Aptamer proteomics for biomarker discovery in heart failure with reduced ejection fraction

Background

Though current heart failure (HF) biomarkers are highly prognostic, systematically characterizing associations between circulating proteins and risk of subsequent events may improve clinical risk prediction and illuminate new biological pathways. Large-scale assays measuring thousands of proteins now enable unbiased proteomic investigation in clinical trials.

Purpose

To identify and replicate serum proteins associated with HF events in patients with chronic HF with reduced ejection fraction (HFrEF), and to develop and validate a proteomic risk score.

Methods

Serum levels of 4076 proteins were measured at baseline in the ATMOSPHERE (n=1261, 487 events over 6 years) and PARADIGM-HF (n=1257, 287 events over 4 years) trials of chronic HFrEF using a modified aptamer-based proteomics assay. Proteins associated with the primary endpoint, HF hospitalization or cardiovascular death, were identified in the ATMOSPHERE discovery cohort (false discovery rate<0.05) by Cox regression adjusted for age, sex, treatment arm, and anticoagulant use, and replicated in PARADIGM-HF (Bonferroni-corrected p<0.05). A proteomic risk score was derived in ATMOSPHERE using Cox LASSO penalized regression and evaluated in PARADIGM-HF compared to the MAGGIC clinical risk score and N-terminal pro-B-type natriuretic peptide (NT-proBNP). For proteins associated with the primary endpoint, pathway analysis was conducted using Ingenuity Pathway analysis and an exploratory two-sample Mendelian randomization was performed using genetic and outcome data from both trials and protein quantitative trait loci from deCODE to infer which identified proteins contribute to HF prognosis.

Results

We identified 377 serum proteins associated with the primary endpoint in ATMOSPHERE and replicated 167 in PARADIGM-HF. Prognostic proteins included known HF biomarkers Growth Differentiation Factor 15, NT-proBNP, and Angiopoietin-2, and also a previously unrecognized HF biomarker: Sushi, Von Willebrand Factor Type A, EGF And Pentraxin Domain Containing 1 (SVEP1) (HR 1.60 [95% CI 1.44–1.79] per standard deviation [SD], p=2x10–17) (Table 1). Proteins related to hepatic fibrosis, granulocyte adhesion, and inhibition of matrix metalloproteinases were over-represented. A 64-protein risk score derived in ATMOSPHERE predicted clinical events in PARADIGM-HF with greater discrimination (c-statistic 0.70) than the MAGGIC clinical score (c-statistic 0.61), NT-proBNP (c-statistic 0.65), or both (c-statistic 0.66) (Figure 1). Genetically predicted levels of NT-proBNP, WISP2, FSTL1, and CTSS were associated with the primary endpoint by Mendelian randomization.

Conclusions

We identify SVEP1, an extracellular matrix protein known to cause inflammation in vascular smooth muscle cells, as a previously unrecognized HF biomarker. A 64-protein score improved risk discrimination compared with NT-proBNP and may assist in identifying high-risk patients for clinical trials or disease management programs.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The ATMOSPHERE and PARADIGM-HF trials were sponsored by Novartis

Association of heart rate with heart failure outcomes and the effects of empagliflozin in patients with preserved ejection fraction – EMPEROR-Preserved trial

Background and objective

High resting heart rate (HR) associates with cardiovascular death (CVD) and heart failure hospitalisation (HFH) in patients with reduced ejection fraction (HFrEF), but data are sparse in patients with preserved (HFpEF) or mildly reduced (HFmrEF) ejection fraction. Empagliflozin reduced the risk of CVD and HFH in HFpEF in the EMPEROR-Preserved trial. This study analyses the influence of HR on outcomes in patients with left ventricular ejection fraction (LVEF) >40% in EMPEROR-Preserved and evaluates the effects of empagliflozin across HR categories.

Methods

Patients (n=5988) with HFpEF (LVEF >40%) were categorised to HR <70 beats per minute (bpm), 70–75 bpm and >75 bpm. The composite of CVD or HFH (primary outcome), first HFH, CVD, recurrent HFH and all-cause mortality were studied in the HR groups and in patients separated by sinus rhythm (SR) or atrial fibrillation (AF) and true HFpEF (EF ≥50%) or HFmrEF (EF 40–49%).

Results

Empagliflozin did not influence HR over time. At HR >75 bpm, the primary outcome (hazard ratio: 1.31, 1.13–1.52, p=0.0003), time to first HFH (hazard ratio: 1.25, 1.04–1.49, p=0.02), recurrent HFH (hazard ratio: 1.29, 1.05–1.60, p=0.02), CVD (hazard ratio: 1.49, 1.21–1.84, p=0.0001) and all-cause mortality (hazard ratio: 1.49, 1.28–1.73, p<0.0001) were increased compared to HR of <70 bpm with HR 70–75 bpm showing intermediate results. The influence of HR on the primary outcome was only observed in SR (p trend=0.005), but not in AF (p trend=0.55). Patients with true HFpEF (≥50%) or HFmrEF (40–49%) showed similar effects. The treatment effects of empagliflozin to reduce the primary outcome, time to first HFH and recurrent HFH were not modified by HR.

Conclusions

HR in SR, but not in AF, predicts heart failure outcomes in HFpEF and HFmrEF, but the effects of empagliflozin were not modified by HR.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim & Eli Lilly and Company Diabetes Alliance

A comprehensive study of the incremental prognostic value of novel biomarkers in PARADIGM-HF (Bio-PREDICT-HF)

Background

Although multiple novel biomarkers have individually been shown to predict outcomes in patients with HFrEF, the value of these over and above conventional clinical and laboratory variables, plus natriuretic peptides, is uncertain.

Purpose

To test the incremental predictive value of 11 novel biomarkers added to a recent prognostic model 1 (PREDICT-HF) derived in PARADIGM-HF and validated in ATMOSPHERE and the Swedish heart failure registry. The PREDICT-HF model includes clinical variables, standard laboratory variables, and BNP or NT-proBNP.

