Palmaz-Schatz stent embolization: long-term clinical and angiographic follow-up

A long-term clinical and angiographic follow-up of a case of peripheral coronary stent embolization is reported. No clinical sequelae occurred in the immediate and long-term (five years) followup. The five-year follow-up angiographic images provided visual documentation of absence of stent-associated stenosis. This case highlights the concept that fibro-intimal hyperplasia may not occur when plaque and balloon trauma are absent at the site of stent embolization.     

Increase in plasma digitalis-like activity during percutaneous transluminal coronary angioplasty in patients with coronary stenosis

Despite the fact that numerous studies have been published regarding the possible presence in plasma of an endogenous Na-K pump inhibitor with a digitalis-like structure in essential hypertension, very little is known about this factor in heart disease in general, and in situations characterized by low cardiac output. We measured the ability of plasma obtained from the femoral vein to inhibit a human renal Na(+)-K+ ATPase before and immediately after percutaneous transluminal coronary angioplasty (PTCA) in 6 patients suffering from angina pectoris and severe coronary stenosis. Intraerythrocyte sodium and potassium concentrations were also measured simultaneously. Na(+)-K+ ATPase inhibition proved significantly greater after angioplasty as compared to basal activity (percentage inhibition: 31.5 +/- 7.8 vs 16.1 +/- 12.2). No significant changes in intraerythrocyte sodium and potassium were detected. Though we are not in a position to define the mechanism underlying the increase in the digitalis-like factor, a plausible hypothesis may be that the reduction in cardiac output during PTCA by raising cardiac pressures may stimulate the production of a factor of compensatory inotropic significance.     

Long-term clinical outcome after stent implantation in coronary arteries

The long-term clinical outcome after planned and unplanned stent implantation was assessed in a single-center, observational study in 178 patients who underwent coronary stent implantation between November 1986 and July 1994. Main outcome measures were survival and event-free survival at 5 years (Kaplan-Meier method). Independent predictors for event-free survival were determined by using multivariate logistic regression analysis. Patients underwent planned (group 1, n 3 101) or unplanned (group 2, n 3 77) stent implantation. During the in-hospital period, there were no deaths. The incidence of Q-wave and non-Q-wave acute myocardial infarction (AMI), coronary artery bypass graft (CABG) and repeat percutaneous transluminal coronary angioplasty (PTCA) was 5.0%, 2.0% and 4.0%, respectively, in group 1, versus 32.5%, 23.4% and 10.4%, respectively, in group 2. During the follow-up period (median 4.0 years, range 0.29-9.8 years), the incidence of death, AMI, and repeat revascularization (CABG and PTCA) was 5.9%, 8.9% and 40.6%, respectively, in group 1, versus 1.3%, 5.2% and 36.4%, respectively, in group 2. Survival and event-free survival at 5 years was 73 (7%) and 47 (7%), respectively, for patients who underwent planned stent implantation. It was 98 (0.1%) and 34 (6%), respectively, for patients who underwent unplanned stent implantation. At the end of follow-up, 31.9% of patients had angina pectoris class III or IV (Canadian Cardiovascular Society). The long-term clinical outcome after both planned and unplanned stent implantation was characterized by a high incidence of repeat revascularization. It is conceivable that changes in stent design and implantation techniques, in addition to novel therapeutic approaches addressing neointima formation and progression of atherosclerosis, may improve the long-term clinical outcome.     

Safety of intracoronary administration of c-myc antisense oligomers after percutaneous transluminal coronary angioplasty (PTCA)

We wished to assess the clinical safety and pharmacokinetics of ascending doses of a synthetic oligodeoxynucleotide (LR-3280) administered after coronary angioplasty. Antisense oligodeoxynucleotides designed to hybridize with target messenger ribonucleic acid (mRNA) in a complementary fashion to inhibit the expression of corresponding protein also have the ability to bind to extracellular growth factors. LR-3280 has been shown to reduce c-myc expression, inhibit growth and collagen biosynthesis in human vascular cells, and reduce neointimal formation in animal models of vascular injury. After successful percutaneous transluminal coronary angioplasty (PTCA), 78 patients were randomized to receive either standard care (n = 26) or standard care and escalating doses of LR-3280 (n = 52) (doses from 1 to 24 mg), administered into target vessel through a guiding catheter. Overall safety was evaluated by clinical adverse events, laboratory tests, and electrocardiograms. Patency was evaluated by quantitative coronary angiography. There were no clinically significant differences between treated and control patients. No adverse effects of LR-3280 on the patency of dilated coronary arteries were observed. Pharmacokinetic data revealed that peak plasma concentrations of LR-3280 occurred at 1 minute over the studied dose range and rapidly decreased after approximately1 hour, with little LR-3280 detected in the urine between 0-6 hours and 12-24 hours. The intracoronary administration of LR-3280 is well tolerated at doses up to 24 mg and produces no adverse effects in dilated coronary arteries. These results provide the basis for the evaluation of local delivery of this phosphorothioate oligodeoxynucleotide for the prevention of human vasculoproliferative disease.     

