Mismatch-based delayed thrombolysis: a meta-analysis

<p><b>Background and Purpose</b>: Clinical benefit from thrombolysis is reduced as stroke onset to treatment time increases. The use of "mismatch" imaging to identify patients for delayed treatment has face validity and has been used in case series and clinical trials. We undertook a meta-analysis of relevant trials to examine whether present evidence supports delayed thrombolysis among patients selected according to mismatch criteria.</p> <p><b>Methods</b>: We collated outcome data for patients who were enrolled after 3 hours of stroke onset in thrombolysis trials and had mismatch on pretreatment imaging. We selected the trials on the basis of a systematic search of the Web of Knowledge. We compared favorable outcome, reperfusion and/or recanalization, mortality, and symptomatic intracerebral hemorrhage between the thrombolyzed and nonthrombolyzed groups of patients and the probability of a favorable outcome among patients with successful reperfusion and clinical findings for 3 to 6 versus 6 to 9 hours from poststroke onset. Results are expressed as adjusted odds ratios (a-ORs) with 95% CIs. Heterogeneity was explored by test statistics for clinical heterogeneity, I2 (inconsistency), and L’Abbé plot.</p> <p><b>Results</b>: We identified articles describing the DIAS, DIAS II, DEDAS, DEFUSE, and EPITHET trials, giving a total of 502 mismatch patients thrombolyzed beyond 3 hours. The combined a-ORs for favorable outcomes were greater for patients who had successful reperfusion (a-OR=5.2; 95% CI, 3 to 9; I2=0%). Favorable clinical outcome was not significantly improved by thrombolysis (a-OR=1.3; 95% CI, 0.8 to 2.0; I2=20.9%). Odds for reperfusion/recanalization were increased among patients who received thrombolytic therapy (a-OR=3.0; 95% CI, 1.6 to 5.8; I2=25.7%). The combined data showed a significant increase in mortality after thrombolysis (a-OR=2.4; 95% CI, 1.2 to 4.9; I2=0%), but this was not confirmed when we excluded data from desmoteplase doses that were abandoned in clinical development (a-OR=1.6; 95% CI, 0.7 to 3.7; I2=0%). Symptomatic intracerebral hemorrhage was significantly increased after thrombolysis (a-OR=6.5; 95% CI, 1.2 to 35.4; I2=0%) but not significant after exclusion of abandoned doses of desmoteplase (a-OR=5.4; 95% CI, 0.9 to 31.8; I2=0%).</p> <p><b>Conclusions</b>: Delayed thrombolysis amongst patients selected according to mismatch imaging is associated with increased reperfusion/recanalization. Recanalization/reperfusion is associated with improved outcomes. However, delayed thrombolysis in mismatch patients was not confirmed to improve clinical outcome, although a useful clinical benefit remains possible. Thrombolysis carries a significant risk of symptomatic intracerebral hemorrhage and possibly increased mortality. Criteria to diagnose mismatch are still evolving. Validation of the mismatch selection paradigm is required with a phase III trial. Pending these results, delayed treatment, even according to mismatch selection, cannot be recommended as part of routine care.</p&gt

pyseer : a comprehensive tool for microbial pangenome-wide association studies

Genome-wide association studies (GWAS) in microbes have different challenges to GWAS in eukaryotes. These have been addressed by a number of different methods. pyseer brings these techniques together in one package tailored to microbial GWAS, allows greater flexibility of the input data used, and adds new methods to interpret the association results.Peer reviewe

Impact of dual antiplatelet therapy after coronary artery bypass surgery on 1 year outcomes in the Arterial Revascularization Trial (ART)