Methods

1559 participants enrolled in PARADIGM-HF had all 11 biomarkers of interest measured. These reflected different pathophysiological pathways: (i) myocyte injury (high sensitivity cardiac troponin T), (ii) cardiac remodelling and inflammation (growth stimulation expressed gene 2, growth differentiation factor-15 and galectin-3), (iii) extracellular matrix remodelling (matrix metalloproteinase-2, matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1), (iv) neurohormonal pathways (aldosterone) and (v) renal dysfunction and injury (cystatin C, kidney injury molecule-1 and urinary albumin to creatinine ratio). The incremental prognostic value of these biomarkers was evaluated using Harrell's C statistic.

Results

The mean age of participants studied was 67.3 (SD 9.9) years, 1254 (80%) were men and 1103 (71%) were in NYHA class II. During a median follow-up of 31 months, 197 patients died and 300 experienced the primary composite outcome (cardiovascular death or heart failure hospitalization).

When each candidate biomarker (log unit) was added individually to the PREDICT-HF base model, GDF-15, ST2, TIMP1, cystatin C, hsTnT and UACR were independent predictors of all-cause mortality (Table 1). GDF-15, TIMP1, hs-TnT and cystatin C consistently increased the risk of both all-cause mortality and the primary outcome. Individuals who had all 4 biomarkers elevated (compared to none elevated) had the highest risk: HR for all-cause mortality 3.65 (2.01–6.64), p<0.0001. Adding these 4 biomarkers to the baseline PREDICT HF model improved the C statistic for all-cause mortality from 0.726 to 0.745.

Conclusion

Several novel biomarkers provide meaningful additional prognostic information in patients with HFrEF. A multimarker approach incorporating biomarkers reflecting different pathophysiological pathways added most information. This approach may be useful in refining risk and targeting treatment.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): The PARADIGM-HF trial was funded by Novartis.J.J.V.M is supported by a British Heart Foundation Centre of Excellence Grant

History of stroke in patients with heart failure: prevalence, baseline characteristics and clinical outcomes

Background

Stroke is an important but neglected comorbidity in patients with heart failure (HF). Little is known about the characteristics and outcomes of HF patients with a history of stroke.

Purpose

To examine the prevalence of prior stroke in patients with HF and reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), the clinical characteristics of patients with a history of stroke, and the clinical outcomes in patients with prior stroke compared to those without.

Methods

Individual patient data analysis using three recent HFrEF trials (ATMOSPHERE, PARADIGM-HF, and DAPA-HF) and HFpEF trials (CHARM-Preserved, I-Preserve, TOPCAT-Americas, and PARAGON-HF). Cox regression was used to analyze clinical outcomes.

Results

Among 20159 HFrEF patients enrolled, 1683 (8.3%) had a history of stroke and among the 13252 patients with HFpEF 1287 (9.7%) had a prior stroke. Compared to patients without stroke, those with stroke were slightly older and more likely to have a history of hypertension, myocardial infarction, atrial fibrillation, diabetes, carotid artery disease, and peripheral artery disease (for both HFrEF and HFpEF). Patients with a history of stroke had worse NYHA class and KCCQ scores, and a higher rate of fatigue; they also had a higher median NT-proBNP level and lower eGFR than those without prior stroke (whether HFrEF or HFpEF). Systolic BP, pulse pressure and LVEF did not differ susbtantialy between patients with and without a history of stroke. The table shows outcomes according to history of stroke or not, stratified by LVEF phenotype. During follow-up, all fatal and non-fatal outcomes were significantly more common in patients with a history of stroke. The augmentation of risk tended to be greater in patients with HFpEF than HFrEF, but was not statistically different.

Conclusion

Approximately 1 in 11 patients in recent HF trials had a history of stroke and these patients were at higher risk of fatal and non-fatal events than those without prior stroke. HF hospitalization as well as atherothrombotic events (myocardial infarction and stroke) were more common among patients with prior stroke – patients with prior stroke had at least 30% higher risk of all events examined, regardless of LVEF, and more than double incidence of repeat stroke.

Funding Acknowledgement

Type of funding sources: Other.

Stroke in patients with heart failure and reduced ejection fraction without atrial fibrillation: external validation of a risk model

Background

Heart failure (HF) ranks only second to atrial fibrillation (AF) as a cause of cardio-embolic stroke. Although anticoagulation reduces this risk in HF patients not in AF, the risk/benefit profile in relatively unselected populations is not favourable. Identification of patients at high risk of stroke may allow targeted and safer use of prophylactic anticoagulant therapy. Previously, we proposed a simple risk model for stroke in patients with HF and reduced ejection fraction (HFrEF). However, this model was derived from the two older trials (published in 2007/2008) and was not externally validated.

Purpose

We aimed to evaluate the current incidence of stroke in patients with HFrEF not in AF receiving modern pharmacological therapy and to validate our stroke prediction model.

Methods

We examined patient-level data from the PARADIGM-HF, ATMOSPHERE, and DAPA-HF trials. The risk score was calculated following: 7.39×(insulin-treated diabetes) + 6.53×(previous stroke) + 2.80×[ln(NT-proBNP (pg/ml)) × 0.1182]). According to the tertile of risk score, we divided the patients into three groups. Patients with AF were defined as those with either AF on an ECG or a history of AF.

