The effect of intended duration of clopidogrel use on early and late mortality and major adverse cardiac events in patients with drug-eluting stents

The Risk of Bleeding and Adverse Events with Clopidogrel in Elective Hip and Knee Arthroplasty Patients

Orthopedic surgeons often face a clinical dilemma on how to manage antiplatelet therapies during the time of surgery. This retrospective study is aimed to investigate the bleeding risk and adverse events in patients who hold or keep clopidogrel during elective major joints arthroplasty. Two hundred and ninety-six patients that were treated with clopidogrel while undergoing total hip or knee joint replacement between January 2009 and December 2018 were studied. Group 1 included 56 patients (18.9%) who kept using clopidogrel preoperatively. Group 2 included 240 patients who hold clopidogrel use ≥5 days preoperatively. Blood transfusion rates, estimated blood loss, complication rates, and adverse cardiocerebral events were collected and analyzed. The mean total blood loss was more in the group 1 patients as compared with that in the group 2 patients (1212.3 mL (685.8 to 2811.8) vs. 1068.9 mL (495.6 to 3294.3), p = 0.03). However, there was no significant difference between the two groups of patients regarding transfusion rates, bleeding-related complications, and infection rates. There was a trend toward a higher incidence of adverse cardiocerebral events in patients withholding clopidogrel for more than 5 days before surgery. The results of this study suggest that clopidogrel continuation could be safe and advisable for patients at thrombotic risk undergoing primary major joint replacement. Acute antiplatelet withdrawal for an extended period of time might be associated with an increased risk of postoperative thromboembolic events. More studies are required in the future to further prove this suggestion.

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.

Trends of Use and Outcomes Associated With Glycoprotein-IIb/IIIa Inhibitors in Patients With Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention

Background: Glycoprotein IIb/IIIa inhibitors (GPIs) are a treatment option in the management of acute coronary syndromes (ACSs). Evidence supporting the use of GPIs predates trials establishing the benefits of P2Y12 inhibitors, routine early invasive therapy, and thrombectomy devices in patients with ACS. Objective: The aim of this study was to determine trends in GPI use and their associated outcomes in contemporary practice. Methods: We assessed GPI use in patients with ACS undergoing percutaneous coronary intervention (PCI) from the Melbourne Interventional Group registry (2005-2013). The primary endpoint was the 30-day incidence of major adverse cardiovascular events (MACE). The safety endpoint was in-hospital major bleeding. Results: GPIs were used in 40.5% of 12 357 patients with ACS undergoing PCI. GPI use decreased over the study period (P for trend <0.0001). Patients were more likely to receive GPIs if they were younger, presented with a ST-elevation myocardial infarction (STEMI), had more complex (B2/C-type) lesions, and when thrombectomy devices were used (all P < 0.0001). MACE were higher in patients receiving GPI (4.9% vs 4.1%, P = 0.03). Propensity score matching revealed no difference in 30-day mortality and 30-day MACE (odds ratio [OR] = 1.00; 95% CI = 0.99-1.004 and OR = 1.01; 95% CI = 0.99-1.02, respectively). GPI use was associated with more bleeding complications (3.6% vs 1.8%, P < 0.0001). Conclusion and Relevance: GPI use in ACS patients undergoing PCI has declined, and use appears to be dictated by ACS type and lesion complexity, as opposed to high-risk comorbidities. GPI use was associated with a doubling in bleeding complications.

Heart Rate as a Predictor of Outcome Following Percutaneous Coronary Intervention

Data from previous studies of patients with heart failure and coronary artery disease suggest that those with higher resting heart rates (HRs) have worse cardiovascular outcomes. We sought to evaluate whether HR immediately before percutaneous coronary intervention (PCI) is an independent predictor for 30-day outcome. We analyzed the outcome of 3,720 patients who had HR recorded before PCI from the Melbourne Interventional Group registry. HR and outcomes were analyzed by quintiles, and secondarily by dichotomizing into <70 or ≥70 beats/min. Patients with cardiogenic shock, intra-aortic balloon pump or inotropic support, and out-of-hospital arrest were excluded. The mean ± SD HR was 70.9 ± 14.7 beats/min. HR by quintile was 55 ± 5, 64 ± 2, 70 ± 1, 77 ± 3, and 93 ± 13 beats/min, respectively. Patients with higher HR were more likely to be women, current smokers, have higher systolic and diastolic blood pressure, atrial fibrillation, recent heart failure, lower ejection fraction, and ST-elevation myocardial infarction as the indication for the PCI (all p ≤0.002). However, rates of treated hypertension, multivessel disease, previous myocardial infarction, PCI, and coronary bypass surgery were lower (all p ≤0.004). Increased HR was associated with higher 30-day mortality (p for trend = 0.04), target vessel revascularization (p for trend = 0.003), and 30-day major adverse cardiac events (MACE) (p for trend = 0.004). In a multivariable analysis, HR was an independent predictor of 30-day MACE (OR 1.21 per quintile; 95% confidence interval (CI): 1.06 to 1.39, p = 0.004). When dichotomized into <70 or ≥70 beats/min, HR independently predicted both 30-day MACE (OR 1.59, 95% CI 1.08 to 2.36, p = 0.02) and 30-day mortality (OR 2.80, 95% CI 1.10 to 7.08, p = 0.03). In conclusion, HR immediately before PCI is an independent predictor of adverse 30-day cardiovascular outcomes.

