Treatment of Aortoiliac Occlusive Disease with the Endologix AFX Unibody Endograft.

OBJECTIVE/BACKGROUND: Aorto-bifemoral bypass remains the gold standard for treatment of aortoiliac occlusive disease (AIOD) in patients with advanced (TASC D) lesions, but has significant associated morbidity and mortality. Treatment with a unibody stent-graft positioned at the aortic bifurcation is a potential endovascular option for the treatment of AIOD. The current study examines the safety, efficacy, and early patency rates of the Endologix AFX unibody stent-graft for treatment of AIOD. METHODS: A multicenter retrospective review was conducted of patients treated exclusively for AIOD with the AFX device. Primary, assisted primary, and secondary patency rates were noted. Clinical improvement was assessed using Rutherford classification and ankle brachial index. Mean duration of follow-up was 22.2 ± 11.2 months. Ninety-one patients (56 males [62%]) were studied. RESULTS: Sixty-seven patients (74%) presented with lifestyle-limiting intermittent claudication and the remaining 24 (26%) had critical limb ischemia. Technical success was 100%. Complications included groin infection (n = 4 [4%]), groin hematoma (n = 4 [4%]), common iliac rupture (n = 4 [4%]), iliac dissection (n = 4 [4%]), and thromboembolic event (n = 3 [3%]; one femoral, one internal iliac artery, and one internal iliac with bilateral popliteal/tibial thromboemboli). Thirty-day mortality was 1% (1/91) resulting from a case of extensive pelvic thromboembolism. At 1 year, 73% of patients experienced improvement in Rutherford stage of -3 or greater compared with baseline. Nine patients (10%) required 16 secondary interventions. At all time points, primary patency rates were > 90%, assisted patency rates were > 98%, and secondary patency rates were 100%. CONCLUSION: This is the largest study to examine the use of the Endologix AFX unibody stent-graft for the treatment of AIOD. Use of the AFX stent-graft appears to be a safe and effective endovascular treatment for complex AIOD.

Dalteparin in combination with abciximab during percutaneous coronary intervention.

BACKGROUND: Despite proved efficacy for either dalteparin or platelet glycoprotein IIb/IIIa blockade in improving clinical outcomes of patients with non-ST-segment elevation acute coronary syndromes, algorithms guiding concomitant therapy with these agents have not been devised. The purpose of this study was to assess anticoagulant effect and clinical safety for several dose regimens of dalteparin administered in combination with abciximab during percutaneous coronary intervention (PCI). METHODS AND RESULTS: Patients undergoing PCI with standard dose abciximab received dalteparin as follows: 120 IU/kg subcutaneously (SQ) to a maximum of 10,000 U if < or =8 hours before PCI (n = 3); for PCI 8-12 hours after the SQ dose, an additional 40 IU/kg intravenously (IV) was administered (n = 1); for PCI >12 hours after SQ dalteparin or with no prior dalteparin therapy, random allocation to 40 (n = 27) or 60 (n = 28) IU/kg IV during PCI was performed. Those patients who received 60 IU/kg of dalteparin IV had a lower incidence of procedural thrombosis (0% vs 11.1%, P <.01), more consistent antithrombotic effect (anti-factor Xa activity) and a similar incidence of major bleeding (3.7% vs 2.6%) compared with patients who received 40 IU/kg of intravenous dalteparin. CONCLUSIONS: Dalteparin 60 IU/kg IV appears to be safe and effective when administered in conjunction with abciximab for percutaneous coronary intervention.

Coronary perforation during percutaneous coronary intervention in the era of abciximab platelet glycoprotein IIb/IIIa blockade: an algorithm for percutaneous management.

Coronary perforation is an uncommon but potentially life-threatening complication of percutaneous coronary intervention. The use of both atheroablative technologies for coronary intervention and adjunctive platelet glycoprotein blockade pharmacology may increase the incidence of or risk for life-threatening bleeding complications following the occurrence of coronary artery perforation. The interventional database for 6,214 percutaneous coronary interventions performed between January 1995 and June 1999 was analyzed. Hospital charts and cine angiograms for all patients identified in the database as having had coronary perforation were reviewed. Coronary perforation complicated 0.58% of all procedures and was more commonly observed in patients with a history of congestive heart failure and following use of atheroablative interventional technologies (2.8%). There was no association of abciximab therapy with either the incidence of or classification for coronary perforation. Adverse clinical outcomes (death, emergency surgical exploration) were related to the angiographic classification of perforation and were more frequently observed in patients who experienced a class 3 coronary perforation. These data suggest that specific clinical and procedural demographic factors are associated with the occurrence and severity of angiographic coronary perforation. An angiographic perforation class-specific algorithm for treatment of coronary perforation is proposed.

