Derek D. Cyr

Clinical outcomes of fractional flow reserve by computed tomographic angiography-guided diagnostic strategies vs. usual care in patients with suspected coronary artery disease: the prospective longitudinal trial of FFRCT: outcome and resource impacts study

Aims In symptomatic patients with suspected coronary artery disease (CAD), computed tomographic angiography (CTA) improves patient selection for invasive coronary angiography (ICA) compared with functional testing. The impact of measuring fractional flow reserve by CTA (FFRCT) is unknown. Methods and results At 11 sites, 584 patients with new onset chest pain were prospectively assigned to receive either usual testing (n = 287) or CTA/FFRCT (n = 297). Test interpretation and care decisions were made by the clinical care team. The primary endpoint was the percentage of those with planned ICA in whom no significant obstructive CAD (no stenosis ≥50% by core laboratory quantitative analysis or invasive FFR < 0.80) was found at ICA within 90 days. Secondary endpoints including death, myocardial infarction, and unplanned revascularization were independently and blindly adjudicated. Subjects averaged 61 ± 11 years of age, 40% were female, and the mean pre-test probability of obstructive CAD was 49 ± 17%. Among those with intended ICA (FFRCT-guided = 193; usual care = 187), no obstructive CAD was found at ICA in 24 (12%) in the CTA/FFRCT arm and 137 (73%) in the usual care arm (risk difference 61%, 95% confidence interval 53–69, P< 0.0001), with similar mean cumulative radiation exposure (9.9 vs. 9.4 mSv, P = 0.20). Invasive coronary angiography was cancelled in 61% after receiving CTA/FFRCT results. Among those with intended non-invasive testing, the rates of finding no obstructive CAD at ICA were 13% (CTA/FFRCT) and 6% (usual care; P = 0.95). Clinical event rates within 90 days were low in usual care and CTA/FFRCT arms. Conclusions Computed tomographic angiography/fractional flow reserve by CTA was a feasible and safe alternative to ICA and was associated with a significantly lower rate of invasive angiography showing no obstructive CAD.

Frailty is associated with worse outcomes in non-ST-segment elevation acute coronary syndromes: Insights from the TaRgeted platelet Inhibition to cLarify the Optimal strateGy to medicallY manage Acute Coronary Syndromes (TRILOGY ACS) trial

Aims: Little is known regarding consequences of frailty in patients with acute coronary syndrome (ACS). We assessed the associations of frailty and outcomes in ACS patients who were participating in a clinical trial. Methods and results: The TaRgeted platelet Inhibition to cLarify the Optimal strateGy to medicallY manage Acute Coronary Syndromes (TRILOGY ACS) trial randomized 9326 patients planned for medical management to prasugrel or clopidogrel. The primary endpoint was a composite of cardiovascular death, myocardial infarction (MI), or stroke over a period of 30 months. A frailty score based upon the Fried score was self-reported at baseline in patients aged ⩾65 years. Five frailty questions were recorded for 4996/5102 (97.9%) patients: 72.3% were classified as not-frail (0 items), 23.0% as pre-frail (1–2 items), and 4.7% as frail (⩾3 items). Increasing frailty score was associated with older age, diabetes, and higher Global Registry of Acute Coronary Events (GRACE) scores. Frailty was associated with a higher unadjusted incidence of the primary endpoint (pre-frail vs not-frail: 29.2% vs 23.1%; hazard ratio [HR]: 1.39; 95% confidence interval [CI]: 1.19–1.61; p<0.001; frail vs not-frail: 39.7% vs 23.1%; HR: 1.76; 95% CI: 1.36–2.28; p<0.001), and all-cause mortality (pre-frail vs not-frail: 21.7% vs 15.0%; HR: 1.45; 95% CI: 1.22–1.73; p<0.001; frail vs not-frail: 30.2% vs 15.0%; HR: 1.98; 95% CI: 1.47–2.68; p<0.001). After adjustment for baseline characteristics and GRACE covariates, frailty remained independently associated with the primary endpoint: pre-frail vs not-frail, HR: 1.33; 95% CI: 1.15–1.54; p<0.001; frail vs not-frail, HR: 1.52; 95% CI: 1.18–1.98; p=0.002. There was no association of frailty with bleeding. Conclusion: Frailty is associated with the composite of cardiovascular death, MI, or stroke. Frailty assessment contributes to risk prediction and adds to the GRACE score.

