Victoria Martín-Yuste

Everolimus-eluting stent versus bare-metal stent in ST-segment elevation myocardial infarction (EXAMINATION): 1 year results of a randomised controlled trial

BACKGROUND Everolimus-eluting stent (EES) reduces the risk of restenosis in elective percutaneous coronary intervention. However, the use of drug-eluting stent in patients with ST-segment elevation myocardial infarction (STEMI) is still controversial. Data regarding the performance of second-generation EES in this setting are scarce. We report the 1-year result of the EXAMINATION (clinical Evaluation of the Xience-V stent in Acute Myocardial INfArcTION) trial, comparing EES with bare-metal stents (BMS) in patients with STEMI. METHODS This multicentre, prospective, randomised, all-comer controlled trial was done in 12 medical centres in three countries. Between Dec 31, 2008, and May 15, 2010, we recruited patients with STEMI up to 48 h after the onset of symptoms requiring emergent percutaneous coronary intervention. Patients were randomly assigned (ratio 1:1) to receive EES or BMS. Randomisation was in blocks of four or six patients, stratified by centre and centralised by telephone. Patients were masked to treatment. The primary endpoint was the patient-oriented combined endpoint of all-cause death, any recurrent myocardial infarction, and any revascularisation at 1 year and was analysed by intention to treat. The secondary endpoints of the study included the device-oriented combined endpoint of cardiac death, target vessel myocardial infarction or target lesion revascularisation, and rates of all cause or cardiac death, recurrent myocardial infarction, target lesion or target vessel revascularisation, stent thrombosis, device and procedure success, and major and minor bleeding. This trial is registered with ClinicalTrials.gov, number NCT00828087. FINDINGS Of the 1504 patients randomised, 1498 patients were randomly assigned to receive EES (n=751) or BMS (n=747). The primary endpoint was similar in both groups (89 [11·9%] of 751 patients in the EES group vs 106 [14·2%] of 747 patients in the BMS group; difference -2·34 [95% CI -5·75 to 1·07]; p=0·19). Device-oriented endpoint (44 [5·9%] in the EES group vs 63 [8·4%] in the BMS group; difference -2·57 [95% CI -5·18 to 0·03]; p=0·05) did not differ between groups, although rates of target lesion and vessel revascularisation were significantly lower in the EES group (16 [2·1%] vs 37 [5·0%], p=0·003, and 28 [3·7%] vs 51 [6·8%], p=0·0077, respectively). Rates of all cause (26 [3·5%] for EES vs 26 [3·5%] for BMS, p=1·00) or cardiac death (24 [3·2%] for EES vs 21 [2·8%] for BMS, p=0·76) or myocardial infarction (10 [1·3%] vs 15 [2·0%], p=0·32) did not differ between groups. Stent thrombosis rates were significantly lower in the EES group (4 [0·5%] patients with definite stent thrombosis in the EES group vs 14 [1·9%] in the BMS group and seven [0·9%] patients with definite or probable stent thrombosis in the EES group vs 19 [2·5%] in the BMS group, both p=0·019). Although device success rate was similar between groups, procedure success rate was significantly higher in the EES group (731 [97·5%] vs 705 [94·6%]; p=0·0050). Finally, Bleeding rates at 1 year were comparable between groups (29 [3·9%] patients in the EES group vs 39 [5·2%] in the BMS group; p=0·19). INTERPRETATION The use of EES compared with BMS in the setting of STEMI did not lower the patient-oriented endpoint. However, at the stent level both rates of target lesion revascularisation and stent thrombosis were reduced in recipients of EES. FUNDING Spanish Heart Foundation.

Background, Incidence, and Predictors of Antiplatelet Therapy Discontinuation During the First Year After Drug-Eluting Stent Implantation

