Predictors of In-Hospital De-Escalation of P2Y12 Inhibitors to Clopidogrel in Patients With Acute Myocardial Infarction Treated With Percutaneous Coronary Intervention.

BACKGROUND: Ticagrelor or prasugrel are recommended to reduce ischemic events in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI). However, in clinical practice, patients are often switched from a potent P2Y12 inhibitor to clopidogrel prior to or at discharge ('de-escalation'). We sought to assess the incidence and predictors of de-escalation. METHODS: Consecutive patients who received either a ticagrelor or prasugrel loading dose for AMI PCI at two tertiary centers between Jan 2015-Mar 2019 who survived to discharge were included. Data were obtained from the electronic health record and institutional NCDR CathPCI data. Patients who were de-escalated to clopidogrel were compared with those who remained on potent P2Y12 inhibitors through the time of discharge. RESULTS: Of the1818 patients in the cohort, 1146 (63%) were de-escalated. Patients in the de-escalation group were older, more often Black, had lower prevalence of co-morbidities, less often had private insurance, and had less complex PCI. After adjustment, older age remained positively associated (OR 1.2, CI 1.08-1.34, p = .001) and Caucasian race (OR 0.5, CI 0.33-0.77, p = .002), prior MI (OR 0.7, CI 0.5-0.97, p = .032), bifurcation lesion (OR 0.71, CI 0.53-0.95, p = .019), and greater number of stents (OR 0.82, CI 0.75-0.91, p = .0001) were negatively associated with de-escalation. In de-escalated patients, the rationale was not documented in 75.9% of cases. CONCLUSIONS: De-escalation occurred frequently in patients with AMI and was associated with both non-clinical and clinical factors. Medical decision making was poorly documented and represent an area for improvement.

Ovarian hormones modulate multidrug resistance transporters in the ovary.

BACKGROUND: Multidrug resistance transporters (MDRs) are transmembrane proteins that efflux metabolites and xenobiotics. They are highly conserved in sequence and function in bacteria and eukaryotes and play important roles in cellular homeostasis, as well as in avoidance of antibiotics and cancer therapies. Recent evidence also documents a critical role in reproductive health and in protecting the ovary from environmental toxicant effects. The most well understood MDRs are MDR-1 (P-glycoprotein (P-gp) also known as ABCB1) and BCRP (breast cancer resistance protein) and are both expressed in the ovary. We have previously shown that MDR-1 mRNA steady state expression changes throughout the murine estrous cycle, but expression appears to increase in association with the surge in estradiol during proestrus. METHODS: Here we test the model that MDR-1 and BCRP are regulated by estrogen, the major hormonal product of the ovary. This was performed by administering 6-week-old female mice either sesame oil (vehicle control) or oral ethinyl estradiol at 1 µg, 10 µg, and 100 µg or PROGESTERONE at 0.25mg, 0.5 mg or 1 mg or a combination of both for 5 days. The mice were then sacrificed, and the ovaries were removed and cleaned. Ovaries were used for qPCR, immunoblotting, and immnunolabeling. RESULTS: We found that oral ethinyl estradiol did not influence the steady state mRNA of MDR-1 or BCRP. Remarkably, the effect on mRNA levels neither increased or decreased in abundance upon estrogen exposures. Conversely, we observed less MDR-1 protein expression in the groups treated with 1 µg and 10 µg, but not 100 µg of ethinyl estradiol compared to controls. MDR-1 and BCRP are both expressed in pre-ovulatory follicles. When we tested progesterone, we found that MDR-1 mRNA increased at the dosages of 0.25 mg and 0.5 mg, but protein expression levels were not statistically significant. Combined oral ethinyl estradiol and progesterone significantly lowered both MDR-1 mRNA and protein. CONCLUSIONS: Progesterone appears to influence MDR-1 transcript levels, or steady state levels. This could have implications for better understanding how MDR-1 can be modulated during times of toxic exposure. Understanding the normal physiology of MDR-1 in the ovary will expand the current knowledge in cancer biology and reproduction.

Multidrug resistance transporter-1 and breast cancer resistance protein protect against ovarian toxicity, and are essential in ovarian physiology.

Ovarian protection from chemotoxicity is essential for reproductive health. Our objective is to determine the role of ATP-dependent, Multidrug Resistance Transporters (MDRs) in this protection. Previously we identified MDR-dependent cytoprotection from cyclophosphamide in mouse and human oocytes by use of MDR inhibitors. Here we use genetic deletions in MDR1a/b/BCRP of mice to test MDR function in ovarian somatic cells and find that mdr1a/b/bcrp-/- mice had significantly increased sensitivity to cyclophosphamide. Further, estrus cyclicity and follicle distribution in mdr1a/b/bcrp-/- mice also differed from age-matched wildtype ovaries. We found that MDR gene activity cycles through estrus and that MDR-1b cyclicity correlated with 17ß-estradiol surges. We also examined the metabolite composition of the ovary and learned that the mdr1a/b/bcrp-/- mice have increased accumulation of metabolites indicative of oxidative stress and inflammation. We conclude that MDRs are essential to ovarian protection from chemotoxicity and may have an important physiological role in the ovary.