Bridging the gap between clinical trials of antiplatelet therapies and applications among elderly patients

PRECISE-DAPT, ARC-HBR, or Simplified Clinical Evaluation for the Prediction of Major Bleeding After Percutaneous Coronary Intervention in older Patients

Older patients have been remarkably underrepresented in bleeding risk cohorts. Thus, the PRECISE-DAPT (Derivation and validation of the predicting bleeding complications in patients undergoing stent implantation and subsequent dual antiplatelet therapy) and Academic Research Consortium for High Bleeding Risk (ARC-HBR) scores are not validated in older adults. Therefore, we sought to evaluate the PRECISE-DAPT and ARC-HBR scores in an exclusively older population and assess the prognostic value of a truly simplified clinical evaluation (SCE), consisting of only 3 binary clinical variables (hemoglobin <11 g/100 ml, previous bleeding, and anticipated use of anticoagulants). This is a retrospective analysis of the prospective single-center older-HCD registry. Consecutive patients aged ≥75 years who underwent percutaneous coronary intervention from 2012 to 2019 were included. The primary end point was postdischarge bleeding at 12 months of follow-up, defined according to the Bleeding Academic Research Consortium 3 or 5 criteria. A total of 693 patients with a mean age of 81 (±4.4) years were included in the study and 60 patients (6.8%) met the primary end point. The PRECISE-DAPT and ARC-HBR scores did not significantly predict postdischarge bleeding in the Cox regression models (hazard ratio 1.65 [0.78 to 3.42] and 1.46 [0.72 to 4.24], respectively), whereas the SCE outperformed both scores (hazard ratio 2.47, 1.34 to 4.49). All 3 scores exhibited a moderate discriminatory potential, as determined by a receiver-operating characteristic curve analysis (areas under the curve 0.601, 0.621, and 0.616, respectively), with no significant differences between them. The SCE showed an Integrated Discrimination Improvement of 0.25, p = 0.02 (SCE vs ARC-HBR) and 0.24, p = 0.01 (SCE vs PRECISE-DAPT), with an Net Reclassification Improvement of 6.54%, p = 0.37 and 7.12%, p = 0.43, respectively. In conclusion, the PRECISE-DAPT score and ARC-HBR criteria showed insufficient predictive value in older adults. A truly SCE consisting of 3 easily accessible variables not only provides equal discriminatory potential but also demonstrates superior predictive value, as determined by Cox regression models. This makes it a highly appealing tool for risk stratification, pending its evaluation in larger prospective studies.

Gender-differences in antithrombotic therapy across the spectrum of ischemic heart disease: Time to tackle the Yentl syndrome?

The incidence and clinical presentation of ischemic heart disease (IHD), as well as thrombotic and bleeding risks, appear to differ between genders. Compared with men, women feature an increased thrombotic risk, probably related to an increased platelet reactivity, higher level of coagulation factors, and sex-associated unique cardiovascular risk factors, such as pregnancy-related (i.e., pre-eclampsia and gestational diabetes), gynecological disorders (i.e., polycystic ovary syndrome, early menopause) and autoimmune or systemic inflammatory diseases. At the same time, women are also at increased risk of bleeding, due to inappropriate dosing of antithrombotic agents, smaller blood vessels, lower body weight and comorbidities, such as diabetes and chronic kidney disease. Pharmacological strategies focused on the personalization of antithrombotic treatment may, therefore, be particularly appealing in women in light of their higher bleeding and ischemic risks. Paradoxically, although women represent a large proportion of cardiovascular patients in our practice, adequate high-quality clinical trial data on women remain scarce and inadequate to guide decision-making processes. As a result, IHD in women tends to be understudied, underdiagnosed and undertreated, a phenomenon known as a "Yentl syndrome." It is, therefore, compelling for the scientific community to embark on dedicated clinical trials to address underrepresentation of women and to acquire evidence-based knowledge in the personalization of antithrombotic therapy in women.