Objectives: There is still little evidence to support routine dual antiplatelet therapy (DAPT) with P2Y12 antagonists following coronary artery bypass grafting (CABG). The Arterial Re-vascularization Trial (ART) was designed to compare 10-year survival after bilateral versus single internal thoracic artery grafting. We aimed to get insights into the effect of DAPT (with clopidogrel) following CABG on 1 year outcomes by performing a post-hoc ART anal-ysis. Methods: Among patients enrolled in the ART (n=3102), 609 (21%) and 2308 (79%) were discharged on DAPT or aspirin alone respectively. The primary endpoint was the incidence of major adverse cerebrovascular and cardiac events (MACCE) at 1 year including cardiac death, myocardial infarction, cerebrovascular accident and reintervention; safety endpoint was bleeding requiring hospitalization. Propensity score (PS) matching was used to create comparable groups. Results: Among 609-PS matched pairs, MACCE occurred in 34 (5.6%) and 34 (5.6%) in the DAPT and aspirin alone groups respectively with no significant difference between the two groups (HR 0.97; 95%CI 0.59-1.59; P=0.90). Only 188 (31%) subjects completed 1 year of DAPT and in this subgroup, MACCE rate was 5.8% (HR 1.11; 95%CI 0.53-2.30; P=0.78). In the overall sample, bleeding rate was higher in DAPT group (2.3% versus 1.1%; P=0.02) although this difference was no longer significant after matching (2.3% vs 1.8%; P=0.54). Conclusions: Based on these findings, when compared to aspirin alone, DAPT with clopidogrel prescribed at discharge was not associated with a significant reduction of adverse cardiac and cerebrovascular events at 1 year following CABG

Incidence and clinical implications of intraoperative BITA grafts conversion. Insights from the Arterial Revascularization Trial

Background: The arterial revascularization trial (ART) has been designed to answer the question whether the use of bilateral internal thoracic arteries (BITA) can improve 10-year outcomes when compared to single internal thoracic artery (SITA). In the ART, a significant proportion of patients initially allocated to BITA received other conduit strategies. We sought to investigate the incidence and clinical implication of BITA grafts conversion in the ART. Methods: Among patients enrolled in the ART (n=3102), we excluded those allocated to SITA (n=1554), those who did not undergo surgery (n=16) and those operated on but withdrew after randomization (n=7). Propensity score matching was used to compare converted vs non-converted BITA groups. Results: A total of 1525 patients were operated with intention to receive BITA grafting. Of those, 233 (15.3%) were converted to other conduit selection strategies. Incidence of conversion largely varied across 28 centres involved (from 0% to 42.9%). The most common reason for BITA grafts conversion was the evidence of at least one internal thoracic artery not suitable which was reported in 77 cases. Patients with intraoperative BITA graft conversion received a lower number of grafts (2.95±0.84 vs 3.21±0.74; P<0.001). However, hospital mortality rate was comparable to those who did not require BITA graft conversion (0 vs 1.6%; P=0.1) as well as the incidence of major complications. At 5 years we found a non-significant excess of deaths (11.9% vs 8.4%; P=0.1) and major adverse events (17.1% 13.2%; P=0.1) mainly driven by an excess of revascularization in patients requiring conversion. Conclusions: The incidence of intraoperative BITA graft conversion is not irrelevant . BITA graft conversion is not associated with increased operative morbidity but its effect on late outcomes remain uncertain

Post-operative atrial fibrillation and long-term risk of stroke after isolated coronary artery bypass graft surgery

Background: Post-operative atrial fibrillation (pAF) following coronary artery bypass graft-ing (CABG) is a common complication. Whether pAF is associated with an increased risk of cerebrovascular accident (CVA) remains uncertain. We investigated the association between pAF and long-term risk of CVA by performing a post-hoc analysis of 10-year outcomes of the Arterial Revascularization Trial (ART). Methods: For the present analysis, among patients enrolled in the ART (n=3102), we ex-cluded those who did not undergo surgery (n=25), had a prior history of atrial fibrillation (n=45), or had no information regarding the incidence of pAF (n=9). The final population consisted of 3023 patients of whom 734 (24.3%) developed pAF with the remaining 2289 maintaining sinus rhythm (SR). Competing risk and Cox regression analysis were used to investigate the association between pAF and the risk of CVA. Results: At 10 years, the cumulative incidence of CVA was 6.3% (4.6-8.1) vs 3.7% (2.9-4.5) in patients with pAF and SR respectively. pAF was an independent predictor of CVA at 10 years (HR 1.53; 95%CI 1.06-2.23; P-value=0.025) even when CVAs that occurred during the index admission were excluded from the analysis (HR 1.47; 95% 1.02-2.11; P=0.04). Conclusions: Patients with pAF after CABG are at higher risk of CVA. These findings chal-lenge the notion that pAF is a benign complication.</p

Genome-wide identification of lineage and locus specific variation associated with pneumococcal carriage duration.