Preoperative Use of Clopidogrel Does Not Affect Outcomes for Femoral Neck Fractures Treated With Hemiarthroplasty

BACKGROUND

The antiplatelet effect of clopidogrel on blood loss and perioperative complications after surgical intervention remains ambiguous. The purpose of this study was to determine if patients on clopidogrel before hemiarthroplasty for femoral neck fracture are predisposed to greater surgical bleeding and perioperative complications compared with those not taking clopidogrel before surgery.

METHODS

We conducted a review of our electronic medical record from 2006-2013 and identified 602 patients who underwent 623 hemiarthroplasty procedures for displaced femoral neck fracture, of which 54 cases (9%) were taking clopidogrel before hospital admission. Patient demographics and comorbidities, operative and surgical variables, and perioperative complications at 90 days were compared between the clopidogrel and nonclopidogrel user groups.

RESULTS

The 2 groups of patients had similar baseline characteristics, but patients taking clopidogrel preoperatively were sicker with higher American Society of Anesthesiologists scores (P = .049) and age-adjusted Charlson index (P = .001). They also had a greater incidence of cerebrovascular disease (P = .01), chronic obstructive pulmonary disease (P = .03), diabetes (0.03), and malignancy (P < .001). There was no significant difference between the 2 patient groups with respect to 90-day postoperative medical readmissions (P = .85), surgical readmissions (P = .26), infection (P = .99), and mortality (P = .89).

CONCLUSION

Patients taking clopidogrel who present with a displaced femoral neck fracture can safely undergo a hemiarthroplasty while actively on clopidogrel without an increase in medical or surgical complications and mortality. We do not recommend delaying surgical intervention until the antiplatelet effects of clopidogrel subside.

Using nationwide ‘big data’ from linked electronic health records to help improve outcomes in cardiovascular diseases: 33 studies using methods from epidemiology, informatics, economics and social science in the ClinicAl disease research using LInked Bespoke studies and Electronic health Records (CALIBER) programme

Background

Electronic health records (EHRs), when linked across primary and secondary care and curated for research use, have the potential to improve our understanding of care quality and outcomes.

Objective

To evaluate new opportunities arising from linked EHRs for improving quality of care and outcomes for patients at risk of or with coronary disease across the patient journey.

Design

Epidemiological cohort, health informatics, health economics and ethnographic approaches were used.

Setting

230 NHS hospitals and 226 general practices in England and Wales.

Participants

Up to 2 million initially healthy adults, 100,000 people with stable coronary artery disease (SCAD) and up to 300,000 patients with acute coronary syndrome.

Main outcome measures

Quality of care, fatal and non-fatal cardiovascular disease (CVD) events.

Data platform and methods

We created a novel research platform [ClinicAl disease research using LInked Bespoke studies and Electronic health Records (CALIBER)] based on linkage of four major sources of EHR data in primary care and national registries. We carried out 33 complementary studies within the CALIBER framework. We developed a web-based clinical decision support system (CDSS) in hospital chest pain clinics. We established a novel consented prognostic clinical cohort of SCAD patients.

Results

CALIBER was successfully established as a valid research platform based on linked EHR data in nearly 2 million adults with > 600 EHR phenotypes implemented on the web portal (seehttps://caliberresearch.org/portal). Despite national guidance, key opportunities for investigation and treatment were missed across the patient journey, resulting in a worse prognosis for patients in the UK compared with patients in health systems in other countries. Our novel, contemporary, high-resolution studies showed heterogeneous associations for CVD risk factors across CVDs. The CDSS did not alter the decision-making behaviour of clinicians in chest pain clinics. Prognostic models using real-world data validly discriminated risk of death and events, and were used in cost-effectiveness decision models.

Conclusions

Emerging ‘big data’ opportunities arising from the linkage of records at different stages of a patient’s journey are vital to the generation of actionable insights into the diagnosis, risk stratification and cost-effective treatment of people at risk of, or with, CVD.

Future work

The vast majority of NHS data remain inaccessible to research and this hampers efforts to improve efficiency and quality of care and to drive innovation. We propose three priority directions for further research. First, there is an urgent need to ‘unlock’ more detailed data within hospitals for the scale of the UK’s 65 million population. Second, there is a need for scaled approaches to using EHRs to design and carry out trials, and interpret the implementation of trial results. Third, large-scale, disease agnostic genetic and biological collections linked to such EHRs are required in order to deliver precision medicine and to innovate discovery.

Study registration

CALIBER studies are registered as follows: study 2 – NCT01569139, study 4 – NCT02176174 and NCT01164371, study 5 – NCT01163513, studies 6 and 7 – NCT01804439, study 8 – NCT02285322, and studies 26–29 – NCT01162187. Optimising the Management of Angina is registered as Current Controlled Trials ISRCTN54381840.

Funding

The National Institute for Health Research (NIHR) Programme Grants for Applied Research programme (RP-PG-0407-10314) (all 33 studies) and additional funding from the Wellcome Trust (study 1), Medical Research Council Partnership grant (study 3), Servier (study 16), NIHR Research Methods Fellowship funding (study 19) and NIHR Research for Patient Benefit (study 33).