Impact of Anemia on the Risk of Bleeding Following Percutaneous Coronary Interventions in Patients ≥75 Years of Age

Bleeding risk stratification is an unresolved issue in older adults. Anemia may reflect subclinical blood losses that can be exacerbated after percutaneous coronary intervention . We sought to prospectively determine the contribution of anemia to the risk of bleeding in 448 consecutive patients aged 75 or more years, treated by percutaneous coronary interventions without concomitant indication for oral anticoagulation. We evaluated the effect of WHO-defined anemia on the incidence of 1-year nonaccess site-related major bleeding. The prevalence of anemia was 39%, and 13.1% of anemic and 5.2% of nonanemic patients suffered a bleeding event (hazard ratio 2.75, 95% confidence interval 1.37 to 5.54, p = 0.004). Neither PRECISE-DAPT nor CRUSADE scores were superior to hemoglobin for the prediction of bleeding. In conclusion, anemia is a powerful predictor of bleeding with potential utility for simplifying tailoring therapies.

Role of Gender in Dual Antiplatelet Therapy After Acute Coronary Syndrome

PURPOSE OF REVIEW

The effect of gender on use of dual antiplatelet therapy (DAPT) in treatment of acute coronary syndrome (ACS) is not well established. The purpose of this review is to understand gender-based differences in response to DAPT, so that treatment of ACS can be optimized in women to prevent ischemic events while minimizing bleeding risk.

RECENT FINDINGS

There are innate gender differences in platelet reactivity and response. However, it is unknown if this translates into differences in clinical outcomes. In all major studies evaluating the effect of DAPT in ACS, women are underrepresented. Hence, the results from the existing trials cannot be generalizable to women. There is a significant knowledge gap regarding how to balance the bleeding and ischemic risk profile among women with ACS. Currently, there is no recommendation to consider gender as covariate in choosing the type of antiplatelet drug or duration. The existing clinical evidence is limited by under representation of women in DAPT trials. The current literature does not strongly support considering gender in decision making regarding type or duration of DAPT after ACS. Future dedicated trial designs with adequate representation from women and gender specific analysis from large registry data are warranted to enhance our understanding of the interaction of gender with DAPT after ACS.

Improved short and long term survival associated with percutaneous coronary intervention in the elderly patients with acute coronary syndrome

BACKGROUND

Percutaneous coronary intervention (PCI) are increasingly used in daily clinical practice in elderly patients with acute coronary syndrome (ACS) despite limited evidence. The purpose of this study was to assess the impact of PCI on short and long term survivals in a large cohort of elderly patients with ACS from a "real world".

METHODS

We enrolled 491 patients aged ≥70 years admitted to our institution with ACS from 2006 to 2012. Effect of PCI on short and long term survival was evaluated in both overall and a propensity score-matched cohort.

RESULTS

The mean age of the overall cohort is 83 ± 6 years. Among them, 285 were treated with PCI, whereas 206 were not. Patients treated with PCI were younger (82 ± 5 vs. 85 ± 6), more males (67% vs. 46%), with lower heart rate (77 ± 22 vs. 84 ± 21), higher eGFR (58 ± 20 vs. 47 ± 23), and less with heart failure (29% vs. 15%) (all p < 0.001). In both overall and propensity-matched population, improved survival was associated with PCI-treatment at 1 and 3 years (p < 0.001 for all comparisons). Furthermore, by using multivariate Cox proportional-hazards regression model following factors were identified as independent predictors of 3-year all-cause mortality: age (HR 1.08, 95% CI 1.00-1.16), heart rate (HR 1.02, 95% CI 1.01-1.03), eGFR (HR 3.07, 95% CI 1.63-5.77), malignancy (HR 2.03, 95% CI 1.27-4.57), prior CABG (HR 2.033, 95% CI 1.27-4.57), medication with statin (HR 0.40, 95% CI 0.19-0.86) in PCI group, whereas age (HR 1.08, 95% CI 1.03-1.13), heart rate (HR 1.01, 95% CI 1.01-1.02), hypertension (HR 1.87, 95% CI 1.01-3.49) and using of ACEI/ARB (HR 0.46, 95% CI 0.28-0.76) in non-PCI group.

CONCLUSIONS

In elderly ACS patients, PCI-treatment was associated with improved 1 and 3-year survival and PCI-treated patients had different prognostic profile compared to those without PCI treatment.

