Dapagliflozin in Heart Failure with Mildly Reduced or Preserved Ejection Fraction.

BACKGROUND: Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of hospitalization for heart failure and cardiovascular death among patients with chronic heart failure and a left ventricular ejection fraction of 40% or less. Whether SGLT2 inhibitors are effective in patients with a higher left ventricular ejection fraction remains less certain. METHODS: We randomly assigned 6263 patients with heart failure and a left ventricular ejection fraction of more than 40% to receive dapagliflozin (at a dose of 10 mg once daily) or matching placebo, in addition to usual therapy. The primary outcome was a composite of worsening heart failure (which was defined as either an unplanned hospitalization for heart failure or an urgent visit for heart failure) or cardiovascular death, as assessed in a time-to-event analysis. RESULTS: Over a median of 2.3 years, the primary outcome occurred in 512 of 3131 patients (16.4%) in the dapagliflozin group and in 610 of 3132 patients (19.5%) in the placebo group (hazard ratio, 0.82; 95% confidence interval [CI], 0.73 to 0.92; P<0.001). Worsening heart failure occurred in 368 patients (11.8%) in the dapagliflozin group and in 455 patients (14.5%) in the placebo group (hazard ratio, 0.79; 95% CI, 0.69 to 0.91); cardiovascular death occurred in 231 patients (7.4%) and 261 patients (8.3%), respectively (hazard ratio, 0.88; 95% CI, 0.74 to 1.05). Total events and symptom burden were lower in the dapagliflozin group than in the placebo group. Results were similar among patients with a left ventricular ejection fraction of 60% or more and those with a left ventricular ejection fraction of less than 60%, and results were similar in prespecified subgroups, including patients with or without diabetes. The incidence of adverse events was similar in the two groups. CONCLUSIONS: Dapagliflozin reduced the combined risk of worsening heart failure or cardiovascular death among patients with heart failure and a mildly reduced or preserved ejection fraction. (Funded by AstraZeneca; DELIVER ClinicalTrials.gov number, NCT03619213.).

Restoration of Cardiac Myosin Light Chain Kinase Ameliorates Systolic Dysfunction by Reducing Superrelaxed Myosin.

BACKGROUND: Cardiac-specific myosin light chain kinase (cMLCK), encoded by MYLK3, regulates cardiac contractility through phosphorylation of ventricular myosin regulatory light chain. However, the pathophysiological and therapeutic implications of cMLCK in human heart failure remain unclear. We aimed to investigate whether cMLCK dysregulation causes cardiac dysfunction and whether the restoration of cMLCK could be a novel myotropic therapy for systolic heart failure. METHODS: We generated the knock-in mice (Mylk3+/fs and Mylk3fs/fs) with a familial dilated cardiomyopathy-associated MYLK3 frameshift mutation (MYLK3+/fs) that had been identified previously by us (c.1951-1G>T; p.P639Vfs*15) and the human induced pluripotent stem cell-derived cardiomyocytes from the carrier of the mutation. We also developed a new small-molecule activator of cMLCK (LEUO-1154). RESULTS: Both mice (Mylk3+/fs and Mylk3fs/fs) showed reduced cMLCK expression due to nonsense-mediated messenger RNA decay, reduced MLC2v (ventricular myosin regulatory light chain) phosphorylation in the myocardium, and systolic dysfunction in a cMLCK dose-dependent manner. Consistent with this result, myocardium from the mutant mice showed an increased ratio of cardiac superrelaxation/disordered relaxation states that may contribute to impaired cardiac contractility. The phenotypes observed in the knock-in mice were rescued by cMLCK replenishment through the AAV9_MYLK3 vector. Human induced pluripotent stem cell-derived cardiomyocytes with MYLK3+/fs mutation reduced cMLCK expression by 50% and contractile dysfunction, accompanied by an increased superrelaxation/disordered relaxation ratio. CRISPR-mediated gene correction, or cMLCK replenishment by AAV9_MYLK3 vector, successfully recovered cMLCK expression, the superrelaxation/disordered relaxation ratio, and contractile dysfunction. LEUO-1154 increased human cMLCK activity ≈2-fold in the Vmax for ventricular myosin regulatory light chain phosphorylation without affecting the Km. LEUO-1154 treatment of human induced pluripotent stem cell-derived cardiomyocytes with MYLK3+/fs mutation restored the ventricular myosin regulatory light chain phosphorylation level and superrelaxation/disordered relaxation ratio and improved cardiac contractility without affecting calcium transients, indicating that the cMLCK activator acts as a myotrope. Finally, human myocardium from advanced heart failure with a wide variety of causes had a significantly lower MYLK3/PPP1R12B messenger RNA expression ratio than control hearts, suggesting an altered balance between myosin regulatory light chain kinase and phosphatase in the failing myocardium, irrespective of the causes. CONCLUSIONS: cMLCK dysregulation contributes to the development of cardiac systolic dysfunction in humans. Our strategy to restore cMLCK activity could form the basis of a novel myotropic therapy for advanced systolic heart failure.