Agreement of treatment effects for mortality from routinely collected data and subsequent randomized trials: meta-epidemiological survey

OBJECTIVE

To assess differences in estimated treatment effects for mortality between observational studies with routinely collected health data (RCD; that are published before trials are available) and subsequent evidence from randomized controlled trials on the same clinical question.

DESIGN

Meta-epidemiological survey.

DATA SOURCES

PubMed searched up to November 2014.

METHODS

Eligible RCD studies were published up to 2010 that used propensity scores to address confounding bias and reported comparative effects of interventions for mortality. The analysis included only RCD studies conducted before any trial was published on the same topic. The direction of treatment effects, confidence intervals, and effect sizes (odds ratios) were compared between RCD studies and randomized controlled trials. The relative odds ratio (that is, the summary odds ratio of trial(s) divided by the RCD study estimate) and the summary relative odds ratio were calculated across all pairs of RCD studies and trials. A summary relative odds ratio greater than one indicates that RCD studies gave more favorable mortality results.

RESULTS

The evaluation included 16 eligible RCD studies, and 36 subsequent published randomized controlled trials investigating the same clinical questions (with 17,275 patients and 835 deaths). Trials were published a median of three years after the corresponding RCD study. For five (31%) of the 16 clinical questions, the direction of treatment effects differed between RCD studies and trials. Confidence intervals in nine (56%) RCD studies did not include the RCT effect estimate. Overall, RCD studies showed significantly more favorable mortality estimates by 31% than subsequent trials (summary relative odds ratio 1.31 (95% confidence interval 1.03 to 1.65; I(2)=0%)).

CONCLUSIONS

Studies of routinely collected health data could give different answers from subsequent randomized controlled trials on the same clinical questions, and may substantially overestimate treatment effects. Caution is needed to prevent misguided clinical decision making.

Continuation of Dual-Antiplatelet Therapy Following Percutaneous Revascularization with a Drug-Eluting Stent: What Duration Is Optimal?

Dual-antiplatelet therapy (DAPT) is required after percutaneous coronary intervention with drug-eluting stents (DESs) to prevent thrombotic complications, particularly stent thrombosis (ST). However, there is still disagreement regarding the optimal duration of DAPT post-DES placement. Compared to bare metal stents, DESs are known to reduce restenosis and target vessel revascularization but may be more prone to late and very late ST due to delayed endothelialization. Several trials have suggested that longer (>12 months) DAPT reduces ischemic events but does so at the cost of increased bleeding. Other trials have demonstrated non-inferiority of shorter (3 to 6 months) DAPT compared to long-term DAPT, with fewer bleeding events. The clinical challenge is how to balance the reduced ischemic risk with increased bleeding associated with longer DAPT. Furthermore, ST is associated with multiple patient- and procedure-specific factors, thereby limiting a "one-size-fits-all" approach to determining optimal duration of DAPT. The evaluation of DAPT duration should therefore be tailored individually. We will review the data supporting current recommendations for DAPT and recent clinical trials comparing varying DAPT durations and discuss patient- and procedure-specific factors affecting the "optimal" DAPT duration.

Impact of prolonged dual antiplatelet therapy after acute myocardial infarction on 5-year mortality in the FAST-MI 2005 registry

BACKGROUND

We document dual antiplatelet therapy (DAPT) use from discharge to 4 years after acute myocardial infarction (AMI), and investigate whether prolonged DAPT (beyond 1 year) is related to 5-year mortality.

METHODS

The French Registry of Acute ST-elevation or non-ST-elevation Myocardial Infarction (FAST-MI 2005) included 3670 patients with AMI in 223 French centres. We identified predictors of DAPT (aspirin+clopidogrel) beyond 1 and 2 years, and relation with all-cause 5-year mortality.

RESULTS

Among 3319 (96%) patients with discharge data, 2432 (73%) had DAPT, 582 (17%) single antiplatelet therapy (SAPT), and 305 (9%) no antiplatelet treatment. DAPT decreased from 75% at 1 year to 29% at 4 years, with a corresponding increase in SAPT (p<0.05 for trend). Patients with DAPT were more often male, treated with a drug-eluting stent (DES), and without oral anticoagulants. Independent predictors at 1 year of prolonged DAPT were age<75 years, in-hospital bleeding, history of MI, use of DES, discharge use of beta-blockers or statins and no chronic anticoagulation. Predictors at 2 years were age<75 years, male gender, previous MI, diabetes, DES implantation, no chronic oral anticoagulation. By multivariate analysis, there was no difference in 5-year mortality between those on SAPT vs DAPT at 1 year. DAPT at 2 years was also not significantly related to 5-year mortality (Hazard Ratio 1.3, 95% CI [0.9; 1.8], p=0.21).

CONCLUSION

Prolonged DAPT in selected AMI patients, observed in 47% at 1 year and 21% at 2 years, had no impact on 5-year mortality. These findings do not support the use of DAPT beyond 1 year after an initial ACS.

Dual antiplatelet therapy duration after the placement of a drug-eluting stent: what are the data?