Background— Predictors of antiplatelet therapy discontinuation (ATD) during the first year after drug-eluting stent implantation are poorly known. Methods and Results— This was a prospective study with 3-, 6-, 9-, and 12-month follow-up of patients receiving at least 1 drug-eluting stent between January and April 2008 in 29 hospitals. Individual- and hospital-level predictors of ATD were assessed by hierarchical-multinomial regression analysis. ATD could be assessed in 1622 candidates for follow-up (82.5%). A total of 234 patients (14.4%) interrupted at least 1 antiplatelet therapy drug, predominantly clopidogrel (n=182, 11.8%). Bleeding events or invasive procedures led to ATD in 109 patients. This was predicted by renal impairment (odds ratio [OR] 2.81, 95% confidence interval [CI] 1.48 to 5.34), prior major hemorrhage (OR 3.77, 95% CI 1.41 to 10.03), and peripheral arterial disease (OR 1.78, 95% CI 1.01 to 3.15). Medical decisions led to ATD in 70 patients; this was predicted by long-term use of anticoagulant therapy (OR 3.88, 95% CI 1.26 to 11.98), undergoing the procedure in a private hospital (OR 13.3, 95% CI 1.69 to 105), and not receiving instructions about medication (OR 2.8, 95% CI 1.23 to 6.36). Thirty-nine patients interrupted ATD on their own initiative, mainly immigrants (OR 3.78, 95% CI 1.2 to 11.98) and consumers of psychotropic drugs (OR 2.58, 95% CI 1.3 to 5.12). Conclusions— ATD during the first year after drug-eluting stent implantation is based mainly on patient decision or a medical decision not associated with major bleeding events or major surgical procedures. Individual- and hospital-level variables are important to predict ATD.

Double Antiplatelet Therapy After Drug-Eluting Stent Implantation Risk Associated With Discontinuation Within the First Year

OBJECTIVES The goal of this study was to assess the risk associated with double antiplatelet therapy (DAT) discontinuation, and specifically, temporary discontinuation, during the first year after drug-eluting stent (DES) implantation. BACKGROUND Doubts remain about the risk of temporary DAT discontinuation within 1 year after DES implantation. METHODS A total of 1,622 consecutive patients undergoing DES implantation at 29 hospitals were followed up at 3, 6, 9, and 12 months to record the 1-year antiplatelet therapy discontinuation (ATD) rate, the number of days without DAT, and the rate of 1-year major cardiac events. Cox regression was used to analyze the association between ATD considered as a time-dependent covariate and 1-year cardiac events. RESULTS One hundred seventy-two (10.6%) patients interrupted at least 1 antiplatelet drug during the first year after DES implantation, although only 1 during the first month. Most (n=111, 64.5%) interrupted DAT temporarily (median: 7 days; range: 5 to 8.5): 79 clopidogrel (31 temporarily), 38 aspirin (27 temporarily), and 55 both drugs (53 temporarily). Discontinuation was followed by acute coronary syndrome in 7 (4.1%; 95% confidence interval [CI]: 1.7 to 8.2), a similar rate of major cardiac events to that in patients without ATD (n=80; 5.5%; 95% CI: 4.4 to 6.8; p=0.23). ATD was not independently associated with 1-year major cardiac events (hazard ratio: 1.32 [95% CI: 0.56 to 3.12]). CONCLUSIONS ATD within the first year and beyond the first month after DES is not exceptional, is usually temporary, and does not appear to have a large impact on risk.

Accurate Coronary Centerline Extraction, Caliber Estimation, and Catheter Detection in Angiographies

Segmentation of coronary arteries in X-ray angiography is a fundamental tool to evaluate arterial diseases and choose proper coronary treatment. The accurate segmentation of coronary arteries has become an important topic for the registration of different modalities, which allows physicians rapid access to different medical imaging information from computed tomography (CT) scans or magnetic resonance imaging (MRI). In this paper, we propose an accurate fully automatic algorithm based on Graph-cuts for vessel centerline extraction, caliber estimation, and catheter detection. Vesselness, geodesic paths, and a new multiscale edgeness map are combined to customize the Graph-cuts approach to the segmentation of tubular structures, by means of a global optimization of the Graph-cuts energy function. Moreover, a novel supervised learning methodology that integrates local and contextual information is proposed for automatic catheter detection. We evaluate the method performance on three datasets coming from different imaging systems. The method performs as good as the expert observer with respect to centerline detection and caliber estimation. Moreover, the method discriminates between arteries and catheter with an accuracy of 96.5%, sensitivity of 72%, and precision of 97.4%.

