Impact of obesity and the metabolic syndrome on response to clopidogrel or prasugrel and bleeding risk in patients treated after coronary stenting

Impact of body mass on P2Y12-inhibitor de-escalation in acute coronary syndromes-a substudy of the TROPICAL-ACS trial

AIMS

Clinical guidelines recommend de-escalation antiplatelet strategies to reduce bleeding risk in acute coronary syndrome (ACS) patients, albeit with a weak recommendation. This substudy of the TROPICAL-ACS trial aimed to determine the impact of body mass on the efficacy of a platelet function testing-guided de-escalation regimen in ACS patients after percutaneous coronary intervention.

METHODS AND RESULTS

Patients were randomized to prasugrel (control group) or a platelet function testing-guided regimen with clopidogrel or prasugrel defined after 1-week clopidogrel. The primary endpoint was the net clinical benefit [cardiovascular death, myocardial infarction, stroke, or Bleeding Academic Research Consortium (BARC) 2-5 bleeding] for 12 months. Overweight was defined as a body mass index >25 kg/m2.Patients without overweight showed a significant net clinical benefit from the de-escalation strategy, while in overweight cases de-escalation was comparable to prasugrel treatment [hazard ratio (HR): 0.52; 95% confidence interval (CI): 0.31-0.88; P = 0.013 and HR: 0.95; 95% CI: 0.69-1.31, P = 0.717, P-non-inferiority = 0.03, respectively, P-interaction = 0.053]. The benefit of de-escalation in terms of the risk of bleeding or of the ischaemic events did not reach statistical significance. Bleeding events with de-escalation were less frequent in non-overweight patients but comparable in overweight patients (HR: 0.55; 95% CI: 0.30-1.03; P = 0.057 and HR: 0.95; 95% CI: 0.64-1.41, respectively, P-interaction = 0.147). Non-overweight patients had lower ischaemic event rates with de-escalation, while overweight cases had slightly less (HR: 0.47; 95% CI: 0.18-1.25; P = 0.128 and HR: 0.89; 95% CI: 0.53-1.50, respectively, P-interaction = 0.261).

CONCLUSION

The strategy of guided dual antiplatelet therapy de-escalation was associated with a significant net clinical benefit in non-overweight patients, while the two strategies were equivalent in overweight patients.

Being Overweight or Obese Is Associated with an Increased Platelet Reactivity Despite Dual Antiplatelet Therapy with Aspirin and Clopidogrel

PURPOSE

Obese patients exhibit an overall increased platelet reactivity and a reduced sensitivity to antiplatelet therapy. The aim of this study is to evaluate the platelet reactivity measured by impedance aggregometry in overweight and obese patients and chronic coronary syndrome (CCS) that were treated with dual antiplatelet therapy (DAPT).

METHODS

Platelet aggregation was assessed by impedance aggregometry in patients with CCS receiving DAPT (aspirin plus clopidogrel). We compared the platelet reactivity in patients with a normal weight versus overweight or obese patients. Furthermore, the correlation between the body mass index (BMI) and adenosine diphosphate- (ADP-) or thrombin receptor-activating peptide- (TRAP-) dependent platelet aggregation was analyzed.

RESULTS

64 patients were included in the study of which 35.9% were patients with normal weight. A higher ADP- and TRAP-dependent platelet reactivity was observed in overweight and obese patients (ADP: median 27 units (U) [IQR 13-39.5] vs. 7 U [6-15], p < 0.001 and TRAP: 97 U [73-118.5] vs. 85 U [36-103], p = 0.035). Significant positive correlations were observed between agonist-induced platelet reactivity and BMI.

CONCLUSION

Despite the use of DAPT, a higher platelet reactivity was found in overweight and obese patients with CCS. If these patients will benefit from treatment with more potent platelet inhibitors, it needs to be evaluated in future clinical trials.

Dual Antiplatelet Therapy with 3rd Generation P2Y12 Inhibitors in STEMI Patients: Impact of Body Mass Index on Loading Dose-Response

PURPOSE

This study aims to assess the association between body mass index (BMI) and platelet reactivity in STEMI patients treated with oral 3rd generation P2Y12 inhibitors.

METHODS

Overall, 429 STEMI patients were enrolled in this study. Patients were divided into two groups according to BMI (BMI < 25 vs ≥ 25 kg/m2). A propensity score matching (1:1) was performed to balance potential confounders in patient baseline characteristics. Platelet reactivity was assessed by VerifyNow at baseline and after 3rd generation P2Y12 inhibitor (ticagrelor or prasugrel) loading dose (LD). Blood samples were obtained at baseline (T0), 1 h (T1), 2 h (T2), 4-6 h (T3), and 8-12 h (T4) after the LD. High on-treatment platelet reactivity (HTPR) was defined as a platelet reactivity unit value ≥ 208 units.