Ticagrelor Versus Clopidogrel in Patients With Acute Coronary Syndromes and Chronic Obstructive Pulmonary Disease: An Analysis From the Platelet Inhibition and Patient Outcomes (PLATO) Trial

Background Patients with chronic obstructive pulmonary disease (COPD) experiencing acute coronary syndromes (ACS) are at high risk for clinical events. In the Platelet Inhibition and Patient Outcomes (PLATO) trial, ticagrelor versus clopidogrel reduced the primary endpoint of death from vascular causes, myocardial infarction, or stroke after ACS, but increased the incidence of dyspnea, which may lead clinicians to withhold ticagrelor from COPD patients. Methods and Results In 18 624 patients with ACS randomized to treatment with ticagrelor or clopidogrel, history of COPD was recorded in 1085 (5.8%). At 1 year, the primary endpoint occurred in 17.7% of patients with COPD versus 10.4% in those without COPD (P<0.001). The 1‐year event rate for the primary endpoint in COPD patients treated with ticagrelor versus clopidogrel was 14.8% versus 20.6% (hazard ratio [HR]=0.72; 95% confidence interval [CI]: 0.54 to 0.97), for death from any cause 8.4% versus 12.4% (HR=0.70; 95% CI: 0.47 to 1.04), and for PLATO‐defined major bleeding rates at 1 year 14.6% versus 16.6% (HR=0.85; 95% CI: 0.61 to 1.17). Dyspnea occurred more frequently with ticagrelor (26.1% vs. 16.3%; HR=1.71; 95% CI: 1.28 to 2.30). There was no differential increase in the relative risk of dyspnea compared to non‐COPD patients (HR=1.85). No COPD status‐by‐treatment interactions were found, showing consistency with the main trial results. Conclusions In this post‐hoc analysis, COPD patients experienced high rates of ischemic events. Ticagrelor versus clopidogrel reduced and substantially decreased the absolute risk of ischemic events (5.8%) in COPD patients, without increasing overall major bleeding events. The benefit‐risk profile supports the use of ticagrelor in patients with ACS and concomitant COPD. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00391872.

Gene expression-based classifiers identify Staphylococcus aureus infection in mice and humans.

Staphylococcus aureus causes a spectrum of human infection. Diagnostic delays and uncertainty lead to treatment delays and inappropriate antibiotic use. A growing literature suggests the host’s inflammatory response to the pathogen represents a potential tool to improve upon current diagnostics. The hypothesis of this study is that the host responds differently to S. aureus than to E. coli infection in a quantifiable way, providing a new diagnostic avenue. This study uses Bayesian sparse factor modeling and penalized binary regression to define peripheral blood gene-expression classifiers of murine and human S. aureus infection. The murine-derived classifier distinguished S. aureus infection from healthy controls and Escherichia coli-infected mice across a range of conditions (mouse and bacterial strain, time post infection) and was validated in outbred mice (AUC>0.97). A S. aureus classifier derived from a cohort of 94 human subjects distinguished S. aureus blood stream infection (BSI) from healthy subjects (AUC 0.99) and E. coli BSI (AUC 0.84). Murine and human responses to S. aureus infection share common biological pathways, allowing the murine model to classify S. aureus BSI in humans (AUC 0.84). Both murine and human S. aureus classifiers were validated in an independent human cohort (AUC 0.95 and 0.92, respectively). The approach described here lends insight into the conserved and disparate pathways utilized by mice and humans in response to these infections. Furthermore, this study advances our understanding of S. aureus infection; the host response to it; and identifies new diagnostic and therapeutic avenues.

Characterization of serum proteins associated with IL28B genotype among patients with chronic hepatitis C.

Introduction Polymorphisms near the IL28B gene (e.g. rs12979860) encoding interferon λ3 have recently been associated with both spontaneous clearance and treatment response to pegIFN/RBV in chronic hepatitis C (CHC) patients. The molecular consequences of this genetic variation are unknown. To gain further insight into IL28B function we assessed the association of rs12979860 with expression of protein quantitative traits (pQTL analysis) generated using open-platform proteomics in serum from patients. Methods 41 patients with genotype 1 chronic hepatitis C infection from the Duke Liver Clinic were genotyped for rs12979860. Proteomic profiles were generated by LC-MS/MS analysis following immunodepletion of serum with MARS14 columns and trypsin-digestion. Next, a latent factor model was used to classify peptides into metaproteins based on co-expression and using only those peptides with protein identifications. Metaproteins were then analyzed for association with IL28B genotype using one-way analysis of variance. Results There were a total of 4,186 peptides in the data set with positive identifications. These were matched with 253 proteins of which 110 had two or more associated, identified peptides. The IL28B treatment response genotype (rs12979860_CC) was significantly associated with lower serum levels of corticosteroid binding globulin (CBG; p = 9.2×10−6), a major transport protein for glucocorticoids and progestins. Moreover, the CBG metaprotein was associated with treatment response (p = 0.0148), but this association was attenuated when both IL28B genotype and CBG were included in the model, suggesting that the CBG association may be independent of treatment response. Conclusions In this cohort of chronic hepatitis C patients, IL28B polymorphism was associated with serum levels of corticosteroid binding globulin, a major transporter of cortisol, however, CBG does not appear to mediate the association of IL28B with treatment response. Further investigation of this pathway is warranted to determine if it plays a role in other comorbidities of HCV-infection.