Streptococcus pneumoniae is a leading cause of invasive disease in infants, especially in low-income settings. Asymptomatic carriage in the nasopharynx is a prerequisite for disease, but variability in its duration is currently only understood at the serotype level. Here we developed a model to calculate the duration of carriage episodes from longitudinal swab data, and combined these results with whole genome sequence data. We estimated that pneumococcal genomic variation accounted for 63% of the phenotype variation, whereas the host traits considered here (age and previous carriage) accounted for less than 5%. We further partitioned this heritability into both lineage and locus effects, and quantified the amount attributable to the largest sources of variation in carriage duration: serotype (17%), drug-resistance (9%) and other significant locus effects (7%). A pan-genome-wide association study identified prophage sequences as being associated with decreased carriage duration independent of serotype, potentially by disruption of the competence mechanism. These findings support theoretical models of pneumococcal competition and antibiotic resistance

Safety of Perioperative Aprotinin Administration During Isolated Coronary Artery Bypass Graft Surgery: Insights From the ART (Arterial Revascularization Trial)

Background There is still uncertainty about the safety of aprotinin for coronary artery bypass graft surgery. The ART (Arterial Revascularization Trial) was designed to compare survival after bilateral versus single internal thoracic artery grafting. Many of the ART patients (≈30%) received perioperative aprotinin. We investigated the association between perioperative aprotinin administration and short‐term (in‐hospital) and long‐term outcomes by performing a post hoc analysis of the ART. Methods and Results Among patients enrolled in the ART (n=3102) from 2004 to 2007, we excluded those who did not undergo surgery (n=18) and those with no information about use of perioperative aprotinin (n=9). Finally, 836 of 3076 patients (27%) received aprotinin. Propensity matching was used to select 536 pairs for final comparison. Aprotinin was also associated with an increased risk of hospital mortality (9 [1.7%] versus 1 [0.2%]; odds ratio, 9.12; 95% confidence interval [CI], 1.15–72.2; P=0.03), intra‐aortic balloon pump insertion (37 [6.9%] versus 17 [3.2%]; odds ratio, 2.26; 95% CI, 1.26–4.07; P=0.006), and acute kidney injury (102 [19.0%] versus 76 [14.2%]; odds ratio, 1.42; 95% CI, 1.03–1.97; P=0.03). Aprotinin was not associated with a lower incidence of transfusion (37 [6.9%] versus 28 [5.2%]; odds ratio, 1.34; 95% CI, 0.81–2.23; P=0.25) and reexploration (26 [4.9%] versus 19 [3.5%]; hazard ratio, 1.39; 95% CI, 0.76–2.53; P=0.28). At 5 years, all‐cause mortality was significantly increased in the aprotinin group (56 [10.6%] versus 38 [7.3%]; hazard ratio, 1.51; 95% CI, 1.0–2.28; P=0.045). Conclusions In the present post hoc ART analysis, aprotinin was associated with a significantly increased risk of early and late mortality

Associations between adding a radial artery graft to single and bilateral internal thoracic artery grafts and outcomes. Insights from the Arterial Revascularization Trial