RESULTS

After propensity score matching, patients with BMI ≥ 25 had similar values of baseline platelet reactivity, while they had higher level of platelet reactivity at 1 and 2 h after the LD and higher rate of HRPT. Furthermore, multivariate analysis demonstrated that BMI ≥ 25 was an independent predictor of HTPR at 2 h (OR 2.01, p = .009). Conversely, starting from 4 h after the LD, platelet reactivity values and HRPT rates were comparable among the two study groups.

CONCLUSIONS

A BMI ≥ 25 kg/m2 is associated with delayed pharmacodynamic response to oral 3rd generation P2Y12 inhibitor LD, and it is a strong predictor of HTPR in STEMI patients treated by dual antiplatelet therapy with ticagrelor or prasugrel.

Variability of response on prophylactic prasugrel for endovascular treatment of intracranial aneurysms: Clinical implications

BACKGROUND AND PURPOSE

Prophylactic prasugrel for endovascular treatment of intracranial aneurysms has been introduced and increased, but HTPR (high on-treatment platelet reactivity) or LTPR (low on-treatment platelet reactivity) of prasugrel is not uncommon in clinical circumstances. To investigate the predisposing factors of HTPR and LTPR on prasugrel premedication in the neurointerventional field and to determine its clinical implications.

MATERIALS AND METHODS

Between February 2016 and December 2020, 191 patients treated with coil embolization using prophylactic prasugrel in 234 intracranial aneurysms were the final candidates for this study. Patient and aneurysm characteristics, clinical status, and laboratory study values were carefully reviewed retrospectively. We performed risk factor analyses for HTPR and LTPR on prasugrel.

RESULTS

Ultimately, 20 patients (10.5%) had HTPR, and 74 patients (38.7%) were categorized as having LTPR. In multivariable analyses, the factors related to HTPR were BMI (adjusted OR 1.21, 95% CI 1.04-1.41, p = 0.01), history of antithrombotics (adjusted OR 3.79, 95% CI 1.39-10.34, p = 0.01), and hematocrit (adjusted OR 0.91, 95% CI 0.84-0.99, p = 0.03). Low BMI was the only risk factor for LTPR (adjusted OR 0.84, 95% CI 0.76-0.94, p = 0.001).

CONCLUSION

In the neurointerventional field, high BMI and prior use of antithrombotic agents were related to HTPR, and low BMI was associated with LTPR on prophylactic prasugrel. High hematocrit levels decreased the risk of HTPR. When preparing endovascular treatment for intracranial aneurysms, attention to patients with these clinical features is required to address the possibility of ischemic or bleeding complications.

Challenges in Cardiovascular Evaluation and Management of Obese Patients: JACC State-of-the-Art Review

Many unique clinical challenges accompany the diagnosis and treatment of cardiovascular disease (CVD) in people living with overweight/obesity. Similarly, physicians encounter numerous complicating factors when managing obesity among people with CVD. Diagnostic accuracy in CVD medicine can be hampered by the presence of obesity, and pharmacological treatments or cardiac procedures require careful adjustment to optimize efficacy. The obesity paradox concept remains a source of confusion within the clinical community that may cause important risk factors to go unaddressed, and body mass index is a misleading measure that cannot account for body composition (eg, lean mass). Lifestyle modifications that support weight loss require long-term commitment, but cardiac rehabilitation programs represent a potential opportunity for structured interventions, and bariatric surgery may reduce CVD risk factors in obesity and CVD. This review examines the key issues and considerations for physicians involved in the management of concurrent obesity and CVD.

Visceral adipose tissue quantity and dysfunction and the occurrence of major bleeding in patients with established cardiovascular disease

OBJECTIVES

To determine the association between both visceral fat quantity and adipose tissue dysfunction, and major bleeding in patients with established cardiovascular disease.

METHODS

Patients from the Second Manifestations of ARTerial disease study with established cardiovascular disease were included. Visceral fat was measured using ultrasound and adipose tissue dysfunction was depicted using metabolic syndrome criteria (revised National Cholesterol Education Program). Cox regression models were fitted to study the relation with major bleeding defined as Bleeding Academic Research Consortium (BARC) type 3 or 5, or International Society on Thrombosis and Haemostasis (ISTH) major bleeding. Sensitivity analyses were performed using C-reactive protein levels to reflect adipose tissue dysfunction.

RESULTS

In 6927 patients during a median follow up of 9.2 years, a total of 237 BARC type 3 or 5 bleedings and 224 ISTH major bleedings were observed. Visceral fat quantity was not related to major bleeding (HR 1.01, 95%CI 0.88-1.16 for BARC type 3 or 5 bleeding and HR 1.00, 95%CI 0.87-1.15 for ISTH major bleeding), nor was metabolic syndrome (HR 0.97, 95%CI 0.75-1.26 for BARC type 3 or 5 bleeding and HR 0.98, 95%CI 0.75-1.28 for ISTH major bleeding). Sensitivity analyses using C-reactive protein levels showed similar results. No effect modification was observed by sex, antithrombotic therapy, presence of metabolic syndrome or diabetes.