Results

Of the total of 20,159 patients (who experienced 590 strokes) enrolled in the three trials, 12,751 patients did not have AF at baseline. Of those, 1,143 patients (9%) had insulin-treated diabetes, 873 patients (6.8%) had a history of the previous stroke, and the median value of NT-proBNP was 1,243 pg/ml. During a median follow-up of 2.0 years, 346 (2.7%) experienced a stroke (11.7 per 1000 patient-years). Figure 1 shows cumulative incidence function plots for stroke according to the tertile of risk score in 12,331 patients whose risk score can be calculated. The number of strokes in tertile 1, 2 and 3 were 80, 102 and 149, respectively. The 3-year cumulative incidence function rates of stroke were 2.0 (95% CI: 1.5–2.5) % in tertile 1, 2.6 (95% CI: 2.1–3.2) % in tertile 2, and 4.3 (95% CI: 3.6–5.2) % in tertile 3, respectively. In patients with tertile 3, the stroke rate was 18.1 per 1000 patient-years (compared to 20.1 per 1000 patient-years in patients with AF not receiving anticoagulation). In the Cox model, risk for stroke increased according to the elevation in the risk score (tertile 2: HR 1.47 (95% CI 1.09–1.97), tertile 3: HR 2.53 (95% CI 1.92–3.33), with tertile 1 as reference). Figure 2 shows calibration plots by comparing observed and predicted probabilities of stroke at 1 to 3 years. Discrimination evaluated using the overall c-index 0.84 (95% CI: 0.75–0.91) was good.

Conclusions

These findings validate a previously described predictive model and confirm that it is possible to identify a subset of HFrEF patients without AF who have a risk of stroke that approximates to that in patients with AF. In these patients, the risk/benefit balance might justify the use of prophylactic anticoagulation, but this hypothesis needs to be tested prospectively.

Funding Acknowledgement

Type of funding sources: Foundation.

Prognostic implications of NYHA class and NT-proBNP levels in mild heart failure: a PARADIGM-HF analysis

Background

Treatment recommendations for heart failure (HF) with reduced ejection fraction are primarily centered on New York Heart Association (NYHA) classification, such that apparently asymptomatic patients might not be eligible for disease-modifying therapies. NYHA classification, however, may be particularly limited to discriminate mild forms of HF.

Purpose

The present study aimed to determine the relationship between NYHA classification and an objective measure of HF severity (N-terminal pro–B-type natriuretic peptide [NT pro-BNP]), and their association with long-term prognosis in the PARADIGM-HF trial.

Methods

We compared PARADIGM-HF patients classified as NYHA class I, II, and III at randomization (NYHA class IV patients or with unavailable NYHA class were excluded [n=73]). We present kernel density estimation (KDE) plots–a non-parametric way to describe the underlying distribution of a variable–to compare NT-proBNP levels across NYHA classes. Logistic regression and the area under the receiver operating characteristic curve (AUC) were used to assess the ability to predict a patient's NYHA class using NT-proBNP levels. Time-to-event data were calculated with Kaplan–Meier estimates and NYHA class were further stratified by median baseline NT-proBNP (< or ≥1600 pg/ml). The primary outcome was cardiovascular death or first HF hospitalization.

Results

8326 patients were included in this analysis (median age, 64 years; women, 22%; and median left ventricular ejection fraction, 30%). Of 389 patients classified as NYHA class I at randomization, 228 (59%) changed functional class during the first year after randomization. For log-transformed NT-proBNP, KDE overlapped substantially across NYHA classes (Figure 1A). NT-proBNP levels were a poor predictor of NYHA classification: for NYHA class I vs. II, AUC (95% confidence interval [CI]) was 0.51 (0.48–0.54); for NHYA I vs. III, 0.57 (0.54–0.60); and for NYHA II vs. III, 0.56 (0.54–0.57). NYHA class III patients displayed a distinctively higher rate of cardiovascular deaths or first HF hospitalizations (Figure 1B). NYHA class I and II patients revealed lower event rates that were not significantly different (NYHA II vs. I, HR 1.24 [0.97–1.58]). Stratification by NT-proBNP levels identified subgroups with distinctive risk, such that NYHA I patients with high NT-proBNP levels (n=175) had a higher event rate than patients with low NT-proBNP with any NYHA class (Figure 1C).

Conclusion

NYHA class I and II patients overlapped substantially in objective HF measures and long-term prognosis. NYHA classification remains a powerful predictor of cardiovascular events but might be limited to differentiate mild forms of HF, as apparently asymptomatic patients based on physician-defined functional class might become symptomatic within a year and conceal subjects at substantial risk for adverse outcomes.

Funding Acknowledgement

Type of funding sources: None.

Alkaline phosphatase and bilirubin combined are a powerful predictor of outcome in patients with heart failure and reduced ejection fraction: an analysis of the ATMOSPHERE and PARADIGM-HF trials

Introduction

Bilirubin is a recognized predictor of adverse outcomes in patients with heart failure and reduced ejection fraction (HFrEF), possibly because it is a marker of congestion. Alkaline phosphatase (ALP) is an enzyme produced in many tissues including the biliary ducts and elevated levels are also associated with congestion.

Purpose

To examine the prognostic value of ALP alone and in combination with bilirubin in patients with HFrEF.

Methods

The study population was ambulatory patients with HFrEF enrolled in 2 recent clinical trials with similar inclusion and exclusion criteria: ATMOSPHERE (derivation cohort) and PARADIGM-HF (validation). Cut points to define elevated bilirubin and alkaline phosphatase were >17mg/dL and >120 U/L respectively. The composite of cardiovascular death or HF hospitalization, its components, and all-cause death related to elevation of one, other or both of bilirubin and ALP was examined using Cox regression. Univariable and multivariable models with adjustment for other recognized prognostic variables including NT-proBNP were analyzed.

