Thrombocytopenia after transcatheter aortic valve implantation. A comparison between balloon-expandable and self-expanding valves.

BACKGROUND: Thrombocytopenia after transcatheter aortic valve implantation (TAVI) is common and has been related to higher mortality and major complications. No comparison between balloon-expandable (BEV) and self-expanding valves (SEV) regarding drop platelet count (DPC) has been reported to date. The objectives of this study were to analyze the differences in DPC between BEVs or SEVs and their prognostic implications in clinical outcomes. METHODS: We retrospectively analyzed patients undergoing TAVI. Platelet counts after TAVI were collected. Two groups were created: DPC ≤ 30% and DPC > 30%. VARC-2 criteria were used to define outcomes. RESULTS: Study population was composed of 195 patients (age 77.5 ± 6.7, 57.4% males). All of them but one experienced DPC (mean DPC 31.9 ± 15.3%). DPC was significantly higher among the patients treated with BEV compared to those treated with SEV (36.3 ± 15.1% vs 27.7 ± 14.4, P < 0.001). After multivariate analysis, the use of BEV was independently associated with a higher rate of DPC > 30% (67.4% vs 36.0%; OR 3.4; 95% CI, 1.42-8.16). At 30 days, the DPC > 30% was associated with a higher rate of life-threatening/major bleeding, major vascular complications, in-hospital sepsis and mortality. At one year, there were no statistically significant differences in the mortality rate between groups (6.35% vs 10.0%, HR 1.54; 95% CI, 0.56-4.25). CONCLUSIONS: In this study, the use of BEV was associated with a higher risk of DPC after TAVI. A DPC rate > 30% was associated with an increased risk of major complications at 30 days.

The benefit of a second burst antitachycardia sequence for fast ventricular tachycardia in patients with implantable cardioverter defibrillators.

BACKGROUND: In patients with implantable cardioverter defibrillators (ICDs), an empirical burst of antitachycardia pacing (ATP) is moderately effective in terminating fast ventricular tachycardias (FVTs). It is unknown whether, in the case of failure of a first burst, a second burst attempt increases the efficacy of the intervention, without increasing morbidity. Our aim was to evaluate the safety and efficacy of a strategy of programming successive ATP sequences for FVT episodes. METHODS: A prospective study evaluated the safety and effectiveness of programming successive ATP sequences for termination of FVT episodes (cycle lengths [CLs] 250-320 ms) treated by one ATP sequence and, in the event of failure, by successive ATP attempts or shocks. RESULTS: Over a median follow-up of 54 months, 267 FVT episodes (mean CL of 295 ± 18 ms) were detected in 35 patients. Effectiveness of the first burst ATP was 64% (65% GEE-adjusted, where GEE is generalized estimating equation) and increased significantly to 83% (75% GEE-adjusted) with the second burst ATP sequence (P = 0.01). In the remaining 17% of FVT episodes with failure of the second ATP, successive bursts and shocks were required. Multivariate analysis showed that primary prevention ICD (odds ratio [OR] 5.3, 95% confidence interval [CI] 1.9-14.5, P = 0.001), sinus rhythm (OR 4.34, 95% CI 1.4-13.4, P = 0.01), nonischemic cardiomyopathy (OR 2.36, 95% CI 1.2-4.8, P = 0.02), and longer VT CL (OR 1.32, 95% CI 1.1-1.6, P = 0.002) were independently associated with effectiveness of the first or second burst pacing sequence. CONCLUSION: The addition of a second burst pacing attempt increases the effectiveness of ATP for FVT and, therefore, reduces the need for high-energy shocks.

MGuard mesh-covered stent for treatment of ST-segment elevation myocardial infarction with high thrombus burden despite manual aspiration.