Plasma proteomics of patients with non-valvular atrial fibrillation on chronic anti-coagulation with warfarin or a direct factor Xa inhibitor

Plasma proteins mediate thrombogenesis, inflammation, endocardial injury and structural remodelling in atrial fibrillation (AF). We hypothesised that anti-coagulation with rivaroxaban, a direct factor Xa inhibitor, would differentially modulate biologically-relevant plasma proteins, compared with warfarin, a multi-coagulation protein antagonist. We performed unbiased liquid chromatography/tandem mass spectroscopy and candidate multiplexed protein immunoassays among Japanese subjects with non-valvular chronic AF who were randomly assigned to treatment with 24 weeks of rivaroxaban (n=93) or warfarin (n=94). Nine metaproteins, including fibulin-1 (p=0.0033), vitronectin (p=0.0010), haemoglobin α (p=0.0012), apolipoproteins C-II (p=0.0017) and H (p=0.0023), complement C5 precursor (p=0.0026), coagulation factor XIIIA (p=0.0026) and XIIIB (p=0.0032) subunits, and 10 candidate proteins, including thrombomodulin (p=0.0004), intercellular adhesion molecule-3 (p=0.0064), interleukin-8 (p=0.0007) and matrix metalloproteinase-3 (p=0.0003), were differentially expressed among patients with and without known clinical risk factors for stroke and bleeding in AF. Compared with warfarin, rivaroxaban treatment was associated with a greater increase in thrombomodulin (Δ 0.1 vs. 0.3 pg/ml, p=0.0026) and a trend towards a reduction in matrix metalloproteinase-9 (Δ 2.2 vs. -4.9 pg/ml, p=0.0757) over 24 weeks. Only modest correlations were observed between protein levels and prothrombin time, factor Xa activity and prothrombinase-induced clotting time. Plasma proteomics can identify distinct functional patterns of protein expression that report on known stroke and bleeding risk phenotypes in an ethnically-homogeneous AF population. The greater upregulation of thrombomodulin among patients randomised to rivaroxaban represents a proof-of-principle that pharmacoproteomics can be employed to discern novel effects of factor Xa inhibition beyond standard pharmacodynamic measures.

Dusp3 and Psme3 Are Associated with Murine Susceptibility to Staphylococcus aureus Infection and Human Sepsis

Using A/J mice, which are susceptible to Staphylococcus aureus, we sought to identify genetic determinants of susceptibility to S. aureus, and evaluate their function with regard to S. aureus infection. One QTL region on chromosome 11 containing 422 genes was found to be significantly associated with susceptibility to S. aureus infection. Of these 422 genes, whole genome transcription profiling identified five genes (Dcaf7, Dusp3, Fam134c, Psme3, and Slc4a1) that were significantly differentially expressed in a) S. aureus –infected susceptible (A/J) vs. resistant (C57BL/6J) mice and b) humans with S. aureus blood stream infection vs. healthy subjects. Three of these genes (Dcaf7, Dusp3, and Psme3) were down-regulated in susceptible vs. resistant mice at both pre- and post-infection time points by qPCR. siRNA-mediated knockdown of Dusp3 and Psme3 induced significant increases of cytokine production in S. aureus-challenged RAW264.7 macrophages and bone marrow derived macrophages (BMDMs) through enhancing NF-κB signaling activity. Similar increases in cytokine production and NF-κB activity were also seen in BMDMs from CSS11 (C57BL/6J background with chromosome 11 from A/J), but not C57BL/6J. These findings suggest that Dusp3 and Psme3 contribute to S. aureus infection susceptibility in A/J mice and play a role in human S. aureus infection.

Chronic obstructive pulmonary disease in patients with atrial fibrillation: Insights from the ARISTOTLE trial.