Results

Of 7016 patients with HFrEF enrolled in ATMOSPHERE, 6870 had a measurement of both bilirubin and ALP at baseline: mean age 63 years, 22% women, mean LVEF 28% and proportion NYHA class III/IV 37%. Bilirubin and ALP were both normal in 4810 (70.0%) patients, bilirubin was elevated in 1393 (20.3%), ALP was elevated in 360 (5.2%) and both were elevated in 307 (4.5%) patients. Patients with elevation of both ALP and bilirubin were older, had lower systolic blood pressure, higher heart rate, higher NT-pro BNP, more clinical features of congestion, more atrial fibrillation and a greater proportion were treated with diuretics and digoxin. The primary endpoint rates (per 100 person-years) were 10.4 (95% CI 9.9–11.0) when both markers were normal, 15.1 (13.9–16.4) when bilirubin was elevated, 12.4 (10.4–14.9) when alkaline phosphatase was elevated, and 25.6 (22.0–29.9) when both markers were elevated (Figure 1). The adjusted hazard ratios (95% CI) were (both biomarkers normal = reference): elevated bilirubin 1.19 (1.07–1.31), P=0.001; elevated ALP 1.03 (0.84–1.26), P=0.81; both elevated 1.45 (1.21–1.73), P<0.001. Elevation of both bilirubin and ALP was a significant independent predictor of the components of the primary outcome and all-cause death, the corresponding hazard ratios for all cause death were 1.12 (0.99–1.25), p=0.06; 1.19 (0.96–1.47), p=0.12; and 1.51 (1.25–1.82), p<0.001. These findings were validated in PARADIGM-HF (Table 1).

Conclusions

Elevation of ALP in combination with elevated bilirubin identifies a small group of patients at very high risk of adverse outcomes. This may reflect more significant congestion. ALP and bilirubin, inexpensive and routinely measured biochemical tests, are useful prognostic markers in patients with HFrEF.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship.

Prevalent and incident anaemia in PARADIGM-HF and effect of sacubitril/valsartan

Background

Anaemia is common in patients with HFrEF and is associated with poor clinical outcomes. Although they reduce rates of mortality and heart failure hospitalization, renin-angiotensin (RAS) blockers lower haemoglobin and may induce anaemia. Concomitant neprilysin inhibition might ameliorate this effect of RAS blockers.

Purpose

We investigated the effect of sacubitril/valsartan compared with enalapril on clinical outcomes, according to anaemia status, and on haemoglobin levels in PARADIGM-HF.

Methods

Patient characteristics and clinical outcomes were compared between patients with and without anaemia (defined as haemoglobin <120 g/L in women and <130 g/L in men) at baseline. We investigated the effect of randomized treatment (sacubitril/valsartan or enalapril) on clinical outcomes according to anaemia status at screening. We also examined the effect of treatment on change in haemoglobin from baseline and on the incidence of anaemia. The primary endpoint in PARADIGM-HF was the composite of heart failure hospitalization or cardiovascular death.

Results

Of 8239 participants with a baseline haemoglobin measurement, 1677 (20.4%) were anaemic. Compared to those without anaemia, patients with anaemia had a more severe heart failure profile, worse kidney function, greater neurohormonal derangement and worse clinical outcomes. Sacubitril/valsartan, compared to enalapril, reduced the risk of the primary endpoint similarly in patients with anaemia (HR 0.84, 95% CI 0.71–1.00) and without anaemia (HR 0.78, 95% CI 0.71–0.87), p-value for interaction=0.478. Between baseline and 12 months, haemoglobin decreased by 1.5 (95% CI 1.7 to 1.2) g/L with sacubitril/valsartan compared with 2.3 (2.6 to 2.0) g/L with enalapril group: mean difference 0.8 (95% CI 0.5 to 1.2) g/L, p<0.001. The between-treatment difference apparent by 12 months, persisted up to 36 months. Patients assigned to sacubitril/valsartan were less likely to develop new anaemia at 12 months [321 of 2806 (11.4%)] compared to patients randomized to enalapril [440 of 2384 (15.6%)], odds ratio 0.70 (95% CI 0.60–0.81), p<0.001.

Conclusions

Compared to enalapril, sacubitril/valsartan reduced mortality and hospitalization in HFrEF patients with and without anaemia. Haemoglobin decreased less with sacubitril/valsartan and the incidence of new anaemia was lower in the sacubitril/valsartan group compared with the enalapril group.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): PARADIGM-HF was funded by Novartis.

Implications of the 2021 CKD-EPI cystatin C/creatinine eGFR equation for eligibility for therapy in HFrEF: insights from PARADIGM-HF

Background

Estimated glomerular filtration rate (eGFR) is a key determinant of eligibility for many life-saving therapies in HFrEF. Recently, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) provided new equations based on creatinine (CKD-EPIcr), cystatin C (CKD-EPIcys) or both (CKD-EPIcyscr) that do not include race. These new equations may reclassify individuals, irrespective of race, from one eGFR category to another, with implications for eligibility for HFrEF treatments.

Purpose

To assess the difference between eGFR estimation using the 2021 CKD-EPIcyscr equation and the 2009 CKD-EPIcr and Modification of Diet in Renal Disease Study (MDRD)-4 equations which are still standard in many European laboratories.

Methods

We included patients from PARADIGM-HF with cystatin C and creatinine values available at the time of randomization. For each patient, baseline eGFRs were calculated using the 3 equations described. Our focus was on patients with chronic kidney disease (CKD) stages III–V.

Results

Overall, 1910 patients were eligible. Mean age was 67.3 (10.1) year and 385 (18.7%) were female. Using 2009 CKD-EPIcr, 779 patients were in CKD stages 3–5, of which 233 (30%) were reclassified to a better CKD stage (higher eGFR) with the 2021 CKD-EPIcyscr equation (Table 1). Similar reclassification was seen when comparing MDRD-4 with the 2021 CKD-EPIcyscr equation: 277 (33%) of 831 patients in CKD stages 3–5 were reclassified to a better CKD stage (Figure 1).

Conclusions

The 2021 CKD-EPIcyscr equation favourably reclassified CKD stage in a large percentage of patients with HFrEF and a low eGFR, potentially increasing the proportion of these patients considered eligible for guideline-recommended therapies.

Funding Acknowledgement

Type of funding sources: None.

Transvesical robotic excision of a Müllerian duct remnant

Müllerian duct remnants are rare and found in patients with disorders of sexual development. Presenting symptoms vary and many parents opt for surgical management. Literature on robotic repair is limited to small series, single case reports and all were approached extravesically. We present our case of a unique transvesical approach. Perioperative parameters were favorable with no complications, suggesting robotic repair is a safe and effective treatment strategy for these unique patients.