OBJECTIVES: To assess the usefulness of the MGuard stent in patients with ST-segment elevation myocardial infarction (STEMI) in whom a high thrombus burden persists after manual aspiration. BACKGROUND: In some patients with STEMI, a high thrombus burden may persist after manual aspiration. These patients may be at high risk of distal embolization and therefore impaired myocardial reperfusion. The MGuard is a novel mesh-covered stent designed to minimize thrombus embolization. METHODS: Single-arm, prospective registry of patients with STEMI and high thrombus burden after aggressive thrombus aspiration treated with the MGuard stent. High thrombus burden was defined as thrombus burden grade 4 or 5 according to the TIMI score. Lesions with a side branch ≥2 mm and patients with cardiogenic shock were not included. The study end-points were proportion of final TIMI 3 flow, normal myocardial blush, and complete ST-segment resolution. RESULTS: Fifty-six patients were included. After MGuard stent implantation >85% of cases had thrombus score = 0. Final TIMI 3 flow was achieved in 82% of cases, normal myocardial blush in 55%, and complete ST-segment resolution in 59%. Occlusion of a side branch (<2 mm) occurred in 2 cases (3.5%), embolization to a distal branch in 5 cases (8.9%), and transient no-reflow in 4 cases (7.1%). Major adverse cardiac events rate at 9 months was 3.6%, including 1 definite acute stent thrombosis and 1 target-vessel revascularization. CONCLUSIONS: The MGuard stent may be useful to prevent distal embolization in patients with STEMI and high thrombus burden despite mechanical aspiration.

Treatment of Slow-Flow After Primary Percutaneous Coronary Intervention With Flow-Mediated Hyperemia: The Randomized RAIN-FLOW Study.

Background ST-segment-elevation myocardial infarction complicated with no reflow after primary percutaneous coronary intervention is associated with adverse outcomes. Although several hyperemic drugs have been shown to improve the Thrombolysis in Myocardial Infarction flow, optimal treatment of no reflow remains unsettled. Saline infusion at 20 mL/min via a dedicated microcatheter causes (flow-mediated) hyperemia. The objective is to compare the efficacy of pharmacologic versus flow-mediated hyperemia in patients with ST-segment-elevation myocardial infarction complicated with no reflow. Methods and Results In the RAIN-FLOW (Treatment of Slow-Flow After Primary Percutaneous Coronary Intervention With Flow-Mediated Hyperemia) study, 67 patients with ST-segment-elevation myocardial infarction and no reflow were randomized to receive either pharmacologic-mediated hyperemia with intracoronary adenosine or nitroprusside (n=30) versus flow-mediated hyperemia (n=37). The angiographic corrected Thrombolysis in Myocardial Infarction frame count and the minimal microcirculatory resistance, as assessed with intracoronary pressure-thermistor wire, dedicated microcatheter, and thermodilution techniques, were compared after study interventions. Both Thrombolysis in Myocardial Infarction frame count(40.2±23.1 versus 39.2±20.7; P=0.858) and minimal microcirculatory resistance (753.6±661.5 versus 993.3±740.8 Wood units; P=0.174) were similar between groups. Thrombolysis in Myocardial Infarction 3 flow was observed in 26.7% versus 27.0% (P=0.899). Flow-mediated hyperemia showed 2 different thermodilution patterns during saline infusion indicative of the severity of the no reflow phenomenon. In-hospital death and nonfatal heart failure were observed in 10.4% and 26.9%, respectively. Conclusions Both treatments showed similar (and limited) efficacy restoring coronary flow. Flow-mediated hyperemia with thermodilution pattern assessment allowed the simultaneous characterization of the no reflow degree and response to hyperemia. No reflow was associated with a high rate of adverse outcomes. Further research is warranted to prevent and to treat no reflow in patients with ST-segment-elevation myocardial infarction. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04685941.

Antiplatelet efficacy of ticagrelor versus clopidogrel in Mediterranean patients with diabetes mellitus and chronic coronary syndromes: A crossover pharmacodynamic investigation.