OPINION STATEMENT

The data supporting the immediate use of dual antiplatelet therapy (DAPT) post implantation of drug-eluting stents (DESs) is irrefutable. DAPT in this early period is necessary to prevent stent thrombosis during endothelialization of the stent, a process known to be delayed when DESs are placed. In addition, DAPT helps prevent thrombosis from plaque rupture that occurs outside of the initial stented area and/or at neo-atherosclerotic lesions within a previously coated stent. The ACC/AHA current guidelines (Levine et al. J Am Coll Cardiol. 58(24):e44-122, 2011) recommend 12 months of DAPT post DES implantation. As the result of several randomized clinical trials (Task Force on Myocardial Revascularization of the European Society of Cardio-Thoracic Surgery (EACTS) et al. Eur Heart J. 31(20):2501-55, 2010) showing the safety of a shorter duration of DAPT, the European Heart Society altered their recommendations to 6-12 months of DAPT post DES implantation. However, recent data from the DAPT trial (Mauri et al. N Engl J Med. 371(23):2156-66, 2014) clearly demonstrated less ischemic events with 30 months of DAPT. This trial and others have established that an increased DAPT duration increases bleeding risk which, in turn, increases subsequent morbidity and mortality. The current conundrum lies in defining the optimal time of DAPT post DES to adequately reduce ischemic events while minimizing bleeding risks. Future studies are required to better stratify patients into low and high risk for both ischemic and bleeding risks to assess whether shorter or longer courses of DAPT are the most appropriate for any specific patients. Until then, instead of a "one size fits all" approach to patients who receive DESs, the treating physician must consider both procedural and patient factors when deciding the optimal duration of DAPT for each patient.

Optimal Duration of Dual Antiplatelet Therapy After Implantation of Drug-Eluting Stents: Shorter or Longer?

Use of dual antiplatelet therapy (DAPT; the combination of aspirin and an inhibitor of platelet P2Y₁₂) is the key pharmacological component in the management of acute coronary syndrome and percutaneous coronary intervention (PCI) with stent implantation, but the optimal treatment duration is still unclear. Although current guidelines recommend prescription of DAPT for at least 12 months after implantation of drug-eluting stents (DES) if patients are not at high risk of bleeding, several studies showed conflicting results. Observational studies have shown inconsistent findings (i.e., some studies suggested longer duration would be better, and others vice versa) and small-to-moderate sized randomized clinical trials suggested that prolonged use of DAPT beyond 12 months would not be more beneficial and could be detrimental in safety outcomes. However, these studies suffer from insufficient statistical power, data from old version of DES, and non-uniform duration of DAPT. Given there might be the relative risk and benefit associated with combination of DES use and DAPT prescription, the optimal decision making with regard to DAPT duration would be essential for patients who underwent PCI with DES. Thus, by understanding and comparing the evidences of recent studies that support for shorter and longer duration of DAPT, we sought to guide the treating physician in deciding optimal duration of DAPT in such patients. Up to now, there is no strong evidence supporting that longer duration of DAPT is better than shorter duration of DAPT in terms of efficacy and safety outcomes after DES placement.

Impact of renal function in patients with multi-vessel coronary disease on long-term mortality following coronary artery bypass grafting compared with percutaneous coronary intervention

BACKGROUND

Comorbidities, such as diabetes, affect revascularization strategy for coronary disease. We sought to determine if the degree of renal impairment affected long-term mortality after percutaneous coronary intervention (PCI) compared to coronary artery bypass grafting (CABG) in patients with multi-vessel coronary disease (MVD).

METHODS AND RESULTS

8970 patients with MVD undergoing revascularization between 2004 and 2008, in two multi-center parallel PCI and CABG Australian registries were assigned to three groups based on their estimated glomerular filtration rate (eGFR)≥60 mL/min/1.73 m2 (n=1678:839), 30-59 mL/min/1.73 m2 (n=452:226) and <30 mL/min/1.73 m2 (n=74:37). We used 2:1 propensity matching to compare 3306 patients undergoing primary CABG versus PCI. Shock, myocardial infarction (MI)<24 h, previous CABG, valve surgery or PCI were exclusions. Long-term mortality (mean 3.1 years) was compared with Cox-proportional hazard-adjusted modeling. Observed long-term mortality rates (CABG vs. PCI) were 4.5% vs. 4.3% p=0.84, 12.8% vs. 17.3% p=0.12, and 23.0% vs. 40.5% p=0.05 in the three strata, respectively. In patients with eGFR≥60 mL/min/1.73 m2, long-term mortality between PCI and CABG (HR 0.99, 95% CI 0.65-1.49, p=0.95) was similar. However, amongst patients with eGFR 30-59 mL/min/1.73 m2, there was a significant mortality hazard with PCI (HR 2.00, 95% CI 1.32-3.04, p=0.001). In patients with eGFR<30 mL/min/1.73 m2, there was a trend for hazard with PCI (HR 1.66, 95% CI 0.80-3.46, p=0.17).

CONCLUSION

Long-term mortality in MVD patients with preserved renal function was very low and similar between PCI and CABG. However there was a long-term mortality hazard associated with PCI amongst patients with moderate renal impairment.

Clopidogrel discontinuation after myocardial infarction and risk of thrombosis: a nationwide cohort study

AIMS

The benefit of extending clopidogrel treatment beyond the 12-month period recommended in current guidelines after myocardial infarction (MI) is debated. We analysed the risk of adverse cardiovascular outcomes after discontinuation of 12 months of clopidogrel treatment.