BACKGROUND Comorbid chronic obstructive pulmonary disease (COPD) is associated with poor outcomes among patients with cardiovascular disease. The risks of stroke and mortality associated with COPD among patients with atrial fibrillation are not well understood. METHODS We analyzed patients from ARISTOTLE, a randomized trial of 18,201 patients with atrial fibrillation comparing the effects of apixaban versus warfarin on the risk of stroke or systemic embolism. Using Cox proportional hazards models, we assessed the associations between comorbid COPD and risk of stroke or systemic embolism and of mortality, adjusting for treatment allocation, smoking history and other risk factors. RESULTS COPD was present in 1950 (10.8%) of 18,134 patients with data on pulmonary disease history. After multivariable adjustment, COPD was not associated with risk of stroke or systemic embolism (adjusted HR 0.85 [95% CI 0.60, 1.21], p=0.356). However, COPD was associated with a higher risk of all-cause mortality (adjusted HR 1.60 [95% CI 1.36, 1.88], p<0.001) and both cardiovascular and non-cardiovascular mortality. The benefit of apixaban over warfarin on stroke or systemic embolism was consistent among patients with and without COPD (HR 0.92 [95% CI 0.52, 1.63] versus 0.78 [95% CI 0.65, 0.95], interaction p=0.617). CONCLUSIONS COPD was independently associated with increased risk of cardiovascular and non-cardiovascular mortality among patients with atrial fibrillation, but was not associated with risk of stroke or systemic embolism. The effect of apixaban on stroke or systemic embolism in COPD patients was consistent with its effect in the overall trial population.

ACLY and ACC1 Regulate Hypoxia-Induced Apoptosis by Modulating ETV4 via α-ketoglutarate.

In order to propagate a solid tumor, cancer cells must adapt to and survive under various tumor microenvironment (TME) stresses, such as hypoxia or lactic acidosis. To systematically identify genes that modulate cancer cell survival under stresses, we performed genome-wide shRNA screens under hypoxia or lactic acidosis. We discovered that genetic depletion of acetyl-CoA carboxylase (ACACA or ACC1) or ATP citrate lyase (ACLY) protected cancer cells from hypoxia-induced apoptosis. Additionally, the loss of ACLY or ACC1 reduced levels and activities of the oncogenic transcription factor ETV4. Silencing ETV4 also protected cells from hypoxia-induced apoptosis and led to remarkably similar transcriptional responses as with silenced ACLY or ACC1, including an anti-apoptotic program. Metabolomic analysis found that while α-ketoglutarate levels decrease under hypoxia in control cells, α-ketoglutarate is paradoxically increased under hypoxia when ACC1 or ACLY are depleted. Supplementation with α-ketoglutarate rescued the hypoxia-induced apoptosis and recapitulated the decreased expression and activity of ETV4, likely via an epigenetic mechanism. Therefore, ACC1 and ACLY regulate the levels of ETV4 under hypoxia via increased α-ketoglutarate. These results reveal that the ACC1/ACLY-α-ketoglutarate-ETV4 axis is a novel means by which metabolic states regulate transcriptional output for life vs. death decisions under hypoxia. Since many lipogenic inhibitors are under investigation as cancer therapeutics, our findings suggest that the use of these inhibitors will need to be carefully considered with respect to oncogenic drivers, tumor hypoxia, progression and dormancy. More broadly, our screen provides a framework for studying additional tumor cell stress-adaption mechanisms in the future.

Impact of Human Development Index on the profile and outcomes of patients with acute coronary syndrome

Objective To study the impact of national economic and human development status on patient profiles and outcomes in the setting of acute coronary syndrome (ACS). Methods We conducted a retrospective analysis of the Targeted Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes trial (TRILOGY ACS) population (51 countries; 9301 patients). Outcome measures compared baseline characteristics and clinical outcomes through 30 months by 2010 country-level United Nations Human Development Indices (HDIs) and per-capita gross national income. Results TRILOGY ACS enrolled 3659 patients from 27 very-high HDI countries, 3744 from 18 high-HDI countries and 1898 from 6 medium-HDI countries. Baseline characteristics of groups varied significantly, with the medium-HDI group having a lower mean age (63.0 years, vs 65.0 and 68.0 years for high-HDI and very-high HDI, respectively; p<0.001), lower baseline Global Registry of Acute Coronary Events risk score and lower rate of non-ST-segment elevation myocardial infarction (58.0%, vs 62.2% and 83.9% among high-HDI and very-high HDI, respectively). Medium-HDI and high-HDI patients had lower unadjusted 30-month rates for the composite of cardiovascular death/myocardial infarction/stroke (17.6%, 16.9% and 23.1% for medium-HDI, high-HDI and very-high HDI, respectively); this difference disappeared after adjusting for baseline characteristics. Adjusted HRs for the composite endpoint were lower in lower-income/middle-income countries vs upper-income/middle-income (0.791(95% CI 0.632 to 0.990)) and high-income countries (0.756 (95% CI 0.616 to 0.928)), with differences largely attributable to myocardial infarction rates. Conclusions Clinical patient profiles differed substantially by country HDI groupings. Lower unadjusted event rates in medium-HDI countries may be explained by younger age and lower comorbidity burden among these countries’ patients. This heterogeneity in patient recruitment across country HDI groupings may have important implications for future global ACS trial design. Trial registration number NCT00699998.