The Evolution of Antiplatelet Therapy After Percutaneous Coronary Interventions: A 40-Year Journey

P2Y12 Inhibitor Loading Time Before Elective PCI and the Prevention of Myocardial Necrosis

BACKGROUND

There are dated and conflicting data about the optimal timing of initiation of P2Y12 inhibitors in elective percutaneous coronary intervention (PCI). Peri-PCI myocardial necrosis is associated with poor outcomes. We aimed to assess the impact of the P2Y12 inhibitor loading time on periprocedural myocardial necrosis in the population of the randomized Assessment of Loading With the P2Y12 Inhibitor Ticagrelor or Clopidogrel to Halt Ischemic Events in Patients Undergoing Elective Coronary Stenting (ALPHEUS) trial, which compared ticagrelor with clopidogrel in high-risk patients who received elective PCI.

METHODS

The ALPHEUS trial divided 1809 patients into quartiles of loading time. The ALPHEUS primary outcome was used (type 4 [a or b] myocardial infarction or major myocardial injury) as well as the main secondary outcome (type 4 [a or b] myocardial infarction or any type of myocardial injury).

RESULTS

Patients in the first quartile group (Q1) presented higher rates of the primary outcome (P = 0.01). When compared with Q1, incidences of the primary outcome decreased in patients with longer loading times (adjusted odds ratio [adjOR], 0.70 [0.52.-0.95]; P = 0.02 for Q2; adjOR 0.65 [0.48-0.88]; P < 0.01 for Q3; adjOR 0.66 [0.49-0.89]; P < 0.01 for Q4). Concordant results were found for the main secondary outcome. There was no interaction with the study drug allocated by randomization (clopidogrel or ticagrelor). Bleeding complications (any bleeding ranging between 4.9% and 7.3% and only 1 major bleeding at 48 hours) and clinical ischemic events were rare and did not differ among groups.

CONCLUSIONS

In elective PCI, administration of the oral P2Y12 inhibitor at the time of PCI could be associated with more frequent periprocedural myocardial necrosis than an earlier administration. The long-term clinical consequences remain unknown.

Impact of Age on Antiplatelet Monotherapy in the Chronic Maintenance Period After Percutaneous Coronary Intervention: A Post Hoc Analysis From the HOST-EXAM Extended Study

BACKGROUNDS

The HOST-EXAM Extended study reported the benefit of clopidogrel monotherapy over aspirin monotherapy in secondary prevention after percutaneous coronary intervention (PCI). This age-specific subgroup analysis of the study aimed to assess the impact of age on antiplatelet monotherapy after PCI.

METHODS

We analysed data from the per-protocol population (4717 patients) with a median follow-up of 5.8 years. The old age group comprised 2033 patients (43.1%), defined as those 65 years of age or older. The primary end point was the composite of all-cause death, nonfatal myocardial infarction, stroke, readmission due to acute coronary syndrome (ACS), and Bleeding Academic Research Consortium (BARC) bleeding type 3 or greater. The secondary end points were thrombotic composite outcomes and any bleeding.

RESULTS

Age correlated with an elevated risk of adverse events, particularly from age 65. Clopidogrel monotherapy was associated with a reduction of the primary end point in both the old age group (19.4% vs 23.1%, hazard ratio [HR] 0.802, 95% confidence interval [CI] 0.664-0.968; P = 0.022) and the young age group (7.8% vs 11.7%, HR 0.646, 95% CI 0.506-0.825; P < 0.001), without significant interaction (interaction P = 0.167). These findings were consistent for the secondary composite thrombotic end point and any bleeding events (interaction P value of secondary thrombotic end point: 0.786; interaction P value of any bleeding end point: 0.565). Consistent results were observed in analyses with a 75-year age cutoff and in subgroup analyses by 10-year age intervals.

CONCLUSIONS

In patients requiring antiplatelet monotherapy after PCI, occurrence of both ischemic and bleeding events dramatically increased from age 65. The beneficial impact of clopidogrel over aspirin monotherapy was consistent regardless of age.

CLINICAL TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02044250.

Factors affecting variability in free oxylipins in mammalian tissues

PURPOSE OF THE REVIEW

Along with the growing interest in oxylipins is an increasing awareness of multiple sources of variability in oxylipin data. This review summarizes recent findings that highlight the experimental and biological sources of variation in free oxylipins.

RECENT FINDINGS

Experimental factors that affect oxylipin variability include different methods of euthanasia, postmortem changes, cell culture reagents, tissue processing conditions and timing, storage losses, freeze-thaw cycles, sample preparation techniques, ion suppression, matrix effects, use and availability of oxylipin standards, and postanalysis procedures. Biological factors include dietary lipids, fasting, supplemental selenium, vitamin A deficiency, dietary antioxidants and the microbiome. Overt, but also more subtle differences in health affect oxylipin levels, including during resolution of inflammation and long-term recovery from disease. Sex, genetic variation, exposure to air pollution and chemicals found in food packaging and household and personal care products, as well as many pharmaceuticals used to treat health conditions also affect oxylipin levels.

SUMMARY

Experimental sources of oxylipin variability can be minimized with proper analytical procedures and protocol standardization. Fully characterizing study parameters will help delineate biological factors of variability, which are rich sources of information that can be used to probe oxylipin mechanisms of action and to investigate their roles in health.