W.J. van der Giessen

Heparin-coated Palmaz-Schatz stents in human coronary arteries. Early outcome of the Benestent-II Pilot Study.

BACKGROUND The purpose of the Benestent-II Pilot Study was to evaluate the safety of delaying and eliminating anticoagulant therapy in patients receiving a heparin-coated stent in conjunction with antiplatelet drugs. METHODS AND RESULTS The study consisted of three initial phases (I, II, III) during which resumption of heparin therapy after sheath removal was progressively deferred by 6, 12, and 36 hours. In phase IV, coumadin and heparin were replaced by 250 mg ticlopidine and 100 mg aspirin. Of the 207 patients with stable angina pectoris and a de novo lesion in whom heparin-coated stent implantation was attempted, implantation was successful in 202 patients (98%). Stent thrombosis did not occur during all four phases, and the overall clinical success rate at discharge was 99%. Bleeding complications requiring blood transfusion or surgery fell from 7.9% in phase I to 5.9%, 4%, and 0% in the three following phases. Hospital stay was 7.4, 6.1, 7.2, and 3.1 days for the consecutive phases. The restenosis rate for the combined four phases was 13% (15% in phase I, 20% in phase II, 11% in phase III, and 6% in phase IV). The overall rate of reintervention for the four phases was 8.9%. At 6 months, 84%, 75%, 94%, and 92% of the patients of phases I to IV, respectively, were event free. For the four phases, the event-free rate was 86%, which compares favorably with the rate observed in the Benestent-I study (80%; relative risk, 0.68 [0.45 to 1.04]). CONCLUSIONS The implantation of stents coated with polyamine and end-point-attached heparin in stable patients with one significant de novo coronary lesion is well tolerated, is associated with no (sub)acute stent thrombosis, and results in a favorable event-free survival after 6 months.

Biocompatibility of phosphorylcholine coated stents in normal porcine coronary arteries.

OBJECTIVE To improve the biocompatibility of stents using a phosphorylcholine coated stent as a form of biomimicry. INTERVENTIONS Implantation of phosphorylcholine coated (n = 20) and non-coated (n = 21) stents was performed in the coronary arteries of 25 pigs. The animals were killed after five days (n = 6), four weeks (n = 7), and 12 weeks (n = 8), and the vessels harvested for histology, scanning electron microscopy, and morphometry. MAIN OUTCOME MEASURES Stent performance was assessed by studying early endothelialisation, neointima formation, and vessel wall reaction to the synthetic coating. RESULTS Stent thrombosis did not occur in either group. Morphometry showed no significant differences between the two study groups at any time point. At five days both the coated and non-coated stents were equally well endothelialised (91% v92%, respectively). At four and 12 weeks there was no difference in intimal thickness between the coated and non-coated stents. Up to 12 weeks postimplant the phosphorylcholine coating was still discernible in the stent strut voids, and did not appear to elicit an adverse inflammatory response. CONCLUSION In this animal model the phosphorylcholine coating showed excellent blood and tissue compatibility, unlike a number of other polymers tested in a similar setting. Given that the coating was present up to 12 weeks postimplant with no adverse tissue reaction, it may be a potential candidate polymer for local drug delivery.

Routine sirolimus eluting stent implantation for unselected in-stent restenosis: insights from the rapamycin eluting stent evaluated at Rotterdam cardiology hospital (RESEARCH) registry

Objective: To assess the effectiveness of routine sirolimus eluting stent (SES) implantation for unselected patients with in-stent restenosis and to provide preliminary information about the angiographic outcome for lesion subgroups and for different in-stent restenosis patterns. Design: Prospective, single centre registry. Setting: Tertiary referral centre. Patients: 44 consecutive patients (53 lesions) without previous brachytherapy who were treated with SES for in-stent restenosis were evaluated. Routine angiographic follow up was obtained at six months and the incidence of major adverse cardiovascular events was evaluated. Results: At baseline, 42% of the lesions were focal, 21% diffuse, 26% proliferative, and 11% total occlusions. Small vessel size (reference diameter ⩽ 2.5 mm) was present in 49%, long lesions (> 20 mm) in 30%, treatment of bypass grafts in 13%, and bifurcation stenting in 18%. At follow up, post-SES restenosis was observed in 14.6%. No restenosis was observed in focal lesions. For more complex lesions, restenosis rates ranged from 20–25%. At the one year follow up, the incidence of death was 0, myocardial infarction 4.7% (n  =  2), and target lesion revascularisation 16.3% (n  =  7). The target lesion was revascularised because of restenosis in 11.6% (n  =  5). Conclusions: Routine SES implantation is highly effective for focal in-stent restenosis and appears to be a promising strategy for more complex patterns of restenosis.