Background—Whether the use of the radial artery (RA) can improve clinical outcomes in coronary artery bypass graft (CABG) surgery remains unclear. The Arterial Revascularization Trial (ART) was designed to compare survival after bilateral internal thoracic artery (BITA) over single left internal thoracic artery (SITA). In the ART, a large proportion of patients (~20%) also received a RA graft instead of a saphenous vein graft (SVG). We aimed to investigate the associations between using the RA instead of SVG to supplement SITA or BITA grafts and outcomes by performing a post-hoc analysis of the ART.  Methods—Patients enrolled in the ART (n=3102) were classified based on conduits actually received (as treated). The analysis included 2737 patients who received a RA graft (RA group, n=632) or SVG only (SVG group, n=2105) in addition to SITA or BITA grafts. The primary endpoint was the composite of myocardial infarction, cardiovascular death and repeat revascularization at 5 years. Propensity score matching and stratified Cox regression were used to compare the two strategies.  Results—MI, cardiovascular death and repeat revascularization cumulative incidence was 2.3% (95%CI 1.1-3.4), 3.5% (95%CI 2.1-5.0) and 4.4% (95%CI 2.8-6.0) in the RA group and 3.4% (95%CI 2.0-4.8), 4.0% (95%CI 2.5-5.6) and 7.6% (95%CI 5.5- 9.7) in the SVG group respectively. The composite endpoint was significantly lower in the RA group (8.8%; 95%CI 6.5-11.0) when compared with the SVG group (13.6%; 95%CI 10.8-16.3) (P=0.005). This association was present when a RA graft was used to supplement both SITA and BITA grafts (interaction P=0.62).  Conclusions—This post-hoc ART analysis showed that an additional RA was associated with lower risk for mid-term major adverse cardiac events when used to supplement SITA or BITA grafts

Five-year costs from a randomised comparison of bilateral and single internal thoracic artery grafts

Background: The use of bilateral internal thoracic arteries (BITA) for coronary artery bypass grafting (CABG) may improve survival compared with CABG using single internal thoracic arteries (SITA). We assessed the long-term costs of BITA compared with SITA. Methods: Between June 2004 and December 2007, 3102 patients from 28 hospitals in seven countries were randomised to CABG surgery using BITA (n=1548) or SITA (n=1554). Detailed resource use data were collected from the initial hospital episode and annually up to 5 years. The associated costs of this resource use were assessed from a UK perspective with 5 year totals calculated for each trial arm and pre-selected patient subgroups. Results: Total costs increased by approximately £1000 annually in each arm, with no significant annual difference between trial arms. Cumulative costs per patient at 5-year follow-up remained significantly higher in the BITA group (£18 629) compared with the SITA group (£17 480; mean cost difference £1149, 95% CI £330 to £1968, p=0.006) due to the higher costs of the initial procedure. There were no significant differences between the trial arms in the cost associated with healthcare contacts, medication use or serious adverse events. Conclusions: Higher index costs for BITA were still present at 5-year follow-up mainly driven by the higher initial cost with no subsequent difference emerging between 1 year and 5 years of follow-up. The overall cost-effectiveness of the two procedures, to be assessed at the primary endpoint of the 10-year follow-up, will depend on composite differences in costs and quality-adjusted survival

SuperDCA for genome-wide epistasis analysis

The potential for genome-wide modelling of epistasis has recently surfaced given the possibility of sequencing densely sampled populations and the emerging families of statistical interaction models. Direct coupling analysis (DCA) has previously been shown to yield valuable predictions for single protein structures, and has recently been extended to genome-wide analysis of bacteria, identifying novel interactions in the co-evolution between resistance, virulence and core genome elements. However, earlier computational DCA methods have not been scalable to enable model fitting simultaneously to 10(4)-10(5) polymorphisms, representing the amount of core genomic variation observed in analyses of many bacterial species. Here, we introduce a novel inference method (SuperDCA) that employs a new scoring principle, efficient parallelization, optimization and filtering on phylogenetic information to achieve scalability for up to 10(5) polymorphisms. Using two large population samples of Streptococcus pneumoniae, we demonstrate the ability of SuperDCA to make additional significant biological findings about this major human pathogen. We also show that our method can uncover signals of selection that are not detectable by genome-wide association analysis, even though our analysis does not require phenotypic measurements. SuperDCA, thus, holds considerable potential in building understanding about numerous organisms at a systems biological level.Peer reviewe