Introduction: Patients with diabetes mellitus (DM) have augmented platelet reactivity and diminished responsiveness to clopidogrel. Ticagrelor, a more potent P2Y12 inhibitor, is clinically superior to clopidogrel in acute coronary syndromes, although its role in chronic coronary syndromes (CCS) is still the subject of debate. The aim of this investigation was to compare the pharmacodynamic effectiveness of ticagrelor and clopidogrel in Mediterranean DM patients with CCS. Materials and methods: In this prospective, randomized, crossover study, patients (n = 20) were randomized (1:1) to receive, on top of aspirin therapy, either ticagrelor 180 mg loading dose (LD)/90 mg maintenance dose (MD) b.i.d. or clopidogrel 600 mg LD/75 mg MD o.d. for 1 week in a crossover fashion with a 2-4 week washout period between regimens. Platelet function measurements were performed at 4 timepoints in each period (baseline, 2 h and 24 h after LD, and 1 week), including light transmission aggregometry (LTA, primary endpoint), VASP assay, Multiplate and VerifyNow P2Y12. Results: The ticagrelor LD achieved greater platelet inhibitory effect than clopidogrel LD, assessed with LTA (20 µM ADP as agonist), at 2 h (34.9 ± 3.9% vs. 63.6 ± 3.9%; p < 0.001) and 24 h (39.4 ± 3.5% vs. 52.3 ± 3.8%; p = 0.014). After 1 week of therapy, platelet reactivity was again significantly inferior with ticagrelor compared to clopidogrel (30.7 ± 3.0% vs. 54.3 ± 3.0%; p < 0.001). The results were consistent with the other platelet function assays employed. Conclusion: In Mediterranean patients with DM and CCS, ticagrelor provides a more potent antiplatelet effect than clopidogrel after the LD and during the maintenance phase of therapy. Clinical trial registration: [ClinicalTrials.gov], identifier [NCT02457130].

Coronary endothelial and microvascular function distal to polymer-free and endothelial cell-capturing drug-eluting stents. The randomized FUNCOMBO trial.

INTRODUCTION AND OBJECTIVES: The vasomotor function of new-generation drug-eluting stents designed to enhance stent healing and reendothelialization is unknown. This study aimed to compare the endothelial function of the infarct-related artery (IRA) treated with bioactive circulating endothelial progenitor cell-capturing sirolimus-eluting stents (COMBO) vs polymer-free biolimus-eluting stents (BioFreedom) in ST-segment elevation myocardial infarction patients at 6 months. Secondary objectives were to compare the microcirculatory function of the IRA and stent healing at 6 months. METHODS: Sixty patients were randomized to bioactive sirolimus-eluting stent vs polymer-free biolimus-eluting stents implantation. At 6 months, patients underwent coronary angiography with vasomotor, microcirculatory and optical coherence tomography examinations. Endothelial dysfunction of the distal coronary segment was defined as ≥ 4% vasoconstriction to intracoronary acetylcholine infusion. RESULTS: Endothelial dysfunction was similarly observed between groups (64.0% vs 62.5%, respectively; P=.913). Mean lumen diameter decreased by 16.0 ±20.2% vs 16.1 ±21.6% during acetylcholine infusion (P=.983). Microcirculatory function was similar in the 2 groups: coronary flow reserve was 3.23 ±1.77 vs 3.23±1.62 (P=.992) and the index of microcirculatory resistance was 24.8±16.8 vs 21.3±12.0 (P=.440). Optical coherence tomography findings were similar: uncovered struts (2.3% vs 3.2%; P=.466), malapposed struts (0.1% vs 0.3%; P=.519) and major evaginations (7.1% vs 5.6%; P=.708) were observed in few cases. CONCLUSIONS: Endothelial dysfunction of the IRA was frequent and was similarly observed with new-generation drug-eluting stents designed to enhance stent reendothelialization at 6 months. Endothelial dysfunction was observed despite almost preserved microcirculatory function and complete stent coverage. Larger and clinically powered studies are needed to assess the role of residual endothelial dysfunction in ST-segment elevation myocardial infarction patients. Registered in ClinicalTrials.gov: NCT04202172.

Coronary vasomotor function and myocardial flow with bioresorbable vascular scaffolds or everolimus-eluting metallic stents: a randomised trial.

AIMS: The aim of this study was to compare the hyperaemic flow and vasomotor response to endothelium-dependent stimuli between bioresorbable vascular scaffolds (BVS) and metallic everolimus-eluting stents (EES) at 13 months. METHODS AND RESULTS: Seventy non-diabetic patients aiming to achieve complete revascularisation were randomised 1:1 to BVS or EES implantation. At 13 months, invasive coronary angiography was performed using intracoronary pressure and Doppler ultrasound measurements at rest and maximal hyperaemia. A vasomotor test to endothelium-dependent (acetylcholine) and independent (nitroglycerine) stimuli and optical coherence tomography (OCT) were also performed. Fifty-nine patients (30 BVS and 29 EES) underwent 13-month examination. Doppler ultrasound average peak velocity (49.0±17.5 vs 49.3±18.3 cm/sec; p=0.95), coronary blood flow (97.4±53.5 vs 88.3±46.7 ml/min; p=0.51), coronary flow reserve (2.6±0.9 vs 2.7±0.8; p=0.84) and fractional flow reserve (0.92±0.06 vs 0.94±0.04; p=0.17) were similar between the groups. The vasomotor test showed vasoconstriction response to acetylcholine in 75.6% proximal and 72.2% distal peri-scaffold segments without differences between study devices. BVS had larger in-scaffold vasoconstriction than EES (60.0% vs 27.6%; p=0.01) despite similar neointima response as assessed by OCT. CONCLUSIONS: BVS and EES had similar microcirculatory response to hyperaemia and predominant vasoconstrictive response in the peri-scaffold segments to endothelium-dependent stimuli. However, BVS exhibited larger vasoconstriction to endothelium-dependent stimuli in the scaffold segment.