METHODS AND RESULTS

This Danish retrospective nationwide study included all patients treated with clopidogrel after discharge from a first-time MI during 2004-09. The risk of death or recurrent MI after the discontinuation of clopidogrel was studied by multivariable Poisson regression models. Patients treated with and without percutaneous coronary intervention (PCI) were analysed separately. The follow-up was 18 months. Of the 29,268 patients included, 3214 (11.0%) experienced death or recurrent MI. There were 9819 (33.6%) patients treated only medically and 19,449 (66.4%) patients treated with PCI. Twelve months after the index MI, for patients treated only medically, the risk of death or recurrent MI in the first 90-day period of clopidogrel discontinuation was 1.07 (0.65-1.76; P= 0.79) [adjusted incidence rate ratio (IRR) and 95% confidence interval] compared with the next 90-day period of discontinuation. For patients treated with PCI, the corresponding IRR was 1.59 (1.11-2.30; P= 0.013). The risk of recurrent MI yielded an IRR of 0.77 (0.36-1.67; P= 0.51) for patients treated only medically and 1.87 (1.11-3.15; P= 0.019) for PCI-treated patients.

CONCLUSION

Discontinuation of clopidogrel 12 months after MI is associated with an increased risk of death or recurrent MI in the first 90 days of discontinuation compared with the next 90-day period of discontinuation for patients treated with PCI, but not for patients not treated with PCI.

Safety of temporary and permanent suspension of antiplatelet therapy after drug eluting stent implantation in contemporary "real-world" practice

OBJECTIVES

To define the incidence of stent thrombosis (ST) and/or AMI (ST/AMI) associated with temporary or permanent suspension of dual antiplatelet therapy (DAPT) after coronary drug-eluting stent (DES) implantation in "real-world" patients, and additional factors influencing these events.

BACKGROUND

Adherence to DAPT is critical for avoiding ST following DES implantation. However, the outcomes of patients undergoing antiplatelet therapy withdrawal following DES implantation remain to be clearly described.

METHODS

Patients receiving DES from 05/01/2003 to 05/01/2008 were identified from a single-center registry. Complete follow-up data were available for 5,681 patients (67% male, age 66 ± 11 years, duration 1,108 ± 446 days) who were included in this analysis.

RESULTS

Uninterrupted DAPT was maintained in 4,070/5,681 (71.6%) patients, with an annual ST/AMI rate of 0.43%. Antiplatelet therapy was commonly ceased for gastrointestinal-related issues, dental procedures or noncardiac/nongastrointestinal surgery. Temporary DAPT suspension occurred in 593/5,681 (10.4%) patients for 17.6 ± 74.1 days, with 6/593 (1.0%) experiencing ST/AMI during this period. Of patients permanently ceasing aspirin (n = 187, mean 338 ± 411 days poststenting), clopidogrel (n = 713, mean 614 ± 375 days) or both agents (n = 118, mean 459 ± 408 days), ST/AMI was uncommon with an annual rate of 0.1-0.2%. Overall, independent predictors of ST/AMI were unstable initial presentation, uninterrupted DAPT and lower left ventricular ejection fraction. Factors predicting uninterrupted DAPT included diabetes, unstable presentation, prior MI, left main coronary PCI, and multivessel coronary disease.

CONCLUSIONS

In real-world practice, rates of ST/AMI following DES implantation are low, but not insignificant, following aspirin and/or clopidogrel cessation. Use of uninterrupted DAPT appears more common in high-risk patients.

Clopidogrel dilemma for orthopaedic surgeons

BACKGROUND

Patients medicated with clopidogrel who require orthopaedic surgery present a particular challenge. Whether in an emergency or elective situation the orthopaedic surgeon must balance the risks of ceasing clopidogrel versus the risk of increased bleeding that dual antiplatelet therapy generates.

METHOD

This paper reviews the current published evidence regarding the risks of continuing clopidogrel, the risks of discontinuing clopidogrel and associated considerations such as venous thromboprophylaxis.

RESULTS

Little good quality evidence exists in regard to perioperative clopidogrel for orthopaedic surgery. Available evidence across non-cardiac and cardiac surgery were assessed and presented in regards to current practices, blood loss for orthopaedic operations, risks when continuing clopidogrel, risks of stopping clopidogrel and also the consideration of venous thromboembolism.

CONCLUSIONS

The patients at greatest risk, when discontinuing clopidogrel therapy, are those with drug eluting stents who may be at risk of stent thrombosis. Where possible, efforts should be made to continue clopidogrel therapy through the perioperative period, taking precautions to minimize bleeding. If the risk of bleeding is too high, antiplatelet therapy must be reinstated as soon as considered reasonable after surgery. In addition, patients on clopidogrel who sustain a fall or other general trauma need to be carefully assessed because of the possibility of occult bleeding, such as into the retroperitoneal space. Until more definitive evidence becomes available, this review aims to provide a guide for the orthopaedic surgeon in dealing with the difficult dilemma of the patient on clopidogrel therapy, recommending that orthopaedic surgeons take a team approach to assess the individual risks for all patients and consider continuation of clopidogrel therapy perioperatively where possible.

Perioperative clopidogrel and postoperative events after hip and knee arthroplasties

BACKGROUND

Hip and knee arthroplasties are widely performed and vascular disease among patients having these procedures is common. Clopidogrel is a platelet inhibitor that decreases the likelihood of thrombosis. It may cause intraoperative and postoperative bleeding, but its discontinuation increases the risk of vascular events. There is currently no consensus regarding the best perioperative clopidogrel regimen that balances these concerns.

