Andrew T.L. Ong

Late thrombosis in drug-eluting coronary stents after discontinuation of antiplatelet therapy

Although the safety profiles of coronary stents eluting sirolimus or paclitaxel do not seem to differ from those of bare metal stents in the short-to-medium term, concern has arisen about the potential for late stent thromboses related to delayed endothelialisation of the stent struts. We report four cases of angiographically-confirmed stent thrombosis that occurred late after elective implantation of polymer-based paxlitaxel-eluting (343 and 442 days) or sirolimus-eluting (335 and 375 days) stents, and resulted in myocardial infarction. All cases arose soon after antiplatelet therapy was interrupted. If confirmed in systematic long-term follow-up studies, our findings have potentially serious clinical implications.

Short- and Long-Term Clinical Outcome After Drug-Eluting Stent Implantation for the Percutaneous Treatment of Left Main Coronary Artery Disease Insights From the Rapamycin-Eluting and Taxus Stent Evaluated At Rotterdam Cardiology Hospital Registries (RESEARCH and T-SEARCH)

Background—The impact of drug-eluting stent (DES) implantation on the incidence of major adverse cardiovascular events in patients undergoing percutaneous intervention for left main (LM) coronary disease is largely unknown. Methods and Results—From April 2001 to December 2003, 181 patients underwent percutaneous coronary intervention for LM stenosis at our institution. The first cohort consisted of 86 patients (19 protected LM) treated with bare metal stents (pre-DES group); the second cohort comprised 95 patients (15 protected LM) treated exclusively with DES. The 2 cohorts were well balanced for all baseline characteristics. At a median follow-up of 503 days (range, 331 to 873 days), the cumulative incidence of major adverse cardiovascular events was lower in the DES cohort than in patients in the pre-DES group (24% versus 45%, respectively; hazard ratio [HR], 0.52 [95% CI, 0.31 to 0.88]; P=0.01). Total mortality did not differ between cohorts; however, there were significantly lower rates of both myocardial infarction (4% versus 12%, respectively; HR, 0.22 [95% CI, 0.07 to 0.65]; P=0.006) and target vessel revascularization (6% versus 23%, respectively; HR, 0.26 [95% CI, 0.10 to 0.65]; P=0.004) in the DES group. On multivariate analysis, use of DES, Parsonnet classification, troponin elevation at entry, distal LM location, and reference vessel diameter were independent predictors of major adverse cardiovascular events. Conclusions—When percutaneous coronary intervention is undertaken at LM lesions, routine DES implantation, which reduces the cumulative incidence of myocardial infarction and the need for target vessel revascularization compared with bare metal stents, should currently be the preferred strategy.

Post-sirolimus-eluting stent restenosis treated with repeat percutaneous intervention: late angiographic and clinical outcomes.

Background—We evaluated the clinical and angiographic outcomes of patients presenting with restenosis after sirolimus-eluting stent (SES) implantation treated with repeated percutaneous intervention. Methods and Results—A total of 24 consecutive patients have undergone repeated percutaneous intervention to treat post-SES restenosis (27 lesions). The restenosis was located within the stent in 93% of lesions. From the 27 lesions, 1 (4%) was re-treated with a bare stent, 3 (11%) were treated with balloon dilatation, and the remaining 23 lesions (85%) were treated with repeated drug-eluting stent implantation (SES in 12 lesions [44%], paclitaxel-eluting stents in 11 lesions [41%]). The event-free survival rate was 70.8% after a median follow-up of 279 days from the post-SES treatment. The overall recurrent restenosis rate was 42.9%. The risk of recurrent restenosis was increased for patients with hypercholesterolemia, previous angioplasty, failed brachytherapy, post-SES restenosis needing early (<6 months) treatment, and post-SES restenosis treated with balloon dilatation. The recurrent restenosis rate of originally de novo lesions re-treated with drug-eluting stents was 18.2%. Conclusions—Even though de novo lesions treated with SES at baseline and re-treated with drug-eluting stents had reasonably better outcomes than other lesion types and strategies, our study shows that the treatment of post-SES restenosis is currently suboptimal and warrants further investigation.