Association of fractalkine with functional severity of heart failure and impact on clopidogrel efficacy in patients with ischemic heart disease.

INTRODUCTION: Patients with heart failure (HF) display elevated levels of soluble fractalkine, a chemokine involved in inflammation processes, atherosclerosis and platelet activation. Further, fractalkine has been associated with reduced pharmacodynamic (PD) responsiveness to clopidogrel. The aim of this study was to investigate the association of fractalkine with the severity of HF and its impact on platelet activation and clopidogrel response in patients with coronary artery disease (CAD) with and without HF. MATERIALS AND METHODS: This prospective PD study included 116 stable CAD patients on DAPT with aspirin and clopidogrel. Subjects were classified in two groups: patients with HF and reduced (<40%) left ventricular ejection fraction (HFrEF group, n = 56) and patients without HF (no HF group, n = 60). Clinical severity of HF was graded according to NYHA classification. Platelet function assays included vasodilator-stimulated phosphoprotein assay, multiple electrode aggregometry and light transmittance aggregometry. Fractalkine and P-selectin concentrations were determined by ELISA. RESULTS: Fractalkine levels progressively increased with the severity of the disease in the HFrEF group (NYHA I: 471.2 ± 52.4 pg/ml, NYHA II: 500.5 ± 38.4 pg/ml, NYHA III: 638.9 ± 54.3 pg/ml, p for linear trend 0.023). Numerically higher concentrations of fractalkine were observed in the HFrEF group compared to the no HF group with borderline significance (p = 0.052). No significant differences in clopidogrel-induced platelet inhibition according to fractalkine values were observed in any of the groups. CONCLUSIONS: Fractalkine levels were increased in patients with HFrEF and positively associated with the functional severity of the disease. No evident impact of fractalkine on clopidogrel PD efficacy was found.

One-year optical coherence tomography findings in patients with late and very-late stent thrombosis treated with intravascular imaging guided percutaneous coronary intervention.

Patients with late/very-late stent thrombosis (ST) are at high risk of recurrent-ST. The mechanisms of recurrent-ST are largely unknown. The objective is to describe the 1-year optical coherence tomography (OCT) findings of patients suffering from late/very-late ST treated with intravascular imaging guided percutaneous coronary intervention (PCI). All consecutive patients with late/very-late ST undergoing intravascular imaging guided PCI were screened to undergo coronary angiography and OCT examination at 1 year. Patients were classified according to the observation of stent malapposition as most contributing cause of the ST. Thirty-four patients were included. Stent malapposition was observed in 17 (50%) and the remaining 17 cases were classified as: neoatherosclerosis (n = 9), underexpansion (n = 3) and unknown mechanism (n = 5). Patients with malapposition had a remarkable reduction of the malapposition volume (from 6.4 to 1.3 mm3; p = 0.02) during the ST procedure, but this was not fully corrected in 13 (76.5%). At 12 months, two patients of the malapposition group presented with uneventful target vessel re-occlusion. Persistent malapposition was observed in nine patients (60.0%). Major coronary evaginations (46.7 vs. 0%; p = 0.001) and uncovered struts (6.3 vs. 1.0%; p < 0.001) were also more frequent in patients with malapposition than without malapposition. None of the patients had thin-cap fibroatheroma neoatherosclerosis. Contributing causes of late/very-late ST are diverse and have different healing patterns at 12 months. Patients with stent malapposition treated with intravascular imaging guided PCI showed poor re-healing; but patients with other causes of the ST showed optimal stent healing as assessed by OCT.

