The prevalence and importance of frailty in heart failure with reduced ejection fraction – an analysis of PARADIGM-HF and ATMOSPHERE

Aims: Frailty, characterized by loss of homeostatic reserves and increased vulnerability to physiological decompensation, results from an aggregation of insults across multiple organ systems. Frailty can be quantified by counting the number of ‘health deficits’ across a range of domains. We assessed the frequency of, and outcomes related to, frailty in patients with heart failure and reduced ejection fraction (HFrEF). Methods and results: Using a cumulative deficits approach, we constructed a 42‐item frailty index (FI) and applied it to identify frail patients enrolled in two HFrEF trials (PARADIGM‐HF and ATMOSPHERE). In keeping with previous studies, patients with FI ≤0.210 were classified as non‐frail and those with higher scores were divided into two categories using score increments of 0.100. Clinical outcomes were examined, adjusting for prognostic variables. Among 13 625 participants, mean (± standard deviation) FI was 0.250 (0.10) and 8383 patients (63%) were frail (FI >0.210). The frailest patients were older and had more symptoms and signs of heart failure. Women were frailer than men. All outcomes were worse in the frailest, with high rates of all‐cause death or all‐cause hospitalization: 40.7 (39.1–42.4) vs. 22.1 (21.2–23.0) per 100 person‐years in the non‐frail; adjusted hazard ratio 1.63 (1.53–1.75) (P < 0.001). The rate of all‐cause hospitalizations, taking account of recurrences, was 61.5 (59.8–63.1) vs. 31.2 (30.3–32.2) per 100 person‐years (incidence rate ratio 1.76; 1.62–1.90; P < 0.001). Conclusion: Frailty is highly prevalent in HFrEF and associated with greater deterioration in quality of life and higher risk of hospitalization and death. Strategies to prevent and treat frailty are needed in HFrEF

Clinical characteristics and outcomes of patients with heart failure with reduced ejection fraction and chronic obstructive pulmonary disease: insights from PARADIGM-HF

Background: Chronic obstructive pulmonary disease (COPD) is a common comorbidity in heart failure with reduced ejection fraction, associated with undertreatment and worse outcomes. New treatments for heart failure with reduced ejection fraction may be particularly important in patients with concomitant COPD. Methods and Results: We examined outcomes in 8399 patients with heart failure with reduced ejection fraction, according to COPD status, in the PARADIGM‐HF (Prospective Comparison of Angiotensin Receptor Blocker–Neprilysin Inhibitor With Angiotensin‐Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure) trial. Cox regression models were used to compare COPD versus non‐COPD subgroups and the effects of sacubitril/valsartan versus enalapril. Patients with COPD (n=1080, 12.9%) were older than patients without COPD (mean 67 versus 63 years; P<0.001), with similar left ventricular ejection fraction (29.9% versus 29.4%), but higher NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide; median, 1741 pg/mL versus 1591 pg/mL; P=0.01), worse functional class (New York Heart Association III/IV 37% versus 23%; P<0.001) and Kansas City Cardiomyopathy Questionnaire–Clinical Summary Score (73 versus 81; P<0.001), and more congestion and comorbidity. Medical therapy was similar in patients with and without COPD except for beta‐blockade (87% versus 94%; P<0.001) and diuretics (85% versus 80%; P<0.001). After multivariable adjustment, COPD was associated with higher risks of heart failure hospitalization (hazard ratio [HR], 1.32; 95% CI, 1.13–1.54), and the composite of cardiovascular death or heart failure hospitalization (HR, 1.18; 95% CI, 1.05–1.34), but not cardiovascular death (HR, 1.10; 95% CI, 0.94–1.30), or all‐cause mortality (HR, 1.14; 95% CI, 0.99–1.31). COPD was also associated with higher risk of all cardiovascular hospitalization (HR, 1.17; 95% CI, 1.05–1.31) and noncardiovascular hospitalization (HR, 1.45; 95% CI, 1.29–1.64). The benefit of sacubitril/valsartan over enalapril was consistent in patients with and without COPD for all end points. Conclusions: In PARADIGM‐HF, COPD was associated with lower use of beta‐blockers and worse health status and was an independent predictor of cardiovascular and noncardiovascular hospitalization. Sacubitril/valsartan was beneficial in this high‐risk subgroup. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01035255

Effects of dapagliflozin in heart failure with reduced ejection fraction, and chronic obstructive pulmonary disease: an analysis of DAPA-HF

