Bailout and corrective use of Gianturco-Roubin flex stents after percutaneous transluminal coronary angioplasty: operator reports and angiographic core laboratory verification from the National Heart, Lung, and Blood Institute/New Approaches to Coronary Intervention Registry

Mechanical buckling of veins under internal pressure

Venous tortuosity is associated with multiple disease states and is often thought to be a consequence of venous hypertension and chronic venous disease. However, the underlying mechanisms of vein tortuosity are unclear. We hypothesized that increased pressure causes vein buckling that leads to a tortuous appearance. The specific aim of this study was to determine the critical buckling pressure of veins. We determined the buckling pressure of porcine jugular veins and measured the mechanical properties of these veins. Our results showed that the veins buckle when the transmural pressure exceeds a critical pressure that is strongly related to the axial stretch ratio in the veins. The critical pressures of the eight veins tested were 14.2 +/- 5.4 and 26.4 +/- 9.0 mmHg at axial stretch ratio 1.5 and 1.7, respectively. In conclusion, veins buckle into a tortuous shape at high lumen pressures or reduced axial stretch ratios. Our results are useful in understanding the development of venous tortuosity associated with varicose veins, venous valvular insufficiency, diabetic retinopathy, and vein grafts.

Utilization of eptifibatide for treatment of severe dissections as a bail-out procedure

BACKGROUND

It has been shown in several large trials that the inhibition of glycoprotein (GP) IIb/IIIa receptors of platelets can reduce the rate of ischemic complications following percutaneous transluminal coronary angioplasty (PTCA). We sought to determine the efficacy of eptifibatide in patients with severe dissections or threatened vessel closure after PTCA in small coronary arteries (< 2.5 mm).

METHODS

Eptifibatide was used in 51 patients after conventional balloon angioplasty complicated by severe dissections with or without threatened vessel occlusion. Eptifibatide was administered as a double-bolus of 180 microg/kg bodyweight, followed by a continuous infusion at a dosage of 2.0 microg/kg min over a time period of 20 h. In this situation, the implantation of a coronary stent was avoided if a prompt antegrade flow of contrast dye could be maintained.

RESULTS

Using the GP IIb/IIIa antagonist eptifibatide, it was possible to increase or to maintain antegrade blood flow in 28 (55%) patients. In 45% of the patient population, however, repeat PTCA was needed, and in four patients (7.8%) an intracoronary stent had to be implanted. During hospitalization three (6%) patients underwent target lesion revascularization (two Re-PTCAs, one coronary bypass graft operation). There were no myocardial infarctions and there was no intrahospital death. The cumulative event rate including acute and long term events was 25%.

CONCLUSIONS

The findings of our study indicate that eptifibatide is able to prevent vessel occlusion after PTCA complicated by severe dissections with or without threatened vessel occlusion associated with a low-in-hospital complication rate.

Clinical and angiographic results of coronary artery stenting using PURA-VARIO (PUVA) stents

BACKGROUND

Many different stent types are available for intracoronary placement. No clinical trial has demonstrated clearly the superiority of any stent design over another.

METHODS

This study was designed to analyze clinical and angiographic results after using intracoronary PURA-VARIO (Devon Medical, Hamburg, Germany) (PUVA) stents. A total of 306 implanted stents were investigated in a series of 217 unselected patients (61.2 +/- 10.7 years, 74.3% male). Stenting was performed electively and during acute coronary syndromes. Stents were manually mounted on angioplasty balloons and expanded in the target lesion. Angiographic measurements were carried out by quantitative coronary angiography.

RESULTS

Stenting was successful in 214/217 patients (98.8%). During hospitalization (median three days) 206 patients (94.9%) were free from adverse cardiac events. Stent thrombosis occurred in five patients (2.3%), Q-wave infarction in one (0.5%) and urgent percutaneous target vessel revascularization in four (1.8%). Follow-up angiography, performed in 170 patients (78.3%) showed a restenosis (>/=50% diameter stenosis) in 44/170 patients (25.9%), requiring angioplasty in 29 (17.2%). A surgical revascularization was recommended in 13 patients (7.6%). One patient died during follow-up from an unknown cause; however, sudden cardiac death was most likely.

CONCLUSIONS

PUVA stents are characterized by a high level of safety and efficacy. Clinical and angiographic results are comparable with those of other approved stents.