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Mullerian duct remnants (MDR) can occur as part of a disorder of sexual development.

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Symptoms can include lower urinary tract symptoms, pain, and hematuria.

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Robotic repair is safe, with favorable perioperative outcomes.

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Transvesical approach may be optimal based on anatomy and fertility concerns.

A comprehensive, contemporary assessment of the association between the presence of hepatosteatosis and the incidence of coronary artery disease on CT coronary angiography

Funding Acknowledgements

Type of funding sources: None.

Background

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing exponentially. The overall prevalence of NAFLD in the United States is predicted to increase to 33.5% of the adult population by 2030. Hepatosteatosis (HS) has been previously shown to be an independent risk factor for cardiovascular disease events. We sought to investigate the association of clinical covariates and the presence of HS and coronary artery disease (CAD) in patients referred for computed tomography coronary angiography (CTCA).

Methods

We performed a retrospective, observational analysis at a high-volume cardiac CT centre analysing consecutive CTCA studies. All patients referred for investigation of chest pain over a 28-month period (June 2014 to November 2016) were included. Covariates in those with CAD and patients without CAD were compared using compared using student"s t-test for continuous variables and chi-squared test for categorical variables. Logistic regression models were constructed for the multivariate analysis.

Results

In total there were 1499 patients referred for CTCA without prior evidence of CAD. Age, male sex, presence of hypertension and diabetes were significantly higher in those with CAD (table 1). HS evaluation was assessed in 1195 (79.7%). In the multivariate analysis significant predictors of CAD were male sex (OR 3.40, p < 0.001), family history (OR 1.90, p = 0.003), current smoking (OR 1.80, p = 0.03) and increasing age (OR 1.12, p < 0.001). The presence of HS was not associated with CAD when adjusted for risk factors (OR 1.05 CI:0.70-1.60, p = 0.80).

Conclusion

We found a significant association between the increasing age, presence of hypertension, male sex, diabetes and current smoking with presence of CAD as detected by CTCA. In contrast to recent evidence HS may not be an independent risk factor for the development of the development of CAD.

Summary statistics of the cohort No CAD (n = 881) CAD (n = 618) P Age (mean (SD)) 48.86 (±12.1) 57.9(±10.6) <0.005* Male Sex (%) 343 (38.6%) 326 (51.1%) <0.005* Hypertension (%) 193(21.9%) 239 (38.7%) <0.005* Diabetes (%) 59 (6.7%) 86 (13.9%) <0.005* Current Smoking (%) 139 (15.8%) 108 (17.5%) 0.423 FHx (%) 239 (27.1%) 167 (27%) 1 HS (%) 291 (33%) 247 (40%) 0.007* A comparison of clinical covariates for the cohort stratified by the presence of coronary artery disease. Statistical significance was assumed when p < 0.05 and is denoted with *.

Rationally Designed Base Editors for Precise Editing of the Sickle Cell Disease Mutation

Base editors are fusions of a deaminase and CRISPR-Cas ribonucleoprotein that allow programmable installment of transition mutations without double-strand DNA break intermediates. The breadth of potential base editing targets is frequently limited by the requirement of a suitably positioned Cas9 protospacer adjacent motif. To address this, we used structures of Cas9 and TadA to design a set of inlaid base editors (IBEs), in which deaminase domains are internal to Cas9. Several of these IBEs exhibit shifted editing windows and greater editing efficiency, enabling editing of targets outside the canonical editing window with reduced DNA and RNA off-target editing frequency. Finally, we show that IBEs enable conversion of the pathogenic sickle cell hemoglobin allele to the naturally occurring HbG-Makassar variant in patient-derived hematopoietic stem cells.

[What will cataract surgery look like in the future? Alternatives in the pipeline]

Phacoemulsification is the most frequently performed surgery in the world. Over the past few years, this surgery seems to have reached a plateau with no further innovative breakthroughs. In this paper, we focus on alternatives techniques, the latest innovations, and the research and development pipeline in this field.

Object surveillance with radio-frequency atomic magnetometers

The capabilities of a radio-frequency atomic magnetometer for object detection based on magnetic induction tomography are explored. The determination of object orientation is demonstrated by utilizing the measurement geometry. The self-compensation configuration of the atomic magnetometer is implemented to address the issue of saturation of the sensor response by the radio-frequency primary field that generates the object signature. Three methods of "covert" detection are investigated as a testbed for exploring the functionalities of this sensor, where (1) the operational frequency of the sensor is continuously changed, (2) the primary field has non-monochromatic frequency distribution, and (3) the sensor operates in the so-called spin maser mode. The results of the measurements are also discussed in terms of possible magnetic field communication.

Acute, non-COVID related medical admissions during the first wave of COVID-19: A retrospective comparison of changing patterns of disease

COVID-19 may have altered the case-mix of non-COVID acute medical admissions. Retrospective analysis of acute medical admissions to University Hospitals Birmingham NHS Foundation Trust, showed that medical admissions decreased in April 2020 compared to April 2019. The proportion of young adults, non-cardiac chest pain, musculoskeletal conditions and self-discharges decreased. The proportion of admissions due to alcohol misuse, psychiatric conditions, overdoses and falls increased. There were a higher number of patients admitted to ICU and greater inpatient mortality but not once COVID diagnoses were excluded. There was a significant change in hospitalised case-mix with conditions potentially reflecting social isolation increasing and diagnoses which rarely require hospital treatment, reducing. This analysis will help inform service planning.

P2630Incidence and prognostic impact of new-onset left bundle branch block in patients with heart failure and reduced ejection fraction

Background

Cardiac resynchronization therapy (CRT) improves survival in patients with heart failure, reduced ejection fraction (HFrEF) and left bundle branch block (LBBB). However, little is known about the incidence of LBBB in HFrEF and the risk factors for developing this. We addressed these questions in the PARADIGM-HF and ATMOSPHERE trials.

