Impact of Prasugrel and Ticagrelor on Platelet Reactivity in Patients With Acute Coronary Syndrome: A Meta-Analysis

Association between duration, initiation time, routes, and formulations of menopausal hormone therapy use and Alzheimer disease in women: A systematic review and meta-analysis

The purpose of this study was to investigate the effect of menopausal hormone therapy (MHT) on the risk of Alzheimer disease (AD) by examining its duration, initiation time, routes of administration, and formulations through systematic review and meta-analysis. PubMed, Embase, Cochrane Library, Web of Science, and Scopus were searched on March 15, 2023. We selected cohort studies, case-control studies, and randomized controlled trials on the effect of MHT on AD in women. Odds ratio, relative risk, and hazard ratio were extracted. Random-effect models were used to estimate the polled estimates (relative risk [RR] or odds ratio [OR]) and their 95% confidence interval (95% CI). We included 3 randomized controlled trials, 12 cohort studies, and 16 case-control studies. A total of 7,710,379 women were included. Pooled estimates showed that MHT use for 3-5 years (cohort, RR = 0.56, 95% CI: 0.34-0.93) or initiation within 5 years of menopause (cohort, RR = 0.70, 95% CI: 0.49-0.99) reduced the risk of AD. Oral administration reduced AD risk (cohort, RR = 0.42, 95% CI: 0.40-0.44). Combining estrogen and progesterone (case-control, OR = 1.13, 95% CI: 1.05-1.21) or progesterone only (case-control, OR = 1.13, 95% CI: 1.10-1.17) increases AD risk. Tibolone increased AD risk (cohort, RR = 1.04, 95% CI: 1.01-1.07; case-control, OR = 1.07, 95% CI: 1.01-1.14). MHT-protected apolipoprotein E genotype 4 carriers (cohort, RR = 0.13, 95% CI: 0.02-0.90), depressed populations (cohort, RR = 0.85, 95% CI: 0.80-0.90), and Americas (cohort, RR = 0.54, 95% CI: 0.37-0.80; case-control, OR = 0.68, 95% CI: 0.47-0.99) from AD. Using MHT early (within 5 years after menopause) for about 5 years may protect against AD. However, combining estrogen with progesterone, or using progesterone only, could increase AD risk. Oral MHT methods are more effective than transdermal ones in reducing this risk. SIGNIFICANCE STATEMENT: Menopausal hormone therapy (MHT) use within 5 years after menopause could offer protective benefits against Alzheimer disease (AD). A combination of estrogen and progesterone, using progesterone only or tibolone usage was connected with an elevated risk of AD. Oral MHT was more effective than transdermal methods in lowering AD risk. MHT lowered AD risk in apolipoprotein E genotype 4 allele carriers, individuals with depression, and Americans. MHT regimens should be highly personalized.

Clopidogrel resistance and its relevance: Current concepts

Clopidogrel is the most widely used P2Y12 receptor inhibitor (P2Y12i) as a part of dual antiplatelet therapy along with aspirin. Clopidogrel is a pro-drug and is metabolized to its active metabolite by the hepatic enzyme cytochrome P4502C19 (CYP2C19). This active metabolite is responsible for the antiplatelet action of clopidogrel. Recent studies have demonstrated that single nucleotide polymorphisms in the CYP2C19 gene, including CYP2C19*2,*3,*4, and *5 alleles, result in reduced production of the active metabolite of clopidogrel, and hence reduced inhibition of platelet aggregation. This in turn enhances the incidence of stent thrombosis and recurrent cardiovascular (CV) events. We report a case of coronary stent thrombosis due to clopidogrel resistance proven by CYP2C19 genotyping. We then review the literature on clopidogrel resistance and its impact on CV outcomes. Subsequently, we discuss the methods of diagnosis of resistance, evidence from clinical trials for tailoring clopidogrel therapy, the role of potent P2Y12 inhibitors, the current guidelines, and future directions.

Low-dose prasugrel versus standard-dose ticagrelor in east Asian patients with acute coronary syndrome

Low-dose prasugrel demonstrated a similar effectiveness profile to clopidogrel in East Asian ACS patients, but its comparison with another new-generation potent P2Y12 inhibitor, ticagrelor, remains unclear. To compare the effectiveness and safety of low-dose prasugrel against those of standard-dose ticagrelor in East Asian patients with ACS. This retrospective cohort study used Taiwan's National Health and Welfare Database. This study included ACS patients who underwent percutaneous coronary intervention and, at discharge between January 1, 2018 and December 31, 2020, were prescribed with low-dose prasugrel plus aspirin or standard-dose ticagrelor plus aspirin. Stabilized inverse probability of treatment weighting was used to balance the covariates across these two groups. The primary effectiveness outcome was a composite of acute myocardial infarction, ischemic stroke, and cardiovascular death; the secondary effectiveness outcome was each of the individual components of the primary outcome, transient ischemic attack, and repeat revascularization. The primary safety outcome was a composite of intracranial hemorrhage and gastrointestinal bleeding, and the two secondary safety outcomes were intracranial hemorrhage and gastrointestinal bleeding. A total of 24,807 patients were included in this study. Among them, 1,493 were low-dose prasugrel users and 23,314 were standard-dose ticagrelor users. No significant differences were found in primary effectiveness [HR: 0.97 (0.74-1.28)] or primary safety outcomes [HR: 1.22 (0.73-2.01)] between the two study groups. For East Asian patients with ACS, low-dose prasugrel provides comparable effectiveness without increasing bleeding risk compared to standard-dose ticagrelor. Low-dose prasugrel may be an appropriate alternative for East Asian populations.

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.