CONCLUSION

In patients with cardiovascular disease, no association was found between visceral fat quantity measured with ultrasound or measures of adipose tissue dysfunction and the risk of major bleeding, irrespective of antithrombotic agent use.

Resistance on the Latest Oral and Intravenous P2Y12 ADP Receptor Blockers in Patients with Acute Coronary Syndromes: Fact or Myth?

Novel P2Y12 ADP receptor blockers (ADPRB) should be preferred in dual-antiplatelet therapy in patients with acute coronary syndrome. Nevertheless, there are still patients who do not respond optimally to novel ADP receptor blocker therapy, and this nonoptimal response (so-called "high on-treatment platelet reactivity" or "resistance") could be connected with increased risk of adverse ischemic events, such as myocardial re-infarction, target lesion failure and stent thrombosis. In addition, several risk factors have been proposed as factors associated with the phenomenon of inadequate response on novel ADPRB. These include obesity, multivessel coronary artery disease, high pre-treatment platelet reactivity and impaired metabolic status for prasugrel, as well as elderly, concomitant therapy with beta-blockers, morphine and platelet count for ticagrelor. There is no literature report describing nonoptimal therapeutic response on cangrelor, and cangrelor therapy seems to be a possible approach for overcoming HTPR on prasugrel and ticagrelor. However, the optimal therapeutic management of "resistance" on novel ADPRB is not clear and this issue requires further research. This narrative review article discusses the phenomenon of high on-treatment platelet reactivity on novel ADPRB, its importance in clinical practice and approaches for its therapeutic overcoming.

Body mass index and efficacy and safety of ticagrelor versus prasugrel in patients with acute coronary syndromes

INTRODUCTION AND OBJECTIVES

The efficacy and safety of ticagrelor vs prasugrel in patients with acute coronary syndromes (ACS) according to body mass index (BMI) remain unstudied. We assessed the efficacy and safety of ticagrelor vs prasugrel in patients with ACS according to BMI.

METHODS

Patients (n=3987) were grouped into 3 categories: normal weight (BMI <25kg/m²; n=1084), overweight (BMI ≥ 25 to <30kg/m²; n=1890), and obesity (BMI ≥ 30kg/m²; n=1013). The primary efficacy endpoint was the 1 year incidence of all-cause death, myocardial infarction, or stroke. The secondary safety endpoint was the 1 year incidence of Bleeding Academic Research Consortium type 3 to 5 bleeding.

RESULTS

The primary endpoint occurred in 63 patients assigned to ticagrelor and 39 patients assigned to prasugrel in the normal weight group (11.7% vs 7.5%; HR, 1.62; 95%CI, 1.09-2.42; P=.018), 78 patients assigned to ticagrelor and 58 patients assigned to prasugrel in the overweight group (8.3% vs 6.2%; HR, 1.36; 95%CI, 0.97-1.91; P=.076), and 43 patients assigned to ticagrelor and 37 patients assigned to prasugrel in the obesity group (8.6% vs 7.3%; HR, 1.18; 95%CI, 0.76-1.84; P=.451). The 1-year incidence of bleeding events did not differ between ticagrelor and prasugrel in patients with normal weight (6.5% vs 6.6%; P=.990), overweight (5.6% vs 5.0%; P=.566) or obesity (4.4% vs 2.8%; P=.219). There was no significant treatment arm-by-BMI interaction regarding the primary endpoint (P_int=.578) or secondary endpoint (P_int=.596).

CONCLUSIONS

In patients with ACS, BMI did not significantly impact the treatment effect of ticagrelor vs prasugrel in terms of efficacy or safety.

CLINICAL TRIAL REGISTRATION

NCT01944800.

Prasugrel switching from clopidogrel after percutaneous coronary intervention for acute coronary syndrome in Taiwanese patients: an analysis of safety and efficacy

The recommended maintenance dose of prasugrel for East Asian populations (i.e., Japanese and Taiwanese) is 3.75 mg as part of dual antiplatelet therapy (DAPT) for the prevention of recurrent ischemia and stent thrombosis in acute coronary syndrome (ACS). This modified dosage regimen has been established in studies conducted in Japan; however, the efficacy and safety of switching from clopidogrel to prasugrel DAPT among Taiwanese patients remain to be explored. In this phase IV, multicenter, single-arm, open-label study, we evaluated the 4-week pharmacodynamic response, and the 48-week safety outcomes of prasugrel 3.75 mg after a switch from clopidogrel in Taiwanese ACS patients. A total of 203 prasugrel-naïve ACS patients (over 90% male) who had received post-PCI clopidogrel DAPT for at least 2 weeks were enrolled from ten medical centers in Taiwan and subsequently switched to prasugrel 3.75 mg DAPT. Four weeks after the switch, P2Y12 reaction unit (PRU) values were significantly decreased in the total cohort (mean - 18.2 ± 48.1; 95% confidence interval - 24.9 to - 11.5, p < 0.001), and there was an overall consistent antiplatelet response in the treated subjects. The proportion of patients with high on-treatment platelet reactivity (HPR; PRU > 208) dropped from 23.5 to 10% (p < 0.001). Female sex was associated with a greater PRU reduction with prasugrel, whereas HPR at baseline, age ≥ 65 years, and body mass index ≥ 25 best predicted HPR at Week 4. Throughout the 48-week treatment with prasugrel, the incidences of MACE (1.0%) and TIMI major bleeding (2.0%) were rather low, accompanying an acceptable safety profile of TIMI minor (6.4%) and non-major, non-minor clinically relevant bleeding (3.0%). Overall, switching to the maintenance dose of prasugrel (3.75 mg) was observed to be effective and well tolerated among post-PCI ACS patients in Taiwan. Clinical Trial Registration Number: NCT03672097.