Association between coronary atherosclerosis progression and in-stent neoatherosclerosis in patients with ST-elevation myocardial infarction at five-year follow-up.

AIMS: The aim of the study was to investigate the association between in-stent neoatherosclerosis (NA) and atherosclerosis progression (AP) in non-culprit segments in patients with ST-elevation myocardial infarction at five years. METHODS AND RESULTS: Sixty-two out of 169 consecutive patients included in the EXAMINATION study underwent optical coherence tomography (OCT) at five years. NA plaques were observed in 13 (21.0%), signal-rich bands (SRB) in 22 (35.5%) and AP in 11 (17.7%). NA plaques were more frequently observed in patients treated with two stents (53.8% vs. 20.4%; p=0.02). SRB were more frequently observed with longer stent length (29.8±11.6 vs. 22.5±9.1 mm; p<0.01), larger stent size (3.4±0.4 vs. 3.1±0.4 mm; p<0.01) and with bare metal stents (BMS) (68.2% vs. 40.0%; p=0.03). Patients with AP had higher levels of LDL-cholesterol (108.3±27.1 vs. 86.3±27.6 mg/dl; p=0.02). QCA of 744 non-culprit segments showed no association between NA plaques or SRB and reduction of lumen diameters. By multivariate analysis, NA plaques were associated with stent length; SRB were associated with stent length and BMS. AP was associated with mean LDL-cholesterol levels. CONCLUSIONS: NA and SRB had no association with AP or with LDL-cholesterol. NA and SRB were associated with stent-related factors such as stent length and BMS. AP was associated with LDL-cholesterol levels.

In Vivo Evaluation of the Synergic Effect of Metformin and mTOR Inhibitors on the Endothelial Healing of Drug-eluting Stents in Diabetic Patients.

INTRODUCTION AND OBJECTIVES: Recent animal studies have shown metformin (MF) to impair endothelialization of drug-eluting stents (DES). The aim of this study was to evaluate the effect of MF on the healing of DES in human coronary arteries of patients with diabetes mellitus by optical coherence tomography (OCT). METHODS: The RESERVOIR trial randomized 116 lesions in 112 patients with diabetes mellitus to amphilimus- or everolimus-eluting stents and included mandatory OCT at 9 months of follow-up. Patients were divided in 3 groups according to the glucose-lowering agents received: a) no MF; b) MF in noninsulin treated patients, and c) MF in insulin-treated patients. The primary safety endpoint was the rate of uncovered stents. RESULTS: Seventeen patients with 19 lesions did not receive MF, whereas MF was administered to 53 noninsulin treated patients (54 lesions) and 28 insulin-treated patients (28 lesions). Baseline characteristics were comparable, although noninsulin treated patients who received MF had better glycemic control (P < .01). By OCT, rates of uncovered struts were comparable between groups (3.07±4.80% vs 2.23±4.73% vs 3.43±6.69%, respectively; P = .48). Multivariate models confirmed that MF had no effect on the healing of DES (OR, 1.49, 95%CI, 0.71-3.08; P = .29). Similarly, quantitative angiography showed no effect of MF on late lumen loss, whereas patients treated with exogenous insulin had greater late lumen loss (P = .02). CONCLUSIONS: Metformin use does not impair endothelial healing of DES in patients with both insulin- and noninsulin-treated diabetes mellitus. According to these results, MF should not be discouraged in these patients.

Temporal trends in frequency, management and outcomes of coronary perforations.

BACKGROUND: Coronary perforations (CP) have been described as a rare but potentially fatal complication in percutaneous coronary interventions (PCI). Our aim is to compare temporal trends in frequency, management and outcomes of coronary perforations (CP). METHODS: All cases of CP recorded in our prospective institutional percutaneous coronary intervention (PCI) registry from 2003 to 2015 were included. Patients were divided in 2 groups according to the time frame in which the CP occurred: the early period (before 2009, when the chronic total occlusions and primary PCI programs started) and the current period. The primary endpoint was the composite of in-hospital serious adverse events, including final TIMI flow 0-1, cardiac tamponade, emergent cardiac surgery or death. RESULTS: Overall, 88 CP occurred in 17,566 procedures (0.50%). Of these, 17 (0.26%) occurred during the early period and 71 (0.64%) during the current period (P<0.001). CP management differed between groups, with less CP sealed by intracoronary devices in the early period than in the current one (23.5% vs. 47.9%, P=0.068). Moreover, patients with CP during the early period experienced more in-hospital serious adverse events (69% vs. 31% respectively, OR 3.18, 95% CI: 1.07-9.45, P=0.037). CONCLUSIONS: Expansion of indications and complexity of PCI in the current era may be associated with an increased frequency of CP. However, progress in technical and device management of CP have led to an improvement in the prognosis of this feared complication.