Randomized comparison of the coil-design Crossflex and the tubular NIR stent

The purpose of this study was to compare the angiographic outcome of implantation of the coil-design Crossflex stent with the tubular NIR stent for treatment of coronary artery stenoses. Two hundred twenty-three patients with one genuine coronary artery lesion were randomized to implantation with a 15 mm Crossflex stent (n = 112) or a 16 mm NIR stent (n = 111). The patients had angiographic follow-up after 6 months. Primary endpoint was minimal luminal diameter (MLD) after 6 months. There was a similar clinical outcome in the two groups. At 6-month follow-up, the MLD was significantly lower in the Crossflex group (1.94 +/- 0.79 mm) than in the NIR group (2.37 +/- 0.84 mm; P < 0.001). Early gain was the same in the two groups. Late loss and percent diameter stenoses were significantly higher in the Crossflex group. The binary restenoses rate was 26% and 17% in the Crossflex and the NIR groups, respectively (P = NS). The coil-design Crossflex stent was found to be inferior to the tubular NIR stent concerning late loss and MLD at 6-month follow-up.

Clinical trends in stent treatment of simple and complex coronary disease

This is a retrospective analysis of a consecutive group of patients from a single medical center who underwent stent implantation. It describes 316 patients who constituted 53% of the angioplasty procedures carried out in a single year. The authors describe the complications and their 1-year follow-up. We aimed to study the short and long-term results of stenting in our centre in relation to multiple clinical and angiographic variables. During 1996, 316 consecutive patients were treated with stent implantation for a total of 381 coronary lesions. The pharmacological protocol methods of stent implantation and patient characteristics were used. Clinical variables were: age 59.1 3 10.7 years, diabetes mellitus 25.3%, hypertension 33.0% and angina pectoris 88.7% (unstable in 44.1%). Previous coronary surgery had been undergone by 9.2%. Multivessel disease was present in 56% of the patients. The indications for stenting were: primary 58.5%, suboptimal results 33.0% and threatened or acute occlusion 8.5%. Angiographic success was 98.9% and clinical success 96.8%. The major in-hospital complications were acute myocardial infarction (2.2%), acute revascularization (0.3%) and major bleeding (0.6%). All occurred within 24 h of revascularization. Repeated angiography was performed in 115 cases (30.2%) at 160.3 3 109.4 days after stent procedure for unstable angina (38.7%), stable angina (26.1%) and other causes (35.2%). The restenosis rate in those catheterized was 38.1%, with an overall clinical restenosis rate of 11.3% during the follow-up period. Restenosis was more prevalent among diabetic patients (17.9 vs 9.15%, P 3 0.02) and patients with prior balloon angioplasty (18.6 vs 9.75%, P 3 0.046). Clinical follow-up was available in 90.8% of the patients for 291 3 112 days. The actuarial survival at the end of the follow-up period was 93.8%. Death/myocardial infarction was associated with unstable angina pectoris (P 3 0.006), hypertension (P 3 0.001), smoking (P 3 0.046) and threatened or acute occlusion (P < 0.001). In the first year of extensive stent use, stenting is associated with high technical and clinical success rates. Long-term results after stent implantation are associated with the occurrence of acute or threatened occlusion, and the in-hospital complications diabetes mellitus and hypertension.

Argentine Randomized Study: Coronary Angioplasty with Stenting versus Coronary Bypass Surgery in patients with Multiple-Vessel Disease (ERACI II): 30-day and one-year follow-up results. ERACI II Investigators

OBJECTIVE

The purpose of this study was to compare percutaneous transluminal coronary revascularization (PTCR) employing stent implantation to conventional coronary artery bypass graft surgery (CABG) in symptomatic patients with multivessel coronary artery disease.

BACKGROUND

Previous randomized studies comparing balloon angioplasty versus CABG have demonstrated equivalent safety results. However, CABG was associated with significantly fewer repeat revascularization procedures.

METHODS

A total of 2,759 patients with coronary artery disease were screened at seven clinical sites, and 450 patients were randomly assigned to undergo either PTCR (225 patients) or CABG (225 patients). Only patients with multivessel disease and indication for revascularization were enrolled.