Turicibacter faecis sp. nov., isolated from faeces of heart failure mouse model.

Strain TC023T, a Gram-positive, long, rod-shaped, spore-forming anaerobe, was isolated from the faeces of a heart failure mouse model. The strain formed greyish-white coloured colonies with a convex elevation on brain-heart infusion medium supplemented with 0.1 % sodium taurocholate, incubated at 37 °C for 2 days. Taxonomic analysis based on the 16S rRNA gene sequence showed that TC023T belonged to the genus Turicibacter, and was closely related to Turicibacter bilis MMM721T (97.6 %) and Turicibacter sanguinis MOL361T (97.4 %). The whole genome of the strain has a G+C content of 37.3 mol%. The average nucleotide identity and genome-to-genome distance between TC023T and Turicibacter bilis MMM721T were 77.6 % and 24.3 %, respectively, and those with Turicibacter sanguinis MOL361T were 75.4 % and 24.3 %, respectively. These genotypic, phenotypic, and biochemical analyses indicated that the isolate represents a novel species in the genus Turicibacter, and the name Turicibacter faecis sp. nov. is proposed. The type strain is TC023T (RIMD 2002001T=TSD 372T).

Rationale and Design of Prospective, Multicenter, Double-Arm Clinical Trial to Investigate the Efficacy of Tofogliflozin on Left Ventricular Diastolic Dysfunction in Patients with Heart Failure with Preserved Ejection Fraction and Type 2 Diabetes Mellitus (TOP-HFPEF Trial).

BACKGROUND: Recent large clinical trials have revealed that sodium-glucose cotransporter 2 (SGLT2) inhibitors improve cardiovascular outcomes not only in patients with heart failure with reduced ejection fraction, but also in patients with heart failure with mildly reduced or preserved ejection fraction (HFpEF). However, the effect of SGLT2 inhibitors on left ventricular (LV) diastolic function is still controversial. METHODS AND RESULTS: The TOP-HFPEF trial (Efficacy of Tofogliflozin on Left Ventricular Diastolic Dysfunction in Patients with Heart Failure with Preserved Ejection Fraction and Type 2 Diabetes Mellitus) is a multicenter, double-arm, open-label, confirmatory, investigator-initiated clinical study to investigate the effect of SGLT2 inhibitor on LV diastolic function in patients with HFpEF and type 2 diabetes mellitus. The participants are randomly assigned (1:1) to the tofogliflozin group (20 mg once daily) or the control group (administration or continuation of antidiabetic drugs other than SGLT2 inhibitors). The estimated number of patients to be enrolled in this trial is 90 in total (45 in each group). The participants are followed up for 52 weeks with tofogliflozin or control drugs. The primary endpoint is the change in E/e' assessed by echocardiography from the baseline to the end of this study (52 weeks). This trial will also evaluate the effects of tofogliflozin on cardiovascular events, biomarkers, other echocardiographic parameters, the occurrence of atrial fibrillation, and renal function. CONCLUSIONS: The TOP-HFPEF trial will clarify the efficacy of an SGLT2 inhibitor, tofogliflozin, on LV diastolic function in patients with HFpEF and type 2 diabetes mellitus.