Long-Term Coronary Functional Assessment of the Infarct-Related Artery Treated With Everolimus-Eluting Bioresorbable Scaffolds or Everolimus-Eluting Metallic Stents: Insights of the TROFI II Trial.

OBJECTIVES: The study sought to compare the vasomotor and microcirculatory function of the infarct-related artery (IRA) between bioresorbable vascular scaffolds (BVS) and everolimus-eluting stents (EES) at 3 years. BACKGROUND: The ABSORB STEMI TROFI II study showed similar outcomes between BVS and EES in the context of ST-segment elevation myocardial infarction at 3 years. METHODS: Sixty-three consecutive event-free patients of the randomized TROFI II study were screened to undergo coronary angiography with vasomotor, microcirculatory, and optical coherence tomography (OCT) examination at 3 years. Vasomotion was defined as >4% change in mean lumen diameter to acetylcholine (ACH) and nitroglycerin as assessed by quantitative angiography. Microcirculatory examination was performed with pressure or thermodilution techniques. RESULTS: A total of 38 patients (20 BVS and 18 EES) were included. At 3 years, ≥60% of patients exhibited paradoxical vasoconstriction to ACH in the periscaffold or stent segments. Vasoconstriction to ACH and vasodilatation to nitroglycerin were more often observed in the scaffold or stent segment with BVS than with EES (77.8% vs. 25.0%; p = 0.008 and 61.1% vs. 18.8%; p = 0.018). The IRA-depending microcirculation showed similar index of resistance (23.8 vs. 22.4; p = 0.781), coronary flow reserve (2.4 vs. 1.9; p = 0.523), fractional flow reserve (0.91 vs. 0.93; p = 0.317), and absolute flow (135.5 ml/min vs. 147.3 ml/min; p = 0.791). OCT showed remaining strut footprints and larger number of intraluminal scaffold dismantling (26.3% vs. 0%; p = 0.049) in the BVS group. CONCLUSIONS: Both endothelium-dependent and -independent vasomotion of the IRA were more evident with BVS, as compared with EES, at 3 years. Functional microcirculatory parameters were mostly adequate and similar between BVS and EES. Clinical implications of these findings warrant further investigations.

IVUS Findings in Late and Very Late Stent Thrombosis. A Comparison Between Bare-metal and Drug-eluting Stents.

INTRODUCTION AND OBJECTIVES: Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year). METHODS: Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis. RESULTS: The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60). CONCLUSIONS: Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS.

A Randomized Comparison of Reservoir-Based Polymer-Free Amphilimus-Eluting Stents Versus Everolimus-Eluting Stents With Durable Polymer in Patients With Diabetes Mellitus: The RESERVOIR Clinical Trial.

OBJECTIVES: The aim of this study was to compare the efficacy of amphilimus-eluting stents (AES) with that of everolimus-eluting stents (EES) in patients with diabetes mellitus (DM). BACKGROUND: The AES is a polymer-free drug-eluting stent that elutes sirolimus formulated with an amphiphilic carrier from laser-dug wells. This technology could be associated with a high efficacy in patients with DM. METHODS: This was a multicenter, randomized, noninferiority trial. Patients with DM medically treated with oral glucose-lowering agents or insulin and de novo coronary lesions were randomized in a 1:1 fashion to AES or EES. The primary endpoint was the neointimal (NI) volume obstruction assessed by optical coherence tomography at 9-month follow-up. RESULTS: A total of 116 lesions in 112 patients were randomized. Overall, 40% were insulin-treated patients, with a median HbA1c of 7.3% (interquartile range: 6.7% to 8.0%). The primary endpoint, NI volume obstruction, was 11.97 ± 5.94% for AES versus 16.11 ± 18.18% for EES, meeting the noninferiority criteria (p = 0.0003). Pre-specified subgroup analyses showed a significant interaction between stent type and glycemic control (p = 0.02), with a significant reduction in NI hyperplasia in the AES group in patients with the higher HbA1c (p = 0.03). By quantitative coronary angiography, in-stent late loss was 0.14 ± 0.24 for AES versus 0.24 ± 0.57 mm for EES (p = 0.27), with a larger minimal lumen diameter at follow-up for AES (p = 0.02), mainly driven by 2 cases of occlusive restenosis in the EES group. CONCLUSIONS: AES are noninferior to EES for the coronary revascularization of patients with DM. These results suggest a high efficacy of the AES and may support the potential benefit of this stent in patients with DM. (A Randomized Comparison of Reservoir-Based Polymer-Free Amphilimus-Eluting Stents Versus Everolimus-Eluting Stents With Durable Polymer in Patients With Diabetes Mellitus [RESERVOIR]; NCT01710748).