Complete revascularization : Coronary artery bypass graft surgery versus percutaneous coronary intervention

The concept of complete revascularization arose from the early studies on coronary artery bypass grafting (CABG) surgery whereby some publications demonstrated that patients who were completely revascularized enjoyed a mortality benefit over those who were incompletely revascularized, thus setting the standard for the field of CABG.1–3 Over the past 3 decades, CABG has evolved from saphenous vein grafting to more frequent use of arterial grafting, better perioperative management, development of a less invasive approach, and off-pump surgery as a genuine option. The development of percutaneous coronary interventions (PCIs) for the treatment of coronary stenosis has developed out of the treatment of single-vessel disease to become an alternative to CABG in the treatment of multivessel disease.4,5 PCI has progressed from balloon angioplasty to coronary stents,6,7 and now drug-eluting stents,8 with the simultaneous development of new devices to treat chronic total occlusions (CTOs). For both groups of patients treated by either CAGB or PCI, there is recognition that aggressive pharmacological secondary-prevention therapies such as statins and antiplatelet agents are beneficial and are now commonly used. Despite the mantra of complete revascularization, none of the current guidelines set out by the American or European cardiology societies formally discuss the issue in detail. Although this topic has been addressed separately within each revascularization strategy, to date there has been only 1 report from a randomized trial that compared the end point of complete revascularization between CABG and PCI.9 This review will therefore address the issue separately for CABG and for PCI and finally provide a comparison of the 2 strategies. There is no universal definition for what is meant by “complete” revascularization (Table 1). Different studies employ different definitions, and for that reason, comparisons between studies must be interpreted with caution. For example, revascularization may be declared complete if …

Technology Insight: an overview of research in drug-eluting stents

Drug-eluting stents (DESs) have revolutionized interventional cardiology over the past few years to the extent that balloon angioplasty and bare stents did in the 1980s and 1990s. The first DESs became commercially available in Europe in 2002 and in the US in 2003, and it is estimated that up to 80% of patients who undergo stent implantation in the US now receive a DES. Two devices, Cypher® sirolimus-eluting stents (Cordis Corporation, Miami Lakes, FL) and Taxus® paclitaxel-eluting stents (Boston Scientific Corporation, Natick, MN), are currently licensed for sale in both regions. Multiple new devices using different drugs, carriers and stents are currently undergoing clinical trials to establish their efficacy and obtain approval for commercialization. While the remarkable reduction of restenosis has accounted for the success of DESs, concerns remain regarding long-term follow-up; published 3-year follow-up results are available for fewer than 200 patients overall. Reports of late stent thrombosis have emerged, particularly in relation to discontinuation of antiplatelet therapy. In patients treated with DESs, long-term administration of at least one antiplatelet agent must be continued following completion of the mandatory dual antiplatelet regimen. In this review, we summarize the findings available for DESs so far, discuss emerging safety and efficacy data, and look at the future directions for these devices.

Effect of prehospital triage on revascularization times, left ventricular function, and survival in patients with ST-elevation myocardial infarction.

Shorter reperfusion times lead to better outcomes in patients with ST-elevation myocardial infarction (STEMI). We assessed the efficacy of prehospital triage with bypass of community hospitals and early activation of the cardiac catheterization team on revascularization times, left ventricular (LV) ejection fraction, and survival. Patients with STEMI (624) were divided into 3 groups determined by site of triage: ambulance field triage (163), interventional center emergency department (202), and 3 community hospital emergency departments (259). Compared with community hospital and interventional center triages, ambulance field triage resulted in a significant median decrease in door-to-balloon times of 68 and 27 minutes, respectively (p <0.001). LV ejection fraction was highest in the field triage group (52 +/- 13%) compared with the interventional center (49 +/- 12%) and community hospital (48 +/- 12%, p = 0.017) groups. Thirty-day mortality was lowest in the ambulance field group (3%) compared with the interventional facility (11%) and community hospital (4%, p = 0.007) groups. There was a significant difference in long-term survival with up to 30-month follow-up among the 3 triage groups (p = 0.041). With time-dependent Cox regression modeling the difference in survival was significant only during the first week after STEMI (p = 0.020). Every extra minute of symptom onset to reperfusion time was associated with a relative risk of long-term mortality of 1.003 (95% confidence interval 1.000 to 1.006, p = 0.027). In conclusion, field triage of patient with STEMI decreased revascularization times, which preserved LV function, and improved early survival.

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.

Adverse clinical events in patients treated with sirolimus-eluting stents: the impact of Type D personality

