whereas patients with ejection fractions < 40% had 67% and 22+/-12% in-hospital and 9-month event-free survivals, respectively. Nine hospital survivors (10.6%) experienced cardiac death within 6 months of hospital discharge. CONCLUSIONS: While results for selected patients appear promising, until early post-hospital discharge cardiac death can be better understood and minimized, percutaneous revascularization of ULMT stenosis should not be considered an alternative to bypass surgery for most patients. When percutaneous revascularization of ULMT is required, directional atherectomy and stenting appear to be the preferred techniques, and follow-up angiography 6 to 8 weeks after treatment is probably advisable.

Aged↗
PubMed1998

Activation of platelets in platelet-rich plasma by rotablation is speed-dependent and can be inhibited by abciximab (c7E3 Fab; ReoPro).

BACKGROUND: Rotational atherectomy with the Rotablator catheter has improved percutaneous treatment of certain coronary atherosclerotic lesions, but the "no-reflow" phenomenon remains a serious complication. Because platelet activation by rotablation may contribute to the no-reflow phenomenon, we developed an in vitro system to test the effect of rotablation on platelets in the absence or presence of platelet GP IIb/IIIa receptor blockade with abciximab. METHODS AND RESULTS: Platelet-rich plasma (PRP) was prepared from 28 healthy human volunteers. PRP was divided into 4 samples: (1) no treatment, (2) 6D1 (anti-GP Ib), (3) c7E3 Fab (anti-GP IIb/IIIa+alpha(v)beta3), and (4) c7E3 Fab+6D1. Samples were pumped through a flow chamber containing a 2.5-mm burr rotating at various speeds and then placed in an aggregometer. PRP samples tested in the absence of antibody underwent more rapid and extensive aggregation when rotablated at 150000 and 180000 rpm compared with 0 rpm (P<0.001 at both speeds). Preincubation of platelets with c7E3 Fab decreased the slope of aggregation at each rotablation speed, with 98%, 79%, and 71% reductions at 70000, 150000, and 180000 rpm, respectively (P=0.09 for 70000 and P<0.001 for both 150000 and 180000 rpm). Preincubation of platelets with 6D1 did not decrease the slope of aggregation at any rotablation speed (P>0.5, P=0.99, and P=0.091 for 70000, 150000, and 180000 rpm). Platelet ATP release, a marker of granule release and cell damage, was markedly increased at 180000 rpm (P=0.002 compared with 0 rpm in the control group). Electron microscopy revealed extensive rotablation-induced platelet damage at 150000 and 180000 rpm, and leakage of LDH confirmed platelet lysis at these speeds (P=0.002 and P<0.001 compared with 0 rpm). CONCLUSIONS: High-speed rotablation induces platelet activation of PRP, leading to aggregation; pretreating PRP with abciximab decreases the aggregation. These data suggest that pretreatment of patients with abciximab may decrease rotablation-induced platelet aggregation during rotational atherectomy.

Abciximab↗
PubMed1998

Evidence that macrophages in atherosclerotic lesions contain angiotensin II.

BACKGROUND: We have reported that human mononuclear leukocytes contain large amounts of angiotensin II (Ang II). The goal of the present study was to test the hypothesis that Ang II is present in monocyte/macrophages in atherosclerotic lesions. METHODS AND RESULTS: Segments of thoracic aorta and left circumflex coronary artery were obtained from 3 groups of cynomolgus monkeys: normal, atherosclerotic, and regression. Samples of human coronary arterial atherosclerotic lesions were obtained from directional atherectomy. Sections were stained for Ang II with 3 different polyclonal rabbit anti-human Ang II antisera. In aorta and coronary arteries from normal monkeys, there was no or minimal anti-Ang II staining in endothelial cells. All sections from atherosclerotic monkeys displayed discrete, localized regions of staining for Ang II in intima-media. Macrophages were present throughout the atherosclerotic intima-media, and anti-Ang II staining appeared to colocalize with macrophages. All human coronary atherectomy samples stained positive for Ang II and macrophages. Staining for both Ang II and macrophages was observed in vascular lesions from all 5 monkeys after regression of atherosclerosis, but staining was less extensive than in atherosclerotic blood vessels from monkeys. CONCLUSIONS: These findings suggest that Ang II is present in atherosclerotic lesions in monkeys and humans, colocalizes with macrophages in intima-media of atherosclerotic vessels from monkeys, and decreases in lesions in monkeys with regression of atherosclerosis.

Angiotensin II↗