Aims: Chronic obstructive pulmonary disease (COPD) is an important comorbidity in HFrEF, associated with worse outcomes and often suboptimal treatment because of under‐prescription of beta‐blockers. Consequently, additional effective therapies are especially relevant in patients with COPD. To examine outcomes related to COPD in a post hoc analysis of the Dapagliflozin And Prevention of Adverse‐outcomes in Heart Failure trial (DAPA‐HF). Methods and Results: We examined whether the effects of dapagliflozin in DAPA‐HF were modified by COPD status. The primary outcome was the composite of an episode of worsening heart failure (HF) event or cardiovascular (CV) death. 585 (12.3%) of the 4744 patients randomized had a history of COPD. Patients with COPD were more likely to be older men with a history of smoking, worse renal function, and higher baseline NT‐proBNP, and less likely to be treated with a beta‐blocker or mineralocorticoid receptor antagonist. The incidence of the primary outcome was higher in patients with COPD than in those without 18.9 (95% CI 16.0–22.2) versus 13.0 (12.1–14.0) per 100 person‐years; hazard ratio (HR) for COPD versus no COPD 1.44 (1.21–1.72), P<0.001. The effect of dapagliflozin, compared with placebo, on the primary outcome, was consistent in patients with (HR 0.67 [95%CI 0.48–0.93]) and without COPD (0.76 [0.65–0.87]); interaction p‐value 0.47. Conclusions: In DAPA‐HF, one‐in‐eight patients with HFrEF had concomitant COPD. Participants with COPD had a higher risk of the primary outcome. The benefit of dapagliflozin on all prespecified outcomes was consistent in patients with and without COPD

Additional role for the ccd operon of F-plasmid as a transmissible persistence factor

Toxin-antitoxin (TA) systems are found on both bacterial plasmids and chromosomes, but in most cases their functional role is unclear. Gene knockouts often yield limited insights into functions of individual TA systems because of their redundancy. The well-characterized F-plasmid-based CcdAB TA system is important for F-plasmid maintenance. We have isolated several point mutants of the toxin CcdB that fail to bind to its cellular target, DNA gyrase, but retain binding to the antitoxin, CcdA. Expression of such mutants is shown to result in release of the WT toxin from a functional preexisting TA complex as well as derepression of the TA operon. One such inactive, active-site mutant of CcdB was used to demonstrate the contribution of CcdB to antibiotic persistence. Transient activation of WT CcdB either by coexpression of the mutant or by antibiotic/heat stress was shown to enhance the generation of drug-tolerant persisters in a process dependent on Lon protease and RecA. An F-plasmid containing a ccd locus can, therefore, function as a transmissible persistence factor

MazF-induced Growth Inhibition and Persister Generation in Escherichia coli

Background: MazEF is a chromosomally encoded bacterial toxin-antitoxin system whose cellular role is controversial. Results: Expression of chromosomal MazF inhibits cell killing by multiple antibiotics in a Lon and ClpP dependent manner. Conclusion: MazF is involved in reversible growth inhibition and bacterial drug tolerance. Significance: Inactive, active-site toxin mutants yield functional insights by selectively activating the corresponding WT toxin in vivo. Toxin-antitoxin systems are ubiquitous in nature and present on the chromosomes of both bacteria and archaea. MazEF is a type II toxin-antitoxin system present on the chromosome of Escherichia coli and other bacteria. Whether MazEF is involved in programmed cell death or reversible growth inhibition and bacterial persistence is a matter of debate. In the present work the role of MazF in bacterial physiology was studied by using an inactive, active-site mutant of MazF, E24A, to activate WT MazF expression from its own promoter. The ectopic expression of E24A MazF in a strain containing WT mazEF resulted in reversible growth arrest. Normal growth resumed on inhibiting the expression of E24A MazF. MazF-mediated growth arrest resulted in an increase in survival of bacterial cells during antibiotic stress. This was studied by activation of mazEF either by overexpression of an inactive, active-site mutant or pre-exposure to a sublethal dose of antibiotic. The MazF-mediated persistence phenotype was found to be independent of RecA and dependent on the presence of the ClpP and Lon proteases. This study confirms the role of MazEF in reversible growth inhibition and persistence

Antimicrobial action of prototypic amphipathic cationic decapeptides and their branched dimers