Long term outcome after coronary stent implantation: a 10 year single centre experience of 1000 patients

OBJECTIVE To describe the long term clinical outcome (up to 11 years) after coronary stenting. DESIGN A single centre observational study encompassing 1000 consecutive patients with a first stent implantation (1560 stents) between 1986 and 1996, who were followed for at least one year with a median follow up of 29 months (range 12–132 months). RESULTS Up to July 1997 the cumulative incidence of the major adverse cardiac events (MACE) of death, non-fatal acute myocardial infarction, coronary artery bypass grafting, and repeat percutaneous transluminal coronary angioplasty was 8.2%, 12.8%, 13.1%, and 22.4%, respectively. Survival at one, three, and five years was 95%, 91%, and 86%, respectively. Comparison of MACE incidence during the “anticoagulant era” and the “ticlopidine era” revealed significantly improved event free survival with ticlopidine (27% v13%; p < 0.005). Multivariable analyses showed that ejection fraction < 50% (relative risk (RR) 4.1), multivessel disease (RR 3.0), diabetes (RR 2.9), implantation in saphenous vein graft (RR 2.1), indication for unstable angina (RR 1.9), and female sex (RR 1.7) were independent predictors of increased mortality after stenting. Independent predictors of any MACE were multivessel stenting (RR 2.0), implantation in saphenous bypass graft (RR 1.6), diabetes (RR 1.5), anticoagulant treatment (versus ticlopidine and aspirin) (RR 1.5), bailout stenting (RR 1.5), multivessel disease (RR 1.4), and multiple stent implantation (RR 1.5). CONCLUSIONS Long term survival and infarct free survival was good, particularly in non-diabetic men with single vessel disease and good ventricular function, who had a single stent implanted in a native coronary artery. A dramatic improvement was observed in event free survival, both early and late, with the replacement of anticoagulation by ticlopidine. This, of course, cannot be separated from improved stent implantation techniques between 1986 and 1995. Ultimately, almost 40% of the patients experienced an adverse cardiac event (mainly repeat intervention) in the long term. New advances in restenosis treatments and in secondary prevention must be directed at this aspect of patient management after stenting.

β-Particle–Emitting Radioactive Stent Implantation A Safety and Feasibility Study

Background—This study represents the Heart Center Rotterdam’s contribution to the Isostents for Restenosis Intervention Study, a nonrandomized multicenter trial evaluating the safety and feasibility of the radioactive Isostent in patients with single coronary artery disease. Restenosis after stent implantation is primarily caused by neointimal hyperplasia. In animal studies, b-particle‐ emitting radioactive stents decrease neointimal hyperplasia by inhibiting smooth muscle cell proliferation. Methods and Results—The radioisotope 32 P, a b-particle emitter with a half-life of 14.3 days, was directly embedded into the Isostent. The calculated range of radioactivity was 0.75 to 1.5 mCi. Quantitative coronary angiography measurements were performed before and after the procedure and at 6-month follow-up. A total of 31 radioactive stents were used in 26 patients; 30 (97%) were successfully implanted, and 1 was embolized. Treated lesions were in the left anterior descending coronary artery (n512), the right coronary artery (n58), or the left circumflex coronary artery (n56). Five patients received additional, nonradioactive stents. Treated lesion lengths were 13 64 mm, with a reference diameter of 2.9360.47 mm. Minimum lumen diameter increased from 0.8760.28 mm preprocedure to 2.8460.35 mm postprocedure. No in-hospital adverse cardiac events occurred. All patients received aspirin indefinitely and ticlopidine for 4 weeks. Twenty-three patients (88%) returned for 6-month angiographic follow-up; 17% of them had in-stent restenosis, and 13% had repeat revascularization. No restenosis was observed at the stent edges. Minimum lumen diameter at follow-up averaged 1.8560.69 mm, which resulted in a late loss of 0.9960.59 mm and a late loss index of 0.5360.35. No other major cardiac events occurred during the 6-month follow-up. Conclusions—The use of radioactive stents with an activity of 0.75 to 1.5 mCi is safe and feasible. (Circulation. 1999;100:1684-1689.)

Bone marrow cell therapy after acute myocardial infarction: the HEBE trial in perspective, first results.

AbstractDuring the last decennium, the role of bone marrow mononuclear cells (BMMC) has been underscored in the healing process after acute myocardial infarction (AMI). Although these cells improve left ventricular recovery after AMI in experimental studies, results from large-scale randomised trials investigating BMMC therapy in patients with AMI have shown contradictory results. To address this issue the HEBE study was designed, a multicentre, randomised trial, evaluating the effects of intracoronary infusion of BMMCs and the effects of intracoronary infusion of peripheral blood mononuclear cells after primary percutaneous coronary intervention. The primary endpoint of the HEBE trial is the change in regional myocardial function in dysfunctional segments at four months relative to baseline, based on segmental analysis as measured by magnetic resonance imaging. The results from the HEBE trial will provide detailed information about the effects of intracoronary BMMC therapy on post-infarct left ventricular recovery. In addition, further analysis of the data and material obtained may provide important mechanistic insights into the contribution of BMMCs to natural recovery from AMI as well as the response to cell therapy. This may significantly contribute to the development of improved cell-based therapies, aiming at optimising post-infarct recovery and preventing heart failure. (Neth Heart J 2008;16:436-9.)