Methods

We identified 7703 patients with a non-paced rhythm on their baseline ECG, a QRS<130 ms, and at least one follow-up ECG (done at annual visits and end of study). Patients were stratified by baseline QRS duration (≤100 ms - reference; 101–115 ms and 116–129 ms) and followed until development of QRS duration ≥130 ms with a LBBB configuration or latest available ECG. The crude LBBB incidence rate per 100 person-years (py) was identified in the three QRS duration subgroups. Additionally, we examined risk of the primary composite outcome of cardiovascular death or HF hospitalization, and all-cause mortality, in patients with incident LBBB vs. no incident LBBB.

Results

Overall, 313 of 7703 patients (4%) developed LBBB during a mean follow-up of 2.7 years, yielding an incidence rate of 1.5 per 100 py. The rate ranged from 0.9 in those with QRS ≤100 ms to 4.0 per 100 py in patients with QRS 116–129 ms. Other predictors of incident LBBB included male sex, age, lower LVEF, HF duration and absence of AF. The risk of the primary composite endpoint was higher among those who developed incident LBBB vs no incident LBBB; event rates 13.5 vs 10.0 per 100 py, yielding an adjusted HR of 1.43 (1.05–1.96). For all-cause mortality the corresponding rates were 12.6 vs 7.3 per 100 py; HR 1.55 (1.16–2.07) (Table 1).

Table 1. Risk of outcomes according to incident LBBB during follow-up No. events Crude rate per 100py Adjusted* HR (95% CI) HF hospitalization or CV death   No incident LBBB 2145 10.0 (9.6–10.4) 1.00 (ref.)   Incident LBBB 43 13.5 (10.0–18.2) 1.43 (1.05–1.96) All-cause mortality   No incident LBBB 1662 7.3 (6.9–7.6) 1.00 (ref.)   Incident LBBB 48 12.6 (9.5–16.7) 1.55 (1.16–2.07)

Conclusion

Among patients with HFrEF, the annual incidence of new-onset LBBB (and a potential indication for CRT), was around 1.5%, ranging from 1% in those with QRS duration below 100 ms to 4% in those with QRS 116–129 ms. Incident LBBB was associated with a much higher risk of adverse outcomes, highlighting the importance of repeat ECG monitoring in patients with HFrEF.

Acknowledgement/Funding

Novartis

A critical control point approach to the removal of chemicals of concern from water for reuse

The reuse of water in a range of potable and non-potable applications is an important factor in the augmentation of water supply and in improving water security and productivity worldwide. A key hindrance to the reuse of water is the cost of compliance testing and process validation associated with ensuring that pathogen and chemicals in the feedwater are removed to a level that ensures no acute or chronic health and/or environmental effects. The critical control point (CCP) approach is well established and widely adopted by water utilities to provide an operational and risk management framework for the removal of pathogens in the treatment system. The application of a CCP approach to barriers in a treatment system for the removal of chemicals is presented. The application exemplar is to a small community wastewater treatment system that aims to produce potable quality water from a secondary treated wastewater effluent, however, the concepts presented are generic. The example used seven treatment barriers, five of which were designed and operated as CCP barriers for pathogens. The work demonstrates a method and risk management framework by which three of the seven barriers could also include a CCP approach for the removal of chemicals. Analogous to a CCP approach for pathogens, the potential is to reduce the use of chemical analysis as a routine determinant of performance criteria. The operational deployment of a CCP approach for chemicals was augmented with the development of a decision tree encompassing the classification of chemicals and the total removal credits across the treatment train in terms of the mechanistic removal of chemicals for each barrier. Validation of the approach is shown for an activated sludge, ozone and reverse osmosis barrier.

Contrasting effects on the risk of macrovascular and microvascular events of antihyperglycemic drugs that enhance sodium excretion and lower blood pressure

Three classes of anti-hyperglycaemic medications are distinguished by their urinary sodium excretion-enhancing and blood pressure-lowering actions: long-acting glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors and sodium-glucose co-transporter-2 inhibitors. Yet, these drugs exert different effects on macrovascular risk. Glucagon-like peptide-1 receptor agonists reduce atherosclerotic thromboembolic events, but have little effect on heart failure; sodium-glucose co-transporter-2 inhibitors decrease the occurrence of heart failure, but have minimal effect on myocardial infarction and stroke; and dipeptidyl peptidase-4 inhibitors do not ameliorate either atherosclerotic thromboembolic events or heart failure. Similarly, the three classes of drugs differ in their early effects on renal function. Dipeptidyl peptidase-4 inhibitors produce a small decrease in renal function that persists for the duration of treatment, and they do not prevent serious adverse renal events. For glucagon-like peptide-1 receptor agonists, a small early decrease in renal function persists for 2 years and is superseded by a small improvement in renal function, with no effect on renal outcomes. In contrast, an initial decrease in glomerular filtration with sodium-glucose co-transporter-2 inhibitors persists for only 1 year and is superseded by a durable improvement in renal function and a reduced risk of serious adverse renal events. These differences may be related to different actions on the proximal tubular reabsorption of sodium, and thereby, on glomerular hyperfiltration. Anti-hyperglycaemic drugs that have natriuretic actions differ markedly in their ability to modulate macrovascular and microvascular risk. These contrasting profiles cannot be predicted by their effects on blood glucose or blood pressure.

New insights into the molecular mechanism of the Rab GTPase Sec4p activation

Background

Sec4p is a small monomeric Ras-related GTP-binding protein (23 kDa) that regulates polarized exocytosis in S. cerevisiae. In this study we examine the structural effects of a conserved serine residue in the P-loop corresponding to G12 in Ras.

Results

We show that the Sec4p residue serine 29 forms a hydrogen bond with the nucleotide. Mutations of this residue have a different impact than equivalent mutations in Ras and can form stable associations with the exchange factor allowing us to elucidate the structure of a complex of Sec4p bound to the exchange factor Sec2p representing an early stage of the exchange reaction.

