Relationship between stent length and very long-term target lesion failure following percutaneous coronary intervention for ST-elevation myocardial infarction in the drug-eluting stents era: insights from the EXAMINATION-EXTEND study

BACKGROUND

Little data exist on the relationship between total stent length (TSL) and cardiovascular outcomes at very-long follow-up in patients with ST-elevation myocardial infarction (STEMI) in the 2nd generation drug-eluting stents (DES) era.

AIM

To analyze the relationship between TSL and 10-year target-lesion failure (TLF) in STEMI patients treated with percutaneous coronary intervention enrolled in the EXAMINATION-EXTEND.

METHODS

The EXAMINATION-EXTEND was an extended-follow-up study of the EXAMINATION trial, which randomized 1:1 STEMI patients to receive DES or bare metal stent (BMS). The primary endpoint was TLF, defined as a composite of target lesion revascularization (TLR), target vessel myocardial infarction (TVMI), or definite/probable stent thrombosis (ST). Relationship between stent length and TLF was evaluated in the whole study group in a multiple-adjusted Cox regression model with TSL as a quantitative variable. Subgroup analysis was also performed according to stent type, diameter, and overlap.

RESULTS

A total of 1,489 patients with a median TSL of 23 mm (Q1-Q318-35 mm) were included. TSL was associated with TLF at 10 years (adjusted HR per 5 mm increase of 1.07; 95% CI, 1.01-1.14; P = .02). This effect was mainly driven by TLR and was consistent regardless of stent type, diameter, or overlap. There was no significant relationship between TSL and TV-MI or ST.

CONCLUSIONS

In STEMI patients, there is a direct relationship between TSL implanted in the culprit vessel and the risk of TLF at 10 years, mainly driven by TLR. The use of DES did not modify this association.

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.

Impact of Diabetes on 10-Year Outcomes Following ST-Segment-Elevation Myocardial Infarction: Insights From the EXAMINATION-EXTEND Trial

Background Long-term outcomes of ST-segment-elevation myocardial infarction in patients with diabetes have been barely investigated. The objective of this analysis from the EXAMINATION-EXTEND (10-Years Follow-Up of the EXAMINATION trial) trial was to compare 10-year outcomes of patients with ST-segment-elevation myocardial infarction with and without diabetes. Methods and Results Of the study population, 258 patients had diabetes and 1240 did not. The primary end point was patient-oriented composite end point of all-cause death, any myocardial infarction, or any revascularization. Secondary end points were the individual components of the primary combined end point, cardiac death, target vessel myocardial infarction, target lesion revascularization, and stent thrombosis. All end points were adjusted for potential confounders. At 10 years, patients with diabetes showed a higher incidence of patient-oriented composite end point compared with those without (46.5% versus 33.0%; adjusted hazard ratio [HR], 1.31 [95% CI, 1.05-1.61]; P=0.016) mainly driven by a higher incidence of any revascularization (24.4% versus 16.6%; adjusted HR, 1.61 [95% CI, 1.19-2.17]; P=0.002). Specifically, patients with diabetes had a higher incidence of any revascularization during the first 5 years of follow-up (20.2% versus 12.8%; adjusted HR, 1.57 [95% CI, 1.13-2.19]; P=0.007) compared with those without diabetes. No statistically significant differences were found with respect to the other end points. Conclusions Patients with ST-segment-elevation myocardial infarction who had diabetes had worse clinical outcome at 10 years compared with those without diabetes, mainly driven by a higher incidence of any revascularizations in the first 5 years. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04462315.

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].

Impact of age at the time of the first ST-elevation myocardial infarction on 10-year outcomes. A sub-analysis from the EXAMINATION EXTEND trial

Background

The aim of this post-hoc sub analysis of the EXAMINATION-EXTEND study was to analyze 10-year outcomes according to the age of the patient at the time of the first STEMI.

Methods

Out of 1498 STEMI patients included in the EXAMINATION-EXTEND study, those with a previous history of atherosclerotic cardiovascular disease (coronary ischemic event, ischemic stroke, or previous coronary revascularization) were excluded for this analysis. The remaining 1375 patients were divided into three age groups: <55, 55–65 and >65 years. The primary endpoint was 10-year patient oriented composite endpoint (POCE) of all-cause death, any myocardial infarction (MI), or any revascularization. Secondary endpoints included the individual components of the primary endpoint, cardiac death, target vessel myocardial infarction (TVMI), target lesion revascularization (TLR), and stent thrombosis. The association between age and endpoints was adjusted for baseline confounders.

Results

At 10-year follow-up, patients <55 years (Adjusted hazard ratio [HR]: 0.42, 95% CI: 0.33–0.53, p=0.001), and 55–65 years (Adjusted HR: 0.44, 95% IC: 0.35–0.56, p=0.001) showed lower risk of POCE compared with those >65 years, led by a lower incidence of all-cause death (<55: 5.8% vs. 55–65: 11.3% vs. >65 years: 40.67%, p=0.001). Cardiac death was more prevalent in the older group (<55: 3.5% vs. 55–65: 5.5% vs. >65 years: 21.3%, p=0.001). There were not significant differences in the incidence of TVMI, TLR and stent thrombosis among the different age groups. In the landmark analyses, between 5 and 10-year follow-up, young patients exhibited higher incidence of any revascularization (<55: 7.4% vs. 55–65: 4.9% vs. >65 years: 1.7%, p=0.001) and a trend towards a higher incidence of any MI (<55: 5.2% vs. 55–65: 3.6% vs. >65 years: 1.5%, p=0.064). No differences were found in any other endpoints.