Cangrelor in Older Patients Undergoing Percutaneous Coronary Intervention: Findings From CHAMPION PHOENIX

BACKGROUND

Older patients treated with percutaneous coronary intervention are at increased risk of periprocedural events.

METHODS AND RESULTS

CHAMPION (cangrelor versus standard therapy to achieve optimal management of platelet inhibition) PHOENIX randomized 11 145 patients to cangrelor or clopidogrel. We sought to determine the outcomes in the prespecified subgroup of patients ≥75 years old (n=2010; 18%). Cangrelor resulted in directionally consistent effects on the primary end point (death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis) in patients ≥75 years old (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.50-1.02) and in those <75 years old (OR, 0.81; 95% CI, 0.67-0.98; P [interaction]=0.55). Age ≥75 years was an independent predictor of GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) moderate/severe bleeding (1.0% versus 0.3%; adjusted OR, 2.94; 95% CI, 1.28-6.77; P=0.01) when compared with patients <75 years old. There was no significant difference in GUSTO moderate/severe bleeding with cangrelor versus clopidogrel (1.1% versus 1.0%; OR, 1.07; 95% CI 0.45-2.53) in patients ≥75 years old or in those <75 years old (0.4% versus 0.2%; OR, 2.24; 95% CI, 1.02-4.93; P [interaction]=0.21). For the net composite end point of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis plus GUSTO moderate/severe bleeding, the OR for cangrelor in those ≥75 years old was 0.75 (6.4% versus 8.3%; 95% CI, 0.54-1.05; P=0.09). The effects were similar in those <75 years old (4.9% versus 5.8%; OR, 0.85; 95% CI, 0.70-1.02; P=0.08; P [interaction]=0.53).

CONCLUSIONS

Patients ≥75 years old have an overall ≈3-fold increased odds of moderate/severe bleeding. Cangrelor, when compared with clopidogrel, provides similar efficacy and in patients ≥75 years old as in those <75 years old but does not increase the risk of major bleeding.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01156571.

Optimizing the Use of Cangrelor in the Real World

Thrombotic events such as myocardial infarction or stent thrombosis are the major cause of adverse outcomes in patients undergoing percutaneous coronary intervention (PCI). While current antiplatelet agents, anticoagulants, and PCI techniques have reduced the risk of thrombotic events in PCI-treated patients, a considerable hazard still remains. Cangrelor is an intravenous P2Y12 receptor antagonist that provides a rapid onset and maximal platelet inhibition, which is quickly reversible. In the large-scale CHAMPION PHOENIX trial, cangrelor was shown to reduce ischemic events significantly, including myocardial infarction and stent thrombosis, without increasing the risk of severe bleeding across the full spectrum of patients undergoing PCI, with substantial benefits in all patient subgroups examined. The pharmacologic profile of cangrelor makes it a valuable addition to the armamentarium of physicians providing care to a broad range of patients with coronary artery disease. Cangrelor is currently approved for reducing thrombotic events in patients undergoing PCI who have not been pretreated with a P2Y12 receptor inhibitor and are not receiving a glycoprotein IIb/IIIa inhibitor. Future studies are needed to determine the role of cangrelor in other clinical settings, such as upstream therapy in ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation acute coronary syndrome (NSTE-ACS), and as a bridge to coronary artery bypass graft (CABG) or other non-cardiac surgeries in patients who require ongoing adenosine diphosphate receptor blockade.