RESULTS

Both groups had similar clinical demographics: unstable angina in 92%; 38% were older than 65 years, and 23% had a history of peripheral vascular disease. During the first 30 days, PTCR patients had lower major adverse events (death, myocardial infarction, repeat revascularization procedures and stroke) compared with CABG patients (3.6% vs. 12.3%, p = 0.002). Death occurred in 0.9% of PTCR patients versus 5.7% in CABG patients, p < 0.013, and Q myocardial infarction (MI) occurred in 0.9% PTCR versus 5.7% of CABG patients, p < 0.013. At follow-up (mean 18.5 +/- 6.4 months), survival was 96.9% in PTCR versus 92.5% in CABG, p < 0.017. Freedom from MI was also better in PTCR compared to CABG patients (97.7% vs. 93.4%, p < 0.017). Requirements for new revascularization procedures were higher in PTCR than in CABG patients (16.8% vs. 4.8%, p < 0.002).

CONCLUSIONS

In this selected high-risk group of patients with multivessel disease, PTCR with stent implantation showed better survival and freedom from MI than did conventional surgery. Repeat revascularization procedures were higher in the PTCR group.

Mechanical compression of coronary artery stents: potential hazard for patients undergoing cardiopulmonary resuscitation

Mechanical compression of coronary artery stents may be associated with a fatal outcome as the result of refractory myocardial ischemia. We present the history of an 83-yr-old patient, who died owing to hemorrhagic shock 3 days after stent implantation, despite immediate cardiopulmonary resuscitation (CPR). Postmortem examination showed stent compression, probably due to mechanical deformation during CPR. This complication has been reported in two other cases in the literature, suggesting that CPR may be hazardous to patients with coronary artery stents.

Frequency and efficacy of glycoprotein IIb/IIIa therapy for treatment of threatened or acute vessel closure in 1332 patients undergoing percutaneous transluminal coronary angioplasty

BACKGROUND

Glycoprotein (GP) IIb/IIIa antagonists are potent inhibitors of thrombocyte aggregation and thrombus formation. Several large-scale randomized studies for prevention of thrombotic complications have shown their potential to reduce these complications in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). It was the purpose of this observational trial to assess the frequency and efficacy of primary GP IIb/IIIa antagonist therapy as a bailout procedure for the prevention of threatened or abrupt vessel closure in patients after conventional balloon angioplasty.

METHODS AND RESULTS

From January 1995 to December 1996, PTCA was performed in 1332 consecutive patients with coronary artery disease. Overall, threatened or abrupt vessel closure was observed in 63 (4.7%) patients of the patient population. In these patients, abciximab was administered (0.25 mg/kg body weight intravenous bolus, followed by a 12-hour infusion at 10 mg/min). Repeat PTCA was performed shortly after the administration of the abciximab bolus to achieve an optimal flow at the time of active GP IIb/IIIa therapy. One day after intervention, early follow-up angiography was performed. Follow-up after 1 year included the clinical status of all patients and, if possible, control angiography. Overall, the preintervention minimum lumen diameter (MLD) measured 0.74 +/- 0.27 mm and the diameter stenosis was 75% +/- 24%. The postintervention MLD increased to 2.60 +/- 0.55 mm, and the diameter stenosis decreased to 24% +/- 22%. At 24-hour angiographic follow-up, the MLD decreased to 2.47 +/- 0.49 mm and the diameter stenosis increased to 28% +/- 24%, correspondingly. The thrombus score decreased from 2.8 +/- 1.5 before abciximab treatment to 0.88 +/- 0.81 after abciximab treatment, and Thrombolysis In Myocardial Infarction flow grade increased from 2.1 +/- 1.1 to 2.9 +/- 0.3. In-hospital events occurred in 2 patients. Both patients had to undergo emergency coronary artery bypass grafting (1 of these patients died). During long-term follow-up, there were 10 clinical events (1 death, 3 repeat PTCA, and 6 coronary artery bypass graft operations for restenosis at the target lesion site). The cumulative event rate after 1 year (including acute and follow-up events) for both the total group and for the target vessel was 19%.

CONCLUSIONS

The results of this study demonstrate that GP IIb/IIIa antagonists are able to prevent vessel occlusion after PTCA complicated by subsequent threatened or abrupt vessel closure. In these situations, GP IIb/IIIa antagonists provide effective treatment for the reduction of thrombus at the target lesion site, which constitutes a second key element for threatened or abrupt vessel occlusion.