QUESTIONS/PURPOSES

We determined (1) the relationship between time of perioperative clopidogrel administration and postoperative bleeding-related events after hip and knee arthroplasties and (2) patient characteristics or surgical factors that may predict these events.

METHODS

We retrospectively queried our inpatient pharmacy database for patients who received clopidogrel from 2007 to 2009 and identified 116 patients who underwent hip or knee arthroplasty. We recorded the time of perioperative clopidogrel administration, bleeding-related postoperative events, patient characteristics, and surgical factors.

RESULTS

Patients who withheld clopidogrel 5 or more days before hip or knee arthroplasty had lower rates of reoperation for infection and antibiotics prescribed for the surgical wound. Postoperative events did not vary with timing of clopidogrel resumption after surgery. Advanced age, an American Society of Anesthesiologists (ASA) score of 4, and revision surgery predicted increased readmission, reoperation for hematoma or infection, antibiotic use, and death.

CONCLUSIONS

Holding clopidogrel for at least 5 days before hip or knee arthroplasty may lower the rate of bleeding-related events. We found no increase in events when patients resumed clopidogrel immediately after surgery. Advanced age, ASA score of 4, and revision surgery may be risk factors for bleeding-related events.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Impact of periprocedural atrial fibrillation on short-term clinical outcomes following percutaneous coronary intervention

There are few data on the incidence and clinical outcomes of patients with atrial fibrillation (AF) treated in the era of percutaneous coronary intervention (PCI). We analyzed 30-day clinical outcomes in 3,307 consecutive patients with and without AF (sinus rhythm) undergoing PCI from January 2007 through December 2008 enrolled in a multicenter Australian registry. Periprocedural AF was present in 162 patients (4.9%). AF was associated with older age (74.1 ± 8.9 vs 63.9 ± 11.9 years, p <0.001), higher baseline serum creatinine (0.13 ± 0.14 vs 0.10 ± 0.13 mmol/L, p = 0.01), and lower left ventricular ejection fraction (49.5 ± 13.2% vs 53.4% ± 11.6%, p <0.001). Significantly more patients with AF had a history of heart failure and cerebrovascular and peripheral arterial diseases (p ≤0.01 for all comparisons). Periprocedural glycoprotein IIb/IIIa inhibitor (31.5% vs 31.4%, p = 0.98) and antithrombin use were not different between groups, but in-hospital bleeding complications were higher in patients with AF (5.0% vs 2.1%, p = 0.015). Fewer patients with AF received drug-eluting stents (p = 0.004). AF was associated with a greater than fourfold increase in 30-day mortality (9.9% vs 2.2%, p <0.0001) and readmission rates at 30 days (p = 0.01). Fewer patients with AF were on dual antiplatelet therapy at 30 days (86.3% vs 94.3%, p <0.0001), although 28.1% of patients with AF were on triple therapy (dual antiplatelet therapy plus oral anticoagulation). In conclusion, patients with periprocedural AF represent a very high-risk group. Excess 30-day morbidity and mortality after PCI may be due to the higher incidence of co-morbidities, bleeding complications, and suboptimal antiplatelet therapy.

Usefulness of transient and persistent no reflow to predict adverse clinical outcomes following percutaneous coronary intervention

The no reflow phenomenon is reported to occur in >2% of all percutaneous coronary interventions (PCIs) and portends a poor prognosis. We analyzed data from 5,286 consecutive patients who underwent PCI from the Melbourne Interventional Group (MIG) registry from April 2004 through January 2008 who had 30-day follow-up completed. Patients without no reflow (normal reflow, n = 5,031) were compared to 255 (4.8%) with no reflow (n = 217 for transient no reflow, n = 38 for persistent no reflow). Patients with transient or persistent no reflow were more likely to present with ST-elevation myocardial infarction (MI) or cardiogenic shock (p <0.0001 for the 2 comparisons). They were also more likely to have complex lesions (American College of Cardiology/American Heart Association type B2/C), have lesions within a bypass graft, require an intra-aortic balloon pump, receive glycoprotein IIb/IIIa inhibition, and have a longer mean stent length (p <0.0001 for all comparisons). In-hospital outcomes were significantly worse in those patients with transient or persistent no reflow, with increased death, periprocedural MI, renal impairment, and major adverse cardiac events (p <0.0001 for all comparisons). Similarly, transient and persistent no reflow portended worse 30-day clinical outcomes, with a progressive increase in mortality (normal reflow 1.7% vs transient no reflow 5.5% vs persistent no reflow 13.2%, p <0.0001), MI, target vessel revascularization, and major adverse cardiac events (p <0.0001 for all comparisons) compared to patients with normal flow. In conclusion, transient or persistent no reflow complicates approximately 1 in 20 PCIs and results in stepwise increases in in-hospital and 30-day adverse outcomes.

Clopidogrel discontinuation after acute coronary syndromes: frequency, predictors and associations with death and myocardial infarction--a hospital registry-primary care linked cohort (MINAP-GPRD)

Aims

Adherence to evidence-based treatments and its consequences after acute myocardial infarction (MI) are poorly defined. We examined the extent to which clopidogrel treatment initiated in hospital is continued in primary care; the factors predictive of clopidogrel discontinuation and the hazard of death or recurrent MI.