Current status of data on cangrelor

P2Y12 receptor inhibition in addition to aspirin is the cornerstone of treatment in patients with acute coronary syndromes (ACS) and those undergoing percutaneous coronary intervention (PCI). Despite advances in contemporary antithrombotic therapy, periprocedural thrombotic complications such as myocardial infarction and stent thrombosis remain a major concern in patients treated with PCI. Current practice guidelines recommend treatment with a P2Y12 receptor inhibitor as early as possible in patients with ACS. Existing oral P2Y12 receptors inhibitors (clopidogrel, prasugrel, or ticagrelor) have several limitations such as delayed onset and offset of action, interindividual variation, and only oral availability. Cangrelor, an intravenous, fast-onset, direct-acting P2Y12 receptor inhibitor offers potent platelet inhibition that is rapidly reversible. In large randomized trials, cangrelor has shown substantial reduction in ischemic events with no increase in severe bleeding compared with clopidogrel among patients undergoing PCI. Cangrelor is approved as an adjunct to PCI to reduce the risk of periprocedural MI, repeat coronary revascularization, and stent thrombosis in patients who have not been pretreated with a P2Y12 receptor inhibitor and are not receiving a glycoprotein IIb/IIIa inhibitor. This review aims at providing a comprehensive analysis of the current evidence pertaining to the role of cangrelor in contemporary practice.

Outcomes in Traumatic Brain Injury for Patients Presenting on Antiplatelet Therapy

An increasing number of patients are presenting to trauma units with head injuries on antiplatelet therapy (APT). The influence of APTon these patients is poorly defined. This study examines the outcomes of patients on APT presenting to the hospital with blunt head trauma (BHT). Registries of two Level I trauma centers were reviewed for patients older than 40 years of age from January 2008 to December 2011 with BHT. Patients on APT were compared with control subjects. Primary outcome measures were in-hospital mortality, intracranial hemorrhage (ICH), and need for neurosurgical intervention (NI). Hospital length of stay (LOS) was a secondary outcome measure. Multivariate analysis was used and adjusted models included antiplatelet status, age, Injury Severity Score (ISS), and Glasgow coma scale (GCS). Patients meeting inclusion criteria and having complete data (n = 1547) were included in the analysis; 422 (27%) patients were taking APT. Rates of ICH, NI, and in-hospital mortality of patients with BHT in our study were 45.4, 3.1, and 5.8 per cent, respectively. Controlling for age, ISS, and GCS, there was no significant difference in ICH (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.61 to 1.16), NI (OR, 1.26; 95% CI, 0.60 to 2.67), or mortality (OR, 1.79; 95% CI, 0.89 to 3.59) associated with APT. Subgroup analysis revealed that patients with ISS 20 or greater on APT had increased in-hospital mortality (OR, 2.34; 95% CI, 1.03 to 5.31). LOS greater than 14 days was more likely in the APT group than those in the non-APT group (OR, 1.85; 95% CI, 1.09 to 3.12). The effects of antiplatelet therapy in patients with BHT aged 40 years and older showed no difference in ICH, NI, and in-hospital mortality.

Platelet function monitoring in elderly patients on prasugrel after stenting for an acute coronary syndrome: design of the randomized antarctic study

BACKGROUND

Elderly patients are at high risk for both ischemic and bleeding events. Platelet monitoring offers the opportunity to individualized antiplatelet therapy to optimize the therapeutic risk/benefit ratio.

STUDY DESIGN

The ANTARCTIC study is designed to demonstrate the superiority of a strategy of platelet function monitoring with dose and drug adjustment in patients initially on prasugrel 5 mg as compared with a more conventional strategy using prasugrel 5 mg without monitoring and without adjustment (Conventional Treatment Arm) to reduce the primary end point evaluated 1 year after stent percutaneous coronary intervention in elderly patients presenting with an acute coronary syndrome (ACS). ANTARCTIC is a multicenter, prospective, open-label study with 2 parallel arms. A total of 852 elderly patients (≥ 75 years) undergoing stent percutaneous coronary intervention for ACS are to be enrolled. The primary end point is the time to first occurrence of cardiovascular death, myocardial infarction, stroke, definite stent thrombosis, urgent revascularization, and bleeding complications (Bleeding Academic Research Consortium definition 2, 3, or 5). Platelet function analyses will be performed 14 days after randomization and repeated 14 days later in patients who require a change in treatment.

CONCLUSION

ANTARCTIC is a nationwide, prospective, open-label study testing a strategy of platelet function monitoring with dose and drug adjustment to reduce ischemic and bleeding complications in elderly ACS patients undergoing coronary stenting.