Conclusions

Our structural investigation of the Sec4p-Sec2p complex reveals the role of the Sec2p coiled-coil domain in facilitating the fast kinetics of the exchange reaction. For Ras-family GTPases, single point mutations that impact the signaling state of the molecule have been well described however less structural information is available for equivalent mutations in the case of Rab proteins. Understanding the structural properties of mutants such as the one described here, provides useful insights into unique aspects of Rab GTPase function.

Pathogen reduction requirements for direct potable reuse in Antarctica: evaluating human health risks in small communities

Small, remote communities often have limited access to energy and water. Direct potable reuse of treated wastewater has recently gained attention as a potential solution for water-stressed regions, but requires further evaluation specific to small communities. The required pathogen reduction needed for safe implementation of direct potable reuse of treated sewage is an important consideration but these are typically quantified for larger communities and cities. A quantitative microbial risk assessment (QMRA) was conducted, using norovirus, giardia and Campylobacter as reference pathogens, to determine the level of treatment required to meet the tolerable annual disease burden of 10(-6) DALYs per person per year, using Davis Station in Antarctica as an example of a small remote community. Two scenarios were compared: published municipal sewage pathogen loads and estimated pathogen loads during a gastroenteritis outbreak. For the municipal sewage scenario, estimated required log10 reductions were 6.9, 8.0 and 7.4 for norovirus, giardia and Campylobacter respectively, while for the outbreak scenario the values were 12.1, 10.4 and 12.3 (95th percentiles). Pathogen concentrations are higher under outbreak conditions as a function of the relatively greater degree of contact between community members in a small population, compared with interactions in a large city, resulting in a higher proportion of the population being at risk of infection and illness. While the estimates of outbreak conditions may overestimate sewage concentration to some degree, the results suggest that additional treatment barriers would be required to achieve regulatory compliance for safe drinking water in small communities.

Quantification of Immune Cell Populations in the Lamina Propria of Equine Jejunal Biopsy Specimens

The histological diagnosis of inflammatory bowel disease (IBD) in horses and other species is subjective, and pathological assessments vary considerably as a result. One important criterion is increased infiltration of the lamina propria by eosinophils, plasma cells, lymphocytes or macrophages, but this is difficult to assess without a knowledge of the normal immune cell populations and potential for individual variation. Retrospective jejunal specimens were analysed from 14 horses aged 13-15 years which had not shown clinical or post-mortem signs of gastrointestinal disease. Populations of plasma cells, T lymphocytes (CD3+), B lymphocytes (CD79a+ cytoplasmic membranes), eosinophils, macrophages and neutrophils were counted in 9000-microm2 areas of the villous lamina propria and intercryptal lamina propria for each horse. There were significantly higher counts of plasma cells, B lymphocytes and eosinophils in the intercryptal than in the villous region, which accords with previous findings in dogs. This information will be used as control data for future quantitative morphometrical analysis of immune cells in small intestinal specimens from horses in which IBD has been diagnosed.

A prospective multicenter clinical trial to evaluate the safety and effectiveness of the implantable miniature telescope

PURPOSE

To evaluate the safety and preliminary efficacy of a novel visual prosthetic device, the Implantable Miniature Telescope, IMT (by Dr Isaac Lipshitz) (IMT), in a phase I trial in patients with significant bilateral central vision impairment from late-stage age-related macular degeneration (AMD). The IMT is designed to reduce the relative size of the scotoma by rendering enlarged (threefold) central visual field images over the central and peripheral retina.

DESIGN

Prospective, multicenter, open-label clinical trial.

METHODS

In this prospective, multicenter phase I trial, 14 patients aged 60 or older with bilateral geographic atrophy or disciform scar AMD, cataract, and best-corrected visual acuity (BCVA) between 20/80 and 20/400 had an IMT implanted in one eye. Distance and near BCVA, endothelial cell density, and quality of life, measured as activities of daily life (ADL), were evaluated preoperatively and postoperatively.

RESULTS

At 12 months, 10 (77%) of 13 patients gained 2 more lines of either distance or near BCVA, and eight (62%) of 13 patients gained 3 or more lines in either distance or near BCVA. Mean endothelial cell density decreased by 13%. All adverse events resolved without sequelae. ADL scores improved in the majority of patients.

CONCLUSION

The results of this phase I trial support further evaluation of the IMT in a larger study population with late-stage AMD. A phase II/III trial is in progress.

Prognostic importance of the oxidized product of catecholamines, adrenolutin, in patients with severe heart failure

OBJECTIVES

The purpose of this study was to assess whether adrenolutin, the inert product of the highly reactive molecules aminochromes, is increased in severe chronic heart failure and whether it is associated with a poor prognosis.

BACKGROUND

Experimental evidence suggests that oxidative products of catecholamines, aminochromes, are more cardiotoxic than unoxidized catecholamines and may be increased in heart failure.

METHODS

Adrenolutin was measured at baseline and at 1 and 3 months in 263 patients with chronic New York Heart Association class III or IV heart failure and a left ventricular ejection fraction of 22% +/- 7%. Adrenolutin levels were compared with normal levels, and their relation to prognosis was evaluated.

RESULTS

Baseline adrenolutin was increased (55 +/- 90 pg/mL vs 8.4 +/- 9.1 pg/mL for control, P <.02) and remained increased at 1 month (49 +/- 65 pg/mL). During a mean follow-up of 309 +/- 148 days (22-609 days), 57 patients died. Baseline adrenolutin levels correlated with mortality rates by univariate and multivariate analyses (relative risk 1.06, 95% CI 1.01-1.10 for each 17.9-pg/mL rise, P =.032). Left ventricular ejection fraction (P =.013) and New York Heart Association class (P =.009) were the only other variables associated with survival. Age, sex, plasma creatinine, plasma N-terminal atrial natriuretic peptide, and plasma norepinephrine levels were not retained in our model. Adrenolutin levels 1 month after random assignment were not significantly correlated with total mortality rate (P =.061) but were correlated with mortality rate from low output (relative risk 1.14, 95% CI 1.06-1.22, P =.002).