经皮腔内冠状动脉成形术中缺血预适应对C反应蛋白、肌钙蛋白I的影响

目的:通过测定常规经皮冠状动脉血管成形术及支架植入术(PCI)组及缺血预适应处理组术前、术后患者肌钙蛋白I(CTnI)、C-反应蛋白(CRP)的变化,以探讨缺血预适应对术中心肌缺血耐受程度及术后cTnI、CRP的影响.方法:首先设定缺血预适应(IP)方案,观察IP组患者51例、常规PCI组(CP组)患者53例术后CRP、CTnI、SvO2的变化以及术中不良事件发生与否.结果:IP组术前、术后C-反应蛋白(CRP)、肌钙蛋白I(CTnI)的变化程度低于CP组,存在显著性差异(P<0.05).IP组术中发生心绞痛及ECG ST段缺血型改变的几率低于常规PCI组,存在显著性差异(P<0.05).结论:缺血预适应方案可以作为PCI操作的常规方法,它可以减轻介入操作对心肌细胞的损伤,降低冠脉介入术中、术后的不良事件的发生.     

Management of acute coronary occlusion during percutaneous transluminal coronary angioplasty: experience of complications in a hospital without on site facilities for cardiac surgery.

OBJECTIVE--To determine whether percutaneous transluminal coronary angioplasty may be safely performed in cardiology centres in the United Kingdom without immediate on site cardiac surgical cover for complications arising at angioplasty. DESIGN--Retrospective review of coronary angioplasties and complications in a hospital without on site cardiac surgical cover. SETTING--All angioplasties were performed in the catheterisation laboratory of the Belfast City Hospital. Revascularisation surgery for complicated coronary angioplasty was performed in the cardiac surgical unit of the Royal Victoria Hospital, 2.4 km away from the catheterisation laboratory. PATIENTS--540 Coronary angioplasties were performed on 512 patients between late 1982 and November 1988. Indications included stable angina, unstable rest angina, and suitable coronary disease at coronary arteriography after myocardial infarction. MAIN OUTCOME MEASURES--In hospital mortality after complicated coronary angioplasty and delay to surgical revascularisation after acute coronary occlusion at angioplasty. RESULTS--Coronary angioplasty was successful in 444 cases (82%). Acute coronary occlusion occurred in 35 cases (6.5%). Twelve patients required urgent revascularisation surgery and were transferred safely to the surgical unit; none of these patients died. A mean delay of 268 minutes (range 180-390 minutes) occurred before revascularisation compared with 273 minutes (range 108-420 minutes) in the Royal Victoria Hospital, where on site surgical cover was available. The principal cause of delay was the wait for a cardiac operating theatre to become available and not the transfer time between hospitals. Five deaths occurred after coronary angioplasty, a mortality of 0.9%. Three deaths were related to acute coronary occlusion. The absence of immediate surgical help did not influence the outcome in any patient. CONCLUSION--With careful selection of patients coronary angioplasty may be safely performed in a hospital without on site cardiac surgical facilities, provided that these are available at a nearby centre.     