Changes in thrombus composition and profilin-1 release in acute myocardial infarction

AIM Thrombus formation is a dynamic process regulated by flow, blood cells, and plasma proteins. The present study was performed to investigate the characteristics of human coronary thrombus in ST-segment elevation myocardial infarction (STEMI). METHODS AND RESULTS Patients admitted with ST-elevation myocardial infarction, in which thrombectomy was performed, were included (n = 86). Intracoronary thrombi and blood from the culprit coronary site and the systemic circulation were obtained during percutaneous coronary intervention (PCI). Thrombi were categorized by onset-of-pain-to-PCI elapsed time in thrombus of <3 (T3) and more than 6 h of evolution (T6). Clinical, morphological, and proteomic variables were investigated. While T3 were mainly composed by platelets and fibrin(ogen), T6 were characterized by a reduced platelet content, increased leucocytes infiltration (including monocytes, neutrophils, T-cells, and B-cells), and appearance of undifferentiated progenitor cells. Significant differences between T3 and T6 were found in the cell cytoskeleton-associated proteome (beta-actin and tropomyosin 3 and 4). By discovery proteomics, we have identified profilin-1 (Pfn-1) in the coronary thrombi and detected higher levels in T3 than in T6. While plasma Pfn-1 levels were low in T3 patients, levels significantly increased in both coronary and peripheral circulation in T6 patients indicating release. In vitro platelet aggregation studies showed that platelets secrete Pfn-1 upon complete activation. CONCLUSION Coronary thrombi show rapid dynamic changes both in structure and cell composition as a function of elapsed onset-of-pain-to-PCI time. Aged ischaemic thrombi were more likely to have reduced Pfn-1 content releasing Pfn-1 to the circulation. Onset-of-pain-to-PCI elapsed time in STEMI patients and hence age of occlusive thrombus can be profiled by Pfn-1 levels found in the peripheral circulation.

Growing thrombi release increased levels of CD235a+ microparticles and decreased levels of activated platelet-derived microparticles. Validation in ST-elevation myocardial infarction patients

Local fluid dynamics and exposed atherosclerotic lesions regulate thrombus formation. Activated cells in the attached thrombi release microparticles to the circulation (circulating microparticles [cMPs]); however, their phenotype is unknown.

Circulating microparticle signature in coronary and peripheral blood of ST elevation myocardial infarction patients in relation to pain-to-PCI elapsed time

BACKGROUND Circulating microparticle (cMP) levels are increased in the acute phase of ST-elevation myocardial infarction (STEMI) and associate with microvascular obstruction; however, the precise cMP-parental cell signature and activation level are not elucidated. Here, we aimed to study the cMP signature in STEMI-patients and whether cMP phenotype changes in relation to onset of pain-to-PCI [ischemic time (IT)]-elapsed time. METHODS Blood was taken at PCI from the culprit coronary and the peripheral circulation in STEMI-patients (N=40). Two control groups were included: peripheral blood of age-matched patients recovering from STEMI [after 72 h] and of control individuals (N=20/group). cMP-parental origin and activation level were characterized by triple-labeling flow cytometry. RESULTS Procoagulant annexin V-positive cMPs bearing parental cell markers as well as markers of activated cells displayed a significantly different profile in STEMI-patients, in control individuals and in patients recovering from STEMI. cMPs derived from monocytes, endothelium, and activated vascular cells were higher in the culprit coronary artery than in peripheral blood in STEMI-patients, especially in patients intervened at short IT. Indeed, cMP levels in coronary blood were inversely related to IT duration (more abundant in thrombi with pain-to-PCI time<180 min). CONCLUSIONS A characteristic [CD66b+/CD62E+/CD142+] cMP signature in the systemic circulation reflects the formation of coronary thrombotic occlusions in STEMI-patients. Changes in the cMP signature in the culprit coronary artery blood reveal the sensitivity of MPs to detect the ischemia-elapsed time. Interestingly, cMPs in peripheral blood may be sensitive markers of the thrombo-occlusive vascular process developing in the coronary arteries of STEMI-patients.

Endothelial and Smooth Muscle Cells Dysfunction Distal to Recanalized Chronic Total Coronary Occlusions and the Relationship With the Collateral Connection Grade