Combination Enoxaparin and Abciximab During Percutaneous Coronary Intervention: A New Standard of Care?

Evidence from randomized trials supports the administration of platelet glycoprotein (GP) IIb/IIIa blockade both to patients undergoing percutaneous coronary intervention (PCI) and those presenting with non-ST elevation acute coronary syndromes (ACSs). Similarly, the low molecular weight heparin (LMWH), enoxaparin, has demonstrated superior efficacy when compared with unfractionated heparin (UFH) in the treatment of patients with non-ST elevation ACS. Algorithms for seamless integration of pharmacotherpy through the course of hospitalization for patients who present with ACS and who require PCI will likely combine therapy with enoxaparin and platelet GP IIb/IIIa blockade (abciximab). Our preliminary experience with combination enoxaparin and abciximab as adjunctive pharmacotherapy for PCI suggests that this strategy is safe and effective and may offer advantages over a conventional strategy, which employs UFH.

Abciximab provides cost-effective survival advantage in high-volume interventional practice.

BACKGROUND: Placebo-controlled randomized trials of platelet glycoprotein (GP) IIb/IIIa blockade during percutaneous coronary intervention have demonstrated efficacy of these agents for reducing the risk of periprocedural ischemic events. However, cost-effectiveness of this adjunctive pharmacotherapy has been scrutinized. Extrapolation of cost-efficacy observations from clinical trials to "real world" interventional practice is problematic. METHODS: Consecutive percutaneous coronary interventions (n = 1472) performed by Ohio Heart Health Center operators at The Christ Hospital, Cincinnati, Ohio, in 1997 were analyzed for procedural and long-term (6-month) outcomes and charges. Observations on cost and efficacy (survival) were adjusted for nonrandomized abciximab allocation by means of "propensity scoring" methods. RESULTS: Abciximab therapy was associated with a survival advantage to 6 months after percutaneous coronary intervention. The average reduction in mortality rate at 6 months was 3.4% (unadjusted) and 4.9% when adjusted for nonrandomization. The average charge increment to 6 months was $1512 (unadjusted) and $950 when adjusted for nonrandomization. Patients deriving the greatest reduction in mortality rates also had a reduction in total cardiovascular charges to 6 months. Distinguishing demographics of this population included multivessel coronary intervention, coronary stent deployment, intervention within 1 week of myocardial infarction, and lower left ventricular ejection fraction. The average cost per life-year gained in this study was $2875 for all patients (unadjusted) and $1243 when adjusted for nonrandomization. CONCLUSIONS: Abciximab provides a cost-effective survival advantage in high-volume interventional practice that compares favorably with currently accepted standards. Clinical and procedural demographics associated with increased cost-effectiveness included multivessel coronary intervention, stent deployment, recent (<1 week) myocardial infarction, and impaired left ventricular function.

IIb's are not IIb's.

Platelet glycoprotein (GP) IIb/IIIa receptor blockade improves clinical outcomes after percutaneous coronary intervention (PCI) and for patients who present with non-ST-segment elevation acute coronary syndromes. Although this class of therapeutic agents has been defined by a common affinity for the platelet GP IIb/IIIa receptor, the 3 currently available agents differ markedly in pharmacodynamic and pharmacokinetic profile as well as receptor affinity. Differential (separate) binding sites on the GP IIb/IIIa receptor explain the observation that abciximab binding to platelets is not influenced by either tirofiban or eptifibatide. Abciximab (ReoPro, chimeric 7E3 Fab) is a low K(d) (high affinity) agent with a very short plasma t(1/2) and a prolonged duration of action at the platelet target receptor. Eptifibatide and tirofiban are high K(d) (low affinity) agents with a relatively long plasma t(1/2) and short duration of action at the platelet target receptor. These pharmacodynamic differences underlie the phenomena of gradual redistribution in abciximab binding and smooth tapering of abciximab antiplatelet effect after discontinuation of therapy. Furthermore, abciximab demonstrates affinity for both the CD11b/18 (alpha(m)beta(2) or MAC 1) and alpha(V)beta(3) (vitronectin) receptors. Although a survival advantage in favor of abciximab has been observed after PCI in both randomized controlled trials and high-volume clinical practice, no survival benefit has been observed to date after eptifibatide or tirofiban therapy for PCI. The mechanism of survival advantage after abciximab therapy has not been defined but may be distinct from the degree of platelet GP IIb/IIIa receptor inhibition during the duration of intravenous treatment. Although this important new "class" of therapeutic agent was simplistically defined by a common affinity for the GP IIb/IIIa receptor, this solitary unifying attribute may not define agent-specific benefit.