Conclusions

In patients with a first STEMI, advanced age was associated with high rates of POCE at 10-year follow-up, in particular, due to all-cause and cardiac death. Conversely, patients who presented at younger age exhibited a high risk of revascularization at long-term follow-up.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Abbott Vascular

Microvascular dysfunction and absolute coronary blood flow after percutaneous coronary intervention of a chronic total occlusion

 

The development of a coronary chronic total occlusion (CTO) causes changes in the distal epicardial vascular bed and in the microvasculature tributary of the occluded vessel. Studies with positron emission tomography showed an increase in myocardial blood flow and coronary flow reserve (CFR) after percutaneous coronary intervention (PCI) of a CTO (1). These changes are not immediate after PCI, since they usually involve a process of weeks-months (2).

The FLOW-CTO study aims to evaluate the evolution of microvascular resistance and absolute coronary blood flow (ABF) after PCI of a CTO.

The study consecutively included patients in 4 national centers in Spain. In these patients, a coronary physiology study was performed, immediately after PCI and at 6 months follow-up. Fractional flow reserve (FRR), CFR and index of microcirculatory resistance (IMR) were determined. ABF and microvascular resistances were determined by continuous thermodilution during maximal hyperemia induced by serum infusion (3). Coronary microvascular dysfunction (MVD) was defined as an IMR ≥25 and/or an CFR <2.0, in the presence of an FFR >0.80. We present data from the baseline study immediately after PCI of a CTO in the first 49 patients.

Most patients were male (90%), with a median age of 62 years-old [IQR 56–69]. The prevalence of hypertension, dyslipidemia and diabetes were 71, 67 and 41%, respectively. The median left ventricular ejection fraction was 55% [IQR 45–60]. Eighty-six percent of the patients had exertional angina and 14% had history of congestive heart failure.

The most frequently involved vessel was the right coronary artery (55%). The most used technique was antegrade guidewire escalation (74%). The median length of the devices implanted was 59±25 mm. The mean percentage of residual stenosis was 8±4%.

Despite the good angiographic result, 20% of the lesions had an FFR value ≤0.80. Of those patients with a non-significant FFR value (>0.80), 54% had signs of MVD. Those patients with an elevated IMR (≥25) showed a non-significant trend towards a lower ABF (143±79 vs. 192±59 mL/min; p=0.1043), with significantly higher microvascular resistance (694±206 vs. 471±166 mmHg/(l/min); p=0.0328). Those patients with a reduced CFR (<2.0) had lower ABF (166±57 vs. 207±64 ml/min; p=0.0460) and a non-significant trend towards a higher microvascular resistance (535±240 vs. 466±195 mmHg/(l/min); p=0.3419). Diabetes mellitus was identified as a predictor of an elevated IMR (OR 6.3, 95% CI 1.1–13; p=0.046) or reduced CFR (OR 5.7, 95% CI 1.4–22, p=0.013).

In our study, more than half of the patients presented signs of MVD immediately after PCI of a CTO. Despite an optimal angiographic result, in a fifth of the cases we found a significant alteration of the parameters that evaluate the epicardial circulation. Diabetes mellitus was found as a predictor of MVD after PCI of a CTO.

Funding Acknowledgement

Type of funding sources: None.

Real-World Multicenter Coronary Lithotripsy Registry: Long-Term Clinical Follow-Up

OBJECTIVES

Coronary lithotripsy (CL) works by fracturing the calcified plaque, allowing mean area gain, enhancing vessel compliance, and facilitating stent deployment. This study reports the safety, effectiveness, and durability of the clinical benefit of CL at long-term follow-up of a real-world multicenter registry.

METHODS

This was a prospective, multicenter, single-arm study that included consecutive patients with calcified lesions undergoing CL from August, 2018 to October, 2020 with a clinical follow-up of 20 months (interquartile range, 14.5-25). Exclusion criteria were a target lesion located in a vessel <2.5 mm and/or the presence of dissection prior to CL. The primary endpoint was the rate of major adverse cardiovascular event (MACE, defined as death or target-lesion revascularization [TLR] or myocardial infarction [MI]) at follow-up.

RESULTS

This registry included 109 patients (128 lesions). The population was elderly (mean age, 74 years old), with high rates of diabetic patients (58%), renal insufficiency (32%), and multivessel disease (76%). Most of the lesions were predilated with semicompliant/noncompliant balloons (25 with cutting balloon). Rotational atherectomy was used in 20 lesions. On average, CL required the use of 1 balloon delivering a mean of 60 pulses. Twelve patients presented with ST-segment-elevation MI and a culprit calcified coronary lesion undergoing CL. Successful CL was achieved in 99% of cases. There were few procedural complications, with 30-day freedom from MACE rate of 98%. The MACE rate at long-term follow-up was 5.6%.

