Sex differences in the effect of diabetes mellitus on platelet reactivity and coronary thrombosis: From the Assessment of Dual Antiplatelet Therapy with Drug-Eluting Stents (ADAPT-DES) study

Sex differences in antiplatelet therapy: state-of-the art

Antiplatelet therapy is a cornerstone of secondary prevention of cardiovascular diseases (CVDs). However, current guidelines are based on data derived primarily from men, as women are generally underrepresented in trials. Consequently, there are insufficient and inconsistent data on the effect of antiplatelet drugs in women. Sex differences were reported in platelet reactivity, patient management, and clinical outcomes after treatment with aspirin, P2Y₁₂ inhibitor, or dual antiplatelet therapy. To evaluate whether sex-specific antiplatelet therapy is needed, in this review we discuss (i) how sex affects platelet biology and response to antiplatelet agents, (ii) how sex and gender differences translate into clinical challenges and (iii) how the cardiological care in women might be improved. Finally, we highlight the challenges faced in clinical practice regarding the different needs and characteristics of female and male patients with CVD and address issues requiring further investigation.

Gender differences in efficacy and safety of antiplatelet strategies for acute coronary syndromes

INTRODUCTION

Dual antiplatelet therapy (DAPT) represents the cornerstone of secondary prevention in patients presenting with acute coronary syndrome (ACS) and undergoing percutaneous coronary intervention. Despite its undisputed efficacy in reducing thrombotic events, DAPT increases the risk of bleeding, which is associated with higher morbidity and mortality. Novel antiplatelet strategies (i.e. in terms of timing, selection of drugs and their combinations, and modulation strategies) have been tested in randomized trials, suggesting the utility of tailored approaches in selected populations (i.e. patients at high bleeding or ischemic risk). It remains uncertain whether the effect of these strategies is influenced by sex.

AREAS COVERED

This narrative review provides an overview of available evidence surrounding sex differences in the efficacy and safety of antiplatelet strategies for ACS and analyzes the potential reasons behind these findings. Relevant content was searched for in PubMed.

EXPERT OPINION

Significant differences between women and men exist in terms of clinical presentation, pharmacotherapies, interventional management, and prognosis of ACS. However, these observations do not appear to be attributed to different pharmacodynamic effects of antiplatelet therapies between women and men. Unfortunately, a critical issue depends on women being often underrepresented in clinical trials, leading to a substantial lack of sex-specific evidence.

Diabetes Mellitus Is Still a Strong Predictor of Periprocedural Outcomes of Primary Percutaneous Coronary Interventions in Patients Presenting with ST-Segment Elevation Myocardial Infarction (from the ORPKI Polish National Registry)

The impact of diabetes mellitus (DM) on outcomes of patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) was confirmed by several studies. However, it is unclear whether this effect is still present in large groups of unselected patients undergoing up-to-date treatment. Thus, we sought to assess the impact of DM on periprocedural outcomes of primary PCI in STEMI using data from the Polish National Registry of PCI. Data on 150,782 STEMI patients undergoing primary PCI were collected. Of them, 26,360 (17.5%) patients had DM. Patients with DM were higher-risk individuals who experienced longer reperfusion delays and were less likely to have closed infarct-related artery at baseline (TIMI 0 + 1 flow: 73.2% vs. 72.0%; p < 0.0001) and achieve optimal reperfusion after PCI (TIMI 3 flow: 91.8% vs. 88.5%; p < 0.0001). The periprocedural mortality (1.1% vs. 1.9%; p < 0.0001) was higher in patients with DM and DM was identified as an independent predictor of periprocedural death. In conclusion, despite continuous progress in STEMI treatment, DM remains a strong predictor of periprocedural mortality. However, this detrimental effect of DM may be partially explained by the overall higher risk profile of diabetic patients.

Gender differences with short-term vs 12 months dual antiplatelet therapy in patients with acute coronary syndrome treated with the COMBO dual therapy stent: 2-years follow-up results of the REDUCE trial

BACKGROUND

Gender differences in the thrombotic and bleeding risk have been suggested to condition the benefits of antithrombotic therapies in Acute Coronary Syndrome (ACS) patients, and mainly among those undergoing percutaneous coronary interventions with drug eluting stents (DES). The impact of gender on the optimal duration of dual antiplatelet therapy (DAPT) in ACS patients is still unexplored and was, therefore, the aim of the present sub-study.