Effect of Platelet Inhibition by Cangrelor Among Obese Patients Undergoing Coronary Stenting: Insights From CHAMPION

BACKGROUND

In randomized trials, cangrelor reduced periprocedural ischemic events related to percutaneous coronary intervention without increasing GUSTO severe bleeding. However, some antiplatelet agents have shown a differential treatment effect by body mass index (BMI).

METHODS

Patients from the 3 CHAMPION trials (Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition) who were randomized to cangrelor versus clopidogrel during percutaneous coronary intervention were stratified by BMI. The primary efficacy end point was a composite of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis within 48 hours. The principal safety outcome was GUSTO moderate or severe bleeding at 48 hours, although more sensitive bleeding measures such as Thrombolysis in Myocardial Infarction major bleeding were also assessed. We examined obese patients (defined as BMI≥30) versus nonobese patients.

RESULTS

There were 24 893 patients, with 8979 (36.1%) having BMI of ≥30. There was no significant difference in the primary efficacy end point among obese versus nonobese patients (4.3% versus 4.2%; rate ratio, 1.01 [95% CI, 0.89-1.15]; P=0.82). There was a consistent benefit in the primary efficacy end point in patients who received cangrelor versus placebo who were obese (3.9% versus 4.7%, rate ratio, 0.83 [95% CI, 0.68-1.02]; P=0.07) and not obese (3.8% versus 4.7%; rate ratio, 0.81 [95% CI, 0.69-0.94]; P=0.0053); interaction P=0.77. There was no difference in GUSTO moderate or severe bleeding among patients who received cangrelor versus placebo who were obese (0.6% versus 0.6%; rate ratio, 0.99 [95% CI, 0.58-1.67]; P=0.96).

CONCLUSIONS

Cangrelor at the time of percutaneous coronary intervention is effective and safe in obese and nonobese patients. There was no difference in short-term efficacy between obese and nonobese patients. Periprocedural cangrelor is an effective and safe antiplatelet agent, irrespective of BMI.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01156571, NCT00385138, NCT00305162.

A Combination of Aspirin and Clopidogrel Predict More Favorable Dynamics of Platelet Reactivity versus Clopidogrel Alone in the Acute Phase of Minor Stroke

BACKGROUND

The combined use of clopidogrel and aspirin is recommended for the short-term (21 days) therapy of minor stroke or transient ischemic attack. Previous studies have demonstrated its efficacy and superiority over treatment with a single antiplatelet agent. However, there is insufficient support for the advantages of such therapy based on platelet function testing. We aimed to compare the effect of the concomitant use of clopidogrel and aspirin versus clopidogrel alone on the dynamics of platelet reactivity over time to determine the appropriate antiplatelet treatment strategy for minor strokes.

METHODS

We enrolled 74 ischemic stroke subjects, including 38 minor strokes. Platelet reactivity was assessed by impedance aggregometry (Multiplate Analyzer) 48 and 96 h after a first 75 mg dose of clopidogrel, using the acetylsalicylic acid platelet inhibition (ASPI) test and the adenosine diphosphate (ADP) test. Dual antiplatelet therapy was strictly reserved only to minor strokes, as the other strokes received clopidogrel alone in the secondary prevention. The dynamics of platelet reactivity refer to the difference between two assessments, and a decrease in values over time was considered favorable.

RESULTS

The incidence of clopidogrel non-responsiveness was 64.8%, and this was similar in the group of minor strokes and the group of more disabling strokes. We indicated diabetes mellitus as an independent predictor of high on-clopidogrel platelet reactivity (Odds ratio OR 5.69 95% Confidence Interval CI 1.13-41.26, p = 0.0386). Among minor strokes treated with dual antiplatelet therapy, in relation to clopidogrel, we reported a trend toward more favorable dynamics of platelet reactivity over time compared to the group using clopidogrel alone (p = 0.0652 vs. p = 0.3384, respectively). We identified five predictors (sex, female; small-vessel disease; no diabetes; no hyperlipidemia; and no alcohol abuse) related to a significant decrease in platelet reactivity over time with respect to clopidogrel. No significant dynamics of platelet reactivity when using aspirin were found.

