K.G. van Houwelingen

Coating irregularities of durable polymer-based drug-eluting stents as assessed by scanning electron microscopy.

AIMS To classify and quantify post-expansion irregularities in durable polymer-based coatings of drug-eluting stents (DES). METHODS AND RESULTS Taxus Liberté, Endeavor Sprint, Endeavor Resolute and Xience V DES (three samples of each) were explored by light microscopy and scanning electron microscopy (SEM) following expansion at 14 atm in water. Incidence and size of irregularities were measured during thorough quantitative examinations of a 360 SEM images. DES types examined showed a significant difference in the incidence of irregularities (p<0.0001; 6.6+/-4.2/image at 60-fold magnification) with typical patterns specific for each DES. All types showed areas with bare metal-aspects, but incidence, shape, and size differed largely: Sprint showed the largest areas. Cracks were only found in Sprint and Resolute, while wrinkles were seen exclusively in Taxus Liberté and Xience V (p<0.0001). The coating of each DES type showed some inhomogeneity of distribution, but the incidence differed (p<0.0001) and was least in Taxus Liberté, which, on the other hand, was the only DES that showed webbing with large bare-metal exposure. CONCLUSIONS The incidence and size of various coating irregularities on different types of DES varied widely. These data may be considered in ongoing discussions on the differences between DES and may serve as reference to compare novel DES.

Micro-computed tomographic assessment following extremely oversized partial postdilatation of drug-eluting stents

Aims: To assess the spatial geometry of drug-eluting stents (DES) following extremely oversized proximal postdilatation. Interventions of distal left main (LM) disease generally require stenting across the LM bifurcation with inherent vessel tapering along this segment and a high likelihood of stent malapposition, which can be avoided by such postdilations. Methods and results: Sixteen DES (four 3.5 mm-samples of Cypher Select Plus, Taxus Liberte, Endeavor Resolute, Xience V) were deployed in water; 12 samples were then proximally postdilated with noncompliant 5.0 mm balloons at 18 atm. All samples were examined by micro-computed tomography. Taxus Liberte, Endeavor Resolute, and Xience V, showed increased cell areas in the transitional region (just distal to postdilated region), while Cypher Select showed its largest cells inside the postdilated region. Overall, the largest maximum cell area was observed in Endeavor Resolute, while Cypher Select showed the smallest (p<0.001, for both). In addition, the size of the very proximal postdilated cells was relatively small in most DES except Xience V. Conclusions: Extremely oversized partial stent postdilatation demonstrated significant between-DES differences in final spatial stent configuration and maximum cell size. These data could be of practical interest with regard to coronary interventions in LM stems with stenting across the LM bifurcation.

Diagnostic and therapeutic approach of congenital solitary coronary artery fistulas in adults: Dutch case series and review of literature

BackgroundCoronary artery fistulas (CAFs) are infrequent anomalies, coincidentally detected during coronary angiography (CAG).AimTo elucidate the currently used diagnostic imaging modalities and applied therapeutic approaches.Materials and MethodsFive Dutch patients were found to have CAFs. A total of 170 reviewed subjects were subdivided into two comparable groups of 85 each, treated with either percutaneous ‘therapeutic’ embolisation (PTE group) or surgical ligation (SL group).ResultsIn our series, the fistulas were visualised with several diagnostic imaging tests using echocardiography, multidetector computed tomography, and CAG. Four fistulas were unilateral and one was bilateral; five originated from the left and one originated from the right coronary artery. Among the reviewed subjects, high success rates were found in both treatment groups (SL: 97% and PTE: 93%). Associated congenital or acquired cardiovascular disorders were frequently present in the SL group (23%). Bilateral fistulas were present in 11% of the SL group versus 1% of the PTE group. The fistula was ligated surgically in one and abolished percutaneously in another. Medical treatment including metoprolol was conducted in two, and watchful waiting follow-up was performed in one.ConclusionsSeveral diagnostic imaging techniques are available for assessment of the anatomical and functional characteristics of CAFs.

Comparison of Frequency of Periprocedural Myocardial Infarction in Patients With and Without Diabetes Mellitus to Those With Previously Unknown but Elevated Glycated Hemoglobin Levels (from the TWENTE Trial)