Combination enoxaparin and abciximab therapy during percutaneous coronary intervention: "NICE guys finish first".

Data from randomized clinical trials support the administration of both enoxaparin and platelet glycoprotein IIb/IIIa blockade to patients who present with non-ST segment evaluation acute coronary syndromes. Enoxaparin does not activate platelets, has a more predictable dose response that facilitates weight-adjusted dosing and may have enhanced antithrombotic (increased anti-Xa activity) and safety (reduced anti-IIa activity) properties when compared with unfractionated heparin. Abciximab administration during percutaneous coronary intervention reduces the incidence of ischemic adverse outcomes and may improve survival in long-term follow-up. The preliminary experience with combining abciximab and intravenous enoxaparin during percutaneous coronary intervention in the NICE-4 Trial demonstrates a low incidence of minor/major bleeding (TIMI definition) and transfusion and infrequent major cardiac events to 30 days follow-up. Future algorithms to facilitate the transition of patients from the clinical service who have received subcutaneous administration of enoxaparin to the cardiac catheterization laboratory prior to percutaneous coronary intervention are forthcoming and will provide seamless integration of "optimal" adjunctive pharmacology through the course of hospitalization for patients with non-ST elevation acute coronary syndromes.

Therapeutic adjuncts for immediate transfer to the catheterization laboratory in patients with acute coronary syndromes.

Early coronary intervention in patients with non-ST-segment elevation myocardial infarction (MI) and unstable angina may be made safer and more efficacious with concomitant therapies, including glycoprotein IIb/IIIa inhibitors and low-molecular-weight heparins. Stent placement has been shown to improve procedural success and reduce major in-hospital complications when compared with balloon angioplasty alone in patients with unstable angina. However, unstable angina remains a major hazard for adverse coronary events in long-term follow-up after elective stent placement. The currently available glycoprotein IIb/IIIa inhibitors-eptifibatide, tirofiban, and abciximab--have each been shown to reduce ischemic events before percutaneous coronary intervention when administered to patients presenting with non-ST-segment elevation acute coronary syndromes in large clinical trials. The adjunctive role of low-molecular-weight heparins in this scenario has been largely unexplored. Enoxaparin, when given before angiography or percutaneous coronary intervention, has been shown to be superior to unfractionated heparin in preventing major coronary events. In this review, an algorithm for treatment of non-ST-segment elevation acute coronary syndromes is presented and the current role of these newer adjunctive pharmacotherapies is explored. In the future, combinations of these agents may prove to be most beneficial in patients undergoing early percutaneous coronary intervention.

Time course, magnitude, and consistency of platelet inhibition by abciximab, tirofiban, or eptifibatide in patients with unstable angina pectoris undergoing percutaneous coronary intervention.

Adjunctive platelet glycoprotein IIb/IIIa blockade during percutaneous coronary intervention (PCI) reduces platelet-mediated adverse ischemic outcomes. Although abciximab, eptifibatide, and tirofiban have received U.S. Food and Drug Administration approval for use, these agents differ in their pharmacodynamic profiles. Each of these agents has been compared in randomized trials with placebo for patients undergoing PCI, but no randomized comparative studies of these agents have been performed. We compared ex vivo platelet function by both standard light transmission aggregometry and rapid platelet function assay during and after administration of abciximab, eptifibatide, or tirofiban in approved dose regimens on a randomized basis at the time of PCI in patients with unstable angina pectoris. A reduced intensity of platelet inhibition by light transmission aggregometry was observed for tirofiban compared with either eptifibatide or abciximab. In addition, the 30-minute bolus strategy used for tirofiban was associated with delayed onset of maximal platelet inhibition relative to the initiation of bolus infusion. Whether the trends in platelet function observed in this study will be translated into differences in clinical outcomes awaits definition by larger scale randomized clinical trials comparing these platelet glycoprotein IIb/IIIa inhibitors.