Five-Year Optical Coherence Tomography in Patients With ST-Segment-Elevation Myocardial Infarction Treated With Bare-Metal Versus Everolimus-Eluting Stents.

BACKGROUND: The main causes of late (>1 month) stent thrombosis (ST) are stent uncoverage, malapposition, and neoatherosclerosis. First-generation drug-eluting stents were associated with higher rate of late ST compared with bare-metal stents (BMS), especially in patients with ST-segment-elevation myocardial infarction. Second-generation everolimus-eluting stents (EES) have shown similar rate of late ST than BMS. The aims of the study are to compare the ratio of uncovered to total struts per cross-section ≥30% and other optical coherence tomographic findings associated with ST between EES and BMS in patients with ST-segment-elevation myocardial infarction at 5 years. METHODS AND RESULTS: One hundred and sixty-nine consecutive event-free patients of the randomized EXAMINATION study (A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-Segment Elevation Myocardial Infarction) were screened for optical coherence tomographic imaging at 5 years. Patients with target vessel-related events or life-threatening comorbidities were excluded. Finally, 64 patients (32 EES and 32 BMS) underwent optical coherence tomographic imaging. At 5 years, uncovered struts (4.1% versus 1.0%; P<0.01), length of uncoverage (3.4 versus 1.4 mm; P=0.02), and ratio of uncovered to total struts per cross-section ≥30% (35.5% versus 9.7%; P=0.02) were larger with EES than that with BMS. Malapposed struts (1.2% versus 0.3%; P=0.02) and malapposition length (1.3 versus 0.4 mm; P=0.06) were also larger with EES. Neoatherosclerotic plaques (16.1% versus 25.8%; P=0.35) and macrophage accumulations (19.4% versus 48.4%; P=0.02) were numerically more frequent with BMS. CONCLUSIONS: Despite substantial dropout of patients, the healing pattern in event-free ST-segment-elevation myocardial infarction patients differs between EES and BMS at 5 years. EES presented with larger amount of uncovered and malapposed struts and similar rate of neoatherosclerosis as compared with BMS. The clinical relevance of these findings warrants longer follow-up. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00828087.

The MGuard coronary stent: safety, efficacy, and clinical utility.

Atheromatous and thrombotic embolization during percutaneous coronary revascularization is a feared complication that may cause impaired myocardial reperfusion even with a patent epicardial vessel. The MGuard stent is a cobalt chromium bare metal stent with a porous net attached to its outer surface that has been designed to prevent thrombus fragmentation and distal embolization during stent implantation. This review summarizes the available evidence supporting the use of the MGuard stent in different scenarios such as lesions with high thrombus burden, saphenous vein graft interventions, coronary perforations, or carotid lesions.

Longitudinal deformation of drug-eluting stents: evaluation by multislice computed tomography.