METHODS

REDUCE was a prospective, multicenter, randomized investigator-initiated study designed to enroll 1500 ACS patients after treatment with the COMBO Dual Stent Therapy, based on a noninferiority design. Patients were randomized in a 1:1 fashion to either 3 or 12 months of DAPT. Primary study endpoint was a composite of all-cause mortality, myocardial infarction, definite/probable stent thrombosis (ST), stroke, target-vessel revascularization (TVR) and bleedings (BARC II, III, V) at 12 months. Secondary endpoints were cardiovascular mortality and the individual components of the primary endpoint within 24 months.

RESULTS

From June 2014 to May 2016 300 women and 1196 men were included in the study. Among them, 43.7% of females and 51.9% of males were assigned to the 3 months DAPT treatment. Baseline characteristics were well matched between the two arms, with the exception of a lower rate of TIMI flow < 3 (p = 0.04), lower systolic blood pressure (p = 0.05) and use of spironolactone (p = 0.006) among women and a more advanced age (p = 0.05) among men receiving a short-term DAPT. At a mean follow-up of 525 (± 198) days, no difference in the primary endpoint was observed according to DAPT duration in both females [6.9% vs 5.9%, HR (95% CI) = 1.19 (0.48-2.9), p = 0.71] and males [8.2% vs 9%, HR (95% CI) = 0.92 (0.63-1.35), p = 0.67; p INT = 0.20]. Results were confirmed after correction for baseline differences [females: adjusted HR (95% CI) = 1.12 (0.45-2.78), p = 0.81; males: adjusted HR (95% CI) = 0.90 (0.61-1.32), p = 0.60]. Comparable rates of survival, thrombotic (MI, stent thrombosis, TVR, stroke) and bleeding events were observed with the two DAPT strategies, with no impact of gender.

CONCLUSIONS

The present study shows that among ACS patients randomized in the REDUCE trial, a 3 months DAPT strategy offers comparable results as compared to a standard 12 months DAPT at 2-years follow-up in both male and female gender.

Differences in coronary artery disease and outcomes of percutaneous coronary intervention with drug-eluting stents in women and men

INTRODUCTION

Despite common perceptions, coronary artery disease (CAD) is not a male-specific condition, and sex-based differences do occur in many aspects, including clinical outcomes after percutaneous coronary intervention (PCI) with stent implantation. New-generation drug-eluting stents (DES) significantly improved post-PCI outcomes. However, no sex-specific guidelines on PCI and the use of DES are available as current evidence was derived from clinical trials enrolling predominantly male patients.

AREAS COVERED

This review aims at exploring sex-based disparities in CAD characteristics and manifestations, and comparing PCI outcomes and the efficacy and safety profiles of DES according to sex. In addition, a critical approach to trials' interpretation with an analysis of sources of bias is provided to inform future research and clinical practice.

EXPERT OPINION

Sex gap in clinical outcomes after PCI with DES implantation is narrowing due to improved performances of new-generation DES. However, scientific research and biomedical engineering are striving to optimize DES profiles and generate new iterations of devices. At the same time, gender initiatives and sex-specific trials are accruing to overcome current issues in the field. Advances in these areas will foster improvements in early and long-term clinical outcomes of both women and men.

Current state-of-the-art antiplatelet and anticoagulation therapy in diabetic patients with coronary artery disease

Diabetes mellitus is a complex disease that leads to long-term damage to various organ systems. Among the numerous cardiovascular disease-related complications, thrombotic events frequently occur in patients with diabetes. Although guidelines exist for treating and preventing most diabetes-related co-morbidities, the evidence on antithrombotic therapy in primary and secondary prevention is limited due to the scarcity of randomized trials dedicated to patients with diabetes mellitus. Most of the available data are derived from studies that only included a small proportion of patients with diabetes. The present review provides an overview of the status of knowledge on antiplatelet and anticoagulation therapy in patients with diabetes, focusing on the risk-benefit balance of these therapies and future treatment strategies.

Gender Differences in Platelet Reactivity in Diabetic Patients Receiving Dual Antiplatelet Therapy

BACKGROUND

Increased comorbidities and a perceived high-bleeding risk often prevent the use of dual antiplatelet therapy (DAPT) in female patients. However, more aggressive antiplatelet treatment would certainly offer additional outcome benefits in coronary artery disease, especially among diabetic patients. The aim of the present study was to evaluate the gender differences in high-residual on treatment platelet reactivity (HRPR) among diabetic patients treated with DAPT.