Management and decision-making process leading to coronary angiography and revascularization in octogenarians with coronary artery disease: Insights from a large single-center registry

AIMS

Cardiovascular diseases remain the most common cause of death in older adults. Guidelines state that advanced age alone should not limit the use of invasive therapy. However, coronary angiograms and subsequent revascularization are often not carried out in octogenarians. The benefit/risk balance of an invasive strategy and the decision-making process are not clearly defined. The aim of the present study was to assess the decision-making process, and the in-hospital and long-term mortality based on the clinical presentation, the diagnostic approach (coronary angiogram or conservative) and the therapeutic management (revascularization or not).

METHODS

The present study was a single-center retrospective analysis.

RESULTS

A total of 522 patients aged ≥80 years, with a diagnosis of coronary disease were included from 2003 to 2009. The mean age was 82 ± 2.6 years. A total of 195 of 522 (37%) presented with a ST segment elevation myocardial infarction (STEMI). A coronary angiogram was carried out in 316 patients (60.5%) and 71% were treated by percutaneous coronary revascularization. A total of 39.5% were considered ineligible for a coronary angiogram due to cardiological reasons or comorbidities. Excluding cardiogenic shock, overall in-hospital mortality was 4.9%. Clinical presentation strongly influenced both in-hospital and 6-month mortality rates (cardiogenic shock 20% and 28.7%, stable angina 1% and 4.1%, respectively, P < 0.001). Long-term mortality was reduced in the coronary angiography arm compared with the conservative group (14.3% vs 20.9%, P = 0.04) whether or not revascularization was carried out.

CONCLUSION

In the present study, in octogenarians, long-term mortality was lower in the group of patients who underwent a coronary angiogram, regardless of revascularization. The selection process for coronary angiography and angioplasty was mostly influenced by the existence of age-associated comorbidities. Risk prediction models are required to reduce age-dependent biases.

Platelet biology and response to antiplatelet therapy in women: implications for the development and use of antiplatelet pharmacotherapies for cardiovascular disease

Women are underrepresented in cardiovascular studies, even as their preponderance in the aging population steadily increases. Although concerns have been raised about the differential benefit of antiplatelet medications for women, the propensity for increased bleeding among women has also been recognized. A better understanding of the factors contributing to the observed sex-related differences in platelet biology is warranted. These factors include differences in the frequency and expression of genetic polymorphisms affecting platelet responsiveness to agonists (with and without antiplatelet therapies), which might be obtained through population-based studies and in large controlled clinical trials; inflammatory marker levels and their influence on atherothrombotic risk, and the role of specific hormones in mediating platelet activation and function. Knowledge gained about these mechanistic factors might inform the development of sex-specific antithrombotic treatment regimens that confer optimized safety and efficacy.

Ticagrelor: a novel oral antiplatelet agent

OBJECTIVE

To review the pharmacology, clinical efficacy, and tolerability of ticagrelor and to discuss implications for use in the elderly.

DATA SOURCE

A literature search was conducted in MEDLINE from 1966 to July 2010 using the MESH terms and key words AZD6140, ticagrelor, P2Y12 receptor antagonist. The search was limited to studies in English language with human subjects.

STUDY SELECTION AND DATA EXTRACTION

Randomized controlled clinical trials were reviewed. References that were deemed relevant to pharmacodynamic/pharmacokinetic studies of P2Y₁₂ antagonists and their historical background were also included.

DATA SYNTHESIS

Ticagrelor is the first reversible oral P2Y₁₂ antagonist currently undergoing Food and Drug Administration review for approval. The advantages of ticagrelor over clopidogrel are a more rapid onset of action, offset, and reversibility at the platelet P2Y₁₂ receptor site. In the Study of Platelet Inhibition and Patient Outcomes trial, ticagrelor reduced the incidence of death as a result of cardiovascular causes, with no increase in major bleeding or bleeding related to coronary artery bypass graft (CABG) compared with clopidogrel. Subgroup analyses suggested that elderly patients may benefit more from ticagrelor than from clopidogrel. However, the increase in non-CABG-related bleeding and unique adverse events may limit ticagrelor's use in the elderly.

CONCLUSION

The use of ticagrelor in the elderly should be determined on a case-by-case basis. More studies need to be conducted prior to establishing a role in therapy for the elderly.