CONCLUSIONS

Our findings, based on the favorable dynamics of platelet reactivity over time in relation to clopidogrel, confirm the usefulness of dual antiplatelet therapy in minor strokes and support the continuation of the secondary prevention with clopidogrel alone rather than aspirin, particularly among identified beneficiaries of such a strategy.

Obesity and Cardiovascular Disease: A Scientific Statement From the American Heart Association

The global obesity epidemic is well established, with increases in obesity prevalence for most countries since the 1980s. Obesity contributes directly to incident cardiovascular risk factors, including dyslipidemia, type 2 diabetes, hypertension, and sleep disorders. Obesity also leads to the development of cardiovascular disease and cardiovascular disease mortality independently of other cardiovascular risk factors. More recent data highlight abdominal obesity, as determined by waist circumference, as a cardiovascular disease risk marker that is independent of body mass index. There have also been significant advances in imaging modalities for characterizing body composition, including visceral adiposity. Studies that quantify fat depots, including ectopic fat, support excess visceral adiposity as an independent indicator of poor cardiovascular outcomes. Lifestyle modification and subsequent weight loss improve both metabolic syndrome and associated systemic inflammation and endothelial dysfunction. However, clinical trials of medical weight loss have not demonstrated a reduction in coronary artery disease rates. In contrast, prospective studies comparing patients undergoing bariatric surgery with nonsurgical patients with obesity have shown reduced coronary artery disease risk with surgery. In this statement, we summarize the impact of obesity on the diagnosis, clinical management, and outcomes of atherosclerotic cardiovascular disease, heart failure, and arrhythmias, especially sudden cardiac death and atrial fibrillation. In particular, we examine the influence of obesity on noninvasive and invasive diagnostic procedures for coronary artery disease. Moreover, we review the impact of obesity on cardiac function and outcomes related to heart failure with reduced and preserved ejection fraction. Finally, we describe the effects of lifestyle and surgical weight loss interventions on outcomes related to coronary artery disease, heart failure, and atrial fibrillation.

Multifactorial Background for a Low Biological Response to Antiplatelet Agents Used in Stroke Prevention

Effective platelet inhibition is the main goal of the antiplatelet therapy recommended as a standard treatment in the secondary prevention of non-embolic ischemic stroke. Acetylsalicylic acid (aspirin) and clopidogrel are commonly used for this purpose worldwide. A low biological response to antiplatelet agents is a phenomenon that significantly reduces the therapeutic and protective properties of the therapy. The mechanisms leading to high on-treatment platelet reactivity are still unclear and remain multifactorial. The aim of the current review is to establish the background of resistance to antiplatelet agents commonly used in the secondary prevention of ischemic stroke and to explain the possible mechanisms. The most important factors influencing the incidence of a low biological response were demonstrated. The similarities and the differences in resistance to both drugs are emphasized, which may facilitate the selection of the appropriate antiplatelet agent in relation to specific clinical conditions and comorbidities. Despite the lack of indications for the routine assessment of platelet reactivity in stroke subjects, this should be performed in selected patients from the high-risk group. Increasing the detectability of low antiaggregant responders, in light of its negative impact on the prognosis and clinical outcomes, can contribute to a more individualized approach and modification of the antiplatelet therapy to maximize the therapeutic effect in the secondary prevention of stroke.

Impact of body mass index on clinical outcome among elderly patients with acute coronary syndrome treated with percutaneous coronary intervention: Insights from the ELDERLY ACS 2 trial

BACKGROUND AND AIM

Elderly patients are at increased risk of hemorrhagic and thrombotic complications after an acute coronary syndrome (ACS). Frailty, comorbidities and low body weight have emerged as conditioning the prognostic impact of dual antiplatelet therapy (DAPT). The aim of the present study was to investigate the prognostic impact of body mass index (BMI) on clinical outcome among patients included in the Elderly-ACS 2 trial, a randomized, open-label, blinded endpoint study comparing low-dose (5 mg) prasugrel vs clopidogrel among elderly patients with ACS.

METHODS AND RESULTS

Our population is represented by 1408 patients enrolled in the Elderly-ACS 2 trial. BMI was calculated at admission. The primary endpoint of this analysis was cardiovascular (CV) mortality. Secondary endpoints were all-cause death, recurrent MI, Bleeding Academic Research Consortium (BARC) type 2 or 3 bleeding, and re-hospitalization for cardiovascular reasons or stent thrombosis within 12 months after index admission. Patients were grouped according to median values of BMI (<or ≥ 25.7 kg/m2). BMI was associated with hypertension, diabetes, hypercholesterolemia, estimated glomerular filtration rate and hemoglobin (p < 0.001), and inversely with age (p = 0.005). Overweight patients displayed larger use of diuretics at admission (p = 0.03), aspirin pre-randomization (p = 0.01) and radial access (p = 0.04). At a median follow-up of 367 [337-378] days, BMI did not affect CV mortality in the overall population 4% vs 3.8%; adjusted HR [95%CI] = 2.3 [0.8-6.5], p = 0.12. Similar findings were observed for our secondary efficacy and safety endpoints. Results did not change when considering separately higher risk subsets of patients, (female gender, diabetics, ST-segment elevation myocardial infarction or the type of DAPT treatment allocation), with no significant interaction between these population characteristics and BMI.