CONCLUSIONS

Plasma adrenolutin is increased in patients with heart failure and correlates with a poor prognosis independent of other important predictors of survival. This finding has potentially important pathophysiologic, prognostic, and therapeutic implications.

Selecting patients for heart transplantation: which patients are too well for transplant?

In the context of contemporary medical and surgical therapy, the revolutionary procedure of cardiac transplantation should be redefined in its relative role. Based on the assumption that its goal is to prolong life while improving its quality, and in the absence of randomized clinical trial data testing its benefit, data from early breakthrough studies, more recent observational cohort studies, and studies testing other therapies in advanced heart failure must be analyzed to characterize clinical profiles of patients who should be considered too well for cardiac transplantation at specific stages of their disease processes. These profiles likely include advanced heart failure with (1) low risk according to the Heart Failure Survival Score, (2) peak oxygen consumption greater than 14 to 18 mL/kg/min without other indications, (3) left ventricular ejection fraction less than 20% alone, (4) history of New York Heart Association class III to IV symptoms alone, (5) history of ventricular arrhythmias alone, (6) no previous attempt at comprehensive neurohormonal blockade, and (7) no structured cardiac transplantation evaluation in a designated cardiac transplantation center. The evaluation may identify the potential transplant candidate, who could be placed on a national potential transplant candidate list, combining the psychologic benefit of acceptance by the program with an ongoing openness to the diversity of advanced heart failure treatment modalities.

Non diethylstilbesterol induced vaginal adenosis--a case series and review of literature

Non diethylstilbestrol induced vaginal adenosis has a reported incidence of about 10% in adult women. Although in some, it may be an insignificant coincidental finding, it is probably under-diagnosed even in symptomatic women. Little is known about the aetiology, pathogenesis, symptomatology and management of this poorly understood condition. Our experience with the four cases of vaginal adenosis unrelated to diethylstilbestrol (DES) exposure and a review of the literature will probably shed some light on this, as it still remains an enigma in gynaecological oncology.

Prevention of posterior segment complications of phacoemulsification

The prevention of posterior segment complications of cataract surgery depends on the maintenance of an intact lens capsule and zonular apparatus. The phacoemulsification techniques presented here, including cortical cleaving hydrodissection, hydrodelineation, ultrasound power modulation, and management of the epinucleus and cortex, together with the special techniques presented for management of small pupils and compromised zonule, minimize the risk of damage to the posterior capsule by maximizing control of nuclear disassembly and evacuation. Choo-choo chop and flip phacoemulsification, in particular, provides a management strategy for cataracts of all grades of nuclear hardness whether in the presence of a small pupil or compromised zonule.

Association of human DEAD box protein DDX1 with a cleavage stimulation factor involved in 3'-end processing of pre-MRNA

DEAD box proteins are putative RNA helicases that function in all aspects of RNA metabolism, including translation, ribosome biogenesis, and pre-mRNA splicing. Because many processes involving RNA metabolism are spatially organized within the cell, we examined the subcellular distribution of a human DEAD box protein, DDX1, to identify possible biological functions. Immunofluorescence labeling of DDX1 demonstrated that in addition to widespread punctate nucleoplasmic labeling, DDX1 is found in discrete nuclear foci approximately 0.5 microm in diameter. Costaining with anti-Sm and anti-promyelocytic leukemia (PML) antibodies indicates that DDX1 foci are frequently located next to Cajal (coiled) bodies and less frequently, to PML bodies. Most importantly, costaining with anti-CstF-64 antibody indicates that DDX1 foci colocalize with cleavage bodies. By microscopic fluorescence resonance energy transfer, we show that labeled DDX1 resides within a Förster distance of 10 nm of labeled CstF-64 protein in both the nucleoplasm and within cleavage bodies. Coimmunoprecipitation analysis indicates that a proportion of CstF-64 protein resides in the same complex as DDX1. These studies are the first to identify a DEAD box protein associating with factors involved in 3'-end cleavage and polyadenylation of pre-mRNAs.

Cardiovascular critical event pathways for the progression of heart failure; a report from the ATLAS study

AIMS

To determine the sequence of critical cardiovascular events in the progression of heart failure, and whether aetiology or high-dose vs low-dose lisinopril affected these pathways.

METHODS AND RESULTS

This was a post-hoc investigation of the ATLAS database, which comprised 3164 patients with chronic heart failure, randomized to low- (2.5-5.0 mg. day(-1)) or high-dose (32.5-35.0 mg. day(-1)) lisinopril, followed up for a median of 46 months. Two-thirds (64.3%) of patients had heart failure attributed to ischaemic heart disease. During the study, most patients (61.1%) had at least one cardiovascular hospitalization and 42.5% of all patients died: most deaths (88.2%) were cardiovascular. Nearly half (49.7%) of the cardiovascular deaths were considered sudden and 45.2% of cardiovascular deaths occurred as the first cardiovascular event. A third (30.2%) of deaths resulted from heart failure and were generally preceded by hospitalization, either for heart failure (85.5%), myocardial ischaemic events (21.7%) or arrhythmias (18.0%). Compared with low-dose, high-dose lisinopril was associated with a lower risk of death or hospitalization for any reason (P=0.002) and death or hospitalization with worsening heart failure (P<0.001). High-dose lisinopril delayed the time to all-cause mortality and hospitalization for chronic heart failure by 7.1 months.

CONCLUSIONS

Vascular and arrhythmic events may not only be important precipitants of sudden death, but were also seen to contribute to the progression of heart failure. A reduction in vascular events, as well as benefits on ventricular remodelling, could account for the decrease in death or hospitalization with high-dose lisinopril.