In patients without a history of diabetes mellitus, increased levels of glycated hemoglobin (HbA1c) are associated with higher cardiovascular risk. The relation between undetected diabetes and clinical outcome after percutaneous coronary intervention is unknown. To investigate whether these patients may have an increased risk of periprocedural myocardial infarction (PMI), the most frequent adverse event after percutaneous coronary intervention, we assessed patients of the TWENTE trial (a randomized, controlled, second-generation drug-eluting stent trial) in whom HbA1c data were available. Patients were classified as known diabetics or patients without a history of diabetes who were subdivided into undetected diabetics (HbA1c ≥6.5%) and nondiabetics (HbA1c <6.5%). Systematic measurement of cardiac biomarkers and electrocardiographic assessment were performed. One-year clinical outcome was also compared. Of 626 patients, 44 (7%) were undetected diabetics, 181 (29%) were known diabetics, and 401 (64%) were nondiabetics. In undetected diabetics the PMI rate was higher than in nondiabetics (13.6% vs 3.7%, p = 0.01) and known diabetics (13.6% vs 6.1%, p = 0.11). Multivariate analysis adjusting for covariates confirmed a significantly higher PMI risk in undetected diabetics compared to nondiabetics (odds ratio 6.13, 95% confidence interval 2.07 to 18.13, p = 0.001) and known diabetics (odds ratio 3.73, 95% confidence interval 1.17 to 11.89, p = 0.03). After 1 year, target vessel MI rate was significantly higher in undetected diabetics (p = 0.02) than in nondiabetics, which was related mainly to differences in PMI. Target vessel failure was numerically larger in unknown diabetics than in nondiabetics, but this difference did not reach statistical significance (13.6% vs 8.0%, p = 0.25). In conclusion, undetected diabetics were shown to have an increased risk of PMI.

TWENTE Study: The Real-World Endeavor Resolute Versus Xience V Drug-Eluting Stent Study in Twente: study design, rationale and objectives

Background. New-generation drug-eluting stents (DES) may solve several problems encountered with first-generation DES, but there is a lack of prospective head-to-head comparisons between new-generation DES. In addition, the outcome of regulatory trials may not perfectly reflect the outcome in ‘real world’ patients.Objectives. To compare the efficacy and safety of two new-generation DES in a ‘real world’ patient population.Methods. A prospective, randomised, single-blinded clinical trial to evaluate clinical outcome after Endeavor Resolute vs. Xience V stent implantation. The primary endpoint is target vessel failure at one-year follow-up. In addition, the study comprises a two-year and an open-label five-year follow-up. (Neth Heart J 2010;18:360-4.)

High-dose tirofiban pretreatment reduces the need for bail-out study medication in patients with ST-segment elevation myocardial infarction: results of a subgroup analysis of the On-TIME 2 trial

Objective This study investigated the outcome of patients who received bail-out study medication and evaluated whether high-dose tirofiban (HDT) pretreatment may reduce the need for bail-out study medication. Design A prespecified analysis of the multicentre, double-blind, placebo controlled, randomised On-TIME 2 trial. Bail-out use of study medication was predefined and part of the combined clinical end point. Patients 984 patients excluded from many coronary intervention hospitals in different countries were randomly assigned to HDT or placebo. In the subgroup who received blinded bail-out treatment, patients pretreated with placebo who received bail-out HDT were compared with those pretreated with HDT who received bail-out placebo. Interventions Routine prehospital initiation of HDT versus bail-out use of HDT. Main Outcome Measures Electrocardiographic and clinical outcome. Results Blinded bail-out study medication was used in 24% (237/980) of patients, with a higher rate in patients pretreated with placebo: 29% (140/492) versus 20% (97/488), p=0.002. Bail-out versus no bail-out use of study medication was associated with more residual ST deviation (5.5±7.2 vs 3.7±4.8 mm, p=0.005), and worse clinical outcome (major adverse cardiac events (MACE) at 30 days 12.2% vs 5.6%, p<0.001), mainly due to poor outcome in patients who received HDT bail-out. In patients pretreated with HDT who received placebo bail-out study medication, residual ST deviation and clinical outcome did not differ significantly compared with patients who did not receive bail-out medication (4.0±4.6 vs 3.7± 4.8 mm, p=0.703, MACE 7.2% vs 5.6%, p=0.535). Conclusions Routine prehospital treatment with HDT significantly reduced the use of blinded bail-out study medication. The need for bail-out therapy was associated with a less favourable outcome. This analysis suggests that routine pretreatment is superior to provisional use of HDT in patients with ST-segment elevation myocardial infarction.

Primary percutaneous coronary intervention in the left main stem of a monocoronary artery.

In a 71-year-old female with evolving anterior wall myocardial infarction, coronary angiography revealed a monocoronary artery which arose from the right sinus of Valsalva. Originating from a short common trunk, the left main stem showed a thrombotic lesion that occluded the left anterior descending coronary artery while the circumflex artery was obstructed. Intracoronary administration of abciximab, followed by stenting of the transition between the left anterior descending coronary artery and the main stem, and final kissing balloon inflation of the bifurcation resulted in an excellent angiographic result and favourable clinical outcome. (Neth Heart J 2009;17:274–6.)