OBJECTIVES This study sought to assess the vascular function in patients with chronic total coronary occlusions (CTO) immediately after successful percutaneous recanalization and its relation with the pre-existing collateral circulation. BACKGROUND CTOs represent a long-acting occlusion of a coronary vessel, in which the progressively developed collateral circulation may limit ischemia and symptoms. However, it is unknown if the coronary segment distal to the occlusion has a preserved vascular function. METHODS We prospectively enrolled 19 consecutive patients, after percutaneous coronary intervention of a CTO. Luminal diameter, measured by quantitative coronary angiography, and coronary blood flow at level of epicardial coronary artery distal to the treated CTO was assessed before and after administration of acetylcholine (Ach), adenosine, and nitroglycerin (NTG). Collaterals were assessed angiographically by grading of Rentrop and of collateral connections (CC1: threadlike continuous connection; CC2: side branch-like connection). RESULTS Overall, Ach and adenosine caused coronary artery vasoconstriction (p=0.001 and p=0.004, respectively), whereas NTG failed to induce vasodilation (p=0.084). Coronary blood flow significantly decreased with Ach (p=0.005), significantly increased with NTG (p=0.035), and did not change with adenosine (p=0.470). Patients with CC2 collaterals (n=8) had less vasoconstriction response and reduction in coronary blood flow after Ach (p=0.005 and p=0.008, respectively), and better vasomotor response to NTG (p=0.029) than patients with CC1 collaterals (n=11). CONCLUSIONS Significant endothelial and smooth muscle dysfunction is present in the distal segments of successfully recanalized CTOs, and that seems to be more pronounced in the presence of a low grading of collateral circulation.

Optimization in Stent Implantation by Manual Thrombus Aspiration in ST-Segment–Elevation Myocardial Infarction Findings From the EXAMINATION Trial

Background—Manual thrombus aspiration (TA) is effective to reduce the thrombus burden during primary percutaneous coronary intervention for ST-elevation myocardial infarction. The objective of this study is to assess the impact of manual TA on stent implantation during primary percutaneous coronary intervention. Methods and Results—Population of the EXAMINATION trial (n=1498) was divided into 2 groups according to the use of TA. Immediate angiographic results, primary patient-oriented end point (combination of all-cause death, myocardial infarction, and any revascularization) and secondary device-oriented end point (combination of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization), definite/probable stent thrombosis, and major/minor bleeding were evaluated at 2 years. A total of 976 (65.2%) patients were classified into TA group and 522 (34.8%) patients into nonthrombus aspiration group. Manual TA was most frequently used in patients with worse initial thrombolysis in myocardial infarction flow. The TA group received less number of stents implanted (1.35±0.62 versus 1.45±0.71, P=0.005) with bigger size (3.25±0.44 versus 3.11±0.46 mm, P<0.001) compared with the nonthrombus aspiration group. A higher rate of direct stenting (69.2% versus 43.3%, P<0.001) with lower rate of postdilatation (13.0% versus 18.0%, P<0.009) was also present in the TA group compared with the nonthrombus aspiration group. At 2-year follow-up, no differences in clinical end point were observed between groups. Conclusions—Manual TA during primary percutaneous coronary intervention is associated with a higher rate of direct stenting, a lower rate of postdilatation, and larger and less stents in comparison with conventional primary percutaneous coronary intervention. Conversely, manual TA had no apparent impact on clinical outcomes at long-term follow-up. Clinical Trial Registration—http://www.clinicaltrials.gov. Unique identifier: NCT00828087.

Determinantes del éxito de la revascularización de las oclusiones coronarias crónicas: estudio mediante tomografía computarizada con multidetectores

INTRODUCTION AND OBJECTIVES Percutaneous revascularization of chronic total coronary artery occlusion is a technical challenge and has a lower success rate than other angioplasty procedures. Identification of predictors of failure could lead to better selection of patients with the greatest possibility of success. In this study, we investigate the multidetector computed tomography features associated with failure of percutaneous treatment for chronic total coronary occlusion. METHODS This is a prospective, single-center study of 69 consecutive patients with chronic total occlusion in whom multidetector computed tomography study was performed before percutaneous coronary revascularization. RESULTS Seventy-seven lesions were analyzed. The mean length of the occlusion was 19.9 (14.3) mm and the estimated duration of occlusion was 47 (62) months. The only angiographic factor independently predictive of failure was a severe curve between the plaque and the proximal patent vessel (odds ratio 3.8, 95% confidence interval, 1.2-12; P=.02). On multidetector computed tomography, the only factor predictive of failure was an arc of calcium affecting more than 50% of the vessel circumference in the proximal (P=.04) and middle (P=.03) third of the occlusion. CONCLUSIONS Multidetector computed tomography identified a variable that cannot be measured by angiography that can predict failure in percutaneous revascularization of chronic total coronary occlusions. In selected cases, this parameter could be useful for preprocedure screening.