Efficacy and Safety of Dapagliflozin According to Frailty in Patients With Heart Failure: A Prespecified Analysis of the DELIVER Trial.

BACKGROUND: Frailty is increasing in prevalence. Because patients with frailty are often perceived to have a less favorable risk/benefit profile, they may be less likely to receive new pharmacologic treatments. We investigated the efficacy and tolerability of dapagliflozin according to frailty status in patients with heart failure with mildly reduced or preserved ejection fraction randomized in DELIVER (Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure). METHODS: Frailty was measured using the Rockwood cumulative deficit approach. The primary end point was time to a first worsening heart failure event or cardiovascular death. RESULTS: Of the 6263 patients randomized, a frailty index (FI) was calculable in 6258. In total, 2354 (37.6%) patients had class 1 frailty (FI ≤0.210; ie, not frail), 2413 (38.6%) had class 2 frailty (FI 0.211-0.310; ie, more frail), and 1491 (23.8%) had class 3 frailty (FI ≥0.311; ie, most frail). Greater frailty was associated with a higher rate of the primary end point (per 100 person-years): FI class 1, 6.3 (95% CI 5.7-7.1); class 2, 8.3 (7.5-9.1); and class 3, 13.4 (12.1-14.7; P<0.001). The effect of dapagliflozin (as a hazard ratio) on the primary end point from FI class 1 to 3 was 0.85 (95% CI, 0.68-1.06), 0.89 (0.74-1.08), and 0.74 (0.61-0.91), respectively (Pinteraction=0.40). Although patients with a greater degree of frailty had worse Kansas City Cardiomyopathy Questionnaire scores at baseline, their improvement with dapagliflozin was greater than it was in patients with less frailty: placebo-corrected improvement in Kansas City Cardiomyopathy Questionnaire Overall Summary Score at 4 months in FI class 1 was 0.3 (95% CI, -0.9 to 1.4); in class 2, 1.5 (0.3-2.7); and in class 3, 3.4 (1.7-5.1; Pinteraction=0.021). Adverse reactions and treatment discontinuation, although more frequent in patients with a greater degree of frailty, were not more common with dapagliflozin than with placebo irrespective of frailty class. CONCLUSIONS: In DELIVER, frailty was common and associated with worse outcomes. The benefit of dapagliflozin was consistent across the range of frailty studied. The improvement in health-related quality of life with dapagliflozin occurred early and was greater in patients with a higher level of frailty. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03619213.

Efficacy and Safety of Dapagliflozin According to Frailty in Heart Failure With Reduced Ejection Fraction : A Post Hoc Analysis of the DAPA-HF Trial.

BACKGROUND: Frailty may modify the risk-benefit profile of certain treatments, and frail patients may have reduced tolerance to treatments. OBJECTIVE: To investigate the efficacy of dapagliflozin according to frailty status, using the Rockwood cumulative deficit approach, in DAPA-HF (Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure). DESIGN: Post hoc analysis of a phase 3 randomized clinical trial. (ClinicalTrials.gov: NCT03036124). SETTING: 410 sites in 20 countries. PATIENTS: Patients with symptomatic heart failure (HF) with a left ventricular ejection fraction of 40% or less and elevated natriuretic peptide. INTERVENTION: Addition of once-daily 10 mg of dapagliflozin or placebo to guideline-recommended therapy. MEASUREMENTS: The primary outcome was worsening HF or cardiovascular death. RESULTS: Of the 4744 patients randomly assigned in DAPA-HF, a frailty index (FI) was calculable in 4742. In total, 2392 patients (50.4%) were in FI class 1 (FI ≤0.210; not frail), 1606 (33.9%) in FI class 2 (FI 0.211 to 0.310; more frail), and 744 (15.7%) in FI class 3 (FI ≥0.311; most frail). The median follow-up time was 18.2 months. Dapagliflozin reduced the risk for worsening HF or cardiovascular death, regardless of FI class. The differences in event rate per 100 person-years for dapagliflozin versus placebo from lowest to highest FI class were -3.5 (95% CI, -5.7 to -1.2), -3.6 (CI, -6.6 to -0.5), and -7.9 (CI, -13.9 to -1.9). Consistent benefits were observed for other clinical events and health status, but the absolute reductions were generally larger in the most frail patients. Study drug discontinuation and serious adverse events were not more frequent with dapagliflozin than placebo, regardless of FI class. LIMITATION: Enrollment criteria precluded the inclusion of very high-risk patients. CONCLUSION: Dapagliflozin improved all outcomes examined, regardless of frailty status. However, the absolute reductions were larger in more frail patients. PRIMARY FUNDING SOURCE: AstraZeneca.