CONCLUSION

This is the first real-world, multicenter registry that confirms the safety and long-term efficacy of percutaneous coronary intervention for calcified lesions using CL in an unselected and high-risk population with a low long-term follow-up MACE rate.

Gender Differences in 10-Year Outcomes Following STEMI: A Subanalysis From the EXAMINATION-EXTEND Trial

BACKGROUND

Short-term outcomes following ST-segment elevation myocardial infarction (STEMI) in women are worse than in men, with a higher mortality rate. It is unknown whether gender plays a role in very long term outcomes.

OBJECTIVES

The aim of this study was to assess whether very long term outcomes following STEMI treatment are influenced by gender.

METHODS

EXAMINATION-EXTEND (10-Year Follow-Up of the EXAMINATION Trial) was an investigator-driven 10-year follow-up of the EXAMINATION (A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-Segment Elevation Myocardial Infarction) trial, which randomly 1:1 assigned 1,498 patients with STEMI to receive either everolimus-eluting stents or bare-metal stents. The present study was a subanalysis according to gender. The primary endpoint was the composite patient-oriented endpoint (all-cause death, any myocardial infarction, or any revascularization) at 10 years. Secondary endpoints were individual components of the primary endpoint. All endpoints were adjusted for age.

RESULTS

Among 1,498 patients with STEMI, 254 (17%) were women. Overall, women were older, with more arterial hypertension and less smoking history than men. At 10 years, no difference was observed between women and men for the patient-oriented composite endpoint (40.6% vs 34.2%; adjusted HR: 1.14; 95% CI: 0.91-1.42; P = 0.259). There was a trend toward higher all-cause death in women vs men (27.6% vs 19.4%; adjusted HR: 1.30; 95% CI: 0.99-1.71; P = 0.063), with no difference in cardiac death or other endpoints.

CONCLUSIONS

At very long term follow-up, there were no differences in the combined patient-oriented endpoint between women and men, with a trend toward higher all-cause death in women not driven by cardiac death. The present findings underline the need for focused personalized medicine in women after percutaneous revascularization aimed at both cardiovascular and gender-specific risk factor control and targeted treatment. (10-Years Follow-Up of the EXAMINATION Trial [EXAMINAT10N]; NCT04462315).

Magnesium-based resorbable scaffold vs permanent metallic sirolimus-eluting stent in patients with ST-segment elevation myocardial infarction: 3-year results of the MAGSTEMI randomised controlled trial

BACKGROUND

The long-term safety and performance of magnesium-based bioresorbable scaffolds (MgBRS) in ST-segment-elevation myocardial infarction (STEMI) patients are uncertain.

AIMS

The aim of this study was to report the 3-year clinical outcomes of the MAGSTEMI trial.

METHODS

This investigator-driven, multicentre, randomised, single-blind, controlled trial randomised STEMI patients 1:1 to MgBRS or to permanent metallic sirolimus-eluting stents (SES) at 11 academic centres. The main secondary endpoints included device-oriented composite endpoints (DoCE) and patient-oriented composite endpoints (PoCE), their individual components, any bleeding, and device thrombosis rate. All endpoints were defined according to the Academic Research Consortium. Events were adjudicated by an independent committee.

RESULTS

Three-year clinical follow-up was obtained in 142 (90.0%) patients. At 3-year follow-up, MgBRS were associated with a higher rate of DoCE than SES (13 [17.6%] vs 5 [6.6%], diff -11.0 [95% CI: -21.3 to -0.7]; p=0.038). This difference was driven by an increased incidence of DoCE within the first year of follow-up. In the landmark analysis, there was no difference between 1 and 3 years (0 [0.0%] vs 1 [1.4%]; p=1.000). The difference in the rate of DoCE was driven by a higher incidence of target lesion revascularisation (TLR) in the MgBRS group compared to SES (12 [16.2%] vs 4 [5.3%]; diff -10.9% [95% CI: -20.7 to -1.2]; p=0.030). The difference in TLR was observed during the first year, with no further differences observed between 1 and 3 years (0 [0.0%] vs 1 [1.4%]; p=1.000).

CONCLUSIONS

At 3-year follow-up, MgBRS were associated with a higher rate of TLR, which was clustered within the first year, compared to SES.

Coronary Endothelium-Dependent Vasomotor Function After Drug-Eluting Stent and Bioresorbable Scaffold Implantation