Coronary stent implantation throughout technical evolution: immediate and follow-up results

Coronary stenting (stent implantation) has evolved over the last 5 years with changes in stent design, stent material and the implantation technique. The use of high-pressure balloon inflation (HP), intravascular ultrasound (IVUS) and appropriate antiplatelet therapy have contributed to the abolishment of the need for subsequent anticoagulation, allowing extended stent applications. We compared results in three groups of patients having stent implantation throughout the period of evolution: group A: no IVUS, no HP, with subsequent anticoagulation treatment (n 3 434); group B: no IVUS, yes HP, without subsequent anticoagulation treatment (n 3 192); and group C: yes IVUS, yes HP, without subsequent anticoagulation treatment (n 3 588). The primary success rates were comparable in all groups. There was a clear change in indications for stenting in groups B and C compared with group A (elective stenting: group A 3 32%; group B 3 66%; group C 3 69%; P < 0.0001), in reference vessel size (group A 3 3.22 3 0.37 mm; group B 3 2.92 3 0.56 mm; group C 3 2.98 3 0.57 mm; P < 0.0001), and for presence of type B2 and C lesions (group A 3 57%; group B 3 72%; group C 3 74%; P < 0.001). The complication rate significantly decreased in group C (group A 3 3.6%; group B 3 4.1%; group C 3 1.2%; P < 0.001) and the mean patient hospital stay decreased to 2 days in groups B and C due to the abolition of the need for anticoagulant treatment. The angiographic restenosis rate increased in groups B and C (group A 3 20%; group B 3 34%; group C 3 32%; P < 0.001). The need for a repeat procedure increased as stenting of more complex lesions and smaller vessels was attempted: target lesion revascularization (TLR) was performed in 16% of patients in group A (73/434), in 18% of group B (35/192) and in 22% of group C (129/588) (P 3 0.04 for A versus C). Major cardiac events (MACE) occurred in 142 patients in group A (33%), 60 patients in group B (31%) and in 181 patients in group C (30%). The evolving technique of coronary stenting has expanded the spectrum of indications and range of coronary vessels attempted, and decreased the complication rates and hospital stay. However, in less-favorable subsets, additional improvements are needed to affect the long-term outcome.     

Intravascular ultrasound imaging of myocardial-infarction-related arteries after percutaneous transluminal coronary angioplasty reveals significant plaque burden and compensatory enlargement

We studied patients with acute myocardial infarction (MI) by intravascular ultrasound (IVUS) to elucidate the controversy as to the amount and severity of the atherosclerotic disease at the culprit lesion site in acute MI, as discrepancies exist between angiographic and pathological reports. Twenty-five consecutive patients (age 56 3 10.5 years), with acute MI, underwent IVUS study of the MI-related artery immediately following successful PTCA to the culprit lesion. The IVUS images were analyzed quantitatively and qualitatively and were compared with the angiography of the same arteries. At the PTCA site, 64% of the lesions had an area stenosis of 50-70% and the plaque cross-sectional area (CSA) averaged 0.5 3 0.18 of the arterial CSA. IVUS-defined atherosclerosis was found also in 72% of the segments proximal and distal to the culprit lesion with a plaque/artery CSA ratio of 0.25 3 0.2. The angiogram revealed only 30% of these segments to be abnormal (P 3 0.001). Sixty-nine per cent of all the plaques were defined as 'soft' (low echo-genecity) versus 31% 'hard' (high echo-genecity). The hard plaques were larger than the soft plaques (0.5 3 1.6 versus 0.37 3 0.19 CSA index, respectively, P 3 0.01). With the increase in plaque area there was a significant increase in arterial cross-sectional area. This was demonstrated for all the diseased segments with a correlation coefficient of 0.49 (P 3 0.0001) and for the diseased reference sites a similar correlation coefficient of 0.49 (P 3 0.003) was found. Contrary to coronary angiographic-based reports, this IVUS study revealed a significant atheromatous plaque burden at the culprit lesion of MI-related arteries as well as diffuse atherosclerosis in the reference segments proximal and distal to the lesion. The detection of compensatory enlargement may explain the discrepancies between the histopathological and the angiographic studies.     

Immediate and long-term outcomes of coronary stenting in relation to stent implantation pressure in patients with coronary heart disease

The paper evaluates the pressure impact of implantation of intracoronary stents of different designs on the immediate and long-term outcomes of stenting. A retrospective study included 192 patients. Matrix and wire stents were implanted in 97 (50.5%) and 95 (49.5%) patients, respectively. In one part of the patients, the coronary stent was implanted under nominal pressure, in the other, the stent after implantation was extended with a balloon by using high pressure. Good immediate angiographic and clinical results were obtained in all 192 patients. Thirty three (17.2%) patients were found to have coronary spasm at the site of a stent. There was no significant difference in the development of coronary spasm, which was associated with the type of an implanted (matrix or wire) stent and with the pattern of its implantation (under high or nominal pressure). Dissection along the stent edges developed in 17 of the 192 patients, which amounted to 8.8%. It significantly more frequently developed in patients from Subgroup IA than in those from Subgroup IB. There was no significant difference in the development of restenosis in patients after implantation of matrix or wire stents and in the relation to the stent implantation pressure.     