Antihypertrophic Memory After Regression of Exercise-Induced Physiological Myocardial Hypertrophy Is Mediated by the Long Noncoding RNA Mhrt779.

BACKGROUND: Exercise can induce physiological myocardial hypertrophy (PMH), and former athletes can live 5 to 6 years longer than nonathletic controls, suggesting a benefit after regression of PMH. We previously reported that regression of pathological myocardial hypertrophy has antihypertrophic effects. Accordingly, we hypothesized that antihypertrophic memory exists even after PMH has regressed, increasing myocardial resistance to subsequent pathological hypertrophic stress. METHODS: C57BL/6 mice were submitted to 21 days of swimming training to develop PMH. After termination of exercise, PMH regressed within 1 week. PMH regression mice (exercise hypertrophic preconditioning [EHP] group) and sedentary mice (control group) then underwent transverse aortic constriction or a sham operation for 4 weeks. Cardiac remodeling and function were evaluated with echocardiography, invasive left ventricular hemodynamic measurement, and histological analysis. LncRNA sequencing, chromatin immunoprecipitation assay, and comprehensive identification of RNA-binding proteins by mass spectrometry and Western blot were used to investigate the role of Mhrt779 involved in the antihypertrophic effect induced by EHP. RESULTS: At 1 and 4 weeks after transverse aortic constriction, the EHP group showed less increase in myocardial hypertrophy and lower expression of the Nppa and Myh7 genes than the sedentary group. At 4 weeks after transverse aortic constriction, EHP mice had less pulmonary congestion, smaller left ventricular dimensions and end-diastolic pressure, and a larger left ventricular ejection fraction and maximum pressure change rate than sedentary mice. Quantitative polymerase chain reaction revealed that the long noncoding myosin heavy chain-associated RNA transcript Mhrt779 was one of the markedly upregulated lncRNAs in the EHP group. Silencing of Mhrt779 attenuated the antihypertrophic effect of EHP in mice with transverse aortic constriction and in cultured cardiomyocytes treated with angiotensin II, and overexpression enhanced the antihypertrophic effect. Using chromatin immunoprecipitation assay and quantitative polymerase chain reaction, we found that EHP increased histone 3 trimethylation (H3K4me3 and H3K36me3) at the a4 promoter of Mhrt779. Comprehensive identification of RNA-binding proteins by mass spectrometry and Western blot showed that Mhrt779 can bind SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4 (Brg1) to inhibit the activation of the histone deacetylase 2 (Hdac2)/phosphorylated serine/threonine kinase (Akt)/phosphorylated glycogen synthase kinase 3ß(p-GSK3ß) pathway induced by pressure overload. CONCLUSIONS: Myocardial hypertrophy preconditioning evoked by exercise increases resistance to pathological stress via an antihypertrophic effect mediated by a signal pathway of Mhrt779/Brg1/Hdac2/p-Akt/p-GSK3ß.

Dapagliflozin and Recurrent Heart Failure Hospitalizations in Heart Failure With Reduced Ejection Fraction: An Analysis of DAPA-HF.