CONCLUSIONS

Among elderly patients with ACS, BMI did not condition the survival or the risk of major cardiovascular and bleeding complications. The results were consistent across several patient risk categories.

Clopidogrel Resistance in a Murine Model of Diet-Induced Obesity Is Mediated by the Interleukin-1 Receptor and Overcome With DT-678

OBJECTIVE

Clopidogrel is a commonly used P2Y₁₂ inhibitor to treat and prevent arterial thrombotic events. Clopidogrel is a prodrug that requires bioactivation by CYP (cytochrome P450) enzymes to exert antiplatelet activity. Diabetes mellitus is associated with an increased risk of ischemic events, and impaired ability to generate the active metabolite (AM) from clopidogrel. The objective of this study is to identify the mechanism of clopidogrel resistance in a murine model of diet-induced obesity (DIO). Approach and Results: C57BL/6J mice and IL-1R^-/- mice were given high-fat diet for 10 weeks to generate a murine model of diet-induced obesity. Platelet aggregation and carotid arterial thrombosis were assessed in response to clopidogrel treatment. Wild-type DIO mice exhibited resistance to antiplatelet and antithrombotic effects of clopidogrel that was associated with reduced hepatic expression of CYP genes and reduced generation of the AM. IL (Interleukin)-1 receptor-deficient DIO (IL1R^-/- DIO) mice showed no resistance to clopidogrel. Lack of resistance was accompanied by increased exposure of the clopidogrel AM. This resistance was also absent when wild-type DIO mice were treated with the conjugate of the clopidogrel AM, DT-678.

CONCLUSIONS

These findings indicate that antiplatelet effects of clopidogrel may be impaired in the setting of diabetes mellitus due to reduced prodrug bioactivation related to IL-1 receptor signaling. Therapeutic targeting of P2Y₁₂ in patients with diabetes mellitus using the conjugate of clopidogrel AM may lead to improved outcomes.

Highlights from the 2019 International Aspirin Foundation Scientific Conference, Rome, 28 June 2019: benefits and risks of antithrombotic therapy for cardiovascular disease prevention

At the 2019 International Aspirin Foundation Scientific Conference 'Benefits and Risks of Antithrombotic Therapy for Cardiovascular Disease Prevention', held in Rome, Italy, international experts sought to discuss and debate the optimal antithrombotic strategy for the secondary prevention of cardiovascular disease (CVD) and to seek agreement around dosing and target populations for aspirin use in primary disease prevention. Getting the best evidence to support real-life decisions in the clinic can be complex, and individualising management in order to balance both the risks and benefits of different disease prevention strategies appears to be the best approach. It is hoped that future decision-making tools and biomarkers will help direct treatments at those most likely to benefit.

Monitoring platelet function: what have we learned from randomized clinical trials?

Dual antiplatelet therapy, with aspirin plus a P2Y12 inhibitor agent, remains the cornerstone treatment after percutaneous coronary intervention. However, significant proportion of patients did experience recurrent ischemic events on aspirin plus clopidogrel and the concept of non-response to P2Y12 inhibitor emerged. Evaluation of platelet reactivity has known a promising era aiming to improve platelet inhibition conferred by clopidogrel. Then, the development of more potent antiplatelet agents (i.e., prasugrel and ticagrelor) shifted the concern to excessive platelet inhibition and increased risk of bleeding. Therefore, personalized antiplatelet therapy according to platelet function testing has been tested in several randomized trials for both escalation and de-escalation of antiplatelet regimen. This review aims to report the evidence from randomized trials in this field and upcoming roles for platelet function testing.

Effect of dual antiplatelet on recurrent stroke in minor stroke or TIA depends on bodyweight

Objective

To assess whether bodyweight influences the efficacy and safety of dual antiplatelet therapy (DAT) in male patients with minor stroke or transient ischemic attack patients.

Materials and methods

All 3,420 male participants coming from the Clopidogrel in High-Risk Patients with Acute Non-disabling Cerebrovascular Events trial were divided into 3 groups based on bodyweight (<65 kg, 65–75 kg, and ≥75 kg). The stroke outcomes included stroke recurrence, combined vascular events, and bleeding events during 90 days of follow-up. The interaction of the treatment effects of DAT among patients with different bodyweight was assessed by Cox proportional hazards models.

Results

DAT is superior to mono antiplatelet therapy (MAT) for reducing stroke recurrence among patients with weight <65 kg (5.0% vs 11.7%; hazard ratio [HR], 0.41; 95% CI: 0.22–0.76) and 65–75 kg (6.7% vs 10.8%, HR, 0.62; 95% CI: 0.43–0.89). However, no significant difference was found in stroke recurrence between DAT and MAT in patients with weight ≥75 kg (9.4% vs 11.6%; HR, 0.80; 95% CI: 0.58–1.10). A significant interaction was observed between weight and antiplatelet therapy on stroke recurrence (p<0.05). Similar result was found for combined vascular events. More bleeding events were found in DAT group among patients with <65 kg (3.7% vs 2.2%), but with no significant difference.

