Intracoronary stenting compared with conventional therapy for abrupt vessel closure complicating coronary angioplasty: a matched case-control study.

OBJECTIVES: A case-control analysis was performed to compare clinical outcome after intracoronary stenting with that after conventional therapy for abrupt vessel closure. BACKGROUND: Previous studies have demonstrated that stenting after abrupt vessel closure results in marked angiographic improvement and preservation of coronary flow, leading to the anticipation of similar improvement in clinical outcome. METHODS: Sixty-one of 92 consecutive patients treated at two clinical sites by intracoronary stenting for abrupt vessel closure were matched, according to angiographic features of closure and estimated left ventricular mass threatened by ischemia, with patients treated conventionally during the 18 months before stent availability. In 33 pairs of matched patients, vessel closure was established; in 28 pairs, it was threatened (coronary dissection or worsening stenosis with preservation of normal anterograde flow). Baseline clinical and angiographic characteristics were comparable in the two matched groups. Patients with indeterminate mechanisms of total occlusion (31%) or dissections < 15 mm long (43%) predominated; patients with visible thrombus (8%) or dissections > 15 mm long (18%) were infrequently represented. Stents were successfully deployed in 60 of 61 patients at a median of 52 min (range 3 to 269) after the onset of closure. RESULTS: When compared with conventional treatment, stenting resulted in less residual stenosis (26% vs. 49% diameter stenosis, p < 0.001), a greater likelihood of restoration of Thrombolysis in Myocardial Infarction (TIMI) grade 3 blood flow (97% vs. 72%, p < 0.001) and a reduction in the need for emergency bypass surgery (4.9% vs. 18%, p = 0.02). However, the incidence of Q wave myocardial infarction was nearly the same in the two groups (32% vs. 20%, respectively, p = NS). In the group with stenting, peak creatine kinase level and the frequency of Q wave infarction after established vessel closure increased with the time to stent placement (p = 0.001 and 0.054, respectively); the incidence of procedure-related Q wave infarction in patients who underwent stenting within 45 min of closure was very low (3.9%). In-hospital death occurred in 3.3% of patients in each treatment group. At a mean of 6.3 months of follow-up after hospital discharge, survival free from late cardiac death, myocardial infarction, bypass surgery or coronary angioplasty was 74.9% and 81.3% in the stent and the control treatment group, respectively (p = NS). CONCLUSIONS: Although early treatment of established vessel closure by intracoronary stenting was associated with a low incidence of both myocardial infarction and emergency bypass surgery, the likelihood or severity of infarction was not reduced among those in whom stents were implanted later. Patients with threatened vessel closure could not be shown to benefit from stent treatment. These data provide preliminary indications for stent placement in the acute period to be validated in larger randomized studies.

Thrombosis of a flexible coil coronary stent: frequency, predictors and clinical outcome.

OBJECTIVES: The aim of this study was to evaluate the predictors and clinical sequelae of stent thrombosis. BACKGROUND: Although coronary artery stenting is being increasingly applied, the major unique complication of stent thrombosis is not well characterized. METHODS: We studied 145 patients who underwent coronary artery stenting with the Gianturco-Roubin flexible coil design for abrupt vessel closure or to prevent restenosis. There were 17 stented vessel closures (11.7%), 7 as a result of acute (< 24 h) and 10 of subacute (days 1 to 21) thrombosis. RESULTS: In seven patients successful coronary recanalization was achieved with thrombolytic agents and balloon angioplasty. Creatine kinase was significantly elevated in 13 patients, with a Q wave myocardial infarction in 11 and emergency coronary artery bypass grafting in 8. Comparisons (multivariate analysis) with a control cohort (n = 33) of patients without thrombosis matched for age, gender and vessel stented revealed lesion eccentricity (p = 0.003), unstable angina (p = 0.048) and indication for stent implantation (abrupt closure versus restenosis) (p = 0.002), as predictors of thrombotic occlusion of stented vessels. Subtherapeutic anticoagulation (activated partial thromboplastin time < 2 times control value, prothrombin time < 1.4 control value) occurred at least once during the hospital stay in all 10 patients with subacute thrombosis and in 20 of 33 control patients (p = 0.047). In 2 patients with subacute thrombosis and 11 control subjects, subtherapeutic anticoagulation was necessitated by bleeding. CONCLUSIONS: Early thrombosis after coronary stenting was relatively common (> 10%), occurring predominantly in eccentric lesions and in patients with unstable angina pectoris. This complication is associated with significant adverse clinical outcomes and may be reduced by more intensive anticoagulation yet, in a delicate balance, can be precipitated by inadequate heparin therapy.