BACKGROUND: Patients with heart failure (HF) and reduced ejection fraction will experience multiple hospitalizations for heart failure during the course of their disease. We assessed the efficacy of dapagliflozin on reducing the rate of total (ie, first and repeat) hospitalizations for heart failure in the DAPA-HF trial (Dapagliflozin and Prevention of Adverse-Outcomes in Heart Failure). METHODS: The total number of HF hospitalizations and cardiovascular deaths was examined by using the proportional-rates approach of Lei-Wei-Yang-Ying and a joint frailty model for each of recurrent HF hospitalizations and time to cardiovascular death. Variables associated with the risk of recurrent hospitalizations were explored in a multivariable Lei-Wei-Yang-Ying model. RESULTS: Of 2371 participants randomly assigned to placebo, 318 experienced 469 hospitalizations for HF; of 2373 assigned to dapagliflozin, 230 patients experienced 340 admissions. In a multivariable model, factors associated with a higher risk of recurrent HF hospitalizations included higher heart rate, higher N-terminal pro-B-type natriuretic peptide, and New York Heart Association class. In the Lei-Wei-Yang-Ying model, the rate ratio for the effect of dapagliflozin on recurrent HF hospitalizations or cardiovascular death was 0.75 (95% CI, 0.65-0.88), P=0.0002. In the joint frailty model, the rate ratio for total HF hospitalizations was 0.71 (95% CI, 0.61-0.82), P<0.0001, whereas, for cardiovascular death, the hazard ratio was 0.81 (95% CI, 0.67-0.98), P=0.0282. CONCLUSIONS: Dapagliflozin reduced the risk of total (first and repeat) HF hospitalizations and cardiovascular death. Time-to-first event analysis underestimated the benefit of dapagliflozin in HF and reduced ejection fraction. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03036124.

Efficacy of Dapagliflozin on Renal Function and Outcomes in Patients With Heart Failure With Reduced Ejection Fraction: Results of DAPA-HF.

BACKGROUND: Many patients with heart failure and reduced ejection fraction (HFrEF) have chronic kidney disease that complicates pharmacological management and is associated with worse outcomes. We assessed the safety and efficacy of dapagliflozin in patients with HFrEF, according to baseline kidney function, in the DAPA-HF trial (Dapagliflozin and Prevention of Adverse-outcomes in Heart Failure). We also examined the effect of dapagliflozin on kidney function after randomization. METHODS: Patients who have HFrEF with or without type 2 diabetes and an estimated glomerular filtration rate (eGFR) ≥30 mL·min-1·1.73 m-2 were enrolled in DAPA-HF. We calculated the incidence of the primary outcome (cardiovascular death or worsening heart failure) according to eGFR category at baseline (<60 and ≥60 mL·min-1·1.73 m-2) and used eGFR at baseline as a continuous measure, as well. Secondary cardiovascular outcomes and a prespecified composite renal outcome (≥50% sustained decline eGFR, end-stage renal disease, or renal death) were also examined, along with a decline in eGFR over time. RESULTS: Of 4742 patients with a baseline eGFR, 1926 (41%) had eGFR <60 mL·min-1·1.73 m-2. The effect of dapagliflozin on the primary and secondary outcomes did not differ by eGFR category or examining eGFR as a continuous measurement. The hazard ratio (95% CI) for the primary end point in patients with chronic kidney disease was 0.71 (0.59-0.86) versus 0.77 (0.64-0.93) in those with an eGFR ≥60 mL·min-1·1.73 m-2 (interaction P=0.54). The composite renal outcome was not reduced by dapagliflozin (hazard ratio=0.71 [95% CI, 0.44-1.16]; P=0.17) but the rate of decline in eGFR between day 14 and 720 was less with dapagliflozin, -1.09 (-1.40 to -0.77) versus placebo -2.85 (-3.17 to -2.53) mL·min-1·1.73 m-2 per year (P<0.001). This was observed in those with and without type 2 diabetes (P for interaction=0.92). CONCLUSIONS: Baseline kidney function did not modify the benefits of dapagliflozin on morbidity and mortality in HFrEF, and dapagliflozin slowed the rate of decline in eGFR, including in patients without diabetes. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03036124.