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.

Coronary angioplasty versus repeat coronary artery bypass grafting for patients with previous bypass surgery.

OBJECTIVES: We attempted to determine the relative risks and benefits of percutaneous transluminal coronary angioplasty (PTCA) and repeat coronary artery bypass grafting (re-CABG) in patients with previous coronary bypass surgery (CABG). BACKGROUND: Due to an expanding population of patients with surgically treated coronary artery disease and the natural progression of atherosclerosis, an increasing number of patients with previous CABG require repeat revascularization procedures. Although there are randomized comparative data for CABG versus medical therapy and, more recently, versus PTCA, these studies have excluded patients with previous CABG. METHODS: We retrospectively analyzed data from 632 patients with previous CABG who required either elective re-CABG (n = 164) or PTCA (n = 468) at a single center during 1987 through 1988. The PTCA and re-CABG groups were similar with respect to gender (83% vs. 85% male), age > 70 years (21% vs. 23%), mean left ventricular ejection fraction (46% vs. 48%), presence of class III or IV angina (70% vs. 63%) and three-vessel coronary artery disease (77% vs. 74%). RESULTS: Complete revascularization was achieved in 38% of patients with PTCA and 92% of those with re-CABG (p < 0.0001). The in-hospital complication rates were significantly lower in the PTCA group: death (0.3% vs. 7.3%, p < 0.0001) and Q wave myocardial infarction (MI) (0.9% vs. 6.1%, p < 0.0001). Actuarial survival was equivalent at 1 year (PTCA 95% vs. re-CABG 91%) and 6 years (PTCA 74% vs. re-CABG 73%) of follow-up (p = 0.32). Both procedures resulted in equivalent event-free survival (freedom from dealth or Q wave MI) and relief of angina; however, the need for repeat percutaneous or surgical revascularization, or both, by 6 years was significantly higher in the PTCA group (PTCA 64% vs. re-CABG 8%, p < 0.0001). Multivariate analysis identified age > 70 years, left ventricular ejection fraction < 40%, unstable angina, number of diseased vessels and diabetes mellitus as independent correlates of mortality for the entire group. CONCLUSIONS: In this nonrandomized series of patients with previous CABG requiring revascularization, an initial stategy of either PTCA or re-CABG resulted in equivalent overall survival, event-free survival and relief of angina. PTCA offers lower procedural morbidity and mortality risks, although it is associated with less complete revascularization and a greater need for subsequent revascularization procedures.

Results of direct percutaneous transluminal coronary angioplasty in octogenarians.

Direct percutaneous transluminal coronary angioplasty (PTCA) has emerged as effective reperfusion therapy for acute myocardial infarction; however, few data exist on its use in octogenarians. Thrombolytic therapy in this age group has reduced early mortality from approximately 30% to 20%, but is associated with an increased risk of stroke and major hemorrhage. We analyzed the acute and long-term results of direct PTCA performed on patients aged > or = 80 years at our institution between 1980 and 1993. The study group consisted of 55 patients (mean patient age 83.3 +/- 2.3 years). Infarcts were anterior in 27 patients (49%). Cardiogenic shock was present in 6 patients (11%). The mean time to reperfusion was 4.3 +/- 2.8 hours. Direct PTCA was successful in 53 patients (96%). There were no emergent bypass operations. In-hospital death occurred in 9 patients (16%), including 4 of 6 (67%) presenting in cardiogenic shock and 5 of 49 (10%) who were hemodynamically stable on presentation. Repeat PTCA for recurrent ischemia was performed in 6 patients (11%). There were no strokes during hospitalization. Bleeding complications requiring blood transfusion were present in 4 patients (7%). Thirty-day mortality was 16% and 1-year actuarial survival was 67%. Direct PTCA in patients aged > or = 80 years can be performed safely with a high procedural success rate. The clinical outcome with PTCA in this high risk subset of patients compares favorably with that reported previously for both thrombolytic and medical therapy.

Directional atherectomy of left main stenoses.