Background Early generation drug-eluting stents (DESs) showed a high grade of coronary endothelial dysfunction that was attributed to lack of stent reendothelialization. Endothelium-dependent vasomotor response of current DESs and bioresorbable scaffolds (BRSs) remains unknown. This study sought to assess the device-related endothelial function of current devices and to correlate neointima healing with endothelial function. Methods and Results A total of 206 patients from 4 randomized trials treated with the durable-polymer everolimus-eluting Xience (n=44), bioresorbable-polymer sirolimus-eluting Orsiro (n=35), polymer-free biolimus-eluting Biofreedom (n=24), bioactive endothelial-progenitor cell-capturing sirolimus-eluting Combo DES (n=25), polymer-based everolimus-eluting Absorb (n=44), and Mg-based sirolimus-eluting Magmaris BRS (n=34) underwent endothelium-dependent vasomotor tests and optical coherence tomography imaging, as per protocol, at follow-up. Crude vasomotor responses of distal segments to low-dose acetylcholine (10^-6 mol/L) were different between groups: bioresorbablepolymer DEShad the worst (-8.4%±12.6%) and durable-polymer DES had the most physiologic (-0.4%±11.8%; P=0.014). High-dose acetylcholine (10^-4 mol/L) showed similar responses between groups (ranging from -10.8%±11.6% to -18.1%±15.4%; P=0.229). Device healing was different between devices. Uncovered struts ranged from 6.3%±7.1% (bioresorbable-polymer DES) to 2.5%±4.5% (bioactive DES; P=0.056). In multivariate models, endothelium-dependent vasomotor response was associated with age, bioresorbable-polymer DES, and angiographic lumen loss, but not with strut coverage nor plaque type. Endothelial dysfunction (defined as ≥4% vasoconstriction) was observed in 46.6% of patients with low-dose and 68.9% with high-dose acetylcholine, without differences between groups. Conclusions At follow-up, endothelial dysfunction was frequently observed in distal segments treated with current stents without remarkable differences between devices. Although neointima healing was different between devices, poor healing was not associated with endothelial dysfunction.

Amphilimus- versus zotarolimus-eluting stents in patients with diabetes mellitus and coronary artery disease (SUGAR trial)

Aim

Patients with diabetes mellitus are at high risk of adverse events after percutaneous revascularization, with no differences in outcomes between most contemporary drug-eluting stents. The Cre8 EVO stent releases a formulation of sirolimus with an amphiphilic carrier from laser-dug wells, and has shown clinical benefits in diabetes. We aimed to compare Cre8 EVO stents to Resolute Onyx stents (a contemporary polymer-based zotarolimus-eluting stent) in patients with diabetes.

Methods and results

We did an investigator-initiated, randomized, controlled, assessor-blinded trial at 23 sites in Spain. Eligible patients had diabetes and required percutaneous coronary intervention. A total of 1175 patients were randomly assigned (1:1) to receive Cre8 EVO or Resolute Onyx stents. The primary endpoint was target-lesion failure, defined as a composite of cardiac death, target-vessel myocardial infarction, and clinically indicated target-lesion revascularization at 1-year follow-up. The trial had a non-inferiority design with a 4% margin for the primary endpoint. A superiority analysis was planned if non-inferiority was confirmed. There were 106 primary events, 42 (7.2%) in the Cre8 EVO group and 64 (10.9%) in the Resolute Onyx group [hazard ratio (HR): 0.65, 95% confidence interval (CI): 0.44–0.96; P  _{non-inferiority} < 0.001; P  _superiority = 0.030]. Among the secondary endpoints, Cre8 EVO stents had significantly lower rate than Resolute Onyx stents of target-vessel failure (7.5% vs. 11.1%, HR: 0.67, 95% CI: 0.46–0.99; P = 0.042). Probable or definite stent thrombosis and all-cause death were not significantly different between groups.

Conclusion

In patients with diabetes, Cre8 EVO stents were non-inferior to Resolute Onyx stents with regard to target-lesion failure composite outcome. An exploratory analysis for superiority at 1 year suggests that the Cre8 EVO stents might be superior to Resolute Onyx stents with regard to the same outcome.

Clinical trial registration

ClinicalTrials.gov: NCT03321032.

Long-term vascular function in CTO recanalization: A randomized clinical trial of ticagrelor vs. clopidogrel

BACKGROUND

Coronary vascular function of a chronic coronary total occlusion (CTO) immediately after recanalization is known to be poor and to be partially improved by pre-treatment with loading dose of ticagrelor vs. clopidogrel. It is unknown if this vascular dysfunction is maintained at long-term follow-up and may be improved by 1-year dual antiplatelet therapy (DAPT).

METHODS

The TIGER is a prospective, open-label, two parallel-group controlled clinical trial, which 1:1 randomized 50 CTO patients to pre-PCI loading dose and subsequent 1-year DAPT with ticagrelor vs. clopidogrel. Coronary blood flow (CBF) under stepwise adenosine infusion was assessed after drug loading dose and at follow-up and compared between the two drug groups, adjusting for time of follow-up.

RESULTS

Out of 50 patients with index CBF evaluation, 38 (76%) patients underwent angiographic follow-up (23 and 15 at 1 and 3-year, respectively) and Doppler data was available in 35 (70%). A high CBF area under the curve (AUC), already observed after loading dose in ticagrelor vs. clopidogrel group (p = 0.027), was maintained at follow-up (AUC 34815.22 ± 24,206.06 vs. AUC 22712.47 ± 13,768.95; p = 0.071). Specifically, whereas high ticagrelor loading dose-related CBF was sustained at follow-up (p = 0.933), clopidogrel loading dose-related CBF increased at follow-up (p = 0.039).

CONCLUSION

The TIGER trial showed that DAPT with ticagrelor maintained a non-significantly higher CBF in a recanalized CTO as compared to clopidogrel, whose treated patients exhibit a lower CBF immediately after PCI with a significant increase at follow-up. The clinical value of such sustained high coronary flow should be evaluated in a larger group of patients.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT02211066 (ClinicalTrials.gov number NCT02211066).