Dapagliflozin in Patients with Heart Failure and Reduced Ejection Fraction.

BACKGROUND: In patients with type 2 diabetes, inhibitors of sodium-glucose cotransporter 2 (SGLT2) reduce the risk of a first hospitalization for heart failure, possibly through glucose-independent mechanisms. More data are needed regarding the effects of SGLT2 inhibitors in patients with established heart failure and a reduced ejection fraction, regardless of the presence or absence of type 2 diabetes. METHODS: In this phase 3, placebo-controlled trial, we randomly assigned 4744 patients with New York Heart Association class II, III, or IV heart failure and an ejection fraction of 40% or less to receive either dapagliflozin (at a dose of 10 mg once daily) or placebo, in addition to recommended therapy. The primary outcome was a composite of worsening heart failure (hospitalization or an urgent visit resulting in intravenous therapy for heart failure) or cardiovascular death. RESULTS: Over a median of 18.2 months, the primary outcome occurred in 386 of 2373 patients (16.3%) in the dapagliflozin group and in 502 of 2371 patients (21.2%) in the placebo group (hazard ratio, 0.74; 95% confidence interval [CI], 0.65 to 0.85; P<0.001). A first worsening heart failure event occurred in 237 patients (10.0%) in the dapagliflozin group and in 326 patients (13.7%) in the placebo group (hazard ratio, 0.70; 95% CI, 0.59 to 0.83). Death from cardiovascular causes occurred in 227 patients (9.6%) in the dapagliflozin group and in 273 patients (11.5%) in the placebo group (hazard ratio, 0.82; 95% CI, 0.69 to 0.98); 276 patients (11.6%) and 329 patients (13.9%), respectively, died from any cause (hazard ratio, 0.83; 95% CI, 0.71 to 0.97). Findings in patients with diabetes were similar to those in patients without diabetes. The frequency of adverse events related to volume depletion, renal dysfunction, and hypoglycemia did not differ between treatment groups. CONCLUSIONS: Among patients with heart failure and a reduced ejection fraction, the risk of worsening heart failure or death from cardiovascular causes was lower among those who received dapagliflozin than among those who received placebo, regardless of the presence or absence of diabetes. (Funded by AstraZeneca; DAPA-HF ClinicalTrials.gov number, NCT03036124.).

Aberrant accumulation of TMEM43 accompanied by perturbed transmural gene expression in arrhythmogenic cardiomyopathy.

Arrhythmogenic cardiomyopathy (ACM) caused by TMEM43 p.S358L is a fully penetrant heart disease that results in impaired cardiac function or fatal arrhythmia. However, the molecular mechanism of ACM caused by the TMEM43 variant has not yet been fully elucidated. In this study, we generated knock-in (KI) rats harboring a Tmem43 p.S358L mutation and established induced pluripotent stem cells (iPSCs) from patients based on the identification of TMEM43 p.S358L variant from a family with ACM. The Tmem43-S358L KI rats exhibited ventricular arrhythmia and fibrotic myocardial replacement in the subepicardium, which recapitulated the human ACM phenotype. The four-transmembrane protein TMEM43 with the p.S358L variant (TMEM43S358L ) was found to be modified by N-linked glycosylation in both KI rat cardiomyocytes and patient-specific iPSC-derived cardiomyocytes. TMEM43S358L glycosylation increased under the conditions of enhanced endoplasmic reticulum (ER) stress caused by pharmacological stimulation or age-dependent decline of the ER function. Intriguingly, the specific glycosylation of TMEM43S358L resulted from the altered membrane topology of TMEM43. Moreover, unlike TMEM43WT , which is mainly localized to the ER, TMEM43S358L accumulated at the nuclear envelope of cardiomyocytes with the increase in glycosylation. Finally, our comprehensive transcriptomic analysis demonstrated that the regional differences in gene expression patterns between the inner and outer layers observed in the wild type myocardium were partially diminished in the KI myocardium prior to exhibiting histological changes indicative of ACM. Altogether, these findings suggest that the aberrant accumulation of TMEM43S358L underlies the pathogenesis of ACM caused by TMEM43 p.S358L variant by affecting the transmural gene expression within the myocardium.