Conclusion

DAT does not show benefit in patients with higher weight, compared with MAT. Bleeding events found in the DAT group were not more than the MAT group among patients with lower weight.

Clinical trial registration

URL: http://www.ClinicalTrials.gov. Unique identifier: NCT00979589.

Variability of platelet response to clopidogrel is not related to adverse cardiovascular events in patients with stable coronary artery disease undergoing percutaneous coronary intervention

BACKGROUND

Antiplatelet response to clopidogrel and its influence upon the risk of cardiovascular adverse events among patients with stable coronary artery disease undergoing percutaneous coronary intervention (PCI) has not been investigated fully.

METHODS

Two hundred eleven patients treated with aspirin and clopidogrel were included in the study. Immediately before PCI, residual platelet reactivity testing with impedance aggregometry assay and a single-nucleotide polymorphism genotyping analysis targeting variants of CYP2C19, ABCB1, and PON1 genes was performed. After the index PCI, the patients were screened for cardiovascular events 6 months following bare-metal stent implantation or 12 months following drug-eluting stent implantation.

RESULTS

High on-treatment platelet reactivity (HTPR) was observed in 19.43% individuals and low-TPR (LTPR) in 26.54%. In multivariate analysis, HTPR was significantly (p < 0.05) associated with a history of diabetes, higher systolic blood pressure, and platelet count comparing to that of other patients. LTPR was significantly associated with no history of hypertension, younger age, lower platelet count, absence of the CYP2C19*2 variant, and lower CRP plasma level. Overall, cardiac adverse events were noted in 14.23% patients. Survival analysis with the Cox proportional hazard model showed no influence of residual platelet reactivity during clopidogrel therapy upon both ischemic and hemorrhagic events. However, significant predictors for composite of major adverse cardiac events and hospitalization for cardiovascular causes were identified (the higher CCS class prior to coronary intervention and the higher creatinine serum concentration).

CONCLUSIONS

The platelet response to clopidogrel has no impact upon post-procedural adverse events at mid-term follow-up in patients with stable CAD undergoing PCI. This finding suggests that routine platelet reactivity testing is not beneficial in this group of patients.

Impact of Hemoglobin A1c Levels on Residual Platelet Reactivity and Outcomes After Insertion of Coronary Drug-Eluting Stents (from the ADAPT-DES Study)

An increasing hemoglobin A1c (HbA1c) level portends an adverse cardiovascular prognosis; however, the association between glycemic control, platelet reactivity, and outcomes after percutaneous coronary intervention (PCI) with drug-eluting stents (DES) is unknown. We sought to investigate whether HbA1c levels are associated with high platelet reactivity (HPR) in patients loaded with clopidogrel and aspirin, thereby constituting an argument for intensified antiplatelet therapy in patients with poor glycemic control. In the prospective, multicenter Assessment of Dual Antiplatelet Therapy With Drug Eluting Stents registry, HbA1c levels were measured as clinically indicated in 1,145 of 8,582 patients, stratified by HbA1c <6.5% (n = 551, 48.12%), 6.5% to 8.5% (n = 423, 36.9%), and >8.5% (n = 171, 14.9%). HPR on clopidogrel and aspirin was defined after PCI as P2Y12 reaction units (PRU) >208 and aspirin reaction units >550, respectively. HPR on clopidogrel was frequent (48.3%), whereas HPR on aspirin was not (3.9%). Patients with HbA1c >8.5% were younger, more likely non-Caucasian, had a greater body mass index, and more insulin-treated diabetes and acute coronary syndromes. Proportions of PRU >208 (42.5%, 50.2%, and 62.3%, p <0.001) and rates of definite or probable stent thrombosis (ST; 0.9%, 2.7%, and 4.2%, p = 0.02) increased progressively with HbA1c groups. Clinically relevant bleeding was greatest in the intermediate HbA1c group (8.2% vs 13.1% vs 9.5%, p = 0.04). In adjusted models that included PRU, high HbA1c levels (>8.5) remained associated with ST (hazard ratio 3.92, 95% CI 1.29 to 12.66, p = 0.02) and cardiac death (hazard ratio 4.24, 95% CI 1.41 to 12.70) but not bleeding at 2-year follow-up. There was no association between aspirin reaction units >550 and HbA1c levels. In conclusion, in this large-scale study, HbA1c and HPR were positively associated, but the clinical effect on adverse outcome was driven by poor glycemic control, which predicted ST and cardiac death after PCI regardless of PRU levels, warranting efforts to improve glycemic control after DES implantation in patients with diabetes mellitus.

Obesity and Antiplatelets-Does One Size Fit All?