Reduction in the need for unplanned stenting with the use of platelet glycoprotein IIb/IIIa blockade in percutaneous coronary intervention

Data from the 5 large randomized, double-blind, placebo-controlled trials that used glycoprotein IIb/IIIa inhibitors during percutaneous transluminal coronary angioplasty were pooled for a total of 10,691 patients. We found that the use of glycoprotein IIb/IIIa inhibitors in percutaneous coronary interventions significantly decreases the need for unplanned stenting for abrupt closure.

The use of the Gianturco-Roubin intracoronary stent: the New Approaches to Coronary Intervention (NACI) registry experience

The objective of this study is to compare the in-hospital and follow-up outcome in patients receiving the Gianturco-Roubin stent (GRS) who were enrolled in the New Approaches to Coronary Intervention (NACI) registry. The GRS was approved by the US Food and Drug Administration (FDA) in August 1992 for the treatment of acute or threatened closure after a percutaneous intervention. The application of intracoronary stenting has broadened substantially in the last few years, but less is known about the use of this device for other indications. Since the NACI registry includes patients stented for other indications, a comparison of these groups with patients being stented for acute or threatened closure was undertaken. A GRS was deployed in 497 NACI registry patients. Of these, 466 patients received a GRS in 1 of 3 of the following ways: (1) 351 unplanned stenting after conventional angioplasty of the same lesion; (2) 54 after failed/suboptimal use of a new device in the same lesion; and (3) 61 in planned stenting procedures. This analysis focuses on these 3 patient subgroups and compares their in-hospital outcome and subsequent follow-up to 1 year. There were 520 stented segments in the 466 patients. The group with stenting after failed/suboptimal new-device use had a higher incidence of myocardial infarction (MI) and cardiogenic shock than either the patients with unplanned stenting after percutaneous transluminal coronary angioplasty (PTCA) or planned stenting (MI 22.2% vs 12.0% vs 0%, respectively, and cardiogenic shock 5.6% vs 0.9% vs 0%, respectively; p < 0.05). This group also had significantly lower procedural success (58.7% vs 75.3% vs 81.5%, respectively; p < 0.05). Although not statistically significant, the requirement for transfusion was higher in the unplanned and new-device stented groups than in the planned group (10.5% vs 16.7% vs 1.6%, respectively). Likewise, the incidence of Q-wave MI was higher in the new-device group (22.2% vs 12% vs 0%, respectively; p < 0.05). Despite a higher, in-hospital complication rate in the unplanned groups, follow-up from discharge to 1 year showed similar outcome. In particular, percutaneous reintervention of the stented segment occurred in: 13.0% in the unplanned after new device; 17.4% in the unplanned after PTCA; and 26.2% in the planned group. Although not statistically significant, the higher incidence of percutaneous target lesion revascularization in the planned group probably represents the greater incidence of restenotic lesions in this cohort. In this very heterogeneous group of patients, including those with failure of another new device, the use of the GRS is associated with acceptable in-hospital and follow-up complication rates, although complications were clearly greater when unplanned use of the stent was needed, particularly after failure of another new device. Although the experience is small, patients having the GRS placed in an elective fashion, i.e., the planned group, appear to experience lower in-hospital complication rates, although they have a higher rate of subsequent target lesion revascularization, in this group of predominantly restenotic lesions.

[Patient education in chronic polyarthritis. 3. Intermediate results of a prospective, controlled study of the effectiveness and side effects of patient seminars for polyarthritis patients]

Efficacy and possible negative side effects of a patient education program for rheumatoid arthritis were evaluated in a controlled, prospective study over 3 months. 34 outpatients were educated over a total of 8 h in three groups within a patient-centred design. Before the program the knowledge of the disease depended only on the formal grade of education but not on disease-related variables such as disease duration or disability. Probably due to its individualizing method, the program improved the knowledge of all patients to the same extent, regardless of their intellectual and social prerequisites. The increased cognitive knowledge did not result in negative side effects like increased pain or depression. The pain score remained unchanged. Depression decreased after the education. The group sessions made us suppose that the participants may have represented a selected group of active, psychologically stable patients, who cope well with rheumatoid arthritis. In contrast, we felt that non-participation was the response of the inactive, fatalistic patients with rheumatoid arthritis, who live in social isolation and especially need our care. Therefore, future efforts must particularly focus on the problem of motivation and on an increase in the rate of participation.