Balloon angioplasty (PTCA) of left main (LM) stenoses is limited by frequent clinical restenosis. Directional coronary atherectomy (DCA) may be an effective alternative to PTCA due to its ability to achieve a greater postprocedural luminal diameter when treating bulky, eccentric plaques and aorto-ostial lesions. We analyzed the acute and long-term results following 24 DCA procedures in 22 patients with "protected" LM lesions. Acute success (residual stenosis < or = 40%, no major ischemic complications) was 88% overall, 100% in 13 planned procedures, and 73% in 11 adjunctive DCA procedures that followed suboptimal PTCA. Mean LM stenosis was reduced from 86% to 13% (P < 0.01). There were no procedural complications directly attributed to DCA. At a mean of 24 +/- 3 months, the clinical restenosis rate was 16%, survival was 100%, and event-free survival (freedom from death, MI, or repeat lesion-related interventions) was 89%. We conclude that DCA in protected LM lesions (1) can achieved excellent angiographic results with low procedural complication rates, (2) may succeed where PTCA yields suboptimal results, and (3) may provide late clinical outcomes superior to those of balloon angioplasty.

Initial and long-term outcome of 83 patients after balloon angioplasty of totally occluded bypass grafts.

OBJECTIVES: This study was designed to evaluate the safety and short- and long-term results of coronary angioplasty of totally occluded bypass grafts in patients with clinical conditions other than acute myocardial infarction. BACKGROUND: Total occlusion of bypass grafts after coronary artery surgery often causes recurrent ischemia. The safety and results of percutaneous transluminal coronary angioplasty in occluded bypass grafts are controversial. METHODS: All patients with dilation of a totally occluded bypass graft attempted between 1981 and 1991 were retrospectively identified from a data base. Patients treated in the setting of an acute myocardial infarction were excluded. Eighty-three patients met these criteria and constitute the study group. Hospital records, office charts and procedural reports were reviewed in all patients to supplement details available in the data base. RESULTS: The time from bypass surgery to attempted coronary angioplasty ranged from 1 to 226 months (mean time 88 months). The mean (+/- SD) duration of graft occlusion was 31 +/- 46 days (range 1 to 180). In 27 attempts the bypass graft was the only site dilated, and in 56 attempts (68%) one to six other sites (n = 101) were dilated. Angiographic success (< or = 40% residual lumen stenosis) was achieved in 61 grafts (73%) and 98 of the additional sites (97%) (p < 0.001). Major complications included one procedural death and two Q wave infarctions. Follow-up for a mean of 32 months demonstrated a 1- and 3-year actuarial survival rate of 94% and 80%, respectively. At 3 years, only 34% of patients were free of repeat angioplasty or surgery. CONCLUSIONS: Angioplasty of totally occluded bypass grafts can be successful in the majority of selected patients, although major complications can occur. Strategies for sustained patency are needed to improve the long-term results.

Failed direct coronary angioplasty for acute myocardial infarction: in-hospital outcome and predictors of death.

OBJECTIVES: The purpose of this study was to compare the mechanisms, predictors and outcome of patients with failed direct coronary angioplasty of the infarct-related artery with those in patients with successful direct angioplasty. BACKGROUND: Direct coronary angioplasty of the infarct-related artery, without antecedent thrombolytic therapy, is an effective treatment for patients with acute myocardial infarction. Concern has been expressed over high mortality rates in patients with failed direct infarct angioplasty. METHODS: All patients treated by angioplasty were prospectively entered into a computer data base. The characteristics and outcome of all patients with failed direct angioplasty were reviewed and compared with those of patients with successful direct angioplasty. RESULTS: Direct angioplasty was successful in 705 (94%) of 750 patients and unsuccessful in 45 (6%). Patients in the failure group were more likely to be in cardiogenic shock (22% vs. 7%, p < 0.003), to have had a previous myocardial infarction (44% vs. 28%, p < 0.03) and to have three-vessel coronary artery disease (44% vs. 23%, p < 0.003). Age, gender, ejection fraction, previous bypass surgery and diabetes mellitus were similar in both groups. Only the presence of multivessel coronary artery disease (p < 0.004) and cardiogenic shock (p < 0.025) were independent predictors of failed direct angioplasty. In-hospital death (31% vs. 4.8%, p < 0.001) and the need for emergency coronary artery bypass surgery (27% vs. 0.5%, p < 0.0001) were more frequent in patients with unsuccessful than in patients with successful direct angioplasty. Patients with failed direct angioplasty and in-hospital death usually had multiple high risk characteristics, including cardiogenic shock (50%), previous myocardial infarction (43%) and multivessel coronary artery disease (93%). CONCLUSIONS: Direct coronary angioplasty is an effective method for establishing reperfusion in acute myocardial infarction. Procedural failure is infrequent, usually occurring in patients with high risk baseline characteristics.