Directional atherectomy versus balloon angioplasty for coronary ostial and nonostial left anterior descending coronary artery lesions: results from a randomized multicenter trial. The CAVEAT-I investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial.

OBJECTIVES: We hypothesized that atherectomy would be superior to balloon angioplasty for ostial and nonostial left anterior descending coronary artery lesions. BACKGROUND: Balloon angioplasty of ostial coronary artery lesions has been associated with a lower procedural success rate and a higher rate of complications and of restenosis than angioplasty of nonostial stenoses. Directional coronary atherectomy has been proposed as an alternative therapy for ostial lesions. METHODS: In the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I), 1,012 patients were randomized to undergo either procedure; 563 patients had proximal left anterior descending coronary artery lesions, of which 74 were ostial. We compared balloon angioplasty with directional atherectomy for early and 6-month results for ostial as well as nonostial proximal left anterior descending coronary artery lesions. RESULTS: Directional atherectomy led to an initially higher gain in minimal lumen diameter for ostial lesions (1.13 vs. 0.56 mm, respectively, p < 0.001) but a higher rate of adjudicated non-Q wave myocardial infarction (24% vs. 13%, respectively, p < 0.001) than balloon angioplasty and no improvement in restenosis rates (48% vs. 46%, respectively). In the nonostial proximal left anterior descending coronary artery lesions, angiographic restenosis was reduced (51% vs. 66%, p = 0.012), but this was also associated with a higher rate of periprocedural myocardial infarction (8% vs. 2%, p = 0.008 by site and 24% vs. 8%, p < 0.001 by adjudication) and no difference in the need for subsequent coronary artery bypass surgery (7.3% vs. 8.4%, respectively) or repeat percutaneous coronary intervention (24% vs. 26%, respectively). CONCLUSIONS: For ostial left anterior descending coronary artery stenoses, both procedures yielded similar rates of initial success and restenosis, but atherectomy was associated with more non-Q wave myocardial infarction. In this trial the predominant angiographic benefit (increased early gain and less angiographic restenosis) of atherectomy for the left anterior descending coronary artery was in proximal nonostial lesions. However, the tradeoffs for this angiographic advantage were more in-hospital myocardial infarctions and no decrease in clinical restenosis.

The 6Fr Angio-Seal arterial closure device: results from a multimember prospective registry.

Femoral closure devices help early ambulation after cardiac catheterization without incurring additional risk to the patients. This report summarizes the safety and efficacy data of the 6Fr Angio-Seal device.

An analysis of the safety of performing dobutamine stress echocardiography in an ambulatory setting.

Dobutamine echocardiography has become widely used in the past decade in the evaluation of patients with suspected coronary artery disease who are unable to undergo exercise treadmill or bicycle testing. The safety of this procedure has been studied in a hospital-based setting. However, no studies thus far have evaluated the safety of this procedure in an office-based setting, remote from a hospital. We performed dobutamine echocardiography on 127 patients in an office-based setting, remote from a hospital. Throughout the course of this study there were no deaths, myocardial infarctions, sustained episodes of ventricular tachycardia, or syncopal episodes associated with dobutamine infusion. The frequency of noncardiac side effects was 29%, the majority of which were nausea, vomiting, and paresthesias. Three patients had nonsustained ventricular tachycardia, none of whom had symptoms. We conclude that dobutamine echocardiography is safe, well tolerated, and useful in an office-based setting.

Adjunctive thrombolytic agents with coronary interventional techniques.

Thrombolytics are used in a variety of interventional procedures, including direct lytic therapy, and in conjunction with PTCA, directional atherectomy and intracoronary stenting. The dosage and variety of thrombolytics is controversial. This article examines all potential uses of thrombolytics and reports on major trials using thrombolytics in these situations.

Rapid thrombus dissolution by continuous infusion of urokinase through an intracoronary perfusion wire prior to and following PTCA: results in native coronaries and patent saphenous vein grafts.