Methods and results

We linked the Myocardial Ischaemia National Audit Project registry and the General Practice Research Database to examine adherence to clopidogrel in primary care among patients discharged from hospital after MI (2003–2009). Hospital Episode Statistics and national mortality data were linked, documenting all-cause mortality and non-fatal MI. Of the 7543 linked patients, 4650 were prescribed clopidogrel in primary care within 3 months of discharge. The adjusted odds of still being prescribed clopidogrel at 12 months were similar following non-ST-elevation myocardial infarction (NSTEMI) 53% (95% CI, 51–55) and ST-elevation myocardial infarction (STEMI) 54% (95% CI, 52–56), but contrast with statins: NSTEMI 84% (95% CI, 82–85) and STEMI 89% (95% CI, 87–90). Discontinuation within 12 months was more frequent in older patients [>80 vs. 40–49 years, adjusted hazard ratio (HR) 1.50 (95% CI, 1.15–1.94)] and with bleeding events [HR 1.34 (95% CI, 1.03–1.73)]. 18.15 patients per 100 person-years (95% CI, 16.83–19.58) died or experienced non-fatal MI in the first year following discharge. In patients who discontinued clopidogrel within 12 months, the adjusted HR for death or non-fatal MI was 1.45 (95% CI, 1.22–1.73) compared with untreated patients, and 2.62 (95% CI, 2.17–3.17) compared with patients persisting with clopidogrel treatment.

Conclusion

This is the first study to use linked registries to determine persistence of clopidogrel treatment after MI in primary care. It demonstrates that discontinuation is common and associated with adverse outcomes.

Factors associated with clopidogrel use, adherence, and persistence in patients with acute coronary syndromes undergoing percutaneous coronary intervention

OBJECTIVE

Recent guidelines recommend use of aspirin and either clopidogrel or prasugrel for at least 12 months following use of drug-eluting or bare metal stents in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). This study evaluated factors associated with clopidogrel use and adherence in ACS patients following PCI.

RESEARCH DESIGN AND METHODS

The US employer-based MarketScan commercial claims database was used to examine factors associated with clopidogrel use and adherence. Adherence was defined as a medication possession ratio of 80% or higher. Multivariate logistic regression analyses were conducted to identify factors associated with clopidogrel use and adherence and included patient demographics, comorbidities, and prior beta-blocker, statin, and angiotensin converting enzyme inhibitor (BSI) use as factors.

RESULTS

A total of 10,465 patients aged 18-65 years who met inclusion criteria were hospitalized for ACS and underwent PCI between 01/01/2005 and 12/31/2006. Overall, the rate of clopidogrel use was 92.8% for ACS-PCI patients and 66.8% of the clopidogrel users were adherent. Receiving PCI without stenting (Odds Ratio [OR] = 3.28), comorbid hypertension (OR = 1.50), diabetes (OR = 1.49), and atrial fibrillation (OR = 1.91) were associated with decreased filled prescriptions for clopidogrel. Younger age (OR = 0.83) and prior use of clopidogrel (OR = 0.54) or other BSI medications (OR = 0.44) were associated with increased use of clopidogrel (all p values < 0.05). Factors significantly associated with non-adherence of clopidogrel were prior use of clopidogrel (OR = 1.40), prior hospitalization (OR = 1.34), chronic pulmonary disease (OR = 1.31), PCI without stenting (OR = 1.32), diabetes (OR = 1.17), and younger age (OR = 1.29). Prior use of BSI medications (OR = 0.82) increased adherence to clopidogrel.

CONCLUSIONS

Prior use of clopidogrel, comorbid conditions such as diabetes and chronic pulmonary disease, prior hospitalization, PCI without stenting, and younger age had a negative impact on clopidogrel adherence. These findings may assist programs to improve thienopyridine compliance through a better understanding of patients' disease profiles and concomitant medication use.

Impact of concomitant heart failure on outcomes in patients undergoing percutaneous coronary interventions: analysis of the Melbourne Interventional Group registry

AIMS

The presence of heart failure (HF) is an established risk factor for adverse outcomes in patients undergoing percutaneous coronary intervention (PCI). The aim of this study was to determine the prevalence and impact of concomitant HF on major outcomes in contemporary PCI practice.

METHODS AND RESULTS

We analysed 5006 consecutive PCIs (2004-2006) enrolled in the Melbourne Interventional Group registry. Baseline characteristics, in-hospital, 30-day, and 12-month outcomes of patients with a history of HF (n = 189, 3.8%) were compared with patients without HF (n = 4817, 96.2%). Patients with a history of HF were older (mean age 72.9 ± 9.8 vs. 64.3 ± 12 years, P < 0.01) and had higher rates of diabetes (37.0 vs. 23.5%, P < 0.01), renal dysfunction (Cr > 200 μmol/L; 16.5 vs. 3.9%, P < 0.01), multi-vessel disease (79.8 vs. 58.7%, P < 0.01), and presentation with cardiogenic shock (4.8 vs. 2.1%, P = 0.02). At 12 months, patients with HF had higher overall mortality (13.7 vs. 3.5%, P < 0.01) and rates of HF admission (10.4 vs. 2.0%, P < 0.01). Independent predictors of recurrent HF admission included history of HF [odds ratio (OR) 2.2, 95% confidence interval (CI) 1.2-4.2, P < 0.01] and renal dysfunction (OR 2.5, 95% CI 1.4-4.4, P < 0.01). At 12 months, patients with HF had lower rates of statin (73.9 vs. 89.2%, P < 0.01) and beta-blocker use (55.6 vs. 59.0%, P < 0.01). Angiotensin-converting enzyme-inhibitor/angiotensin receptor blocker use was also relatively low in HF patients (79.6%).