Immediate and long-term results of coronary stent implantation without predilatation (direct stenting) in patients with coronary heart disease

The paper assesses the immediate and long-term results of direct stenting (without the stage of predilation) and compares with the outcomes of conventional stent implantation. A prospective study included 183 patients. All the patients were divided into two groups according to the procedure of stent implantation. In 85 (46.7%) patients, the stent was implanted without preliminary predilation of stenosis (direct stenting). These patients formed Group 1. Group 2 comprised 97 (53.3%) patients in whom the stent was placed by using the routine procedure. All the patients enrolled into the study had types A, B1, and B2 stenoses according to the ACC/AHA classification and received the conventional antiaggregatory and anticoagulant therapy. The technical success of direct stenting was 97.7%. There were no cases of stent dislocation and loss during direct stenting or expansion of a balloon and stent. Analyzing the immediate results in all the patients of the both groups showed a positive angiographic success. Thus, a primary angiographic and clinical success of direct stenting was achieved in all (100%) patients. Recurrent angina pectoris with restenosis was observed in 8 (9.4%) patients in Group 1 and in 21 (21.6%) in Group 2 (p < 0.05). Direct stenting significantly differs from the routine stent implantation in all procedure parameters. Thus, direct stenting in patients with uncomplicated stenoses is a safe and feasible procedure.     

Blood pressure response to percutaneous transluminal angioplasty for renovascular hypertension: an overview of published series.

OBJECTIVE--To evaluate the efficacy and safety of transluminal angioplasty in the treatment of renovascular hypertension. DESIGN--Overview of 10 published case series. SETTING--Mostly tertiary referral centres. PATIENTS--691 Patients treated by angioplasty for renovascular hypertension, 464 for atherosclerotic stenosis, 193 for fibromuscular stenosis, and the remainder mainly for post-transplant stenosis. The inclusion criteria varied considerably between studies. INTERVENTIONS--Percutaneous transluminal renal artery angioplasty (successful or attempted); prophylaxis against restenosis in most cases. Policies on antihypertensive drug treatment and follow up varied. MAIN OUTCOME MEASURES--Blood pressure response as defined in the individual papers, with each patient classified as either cured, improved, or failed. Each study used a different definition of improvement in blood pressure. Complication rates. RESULTS--Follow up data were available for 670 patients. The procedure was technically successful in 611 patients (88%). The overall cure rate for hypertension was 24% (163 patients) and a further 43% (286) were "improved." There were large and significant variations between studies in the rate of technical success and also the blood pressure outcome. In each series patients with fibromuscular lesions, had a higher cure rate than those with atherosclerotic lesions (overall cure 50% v 19% odds ratio 3.9, 95% confidence interval 2.6 to 6.0). Complications were reported in 63 (9%) patients and three patients died (0.4%). CONCLUSIONS--The evidence for the value of angioplasty in treating renovascular hypertension has serious limitations. Angioplasty for fibromuscular disease seems to be worth while, but for atherosclerotic lesions the benefit appears to be small and its efficacy needs to be compared with medical therapy in randomised trials. These findings emphasise the importance of early formal evaluation of new therapeutic techniques.     

One-year clinical follow-up of a registry evaluating a percutaneous revascularisation strategy combining a pre-specified simple selection process with the use of a new thin-strut bare cobalt-chromium stent