Impact of diabetes mellitus on vascular healing process after everolimus-eluting stent implantation: An optical coherence tomography study

BACKGROUND/PURPOSE

To study the impact of diabetes mellitus (DM) on vascular healing process after implantation of everolimus-eluting stent (EES).

METHODS/MATERIALS

Data from 3 prospective studies (HEAL-EES, REVER, and RESERVOIR), including patients with EES implantation and OCT follow-up, were merged. Differences in vascular healing process assessed by OCT were compared between DM and non-DM using generalized estimating equations. Neointimal proliferation, neointimal signal pattern (high, low, and layered), and uncovered/malapposed struts were evaluated.

RESULTS

A total of 96 lesions (61 DM lesions and 35 non-DM lesions) were included. Mean OCT follow-up time was 8.9 ± 1.5 months and comparable between groups. DM were older, high frequently female and acute coronary syndrome, and received smaller stent than non-DM. No differences were observed in quantitative vascular healing process between groups. However, DM exhibited higher low and layered signal pattern neointima compared to non-DM at lesion level (p = 0.030) and cross-section level (p < 0.001). Uncovered/malapposed struts were comparable between groups.

CONCLUSIONS

Quantitative vascular healing process was comparable between groups. However, DM was significantly associated with low signal pattern, which is characteristic of focal inflammation, after EES implantation. Further study might be required to study relationship between neointimal signal pattern and clinical events.

Coronary microvascular dysfunction assessed by continuous intracoronary thermodilution: A comparative study with index of microvascular resistance

BACKGROUND

This study aimed to assess the correlation between the standard of care, the index of microvascular resistance (IMR) versus the novel microvascular resistance (R_micro) and to determine the pathologic cut-off value in a selected population with suspected coronary microvascular dysfunction (CMD).

METHODS

One-hundred and twenty patients with high clinical suspicion of CMD due to ischemic symptoms in the absence of significant epicardial coronary lesions were prospectively included. Following a standardized systematic protocol, coronary flow reserve, IMR, fractional flow reserve, Q and R_micro were measured in the left anterior descending coronary artery using a temperature/pressure sensor-tipped guidewire and a dedicated infusion catheter.

RESULTS

There was a high prevalence of CMD with 50 (42%) patients showing an IMR ≥ 25. Median IMR was 23 [IQR: 14-34] and median R_micro was 464 Woods Units (WU) [IQR: 354-636WU]. ROC analyses identified 500 WU as the optimal R_micro cut-off to identify patients with an IMR ≥ 25, with an area under the ROC curve (C statistic) of 0.83 (95% CI: 0.74 to 0.89, p < 0.0001).

CONCLUSIONS

R_micro derived from continuous intracoronary thermodilution is an accurate index to measure microvascular resistances enabling the invasive diagnostic of CMD.

10-Year Follow-Up of Patients With Everolimus-Eluting Versus Bare-Metal Stents After ST-Segment Elevation Myocardial Infarction

BACKGROUND

Outcomes data for a durable-polymer everolimus-eluting stent (EES) at extended long-term follow-up in patients with ST-segment elevation myocardial infarction (STEMI) are unknown.

OBJECTIVES

The aim of this study was to assess the 10-year outcomes of patients enrolled in the EXAMINATION (A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-Segment Elevation Myocardial Infarction) trial.

METHODS

The EXAMINATION-EXTEND (10-Years Follow-Up of the EXAMINATION Trial) study is an investigator-driven 10-year follow-up of the EXAMINATION trial, which randomly assigned 1,498 patients with STEMI in a 1:1 ratio to receive either EES (n = 751) or bare-metal stents (n = 747). The primary endpoint was a patient-oriented composite endpoint of all-cause death, any myocardial infarction, or any revascularization. Secondary endpoints included a device-oriented composite endpoint of cardiac death, target vessel myocardial infarction, or target lesion revascularization; the individual components of the combined endpoints; and stent thrombosis.

RESULTS

Complete 10-year clinical follow-up was obtained in 94.5% of the EES group and 95.9% of the bare-metal stent group. Rates of the patient-oriented composite endpoint and device-oriented composite endpoint were significantly reduced in the EES group (32.4% vs. 38.0% [hazard ratio: 0.81; 95% confidence interval: 0.68 to 0.96; p = 0.013] and 13.6% vs. 18.4% [hazard ratio: 0.72; 95% confidence interval: 0.55 to 0.93; p = 0.012], respectively), driven mainly by target lesion revascularization (5.7% vs. 8.8%; p = 0.018). The rate of definite stent thrombosis was similar in both groups (2.2% vs. 2.5%; p = 0.590). No differences were found between the groups in terms of target lesion revascularization (1.4% vs. 1.3%; p = 0.963) and definite or probable stent thrombosis (0.6% vs. 0.4%; p = 0.703) between 5 and 10 years.

CONCLUSIONS

At 10-year follow-up, EES demonstrated confirmed superiority in combined patient- and device-oriented composite endpoints compared with bare-metal stents in patients with STEMI requiring primary percutaneous coronary intervention. Between 5- and 10-year follow-up, a low incidence of adverse cardiovascular events related to device failure was found in both groups. (10-Years Follow-Up of the EXAMINATION Trial; NCT04462315).