CONCLUSION

While the overall incidence of HF in patients undergoing PCI is low, underutilization of HF therapies may contribute to an increased likelihood of subsequent re-admission and increased mortality.

Incidence, correlates, and clinical impact of nuisance bleeding after antiplatelet therapy for patients with drug-eluting stents

BACKGROUND

Nuisance bleeding (NB) after dual antiplatelet therapy (DAPT) is not well characterized despite its potential to impact patient compliance. We therefore aimed to evaluate the incidence, correlates, and clinical impact of NB after DAPT after drug-eluting stent (DES) implantation.

METHODS

Included were 2,948 patients with DES implantation who were discharged on DAPT for 12 months. New bleeding classifications were used: alarming bleeding, internal bleeding, and NB.

RESULTS

After excluding patients with alarming bleeding (9 [0.3%]) and internal bleeding (128 [4.3%]), the 2,811 remaining patients were divided into 2 groups: those with NB (812 [28.9%]) and those without (1,999 [71.1%]). Patients with NB were significantly younger (63.0 +/- 11.4 vs 65.2 +/- 11.6 years, P < .001), were more often white (82.0% vs 69.6%, P < .001), had lower body mass indices (29.2 +/- 6.1 vs 29.8 +/- 6.0 kg/m(2), P = .01), and a lower prevalence of diabetes (25.5% vs 34.8%, P < .001) compared to those without NB. At 1 year, the rate of major adverse cardiac events was higher in the NB group compared to the nonbleeding group (77 [9.4%] vs 134 [6.7%], P = .02). In the NB group, 46 patients (5.7%) stopped 1 or both antiplatelet therapies. Thirty-five (4.3%) discontinued clopidogrel, 16 (2.0%) stopped aspirin, and 5 (0.61%) stopped both as a result of the reported NB. Multivariable analysis detected younger age, lower body mass index, white race, and without diabetes as correlates associated with NB while on clopidogrel therapy.

CONCLUSION

Nuisance bleeding is common in patients on prolonged DAPT post-DES implantation and can impact compliance. Nuisance bleeding appears to have important clinical implications and, if confirmed in prospective trials, should be added to the safety end points assessing new antiplatelet agents.

Effectiveness of two-year clopidogrel + aspirin in abolishing the risk of very late thrombosis after drug-eluting stent implantation (from the TYCOON [two-year ClOpidOgrel need] study)

It remains unclear whether dual antiplatelet therapy >12 months might carry a better prognosis after percutaneous coronary intervention (PCI) with drug-eluting stents (DESs). To address the hypothesis that in the real world the risk of very late thrombosis after PCI with DESs can be decreased by an extended use of clopidogrel, we set up the Two-Year ClOpidOgrel Need (TYCOON) registry and prospectively investigated the impact on very late thrombosis of 12- versus 24-month dual antiplatelet regimens in an unselected population. The registry enrolled 897 consecutive patients who underwent PCI with stenting from January 1, 2003, to December 31, 2004, and had dual antiplatelet therapy. All patients had a 4-year clinical follow-up. In the 447 patients with DES implantation, the dual antiplatelet regimen after PCI was given for 12 months in the 173 patients treated in 2003 (12-month group) and for 24 months in the 274 patients treated in 2004 (24-month group). Comparison between groups did not reveal any significant difference in baseline clinical characteristics, angiographic and procedural features, and major adverse cardiac events. During follow-up, there were 5 cases of stent thrombosis after PCI in the 12-month DES group and 1 case in the 24-month DES group (p = 0.02). Specifically, there were 2 cases of subacute thrombosis (1 in each group), no case of late thrombosis, and 4 cases of very late thrombosis occurring at 13, 15, 17, and 23 months after DES implantation in the 12-month group only. In conclusion, a 2-year dual antiplatelet regimen with aspirin and clopidogrel can prevent the occurrence of very late stent thrombosis after PCI with DESs.

Coronary stent thrombosis in patients with chronic renal insufficiency

Renal insufficiency (RI) is a strong predictor of unfavorable outcomes after percutaneous coronary intervention (PCI). After PCI, stent thrombosis (ST) is a considerable concern. The risk of ST in RI has not been independently evaluated before. The mechanism of ST is frequently related to dual antiplatelet underuse. We reviewed the publications listed on Medline, Scopus, and EBSCO Host research database in the last two decades to identify the risk of ST in patients with RI. There are no enough data on the incidence of ST in RI patients. Platelet reactivity, appropriate period of dual antiplatelet therapy, coronary anatomy, selection of stent, and patient compliance are vital issues that warrant detailed evaluation in RI patients. Moreover, prospective trials and new therapeutic strategies are needed for proper assessment and management of ST in high-risk patients.