METHODS

Our population is represented by a consecutive cohort of diabetic patients treated with DAPT (ASA + clopidogrel, ticagrelor or dose-adjusted prasugrel) for an acute coronary syndrome or elective PCI, undergoing platelet reactivity assessment at 30-90 days post-discharge. Aggregation was assessed by multiple-electrode aggregometry and in diabetic patients naïve to antiplatelet therapy, by light transmission aggregometry, surface expression of P-selectin and plasma concentration of Thromboxane B2.

RESULTS

We included 472 patients, 113 (23.9%) women. Female gender was associated with more advanced age, and increased comorbidities. Mean platelet reactivity did not differ according to gender. The rate of HRPR was similar in women as compared to men (for ASA: adjusted OR[95%CI] = 0.59[0.27-1.33], p = 0.21, for ADP-antagonists: adjusted OR[95%CI] = 1.24[0.25-1.80], p = 0.27), however, the benefits of the new ADP-antagonists on platelet reactivity were lower in women than in men (p interaction = 0.01). No impact of gender on platelet reactivity was confirmed among 50 diabetic patients naïve to antiplatelet therapy.

CONCLUSIONS

Among diabetic patients receiving dual antiplatelet therapy gender does not affect platelet reactivity or high-on treatment platelet reactivity. However, the enhanced platelet inhibition provided by the new-ADP antagonists of new-ADP antagonists could be mitigated in women.

Sex differences in the burden of type 2 diabetes and cardiovascular risk across the life course

By 2017 estimates, diabetes mellitus affects 425 million people globally; approximately 90-95% of these have type 2 diabetes. This narrative review highlights two domains of sex differences related to the burden of type 2 diabetes across the life span: sex differences in the prevalence and incidence of type 2 diabetes, and sex differences in the cardiovascular burden conferred by type 2 diabetes. In the presence of type 2 diabetes, the difference in the absolute rates of cardiovascular disease (CVD) between men and women lessens, albeit remaining higher in men. Large-scale observational studies suggest that type 2 diabetes confers 25-50% greater excess risk of incident CVD in women compared with men. Physiological and behavioural mechanisms that may underpin both the observed sex differences in the prevalence of type 2 diabetes and the associated cardiovascular burden are discussed in this review. Gender differences in social behavioural norms and disparities in provider-level treatment patterns are also highlighted, but not described in detail. We conclude by discussing research gaps in this area that are worthy of further investigation.

Impact of Diabetes Mellitus in Women Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents

BACKGROUND

Data examining the impact of diabetes mellitus (DM) on ischemic risk after percutaneous coronary intervention in women are limited as most clinical trial participants are male. We evaluated (1) the impact of DM on ischemic outcomes in women undergoing drug-eluting stent (DES) implantation and (2) whether the outcomes of new- versus early-generation DES vary by DM status.

METHODS AND RESULTS

We pooled patient-level data of 10 448 women undergoing percutaneous coronary intervention with DES from 26 randomized trials. Baseline characteristics and 3-year clinical outcomes were stratified according to DM status (noninsulin-dependent and insulin-dependent) and DES generation. The primary end point was the composite of all-cause death or myocardial infarction. Secondary end points were definite or probable stent thrombosis and target lesion revascularization. Compared with women without DM (n=7154, 68.5%), adjusted risks (adjusted hazard ratios [95% CI]) for death or myocardial infarction among women with noninsulin-dependent DM (n=2241, 21.4%) and insulin-dependent DM (n=1053, 10.1%) were 1.30 (1.11-1.53) and 1.71 (1.41-2.07), respectively ( P_trend<0.001). Similar trends were observed for def/prob stent thrombosis and target lesion revascularization. Compared with early-generation DES, use of newer-generation DES was associated with significant reductions in death or myocardial infarction in the absence of DM whereas differences were nonsignificant in the presence of DM, with similar findings for def/prob stent thrombosis and target lesion revascularization.

CONCLUSIONS

The presence of DM is associated with substantial, graded, and durable risks for ischemic events among women undergoing percutaneous coronary intervention with DES. The safety and efficacy profile of newer-generation DES is preserved among women without DM, while benefits are nonsignificant among women with DM.