The evolution of the human DNA replication timing program.

DNA is replicated according to a defined spatiotemporal program that is linked to both gene regulation and genome stability. The evolutionary forces that have shaped replication timing programs in eukaryotic species are largely unknown. Here, we studied the molecular causes and consequences of replication timing evolution across 94 humans, 95 chimpanzees, and 23 rhesus macaques. Replication timing differences recapitulated the species' phylogenetic tree, suggesting continuous evolution of the DNA replication timing program in primates. Hundreds of genomic regions had significant replication timing variation between humans and chimpanzees, of which 66 showed advances in replication origin firing in humans, while 57 were delayed. Genes overlapping these regions displayed correlated changes in expression levels and chromatin structure. Many human-chimpanzee variants also exhibited interindividual replication timing variation, pointing to ongoing evolution of replication timing at these loci. Association of replication timing variation with genetic variation revealed that DNA sequence evolution can explain replication timing variation between species. Taken together, DNA replication timing shows substantial and ongoing evolution in the human lineage that is driven by sequence alterations and could impact regulatory evolution at specific genomic sites.

Impact of Event Severity on Hospital Rankings Based on Heart Failure Readmission Rates.

The Medicare Readmissions Reduction Program penalizes hospitals with higher than expected readmission rates after discharge for congestive heart failure (CHF). This exploratory study analyzed whether categorizing readmissions by event severity might have implications for the program. The authors used the 5% MedPAR (Medicare Provider and Analysis Review) data for 2008 to 2014 and ranked 1820 hospitals based on all readmissions, readmissions for CHF, short-stay CHF readmissions, and readmissions for severe CHF with evidence of cardiogenic shock. Ranking hospitals based on severe CHF readmissions changes their relative rank order significantly compared to counting all readmissions. If confirmed in the full Medicare data, the finding could inform the design of the Readmission Reduction Program.

Health Economic Evaluation of an Ultrathin, Bioresorbable-Polymer Sirolimus-Eluting Coronary Stent Compared to a Thin, Durable-Polymer Everolimus-Eluting Stent.

OBJECTIVES: The study estimated the health economic impact of a latest generation coronary stent with ultrathin struts and bioresorbable polymer coating. BACKGROUND: The recent BIOFLOW V trial, an international FDA approval trial (ClinicalTrials.gov: NCT02389946), has shown that an ultrathin, bioresorbable polymer sirolimus-eluting stent had a significantly lower rate of target lesion failure and target vessel-related myocardial infarction than a thin, durable polymer everolimus-eluting stent at 12 months, driven by a lower rate of peri-procedural myocardial infarction (ppMI). METHODS: We used a Markov model to project mortality and cost outcomes of that lower ppMI rate from a U.S. health system perspective over a 12-month horizon. Model parameters were derived from BIOFLOW V trial data, a systematic literature review and expert interviews. RESULTS: Use of the bioresorbable polymer sirolimus-eluting stent compared to durable polymer everolimus-eluting stent is associated with net reductions in medical cost of $124 (Interquartile Range (IQR) $97-154) per patient in 2018 US$, of which $115 (IQR $76-124) accrues to the initial admission and $10 (IQR $7-72) to cost of follow-up. The lower rate of ppMI translates into a gain of 0.000017 (IQR 0.000011-0.000022) quality-adjusted life-years (QALY) per patient. CONCLUSIONS: Lower ppMI rates of bioresorbable polymer sirolimus-eluting stent translate into reductions in direct medical cost, while improving patient outcomes. Most of the cost reduction is attributed to the initial admission with moderate savings up to 12 months post-discharge.