Objectives. To evaluate clinical events in a specifically selected cohort of patients with obstructive coronary artery disease (CAD), using a new generation thin-strut bare cobalt-chromium coronary stent. Methods. Patients with single- or multi-vessel, stable or unstable CAD eligible for percutaneous implantation of at least one bare cobalt-chromium stent were evaluated in a single-centre registry. Prospective pre-specified criteria for bare cobalt-chromium stent implantation in our centre were: any acute ST-elevation myocardial infarction (MI), otherwise 1) de novo coronary lesion, and 2) lesion length <20 mm, and 3) reference vessel diameter >2.6 mm, and 4) no diabetes, unless reference vessel diameter >3.5 mm. Endpoints, retrospectively collected, were death, MI and clinically driven target-lesion revascularisation (TLR) and target-vessel revascularisation (TVR) after 12 months. Results. Between September 2005 and June 2007, 712 patients (48.7% one-vessel, 29.9% two-vessel, 20% three-vessel and 1.4% left main disease; 7.9% diabetics) were treated with 800 bare cobalt-chromium stents, for stable angina (40.9%), unstable angina (20.9%) or acute ST-elevation MI (38.2%). The procedural success rate was 99.3%. Peri-procedural MI rate was 2.2% in the semi-elective group. At 12 months there were 17 deaths (2.4%), of which nine non-cardiac, 20 (2.8%) MI, 19 (2.7%) TLR and 29 (4.1%) TVR. Early and late definite stent thrombosis occurred in four (0.6%) and three (0.4%) patients, respectively. Conclusion. A strategy aimed at minimising drug-eluting stent use and combining a pre-specified simple selection process with the use of a new thin-strut bare cobalt-chromium stent is safe and effective at one-year clinical follow-up. (Neth Heart J 2010;18:486-92.)     

Modelling of the provisional side-branch stenting approach for the treatment of atherosclerotic coronary bifurcations: effects of stent positioning

The most common approach to treat atherosclerosis in coronary bifurcations is the provisional side-branch (PSB) stenting, which consists sequentially of the insertion of a stent in the main branch (MB) of the bifurcation and a dilatation of the side branch (SB) passing through the struts of the stent at the bifurcation. This approach can be followed by a redilatation of the MB only or by a Final Kissing Balloon (FKB) inflation, both strategies leading to a minor stent distortion in the MB. The positioning of the stent struts in the bifurcation and the stresses generated in the stent and vessel wall are worthy of investigation for a better understanding of the mechanobiology of the system. For this purpose, a computer model of an atherosclerotic coronary bifurcation based on the finite element method was developed; the effects of performing the final redilatation with the two strategies utilising one or two balloons and those created by a different stent strut positioning around the SB were investigated. Results correlate well with previous experimental tests regarding the deformation following balloon expansion. Furthermore, results confirm firstly that the re-establishment of an optimal spatial configuration of the stent after the PSB approach is achieved with both strategies; secondly, results show that case of stent positioning with one cell placed centrally (with regard to the SB) should be preferred, avoiding the presence of struts inside the vessel lumen, which may reduce hemodynamic disturbances. The central positioning also resulted in a better solution in terms of lower stresses in the stent struts and, more importantly, in the vascular tissues.     

In-hospital resource utilization in coronary angioplasty: the impact of increased coronary stenting rates and antiplatelet therapy

BACKGROUND: The technique of coronary stenting has evolved over recent years, with improved stent technology and effective antiplatelet therapies to prevent stent thrombosis. In Europe, reductions in stent and equipment costs have resulted from increased market competition. The impact of these changes on the in-hospital procedural cost of percutaneous coronary intervention (PCI) in the current clinical setting is not known. METHODS: We compared the initial equipment and pharmaceutical costs of one hundred consecutive, unselected patients undergoing PCI in 1998 to a similar population who underwent PCI in 1994. RESULTS: Similar patient characteristics were noted, yet more complex disease (multivessel, AHA type B2/C lesions) was treated in the 1998 population. The stent utilization rate (83% vs 15%, p < 0.0001) and use of intravenous and/or oral antiplatelet therapy (abciximab, ticlopidine) (64% vs 4%, p < 0.0001) was higher in 1998. Similar angiographic success was achieved in each group with low complication rates. Mean hospital stay was reduced in the 1998 group (2.6 +/- 2.8 vs 4.3 +/- 3.8 days, p < 0.001). Repeat PCI was required more frequently in the 1994 population (26% vs 9%, p < 0.001). Overall there was no significant difference in the mean equipment cost between the two groups ( pound 1551 vs pound 1422, p=ns). CONCLUSION: Despite the widespread use of coronary stenting and antiplatelet therapies there appears to be no difference in current in-hospital equipment costs for PCI compared to 1994. Improved clinical outcomes in the 1998 population imply that stenting is a cost-effective therapy.