Antiplatelet therapy has become a cornerstone in the management of many vascular diseases. With growing antiplatelet options, attention has focused on their comparative effectiveness in specific patient populations. Perhaps one of the least defined factors influencing efficacy of these agents is body mass and obesity. Evidence from preclinical models established that obesity promotes inflammation that in turn enhances platelet reactivity. Thus, adiposity has the potential to diminish or alter the therapeutic effect of antiplatelet therapy. Pharmacodynamic analyses suggest a potential need for dose adjustments of antiplatelet therapy in obese patients. Yet, obese patients paradoxically have better outcomes after acute coronary syndromes. In this review, we identify a critical need for clinical studies with outcome data to enable the development of recommendations for optimal antiplatelet regimens in obese individuals. Until such data exists, healthcare providers should be aware of the potential impact of obesity on the efficacy of anti-platelet therapy.

Effect of clinical factors and gene polymorphism of CYP2C19*2, *17 and CYP4F2*3 on early stent thrombosis

Aim: To determine the main clinical and genetic factors having impact on early coronary stent thrombosis. Materials & methods: Genotyping of CYP2C19*2, *17 and CYP4F2*3 in patients with (n = 31) and without stent thrombosis (n = 456) was performed. Clinical and genetic data were analyzed by binary logistic regression. Results: Smoking (OR: 0.317; 95% CI: 0.131–0.767), high-density lipoprotein level in mmol/l (OR: 0.142; 95% CI: 0.040–0.506), CYP2C19*2*2 versus *1*1 and *1*2 genotype (OR: 11.625; 95% CI: 3.498–38.633), CYP4F2 AA versus GA and GG genotype (OR: 3.532; 95% CI: 1.153–10.822) were associated with early stent thrombosis. Conclusion: For the first time we have identified a clinically important polymorphism (CYP4F2 G1347A) that was independently associated with early stent thrombosis.

Original submitted 18 August 2014; Revision submitted 10 November 2014

Obesity and coronary artery disease: evaluation and treatment

With the increasing prevalence of obesity, clinicians are now facing a growing population of patients with specific features of clinical presentation, diagnostic challenges, and interventional, medical, and surgical management. After briefly discussing the effect of obesity on atherosclerotic burden in this review, we will focus on strategies clinicians might use to ensure better outcomes when performing revascularization in obese and severely obese patients. These patients tend to present comorbidities at a younger age, and their anthropometric features might limit the use of traditional cardiovascular risk stratification approaches for ischemic disease. Alternative techniques have emerged, especially in nuclear medicine. Positron emission tomography-computed tomography might be the diagnostic imaging technique of choice. When revascularization is considered, features associated with obesity must be considered to guide therapeutic strategies. In percutaneous coronary intervention, a radial approach should be favoured, and adequate antiplatelet therapy with new and more potent agents should be initiated. Weight-based anticoagulation should be contemplated if needed, with the use of drug-eluting stents. An "off-pump" approach for coronary artery bypass grafting might be preferable to the use of cardiopulmonary bypass. For patients who undergo bilateral internal thoracic artery grafting, harvesting using skeletonization might prevent deep sternal wound infections. In contrast to percutaneous coronary intervention, lower surgical bleeding has been observed when lean body mass is used for perioperative heparin dose determination.

Single nucleotide polymorphism of CYP3A5*3 contributes to clopidogrel resistance in coronary artery disease patients among Tamilian population

Clopidogrel is an antiplatelet drug. It is used for the treatment as well as for the prophylaxis of coronary artery disease. Clopidogrel resistance is an emerging problem in clinical settings. The aim of the present study was to evaluate the effect of CYP3A5*3 genetic polymorphism on clopidogrel resistance. One hundred and forty-seven patients from outpatient Department of Cardiology on 75 mg/day of clopidogrel as maintenance dose were recruited from April 2010 to July 2011. All subjects gave written informed consent to participate in the study. DNA extraction was performed using phenol chloroform extraction procedure and genotyping by standard Taqman based RT-PCR method. Platelet aggregation was done at the end of 7th and 14th day by using chronolog lumi Aggregometer which is expressed as impedance in ohms. Impedance values of >5 ohms at the end of 6 min were considered as clopidogrel resistance. Subjects (N = 147) were analysed for CYP3A5*3 polymorphism, of which 49 (33%) were found to be clopidogrel resistant. Homomutants of CYP3A5*3 gene had 2.78 (0.97-7.98; p < 0.05) fold risk and heteromutants had 2.4 (0.93-6.46; p < 0.05) fold risk of developing clopidogrel resistance. Carriers of defective allele G of CYP3A5*3 had higher propensity to cause clopidogrel resistance with an odds ratio of 1.63. Variant alleles and genotypes of CYP3A5*3 polymorphism contributed significantly to clopidogrel resistance with a higher odds ratio. Thus, pharmacogenomics paves way for the emergence of stratified medicine in clopidogrel therapy and personalised pharmacotherapy in ischaemic heart disease.