First-in-Man Evaluation of a Sirolimus-Eluting Stent With Abluminal Fluoropolymeric/Triflusal Coating With Ultrathin Struts by OCT at 9 Months' Follow-Up: The PROMETHEUS Study

OBJECTIVES

We sought to investigate stent healing and neointimal hyperplasia with ihtDEStiny drug-eluting stent (DES) by optical coherence tomography (OCT) examination conducted 9 months after implantation.

BACKGROUND

The currently used DES present certain features that have been linked separately to their better performance in terms of efficacy and safety.

METHODS

First-in-man, prospective and multicenter study including patients treated with ihtDEStiny stent undergoing OCT examination at 9 months follow up. The ihtDEStiny stent is a sirolimus eluting stent with an oval shape ultrathin struts (68 μm) and an abluminal coating of a fluoropolymer containing the antiplatelet agent triflusal. Primary endpoint was the percentage of obstruction of the in-stent volume by the neointima.

RESULTS

In 58 patients (63 lesions) in-stent late lumen loss was 0.11 ± 0.23 mm (95% CI 0.05-0.16) with only in 6% of stents being > 0.5 mm and in-segment binary stenosis was 1.6%. In OCT mean neointima volume obstruction was 10.5 ± 6.9% with a mean neointima thickness of 110.9 ± 89.8 μm. The proportion of uncovered struts was 2.5%, malapposed struts 1.1% and malapposed/uncovered struts 0.7% and no subclinical thrombi detected. Mean incomplete stent apposition area was 0.1 ± 0.1 mm². At 12 months target lesion revascularization rate was 3% and no stent thrombosis was reported.

CONCLUSIONS

In this study the ihtDEStiny stent has shown a very low degree of neointimal proliferation associated with a low rate of uncovered/malapposed struts and total absence of subclinical thrombi at 9 months follow up.

Similar degree of intimal coverage and apposition among drug-eluting stents with persistent, absorbable or without polymer at 1 and 6 months after implantation

Background

Despite technological advances in drug-eluting stents (DES) design, delayed vascular healing is still a problem, triggered by the polymers among others. This may induce restenosis and thrombosis. The development of biodegradable polymers and DES without polymer is thought to improve the vascular response and enhance earlier neointimal healing. Optical coherence tomography (OCT) is the best intracoronary imaging tool to evaluate endothelial coverage after stent implantation.

Purpose

We aimed to quantitatively assess the differences on intimal coverage between biodegradable-polymer, durable-polymer and without-polymer DES at 1 and 6-month follow-up OCT.

Methods

A total of 94 patients with de novo coronary lesions were treated with DES: 26% were treated with Biolimus A9 (BA9) stent without polymer, 30% were treated with Everolimus DES with biodegradable polymer (EESb) and 44% with Everolimus DES with persistent polymer (EESp). OCT analysis was performed blindly at an independent Core Lab at three stages: implantation, after one month and after six months.

The primary endpoint was to compare neointimal coverage and apposition of these three different types of DES with OCT at one and six months after implantation.

Results

A total of 16034 struts were analysed (24% BA9, 29% EESb and 47% EESp). No significant differences were found among the groups regarding baseline clinical characteristics. When studying the strut coverage, it is remarkable the relatively low percentage of early neointimal coverage with no significant differences among stents one month after implantation (84–87%). After six months, there was better coverage in the three stent groups compared with one month (p&lt;0.001). The stents without polymer had better neointimal coverage at six months compared with the stents with persistent polymer (99% vs 92%, p=0.0002). No significant differences were found in the strut apposition after one or six months among the three stent types. However, the rate of apposition was higher after six months compared with one month in all stent groups (p=0,001). No significant differences were found in the neointimal hyperplasia at one month among the three stent groups. At six months there was a higher hyperplasia in the stent without polymer compared to the stent with persistent polymer (164μm vs 92μm, p=0,003). The degree of hyperplasia after six months was higher compared to one month in all groups (p=0,001).

Conclusions

The new-generation DES with biodegradable-polymer or without polymer showed relatively poor early neointimal coverage and similar to the last generation durable-polymer EES. According to these results, DAPT may not be shortened in any of the three DES types studied.

Funding Acknowledgement

Type of funding source: None

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.

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.

Bioresorbable vascular scaffolds versus everolimus-eluting metallic stents in patients with ST-segment elevation myocardial infarction: 5-year results of the BVS-EXAMINATION study

AIMS

The aim of this study was to compare five-year clinical outcomes between an everolimus-eluting bioresorbable scaffold (BRS) and an everolimus-eluting metallic stent (EES) in STEMI patients.