Background Little is known about the impact of psychological risk factors on cardiac prognosis in the drug-eluting stent era. We examined whether the distressed personality (Type D) moderates the effect of percutaneous coronary intervention with sirolimus-eluting stent implantation on adverse clinical events at 2-year follow-up. Type D is an emerging risk factor in patients with cardiovascular disease. Design Prospective follow-up study. Methods Three hundred and fifty-eight patients with ischemic heart disease, who consecutively underwent percutaneous coronary intervention with sirolimus-eluting stent as part of the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital registry, completed the Type D Scale (DS14) post-percutaneous coronary intervention (PCI). The end-point was a composite of death and non-fatal myocardial infarction 2 years after PCI. Results At follow-up, there were 22 events (12 deaths and 11 myocardial infarctions). Type D patients had a greater than two-fold risk of an event at follow-up compared with non-Type D patients (10.4 vs. 4.4%, P = 0.031). In multivariable analysis, Type D remained an independent predictor of adverse outcome (hazard ratio: 2.61; 95% confidence interval: 1.12–6.09; P = 0.027) adjusting for sex, age, and history of coronary artery disease, multivessel disease, diabetes, hypercholesterolemia, hypertension, renal impairment and smoking. Previous cardiac history was also an independent predictor of death or myocardial infarction (hazard ratio: 2.83; 95% confidence interval: 1.00–7.96; P = 0.049). Conclusions Type D personality moderated the effect of percutaneous coronary intervention on hard clinical events despite treatment with the latest innovation in interventional cardiology. The inclusion of psychological risk factors in general and personality factors in particular may optimize risk stratification in the drug-eluting stent era. Eur J Cardiovasc Prev Rehabil 14: 135-110

Percutaneous therapy of bifurcation lesions with drug-eluting stent implantation: the Culotte technique revisited.

INTRODUCTION: The most effective strategy for bifurcation stenting is currently undefined. The Culotte technique was developed as a method that ensures complete bifurcation lesion coverage. However, it went out of favour due to a high rate of restenosis when utilizing bare metal stents. Drug‐eluting stents reduce the rate of restenosis and need for repeat lesion revascularization compared with bare metal stents; we re‐evaluated this technique with drug‐eluting stent implantation. METHODS: Between April 2002 and October 2003, 207 patients were treated for at least one bifurcation lesion with drug‐eluting stent implantation to both the main vessel and side branch. Of these, 23 were treated with the Culotte technique (11.1%) for 24 lesions. Sirolimus‐eluting stents were used in 8.3%, and paclitaxel‐eluting stents in the remaining 92.7%. RESULTS: Clinical follow‐up was obtained in 100%. One patient had a myocardial infarction at 14 days (maximum rise in creatine kinase 872IU/L) related to thrombosis occurring in another lesion, and underwent repeat revascularization. There were no episodes of stent thrombosis in the Culotte lesions. At eight months follow‐up, there were no deaths and no further myocardial infarction. One patient required target lesion revascularization (TLR), and a second underwent target vessel revascularization. The cumulative rates of survival‐free of TLR and major adverse cardiac events were 94.7% and 84.6% respectively. Angiographic follow‐up was obtained in 16 patients (69.6%) at a mean period of 8.3±4.3months. The late lumen loss for the main vessel and side branch were 0.48±0.56 mm and 0.53±0.33 mm respectively, with binary restenosis rates of 18.8% and 12.5%. CONCLUSIONS: In this small study of bifurcation stenting utilizing the Culotte technique with drug‐eluting stent implantation, there was a low rate of major adverse events and need for target lesion revascularization at eight months, when compared with historical data of bifurcation stenting with bare metal stents. Further re‐evaluation of this technique utilizing drug‐eluting stents, is warranted in the setting of larger randomized studies.

Guidewire navigation in coronary artery stenoses using a novel magnetic navigation system: first clinical experience.

The objective of this study was to investigate the efficacy of guidewire navigation across coronary artery stenoses using magnetic navigation system (MNS) versus conventional navigation. The MNS is a novel option to facilitate access to target lesions, particularly in tortuous vessels. In an experimental study using a challenging vessel phantom, magnetic‐navigated guidewire passage has been reported to reduce fluoroscopy and procedure time significantly. Both magnetic and manual guidewire navigation were attempted in 21 consecutive diseased coronary arteries. The study endpoint was defined as an intraluminal wire position distal to the stenosis. Procedural success was defined as successful guidewire passage without procedural events. Procedure time, amount of contrast, fluoroscopy time, and radiation dose/area product (DAP) were evaluated. There were no procedural events related to either guidewire. Although the lesions attempted had relatively simple and straightforward characteristics, significantly shorter procedure and fluoroscopy time were observed for manual guidewire navigation compared to MNS (median, 40 vs. 120 sec, P = 0.001; 38 vs. 105 sec, P = 0.001, respectively). Contrast amount and DAP were higher in MNS than in conventional method (median, 13 vs. 9 ml, P = 0.018; 215 vs. 73 Gym2, P = 0.002, respectively). The magnetic wire did not cross in two vessels. Guidewire navigation using MNS presented a novel, safe, and feasible approach to address coronary artery lesions. Clinical studies are needed to evaluate the potential benefit of the MNS in more complex coronary lesions and tortuous anatomy.