The CR9 element is a novel mechanical load-responsive enhancer that regulates natriuretic peptide genes expression.

Enhancers regulate gene expressions in a tissue- and pathology-specific manner by altering its activities. Plasma levels of atrial and brain natriuretic peptides, encoded by the Nppa and Nppb, respectively, and synthesized predominantly in cardiomyocytes, vary depending on the severity of heart failure. We previously identified the noncoding conserved region 9 (CR9) element as a putative Nppb enhancer at 22-kb upstream from the Nppb gene. However, its regulatory mechanism remains unknown. Here, we therefore investigated the mechanism of CR9 activation in cardiomyocytes using different kinds of drugs that induce either cardiac hypertrophy or cardiac failure accompanied by natriuretic peptides upregulation. Chronic treatment of mice with either catecholamines or doxorubicin increased CR9 activity during the progression of cardiac hypertrophy to failure, which is accompanied by proportional increases in Nppb expression. Conversely, for cultured cardiomyocytes, doxorubicin decreased CR9 activity and Nppb expression, while catecholamines increased both. However, exposing cultured cardiomyocytes to mechanical loads, such as mechanical stretch or hydrostatic pressure, upregulate CR9 activity and Nppb expression even in the presence of doxorubicin. Furthermore, the enhancement of CR9 activity and Nppa and Nppb expressions by either catecholamines or mechanical loads can be blunted by suppressing mechanosensing and mechanotransduction pathways, such as muscle LIM protein (MLP) or myosin tension. Finally, the CR9 element showed a more robust and cell-specific response to mechanical loads than the -520-bp BNP promoter. We concluded that the CR9 element is a novel enhancer that responds to mechanical loads by upregulating natriuretic peptides expression in cardiomyocytes.

Antacid Therapy in Coronary Artery Disease and Heart Failure: Proton Pump Inhibitors vs. H2 Receptor Blockers.

PURPOSE: Acid suppressive therapy using histamine H2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) can be utilized for the prevention of gastrointestinal bleeding (GIB) among patients with cardiovascular disease receiving dual antiplatelet therapy (DAPT). However, emerging data suggests underlying associations between PPI or H2RA use and cardiovascular disease incidence, progression, and mortality. This review explores the history of acid suppressive therapies and their use in cardiovascular disease patients and the growing evidence in support of H2RA use. RECENT FINDINGS: PPIs were originally championed as better than H2RAs for preventing GIB events in cardiovascular disease patients on DAPT therapy, but there is evidence to suggest that drug-drug interactions between clopidogrel and PPIs may translate to worse cardiovascular outcomes. Studies demonstrating PPI superiority in the setting of DAPT were also limited due to small sample sizes and high levels of bias. Consequently, there is renewed interest in H2RAs for patients on DAPT with some data demonstrating similar or improved clinical outcomes over PPI therapy. Additionally, studies have discovered a possible role for H2RAs in the management of heart failure (HF) incidence, symptoms, and mortality. Studies comparing H2RAs and PPIs in patients on DAPT have demonstrated mixed results for cardiovascular and GIB outcomes, with several studies being underpowered and limited by biases. Recent clinical and pre-clinical studies now support the noninferiority of H2RAs for major outcomes and even utility in HF. These findings suggest that H2RAs may warrant reconsideration as an acid suppressive therapy over PPIs for patients on DAPT or with HF.

Do We Really Need Aspirin Loading for STEMI?