One year clinical follow up of paclitaxel eluting stents for acute myocardial infarction compared with sirolimus eluting stents

Objective: To compare clinical outcome of paclitaxel eluting stents (PES) versus sirolimus eluting stents (SES) for the treatment of acute ST elevation myocardial infarction. Design and patients: The first 136 consecutive patients treated exclusively with PES in the setting of primary percutaneous coronary intervention for acute myocardial infarction in this single centre registry were prospectively clinically assessed at 30 days and one year. They were compared with 186 consecutive patients treated exclusively with SES in the preceding period. Setting: Academic tertiary referral centre. Results: At 30 days, the rate of all cause mortality and reinfarction was similar between groups (6.5% v 6.6% for SES and PES, respectively, p  =  1.0). A significant difference in target vessel revascularisation (TVR) was seen in favour of SES (1.1% v 5.1% for PES, p  =  0.04). This was driven by stent thrombosis (n  =  4), especially in the bifurcation stenting (n  =  2). At one year, no significant differences were seen between groups, with no late thrombosis and 1.5% in-stent restenosis (needing TVR) in PES versus no reinterventions in SES (p  =  0.2). One year survival free of major adverse cardiac events (MACE) was 90.2% for SES and 85% for PES (p  =  0.16). Conclusions: No significant differences were seen in MACE-free survival at one year between SES and PES for the treatment of acute myocardial infarction with very low rates of reintervention for restenosis. Bifurcation stenting in acute myocardial infarction should, if possible, be avoided because of the increased risk of stent thrombosis.

Optical Coherence Tomography Findings at 5-Year Follow-Up After Coronary Stent Implantation

Optical coherence tomography (OCT) is an in vivo, high-resolution imaging modality (resolution, 12 μm; wavelength, 1300 nm; probe size, 0.018 inch; Lightlab Imaging). The principle is analogous to that of pulse-echo ultrasound imaging; however light is used rather than sound to create the image. The case presented illustrates the 5-year follow-up examination after bare metal stent implantation (Figure 1). Intravascular ultrasound imaging (IVUS) shows concentric, moderate neointimal hyperplasia (Figure 2). Intravascular …

Outcome from balloon induced coronary artery dissection after intracoronary beta radiation

OBJECTIVE To evaluate the healing of balloon induced coronary artery dissection in individuals who have received β radiation treatment and to propose a new intravascular ultrasound (IVUS) dissection score to facilitate the comparison of dissection through time. DESIGN Retrospective study. SETTING Tertiary referral centre. PATIENTS 31 patients with stable angina pectoris, enrolled in the beta energy restenosis trial (BERT-1.5), were included. After excluding those who underwent stent implantation, the evaluable population was 22 patients. INTERVENTIONS Balloon angioplasty and intracoronary radiation followed by quantitative coronary angiography (QCA) and IVUS. Repeat QCA and IVUS were performed at six month follow up. MAIN OUTCOME MEASURES QCA and IVUS evidence of healing of dissection. Dissection classification for angiography was by the National Heart Lung Blood Institute scale. IVUS proven dissection was defined as partial or complete. The following IVUS defined characteristics of dissection were described in the affected coronary segments: length, depth, arc circumference, presence of flap, and dissection score. Dissection was defined as healed when all features of dissection had resolved. The calculated dose of radiation received by the dissected area in those with healed versus non-healed dissection was also compared. RESULTS Angiography (type A = 5, B = 7, C = 4) and IVUS proven (partial = 12, complete = 4) dissections were seen in 16 patients following intervention. At six month follow up, six and eight unhealed dissections were seen by angiography (A = 2, B = 4) and IVUS (partial = 7, complete = 1), respectively. The mean IVUS dissection score was 5.2 (range 3–8) following the procedure, and 4.6 (range 3–7) at follow up. No correlation was found between the dose prescribed in the treated area and the presence of unhealed dissection. No change in anginal status was seen despite the presence of unhealed dissection. CONCLUSION β radiation appears to alter the normal healing process, resulting in unhealed dissection in certain individuals. In view of the delayed and abnormal healing observed, long term follow up is indicated given the possible late adverse effects of radiation. Although in this cohort no increase in cardiac events following coronary dissections was seen, larger populations are needed to confirm this phenomenon. Stenting of all coronary dissections may be warranted in patients scheduled for brachytherapy after balloon angioplasty.

Late stent thrombosis, endothelialisation and drug-eluting stents

Drug-eluting stents (DES) significantly reduce the risk of restenosis after percutaneous coronary revascularisation, but an increased risk of late stent thrombosis (LST) has been put forward as a major safety concern. Meta-analysis of clinical trials, however, does not support this caveat. Even so, many interventional cardiologists think that LST is associated with DES and related to delayed endothelialisation. This hypothesis is based on autopsy studies and clinical intracoronary angioscopy. In autopsy studies, differences between endothelialisation of DES and baremetal stents (BMS) have been reported. Most preclinical studies, however, have failed to show any significant differences in endothelialisation between DES and BMS. Our own studies, using the porcine coronary artery model, also suggest that DES show no differences in re-endothelialisation. However, DES do delay vascular healing and induce endothelial dysfunction. This paper will review clinical and animal studies which consider re-endothelialisation and LST. (Neth Heart J 2009;17:177–81.)