Even with aspirin and heparin therapy, thrombus present prior to or forming after percutaneous transluminal coronary angioplasty (PTCA) results in significant complications. We report on 33 patients who were treated with continuous infusion of Urokinase through an intracoronary perfusion wire for 24 hr because of visible intracoronary thrombus. Seventeen native vessels (9 pre-PTCA and 8 post-PTCA) and sixteen saphenous vein grafts (12 pre-PTCA and 4 post-PTCA) were treated. All vessels were patent at the time of perfusion wire placement. Complete thrombus resolution, successful PTCA and sustained patency was seen in 31 of 33 patients. One native vessel treated post PTCA (originally occluded) re-occluded. One saphenous vein graft treated prior to PTCA showed improvement in thrombus but distal embolization with balloon inflation occurred. No significant complications related to the intracoronary infusion technique were observed. In conclusion, rapid lysis of intra-coronary thrombus can be accomplish safely using this technique and can result in improved PTCA outcome.

The cost:benefit ratio of acute intervention for myocardial infarction: results of a prospective, matched pair analysis.

Parallel to the increased acceptance of intervention for acute myocardial infarction, there has been a decrease in financial resources and reimbursement. To ascertain the relative cost to benefit of intervention, we evaluated 78 matched pairs of acute myocardial infarction patients from a prospective data base of 507 consecutive patients presenting with infarction from May 1986 to July 1987. The pairs were matched for age (mean 61 years), sex (68% male), and infarct location (43% anterior). Intervention (thrombolytics and/or percutaneous transluminal coronary angioplasty [PTCA]) was only applied to patients at less than 6 hours from symptom onset. Nonintervention patients were subsequently considered for angiography and revascularization (PTCA, coronary artery bypass grafting [CABG]) based on clinical criteria. Clinical outcome was evaluated by in-hospital mortality and uncomplicated status (free of angina, heart failure, or arrhythmias) at 72 hours. Intervention was associated with decreased mortality (5.3% versus 13%, p = 0.16) and increased uncomplicated course (43% versus 19%, p less than 0.001) as compared with patients not receiving intervention. Hospital procedures for the intervention and nonintervention group were as follows: diagnostic cardiac catheterization (99% versus 51%); PTCA (60% versus 0%); and CABG (14% versus 19%), respectively. The mean cumulative hospital and professional charges were $31,684 for the intervention group and $29,022 for the nonintervention group (p = 0.50). In conclusion, despite the potential marked incremental expense of technology associated with intervention for acute myocardial infarction, this analysis demonstrates that benefit in clinical outcome can be derived without substantially increased costs.

Recombinant hirudin for unstable angina pectoris. A multicenter, randomized angiographic trial.

BACKGROUND: Coronary artery thrombosis plays an important pathophysiological role in unstable angina and non-Q-wave myocardial infarction. To date, heparin and thrombolytic therapy has not provided complete or consistent benefit. We hypothesized that recombinant hirudin, a direct thrombin inhibitor, would prevent accumulation of coronary artery thrombus in a manner superior to heparin. METHODS AND RESULTS: Patients with rest ischemic pain, abnormal ECG, and baseline angiogram indicating a > or = 60% stenosis of a culprit coronary artery or saphenous vein graft with visual appearance of thrombus were randomized to one of two different doses of heparin (either a target activated partial thromboplastin time [aPTT] of 65 to 90 or 90 to 110 seconds) or one of four doses of hirudin (0.05, 0.10, 0.20, or 0.30 mg.kg-1.h-1 infusion) in a dose-escalating protocol. After 72 to 120 hours of study drug, a repeat coronary angiogram was obtained, and the paired studies underwent quantitative analysis. The primary end point was change in the average cross-sectional area of the culprit lesion. Other efficacy end points also involved changes in culprit lesion dimensions and TIMI flow grade. Recombinant hirudin led to a dose-dependent elevation of aPTT that appeared to plateau at the 0.2-mg/kg dose. A higher proportion of hirudin-treated patients had their aPTT within a 40-second range (16% heparin versus 71% hirudin, P < .001). Overall, the 116 patients treated with hirudin tended to show more improvement than the 50 patients receiving heparin relative to the primary efficacy variable--the average cross-sectional area (P = .08)--as well as minimal cross-sectional area (P = .028), minimal luminal diameter (P = .029), and percent diameter stenosis (P = .07). CONCLUSIONS: Recombinant hirudin appears to be a promising antithrombotic intervention compared with heparin for inhibition of coronary artery thrombus. Large-scale comparative trials are warranted.