Toward delineation of antimicrobial action, a prototypic amphipathic, cationic decapeptide Ac-G-X-R-K-X-H-K-X-W-A-NH2 was designed and peptides for which X was didehydrophenylalanine (ΔFm), α-aminoisobutyric acid (Um), or phenylalanine (Fm) were synthesized. A growth kinetics experiment indicated that the bacteriostatic effects were nil (Um), mild and transient (Fm), and strong and persistent (ΔFm) respectively. Though at par in binding to lipopolysaccharide, ΔFm and Fm, but not Um, caused outer membrane permeabilization. Inner membrane permeabilization was attenuated and membrane architecture rehabilitated with ΔFm but not Fm. Reverse phase high-performance liquid chromatography revealed that ΔFm was translocated into Escherichia coli, while Um and fragments of Fm were detected in the medium. Among these monomers, only ΔFm was modestly antibiotic [minimum inhibitory concentrations (MICs) of 110 μM (E. coli) and 450 μM (Staphylococcus aureus)]. Interestingly, a linear dimer of ΔFm, viz. (ΔFm)2, turned out to be highly potent against E. coli [MIC of 2 μM and minimum bactericidal concentration (MBC) of 2 μM] and modestly potent against S. aureus (MIC of 20 μM and MBC of 20 μM). In contrast, a lysine-based branched dimer of ΔFm, viz. ΔFd, was found to be a potent antimicrobial against both E. coli (MIC of 2.5 μM) and S. aureus (MIC of 5 μM). Studies with analogous branched dimers of Fm and Um have indicated that dimerization represents a scaffold for potentiation of antimicrobial peptides and that the presence of ΔF confers potent activity against both E. coli and S. aureus. De novo design has identified ΔFd as a potent, noncytotoxic, bacterial cell-permeabilizing and -penetrating antimicrobial peptide, more protease resistant than its monomeric counterpart. We report that in comparison to the subdued and sequential "membrane followed by cell interior" mode of action of the monomeric ΔFm, the strong and simultaneous "membrane along with cell interior" targeting by the dimeric ΔFd potentiates and broadens its antibiotic action across the Gram-negative-Gram-positive divide

Structural Correlates of the Temperature Sensitive Phenotype Derived from Saturation Mutagenesis Studies of CcdB

Temperature sensitive (ts) mutants are widely used to reversibly modulate protein function in vivo and to understand functions of essential genes. Despite this, little is known about the protein structural features and mechanisms responsible for generating a ts phenotype. Also, such mutants are often difficult to isolate, limiting their use. In this study, a library consisting of 75% of all possible single-site mutants of the 101-residue, homodimeric Escherichia coli toxin CcdB was constructed. Mutants were characterized in terms of their activity at two different temperatures and at six different expression levels. Of the total of 1430 single-site mutants that were screened, 231 (16%) mutants showed a ts phenotype. The bulk of these consisted of 120 ts mutants found at all 22 buried sites and 34 ts mutants at all seven active site residues involved in binding DNA gyrase. Of the remaining ts mutants, 16 were found at residues in van der Waals contact with active site residues, 36 were at partially buried residues, and 30 resulted from introduction of Pro. Thus virtually all ts mutants could be rationalized in terms of the structure of the native protein and without knowledge of folding pathways. Data were analyzed to obtain insights into molecular features responsible for the ts phenotype and to outline structure- and sequence-based criteria for designing ts mutants of any globular protein. The criteria were validated by successful prediction of ts mutants of three other unrelated proteins, TBP, T4 lysozyme, and Gal4

Mineralocorticoid receptor antagonists, blood pressure, and outcomes in heart failure with reduced ejection fraction

Objectives: The purpose of this study was to investigate the effects of mineralocorticoid receptor antagonists (MRAs) on systolic blood pressure (SBP) and outcomes according to baseline SBP in patients with heart failure with reduced ejection fraction (HFrEF). Background: MRAs are greatly underused in patients with HFrEF, often because of fear of adverse events. Concern about hypotension has been raised by the demonstration that MRAs are particularly effective treatment for resistant hypertension. Methods: The effect of MRA therapy was studied in 4,396 patients with HFrEF randomized in the RALES (Randomized Aldactone Evaluation Study) and EMPHASIS-HF (Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure) trials. Results: Mean SBP change from baseline to 6 months was +1.4 ± 18.1 mm Hg in the placebo group and −1.2 ± 17.9 mm Hg in the MRA group. The between-treatment difference was 2.6 mm Hg (95% confidence interval [CI]: 1.5 to 3.6; p < 0.001). All outcomes were reduced by MRA therapy overall, with consistent effects across SBP categories (e.g., all-cause mortality, overall hazard ratio [HR] of 0.72; 95% CI: 0.64 to 0.82; p < 0.001; SBP ≤105 mm Hg; HR: 0.72; 95% CI: 0.56 to 0.94; SBP >105 to ≤115 mm Hg; HR: 0.78; 95% CI: 0.60 to 1.02; SBP >115 to ≤125 mm Hg; HR: 0.71; 95% CI: 0.53 to 0.94; SBP >125 to ≤135 mm Hg; HR: 0.79; 95% CI: 0.57 to 1.10; and SBP > 135 mm Hg; HR: 0.67; 95% CI: 0.50 to 0.90; p for interaction = 0.95). Hypotension was infrequent and not more common with MRA therapy than with placebo, overall (4.6% vs. 3.9%; p = 0.25) or in any SBP category. Conclusions: MRA treatment had little effect on SBP in patients with HFrEF, and the clinical benefits were not modified by baseline SBP. MRA treatment infrequently caused hypotension, even when the baseline SBP was low. The treatment discontinuation rates between MRA and placebo therapy were similar. Low SBP is not a reason to withhold MRA therapy in patients with HFrEF