In-hospital outcomes of ticagrelor versus clopidogrel in patients 75 years or older with acute coronary syndrome: findings from the Improving Care for Cardiovascular Disease in China (CCC)-Acute Coronary Syndrome Project

BACKGROUND

The evidence for the comparative effectiveness and safety of ticagrelor versus clopidogrel in older patients with acute coronary syndrome (ACS) is limited, especially in the acute phase of ACS. This study aimed to compare the in-hospital outcomes of ticagrelor versus clopidogrel in older patients with ACS.

METHODS

Hospitalised ACS patients aged ≥75 years who were recruited to the Improving Care for Cardiovascular Disease in China-ACS project between November 2014 and December 2019 and received aspirin and P2Y12 receptor inhibitors within 24 h after first medical contact were included. The primary outcomes were in-hospital major adverse cardiovascular events (MACE) and major bleeding. Multivariable Cox regression was performed to evaluate the comparative effectiveness and safety of ticagrelor and clopidogrel. Inverse probability of treatment weighting (IPTW) and propensity score matching analyses were performed to evaluate the robustness of the results.

RESULTS

Of 18,244 ACS patients, 18.5% received ticagrelor. Multivariable-adjusted analysis revealed comparable risks of in-hospital MACE between patients receiving ticagrelor and clopidogrel (hazard ratio [HR] 1.12, 95% confidence interval [CI] 0.92-1.35). However, ticagrelor use was associated with 45% higher risk of in-hospital major bleeding compared with clopidogrel use (HR 1.45, 95% CI 1.09-1.91). Similar results were found in the IPTW analysis.

CONCLUSIONS

ACS patients aged ≥75 years receiving ticagrelor during the acute phase had similar risk of in-hospital MACE, but higher risk of in-hospital major bleeding compared with those receiving clopidogrel. More evidence is needed to guide the use of P2Y12 receptor inhibitors during hospitalisation in older patients with ACS.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02306616.

The genetic diversity of UK, US and Australian cultivars of Triticum aestivum measured by DArT markers and considered by genome

The genetic diversity of UK, US and Australian wheat varieties over the period of modern plant breeding is estimated using diversity array technology markers. Diversity is assessed by both genetic distance between varieties, by AMOVA and as the volumes of multi-dimensional convex hulls estimated from principal co-ordinate analysis. At the whole genome level the three populations are genetically distinct; this is also true of the B genome. However, the US and Australian D genomes are found to occupy the same region of diversity space and the A genomes for these countries are partially overlapping. The use of high-density genotyping with a common marker set allows an unprecedented direct comparison between the diversities of the national populations, between individual genomes and the fluctuation of diversity over time. The highest genetic diversity amongst varieties is reported in the Australian population followed by the US, which in turn is more diverse than the UK. However the average diversity of loci is higher in the US set than in the Australian. Non-random fluctuations in genetic diversity over time are observed.

A comparison of simple sequence repeat and single nucleotide polymorphism marker technologies for the genotypic analysis of maize (Zea mays L.)

We report on the comparative utilities of simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers for characterizing maize germplasm in terms of their informativeness, levels of missing data, repeatability and the ability to detect expected alleles in hybrids and DNA pools. Two different SNP chemistries were compared; single-base extension detected by Sequenom MassARRAY, and invasive cleavage detected by Invader chemistry with PCR. A total of 58 maize inbreds and four hybrids were genotyped with 80 SSR markers, 69 Invader SNP markers and 118 MassARRAY SNP markers, with 64 SNP loci being common to the two SNP marker chemistries. Average expected heterozygosity values were 0.62 for SSRs, 0.43 for SNPs (pre-selected for their high level of polymorphism) and 0.63 for the underlying sequence haplotypes. All individual SNP markers within the same set of sequences had an average expected heterozygosity value of 0.26. SNP marker data had more than a fourfold lower level of missing data (2.1-3.1%) compared with SSRs (13.8%). Data repeatability was higher for SNPs (98.1% for MassARRAY SNPs and 99.3% for Invader) than for SSRs (91.7%). Parental alleles were observed in hybrid genotypes in 97.0% of the cases for MassARRAY SNPs, 95.5% for Invader SNPs and 81.9% for SSRs. In pooled samples with mixtures of alleles, SSRs, MassARRAY SNPs and Invader SNPs were equally capable of detecting alleles at mid to high frequencies. However, at low frequencies, alleles were least likely to be detected using Invader SNP markers, and this technology had the highest level of missing data. Collectively, these results showed that SNP technologies can provide increased marker data quality and quantity compared with SSRs. The relative loss in polymorphism compared with SSRs can be compensated by increasing SNP numbers and by using SNP haplotypes. Determining the most appropriate SNP chemistry will be dependent upon matching the technical features of the method within the context of application, particularly in consideration of whether genotypic samples will be pooled or assayed individually.

Relationships among durum wheat accessions. II. A comparison of molecular and pedigree information

The study of direct ancestry relationships provides information with which to determine essential derivation. SSR profiles were used to determine the pattern of relatedness among 134 durum wheat accessions, representing the most important modern durum wheat gene pools. Simple sequence repeat (SSR)- and amplified fragment length polymorphism (AFLP)-based genetic similarities among cultivars with accurate pedigrees were compared with pedigree-based coefficients of parentage. Sizeable departures of molecular similarities from the expected ones were observed, indicating the unreliability of inferring the pattern of genetic relatedness from the coefficient of parentage. Case studies consisting of parent–progeny cultivar trios and pairs, identified on the basis of their registered pedigree, were studied to evaluate the probability of ancestry of each progeny cultivar, compared with all the remaining accessions. Rare alleles and haplotype sharing were also explored. When the results did not agree with the registered parentages, SSR markers provided information with which to identify the most probable parents (or the corresponding “breeding lineages”) in the collection.