METHODS AND RESULTS

This observational and retrospective study included 235 consecutive STEMI patients treated with BRS, compared with 235 STEMI patients treated with EES from the EXAMINATION trial, by applying propensity score matching. The primary endpoint was a device-oriented endpoint (DOCE), including cardiac death, target vessel myocardial infarction and target lesion revascularisation at five-year follow-up. Device thrombosis, according to the ARC criteria, was also evaluated. Optical coherence tomography (OCT) analysis was also performed at five years in event-free BRS patients. The cumulative incidence of five-year DOCE was higher in the BRS group as compared to the EES group (13.2% vs 7.6%, HR 1.87, 95% CI: 0.94-3.44, p=0.071), mainly driven by a higher rate of TLR (7.6% vs 1.7%, HR 1.15, 95% CI: 0.44-2.30, p=0.004). The five-year definite BRS thrombosis rate was also higher as compared to EES (4.2% vs 1.2%, HR 3.49, 95% CI: 0.95-12.82, p=0.054). OCT analysis showed a high incidence of neoatherosclerosis in the BRS group.

CONCLUSIONS

The five-year event risk was higher with BRS versus EES in STEMI. This suggests that the probability of obtaining favourable results at very long-term follow-up is low. Whether better results will be obtained with new-generation BVS remains to be determined.

Magnesium-Based Resorbable Scaffold Versus Permanent Metallic Sirolimus-Eluting Stent in Patients With ST-Segment Elevation Myocardial Infarction: The MAGSTEMI Randomized Clinical Trial

BACKGROUND

The use of poly-l-lactide acid-based bioresorbable scaffolds is limited in daily clinical practice because of safety concerns and lack of physiological benefit. Magnesium-based bioresorbable scaffold (MgBRS) presents a short resorption period (<1 year) and have the potential of being thromboresistant and exhibiting early restoration of vasomotor function. To date, however, no randomized clinical trial has investigated the performance of MgBRS. Therefore, this study aimed to compare the in-stent/scaffold vasomotion between MgBRS and permanent metallic sirolimus-eluting stent (SES) at 12-month follow-up in ST-segment-elevation myocardial infarction patients.

METHODS

This investigator-driven, multicenter, randomized, single-blind, controlled trial randomized ST-segment-elevation myocardial infarction patients 1:1 to SES or MgBRS at 11 academic centers. The primary end point was the rate of increase (≥3%) after nitroglycerin in mean lumen diameter of the in-stent/scaffold segment at 12 months with superiority of MgBRS over SES in the as-treated population. The main secondary end points included angiographic parameters of restenosis, device-oriented composite end point, their individual components, and device thrombosis rate. Besides, endothelial-dependent vasomotor response to acetylcholine (ie, endothelial function) was also assessed in a subgroup of patients (n=69).

RESULTS

Between June 2017 and June 2018, 150 ST-segment-elevation myocardial infarction patients were randomized (MgBRS, n=74; SES, n=76). At 1 year, the primary end point was significantly higher in the MgBRS arm (56.5% versus 33.8%; P=0.010). Conversely, late lumen loss was significantly lower in the SES group (in-segment: 0.39±0.49mm versus 0.02±0.27mm, P<0.001; in-device: 0.61±0.55mm versus 0.06±0.21mm; P<0.001). The device-oriented composite end point was higher in the MgBRS arm driven by an increase in ischemia-driven target lesion revascularization rate (12[16.2%] versus 4[5.2%], P=0.030). Definite thrombosis rate was similar between groups (1[1.4%] in the MgBRS arm versus 2[2.6%] in the SES group; P=1.0). Endothelial function assessment at device segment evidenced a more pronounced vasoconstrictive response to maximal dose of acetylcholine in the MgBRS arm (-8.3±3.5% versus -2.4±1.3% in the SES group, P=0.003).

CONCLUSIONS

When compared to SES, MgBRS demonstrated a higher capacity of vasomotor response to pharmacological agents (either endothelium-independent or endothelium-dependent) at 1 year. However, MgBRS was associated with a lower angiographic efficacy, a higher rate of target lesion revascularization, without thrombotic safety concerns.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03234348.

Role of ST-Segment Resolution in Patients With ST-Segment Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention (from the 5-Year Outcomes of the EXAMINATION [Evaluation of the Xience-V Stent in Acute Myocardial Infarction] Trial)

In patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI), lack of ST-segment resolution (STR) is associated with poor prognosis at short- and long-term follow-up. The aim of this study was to evaluate the role of STR on very long-term outcomes in patients with STEMI treated with pPCI included in the EXAMINATION (Evaluation of the Xience-V Stent in Acute Myocardial Infarction) trial. Patients were stratified according to the presence of STR < 50% and STR < 70% at the 30-minute post-pPCI electrocardiogram. Primary end point was the patient-oriented composite endpoint (POCE) of all-cause death, any myocardial infarction, or any revascularization at 5-year follow-up. Both baseline and post-PCI 30-minute electrocardiograms were available for STR assessment in 1,351 patients. Of these patients, 228 (16.9%) and 500 (37.0%) exhibited STR < 50% and STR < 70%, respectively. At 5-year follow-up, the POCE was observed more frequently in patients with STR < 50% (hazard ratio [HR] 1.556; 95% confidence interval [CI] 1.194 to 2.027; p <0.001) and in patients with STR < 70% (HR 1.460, 95% CI 1.169 to 1.824, p <0.001) compared with patients with STR > 50% and STR ≥ 70%, respectively. In both cases, this difference was mainly driven by a significant increase in the rate of all-cause death and any revascularization. After multivariable adjustment, STR < 70%, but not STR < 50%, resulted as a 5-year independent predictor of POCE (adjusted HR 1.338, 95% CI 1.008 to 1.778, p = 0.044). In conclusion, in patients with STEMI, the evaluation of 70% STR after pPCI provides independent prognostic information at 5-year follow-up and it can be used to identify patients at high risk of very long-term cardiovascular events.

Long-term prognostic impact of non-invasive follow-up with computed tomography angiography in patients with left main coronary artery stenting

BACKGROUND

Left main coronary artery (LMCA) stenting is an evolving technique. Whether follow-up computed tomography angiography (CTA) might have clinical impact in these patients is controversial. The aim of present study is to compare clinical outcomes of patients with LMCA stenting followed with CTA versus patients with conventional clinical follow-up.

METHODS

From 2003 to 2014 all consecutive patients with unprotected LMCA stenosis treated with single DES implantation were prospectively included. Since 2009 all patients underwent CTA at 6-month after LMCA stenting. Therefore, the non-CTA group included all patients treated from 2003 to 2009 and the CTA group included patients treated from 2009 to 2014. Patients with 6-month cardiac events, renal dysfunction or atrial fibrillation were excluded. All patients underwent at least 2-year clinical follow-up. The primary endpoint was a composite of cardiac death, nonfatal myocardial infarction, and LMCA revascularization.

RESULTS

A total of 236 patients were included (119 in the non-CTA and 117 in the CTA group). Nine event-free patients presented with in-stent restenosis as assessed by CTA at 6 months; 5 had angiographic confirmation and were revascularized. At 2 years, the primary end-point was observed in 15.1% and 7.3% of patients of the non-CTA and CTA groups, respectively (P=0.07). All-cause mortality was higher in the non-CTA group (8.4% vs. 2.6%; P=0.05). Euroscore and CTA were found independent predictors of the primary end-point in the multivariate analysis.

CONCLUSIONS

Elective 6-month CTA after LMCA stenting is associated with better outcomes compared to conventional clinical follow-up.

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.

Preserved endothelial vasomotor function after everolimus-eluting stent implantation

AIMS

To compare the degree of endothelial dysfunction (ED) in patients treated with everolimus-eluting stent (EES) versus bare metal stent (BMS) implantation.

METHODS AND RESULTS

This is an observational study. A total of 30 elective patients (15 treated with EES and 15 with BMS) were recruited. All patients underwent coronary angiography and intracoronary acetylcholine (Ach) test at different doses at six months after stent implantation. Quantitative coronary angiography analysis was performed to evaluate the changes in mean luminal diameter (MLD) of the segments distal to the distal stent edge after increasing doses of Ach. Both EES and BMS groups had similar baseline characteristics except for stent length (18.6±2.5 vs. 16.5±2.5 mm; p=0.033) and diameter (3.1±0.2 vs. 3.4±0.3 mm; p=0.007). The vasomotion test showed that EES had 3.14% of MLD decrease after Ach infusion and BMS had 2.35% of vasoconstriction (p=0.62). After adjustment for baseline characteristics, no statistical difference was observed between groups.

CONCLUSIONS

In our study EES implantation was associated with a low degree of ED and had a similar vasomotion response as compared to BMS. Prospective randomised investigations are warranted to confirm these findings.

Lumen enlargement of the coronary segments located distal to chronic total occlusions successfully treated with drug-eluting stents at follow-up

AIMS

Chronic total occlusions (CTO) are the final stage of atherosclerosis. Occluded coronary arteries have large plaque burden and negative remodelling. The aim of this study was to assess lumen and vessel changes of segments located distal to successfully recanalised CTO.

METHODS AND RESULTS

Ninety-one CTO treated with drug-eluting stents underwent quantitative coronary angiography (QCA) at baseline and at 12-18 months; 31 underwent serial intravascular ultrasound (IVUS) imaging. Angiographic changes were assessed with QCA as differences in minimal, mean and maximal lumen diameter (MinLD, MeanLD and MaxLD, respectively). Vessel changes were assessed with IVUS as changes in plaque and vessel volume. At follow-up, angiographic MinLD increased 23.9% (from 0.88±0.32 to 1.09±0.35 mm; p<0.01), MeanLD 16.4% (from 1.59±0.44 to 1.85±0.45 mm; p<0.01) and MaxLD 11.7% (from 2.39±0.67 to 2.67±0.70 mm; p<0.01). Lumen enlargement was greater in non-restenotic lesions, small lumen area at the end of the index procedure and low LDL-cholesterol levels during the study. By IVUS, lumen volume increased 26.9% (from 108.1±89.2 to 137.3±115.3 mm3; p<0.01), vessel volume increased 12.1% (from 207.1±170.2 to 232.2±196.0 mm3; p<0.01) and plaque volume tended to decrease 3.9% (from 98.9±88.7 to 94.9±89.3 mm3; p=0.07). Small lumen at baseline was related to greater lumen enlargement.

CONCLUSIONS

Segments distal to recanalised CTO showed a notable lumen and vessel enlargement with a trend toward mild plaque regression. Low LDL-cholesterol levels increase lumen enlargement.

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.