BACKGROUND: Some modifications introduced in the design of the new generation of drug-eluting stent (DES) to improve their flexibility may entail a reduction in their longitudinal strength. This study sought to evaluate the longitudinal deformation of DESs by multislice computed tomography (MSCT). METHODS: This study included DESs that could have been potentially deformed by mechanical actions such as: (1) catheter impingement; (2) postdilation; (3) kissing balloon; and (4) intravascular imaging after implantation. Patients on atrial fibrillation or with overlapping stents were excluded. All patients underwent stent length evaluation by MSCT 9-12 months after implantation. RESULTS: Forty-five stents were included: 15 platinum chromium (PtCr-DES), 15 cobalt chromium (CoCr-DES), and 15 stainless-steel (SS-DES). The relative longitudinal deformation by stent type was 6.93 ± 5.82% for PtCr-DES, 6.19 ± 5.79% for CoCr- DES, and 4.03 ± 4.07% for SS-DES (P=.31). Among the mechanical actions studied, only catheter impingement was related to longitudinal stent deformation (P<.01). After adjustment, only catheter impingement (P<.01) and nominal stent length (P=.049) were independently related to longitudinal deformation. There were no stent fractures. CONCLUSIONS: Longitudinal deformation of DESs is common in all the studied platforms when subject to longitudinal forces. Guiding catheter impingement is the only mechanical action significantly associated with DES shortening.

Impact of mild hypothermia on platelet responsiveness to aspirin and clopidogrel: an in vitro pharmacodynamic investigation.

UNLABELLED: The combination of percutaneous coronary intervention (PCI) and therapeutic hypothermia in comatose patients after cardiac arrest due to an acute coronary syndrome has been reported to be safe and effective. However, recent investigations suggest that hypothermia may be associated with impaired response to clopidogrel and greater risk of thrombotic complications after PCI. This investigation aimed to evaluate the effect of hypothermia on the pharmacodynamic response of aspirin and clopidogrel in patients (n = 20) with ST elevation myocardial infarction undergoing primary PCI. Higher platelet reactivity (ADP stimulus) was observed in samples incubated at 33 °C compared with those at 37 °C (multiple electrode aggregometry, 235.2 ± 31.4 AU×min vs. 181.9 ± 30.2 AU×min, p < 0.001; VerifyNow P2Y12, 172.9 ± 20.3 PRU vs. 151.0 ± 19.3 PRU, p = 0.004). Numerically greater rates of clopidogrel poor responsiveness were also observed at 33 °C. No differences were seen in aspirin responsiveness. In conclusion, mild hypothermia was associated with reduced clopidogrel-mediated platelet inhibition with no impact on aspirin effects. CLINICAL RELEVANCE: Mild therapeutic hypothermia is associated with impaired response to clopidogrel therapy, which might contribute to increase the risk of thrombotic events in ACS comatose patients undergoing PCI.

Hallazgos por IVUS en trombosis de stent tardía y muy tardía. Comparación entre stents metálicos y farmacoactivos / IVUS findings in late and very late stent thrombosis. A comparison between bare-metal and drug-eluting stents

Introducción y objetivos: La trombosis de stent (TS) es una complicación grave tras la angioplastia coronaria, y la ecografía intravascular es una herramienta capaz de discernir las causas. El objetivo es comparar los hallazgos por ecografía intravascular entre stents metálicos (SM) y stents farmacoactivos (SFA) en pacientes con TS tardía (de 31 días a 1 año) o muy tardía (>1año). Métodos: Se incluyó a 114 pacientes (el 45,5% con SM y el 54,5% con SFA) de un total de 250 consecutivos con TS tardía o muy tardía en 7 hospitales españoles. Se realizó una ecografía intravascular, que se analizó posteriormente para detectar la presencia de malaposición, infraexpansión y neoateroesclerosis. Resultados: El tiempo hasta la TS fue de 4,0 años en los SM y 3,4 años en los SFA (p = 0,04). La malaposición fue similar en ambos grupos (el 36,5 frente al 46,8%; p = 0,18), aunque numéricamente menor en los SM con trombosis muy tardía (el 26,6 frente al 48,0%; p = 0,07). La infraexpansión se observó de manera similar en ambos grupos (el 13,5 frente al 11,3%; p = 0,47). La neoateroesclerosis solo se observó en TS muy tardías y fue más prevalente en los SM (22,9%) que en los SFA (6,0%; p = 0,02). A los 2,9 años de seguimiento, las muertes cardiacas eran 0 frente a 6,9% respectivamente (p = 0,06) y las recurrencias de TS se produjeron en el 4,0 frente al 5,2% (p = 0,60). Conclusiones: La malaposición es el hallazgo más frecuente en los pacientes con TS tardía y muy tardía, más prevalente en los SFA con TS muy tardías. Sin embargo, la neoateroesclerosis se observó únicamente en pacientes con TS muy tardías, y principalmente en SM

Introduction and objectives: Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year). Methods: Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis. Results: The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60). Conclusions: Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS