Impact of early versus late clopidogrel discontinuation on stent thrombosis following percutaneous coronary intervention with first- and second-generation drug-eluting stents

Adherence and persistence analysis in patients treated with double antiplatelet therapy (DAPT) at two years in real life

INTRODUCTION

Double antiplatelet therapy (DAPT) is indicated for the treatment of coronary artery diseases (CAD). The optimal duration of therapy with DAPT continues to be a subject of debate in the scientific community. To improve adherence to DAPT, the FDC (fixed dose combination) of Acetylsalicylic acid (ASA) and clopidogrel was developed into a single pill instead of two separate pills thus facilitating the dosage and administration of the therapy and increasing compliance. The aim of this study was to assess adherence and persistence over a period of two years in patients treated with DAPT composed of: ASA/clopidogrel, ASA/prasugrel, ASA/ticagrelor and FDC with ASA and clopidogrel in real life and to assess whether the use of ASA and clopidogrel FDC is associated with improved adherence.

MATERIALS AND METHODS

In the following retrospective pharmacological-observational non-interventional study, all patients treated with DAPT in the Hospital of Pescara from January 2010 to October 2019 were considered. Persistence to treatment is defined as the duration of time from initiation to discontinuation of treatment. Adherence was calculated as the ratio between Received Daily Dose (RDD) and Prescribed Daily Dose (PDD).

RESULTS

277 patients treated with ASA/clopidogrel, 77 patients treated with ASA/prasugrel, 57 patients treated with ASA/ticagrelor and 108 patients treated with FDC of ASA/clopidogrel were analysed. Persistence curves at two years showed a statistically significant difference (p < 0.001). Adherence to therapy was optimal with an absolute value at two years of 0.96. Adherence was better in patients treated with ASA/prasugrel with a value of 0.98 and with 97 % of patients with an adherence value greater than or equal to 0.8, while, it was worse in patients treated with FDC ASA/clopidogrel with an absolute value of 0.94 and with 88 % of patients with an optimal adherence value. No statistically significant difference was found between the ASA/clopidogrel FDC in comparison to each component taken as a separate pill (p = 0.0752).

CONCLUSION

DAPT along with ASA/clopidogrel showed a statistically significant better persistence than ASA/ticagrelor and ASA/prasugrel. Whereas, to our knowledge and as per the current literature no statistically significant differences were found, in terms of adherence in real life, between the use of ASA/Clopidogrel FDC and the use of two different pills.

A scoring system to predict the occurrence of very late stent thrombosis following percutaneous coronary intervention for acute coronary syndrome

We aimed to derive and validate an effective risk score to identify high-risk patients of very late stent thrombosis (VLST), following percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Stepwise multivariable Cox regression was used to build the risk model using data from 5,185 consecutive ACS patients treated with PCI (derivation cohort) and 2,058 patients from the external validation cohort. Eight variables were independently associated with the development of VLST: history of diabetes mellitus, previous PCI, acute myocardial infarction as admitting diagnosis, estimated glomerular filtration rate <90 ml/min/1.73 m², three-vessel disease, number of stents per lesion, sirolimus-eluting stent, and no post-dilation. Based on the derived score, patients were classified into low- (≤7), intermediate- (8-9), and high- (≥10) risk categories. Observed VLST rates were 0.5%, 2.2%, and 8.7% and 0.45%, 2.3%, and 9.3% across the 3 risk categories in the derivation and validation cohorts, respectively. High discrimination (c-statistic = 0.80 and 0.82 in the derivation and validation cohorts, respectively) and excellent calibration were observed in both cohorts. VLST risk score, a readily useable and efficient tool to identify high-risk patients of VLST after PCI for ACS, may aid in risk-stratification and pre-emptive decision-making.

Promoting vascular healing using nanofibrous ticagrelor-eluting stents

Objective

The current treatment of atherosclerotic coronary heart disease with limus-eluting stents can lead to incomplete endothelialization and substantial impairment of arterial healing relative to treatment with bare-metal stents. The sustained and local delivery of ticagrelor, a reversibly binding P2Y12 receptor inhibitor, using hybrid biodegradable nanofibers/stents, was developed to reduce neointimal formation and endothelial dysfunction.

Methods

In this investigation, a solution of ticagrelor, poly(D,L)-lactide-co-glycolide, and hexafluoro isopropanol was electrospun to fabricate ticagrelor-eluting nanofibrous drug-eluting stents. The in vitro and in vivo ticagrelor concentrations were measured using a high-performance liquid chromatography assay. The effectiveness of ticagrelor-eluting stents was examined relative to that of sirolimus-eluting stents.

Results

Adequate ticagrelor levels were detected for four weeks in vitro. Less HES5-positive labeling was found near the ticagrelor-eluting stented vessels (0.33±0.12) than close to the sirolimus-eluting stented vessels (0.57±0.15) (p<0.05). Four weeks after deployment, the ticagrelor-eluting stent also exhibited an up-regulated local expression of SOD1 in the stenting area (p<0.001). The ticagrelor-eluting stent substantially preserved endothelial function and re-endothelialization, minimized inflammatory responses, and inhibited neointimal hyperplasia.

Conclusion

Ticagrelor-eluting stents may provide an alternative route for treating patients at a high risk of bleeding to preserve endothelial recovery and to reduce smooth muscle proliferation.

Impact of early (3 months) dual antiplatelet treatment interruption prior to renal transplantation in patients with second-generation DES on perioperative stent thrombosis and MACEs

OBJECTIVE

Early cessation of dual antiplatelet therapy (DAPT) is related to stent thrombosis (ST). The use of second-generation everolimus- and zotarolimus-eluting stents is associated with low restenosis rates and short duration of clopidogrel usage. Non-cardiac surgery in recently stent-implanted patients is associated with major adverse cardiac events (MACEs). Chronic renal failure patients awaiting renal transplantation may also undergo coronary stent implantation prior to surgery. Here we aimed to investigate the safety of early (3 months) DAPT interruption in second-generation drug-eluting stent (DES)-implanted renal transplant recipients.

METHODS

In total, 106 previously stent-implanted chronic renal failure patients who underwent renal transplantation were retrospectively enrolled. Three groups were formed according to stent type and the duration of DAPT: early-interruption (3 months from DES implantation), lateinterruption (3-12 months from DES implantation), and bare-metal stent (BMS; at least 1 month from BMS implantation) groups.

RESULTS

Comparison among BMS, DES-early and DES-late groups indicated no difference in ST, myocardial infarction, death, and MACEs. In addition, no difference was observed in ST (p=0.998), myocardial infarction (p=0.998), death (p=0.999), and MACEs (p=0.998) between DES-early and DES-late groups.

CONCLUSION

Early (3 months) interruption of antiplatelet treatment with second-generation stents before renal transplantation seems to be safe and does not lead to increase in the occurrence of ST and MACEs.

Investigation of standardized administration of anti-platelet drugs and its effect on the prognosis of patients with coronary heart disease

The aim of the present study was to explore the effect of adherence to standardized administration of anti-platelet drugs on the prognosis of patients with coronary heart disease. A total of 144 patients newly diagnosed with coronary heart disease at Lu'an Shili Hospital of Anhui Province (Lu'an, China) between June 2010 and June 2012 were followed up. Kaplan-Meier curves and the Cox regression model were used to evaluate the effects of standardized administration of anti-platelet drugs on primary and secondary end-point events. Of the patients with coronary heart disease, 109 (76%) patients took standard anti-platelet drugs following discharge. Kaplan-Meier curve and Cox regression analysis showed that standardized administration of anti-platelet drugs reduced the risk of primary end-point events (including all-cause mortality, non-lethal myocardial infarction and stroke) of patients with coronary heart disease [hazard ratio (HR)=0.307; 95% confidence interval (CI): 0.099-0.953; P=0.041) and all-cause mortality (HR=0.162; 95% CI: 0.029-0.890; P=0.036); however, standardized administration had no predictive value with regard to secondary end-point events. Standardized administration of anti-platelet drugs obviously reduced the risk of primary end-point events in patients with coronary heart disease, and further analysis showed that only all-cause mortality exhibited a statistically significant reduction.

Long-term effect of stents eluting 6-mercaptopurine in porcine coronary arteries

Background

Drug-eluting stents (DES) have dramatically reduced restenosis rates compared to bare metal stents and are widely used in coronary artery angioplasty. The anti-proliferative nature of the drugs reduces smooth muscle cell (SMC) proliferation effectively, but unfortunately also negatively affects endothelialization of stent struts, necessitating prolonged dual anti-platelet therapy. Cell-type specific therapy may prevent this complication, giving rise to safer stents that do not require additional medication. 6-Mercaptopurine (6-MP) is a drug with demonstrated cell-type specific effects on vascular cells both in vitro and in vivo, inhibiting proliferation of SMCs while promoting survival of endothelial cells. In rabbits, we demonstrated that DES locally releasing 6-MP during 4 weeks reduced in-stent stenosis by inhibiting SMC proliferation and reducing inflammation, without negatively affecting endothelialization of the stent surface. The aim of the present study was to investigate whether 6-MP-eluting stents are similarly effective in preventing stenosis in porcine coronary arteries after 3 months, in order to assess the eligibility for human application.

Methods

6-MP-eluting and polymer-only control stents (both n = 7) were implanted in porcine coronary arteries after local balloon injury to assess the effect of 6-MP on vascular lesion formation. Three months after implantation, stented coronary arteries were harvested and analyzed.

Results

Morphometric analyses revealed that stents were implanted reproducibly and with limited injury to the vessel wall. Unexpectedly, both in-stent stenosis (6-MP: 41.1 ± 10.3 %; control: 29.6 ± 5.9 %) and inflammation (6-MP: 2.14 ± 0.51; control: 1.43 ± 0.45) were similar between the groups after 3 months.

Conclusion

In conclusion, although 6-MP was previously found to potently inhibit SMC proliferation, reduce inflammation and promote endothelial cell survival, thereby effectively reducing in-stent restenosis in rabbits, stents containing 300 μg 6-MP did not reduce stenosis and inflammation in porcine coronary arteries.

Current Strategies to Reduce Gastrointestinal Bleeding Risk Associated with Antiplatelet Agents

Antiplatelet agents remain the cornerstone in the primary and secondary therapeutic intervention for cardiovascular disease. Some patients may be subjected to a year or more of dual antiplatelet therapy to reduce the risk of subsequent cardiovascular events. Patients on antiplatelet therapy have an increased risk of gastrointestinal bleeding; however, not all patients benefit from concomitant acid suppressive therapy. This review will provide an overview of the pharmacology of antiplatelet agents and outline patient risk profiles that ought to be considered when considering prophylactic therapy to reduce gastrointestinal toxicity. In addition, we discuss the current risk-reduction strategies intended to mitigate against the potential for related gastroduodenal injury.

Independent Predictors of Major Adverse Events following Coronary Stenting over 28 Months of Follow-Up

Background: Despite recent advances in stent design and constantly improving protective pharmacological strategies, complications and adverse events following percutaneous coronary interventions (PCI) are still major factors influencing morbidity and mortality. Therefore, predicting secondary vascular occlusions represents an unmet medical need. Objective: The aim of our study was to triage clinical and laboratory predictors of major adverse clinical events (MACE) following coronary stenting. Methods: This was a prospective, case-controlled, single-center study, which included 94 consecutive patients with documented coronary disease who underwent PCI with drug-eluting stent (DES) implantation. All patients received dual antiplatelet therapy with aspirin and clopidogrel. Numerous clinical characteristics and laboratory biomarkers were assessed before stenting and were correlated with poststenting MACE over the mean follow-up of 28 months. MACE included death, nonfatal myocardial infarction, target vessel revascularisation, stroke, stent thrombosis, angina recurrence and instent restenosis. Results: Twenty-three patients experienced MACE. Independent MACE predictors after PCI with DES implantation were antecedent diabetes mellitus (RR = 0.45; 95% CI 0.20-0.97; p = 0.045), prior thrombolytic therapy (RR = 0.42; 95% CI 0.27-0.83; p = 0.039), baseline plasminogen activator inhibitor -1 (PAI-1; p = 0.008) and plasma von Willebrand factor (vWF) activity (p = 0.007). Other clinical characteristics and laboratory indices showed no correlation with MACE. Conclusions: Background diabetes mellitus, prior thrombolytic therapy, PAI-1 and vWF prestenting activity may be useful for MACE prediction over 28 months of follow-up.

Treatment and prevention of gastrointestinal bleeding in patients receiving antiplatelet therapy

Antiplatelet therapy is the standard of care for the secondary prevention of acute coronary syndrome and ischemic stroke, especially after coronary intervention. However, this therapy is associated with bleeding complications such as gastrointestinal bleeding, which is one of the most common life-threatening complications. Early endoscopy is recommended for most patients with acute upper gastrointestinal bleeding. After successful endoscopic hemostasis, immediate resumption of antiplatelet therapy with proton-pump inhibitors (PPIs) is recommended to prevent further ischemic events. PPI prophylaxis during antiplatelet therapy reduces the risk of upper gastrointestinal bleeding. The potential negative metabolic interaction between PPIs and clopidogrel is still unclear.