Aspirin loading (chewable or intravenous) as soon as possible after presentation is a class I recommendation by current ST elevation myocardial infarction (STEMI) guidelines. Earlier achievement of therapeutic antiplatelet effects by aspirin loading has long been considered the standard of care. However, the effects of the loading dose of aspirin (alone or in addition to a chronic maintenance oral dose) have not been studied. A large proportion of myocardial cell death occurs upon and after reperfusion (reperfusion injury). Numerous agents and interventions have been shown to limit infarct size in animal models when administered before or immediately after reperfusion. However, these interventions have predominantly failed to show significant protection in clinical studies. In the current review, we raise the hypothesis that aspirin loading may be the culprit. Data obtained from animal models consistently show that statins, ticagrelor, opiates, and ischemic postconditioning limit myocardial infarct size. In most of these studies, aspirin was not administered. However, when aspirin was administered before reperfusion (as is the case in the majority of studies enrolling STEMI patients), the protective effects of statin, ticagrelor, morphine, and ischemic postconditioning were attenuated, which can be plausibly attributable to aspirin loading. We therefore suggest studying the effects of aspirin loading before reperfusion on the infarct size limiting effects of statins, ticagrelor, morphine, and/ or postconditioning in large animal models using long reperfusion periods (at least 24 h). If indeed aspirin attenuates the protective effects, clinical trials should be conducted comparing aspirin loading to alternative antiplatelet regimens without aspirin loading in patients with STEMI undergoing primary percutaneous coronary intervention.

Daily self-monitoring of blood pressure decreases systolic and diastolic blood pressure in hypertensive participants.

Hypertension is a major risk factor for cardiovascular diseases, and behavior modification has been shown to improve blood pressure (BP). We investigated whether daily self-monitoring of systemic BP and other factors related to cardiovascular events decreased BP in hypertensive participants. In this prospective, randomized, open, blinded-endpoint trial, we assigned 161 participants with hypertension to monitor their BP daily (BP-measurement group) or, in addition to BP, monitor their body fat, sleeping time, and daily step count (multiple-measurement group) or no self-monitoring (control group) for 2 months. The primary endpoint was the absolute change in systolic BP from baseline to 2 months after assignment. There were no differences in the baseline age and gender ratios among the three groups. After 2 months, systolic BP in the morning was unchanged in the control group, at a median of 149 mmHg [interquartile range (IQR) 136-164] from 150 mmHg (IQR 138-164), and was significantly decreased to 139 mmHg (IQR 125-148) from 142 mmHg (IQR 131-157) in the BP-measurement group. BP did not further decrease in the multiple-measurement group, 134 mmHg (IQR 121-146) from 141 mmHg (IQR 131-157). Daily self-monitoring of BP decreased the BP of participants with hypertension, but additional daily self-monitoring of body fat, sleeping time, and daily step count did not further decrease BP. This behavior modification merits use as a nonpharmacological hypertension treatment.

Effects of Dapagliflozin on Symptoms, Function, and Quality of Life in Patients With Heart Failure and Reduced Ejection Fraction: Results From the DAPA-HF Trial.

BACKGROUND: Goals of management in patients with heart failure and reduced ejection fraction include reducing death and hospitalizations, and improving health status (symptoms, physical function, and quality of life). In the DAPA-HF trial (Dapagliflozin and Prevention of Adverse-Outcomes in Heart Failure), sodium-glucose cotransporter-2 inhibitor, dapagliflozin, reduced death and hospitalizations, and improved symptoms in patients with heart failure and reduced ejection fraction. In this analysis, we examine the effects of dapagliflozin on a broad range of health status outcomes, using the Kansas City Cardiomyopathy Questionnaire (KCCQ). METHODS: KCCQ was evaluated at randomization, 4 and 8 months. Patients were divided by baseline KCCQ total symptom score (TSS); Cox proportional hazards models examined the effects of dapagliflozin on clinical events across these subgroups. We also evaluated the effects of dapagliflozin on KCCQ-TSS, clinical summary score, and overall summary score. Responder analyses were performed to compare proportions of dapagliflozin versus placebo-treated patients with clinically meaningful changes in KCCQ at 8 months. RESULTS: A total of 4443 patients had available KCCQ at baseline (median KCCQ-TSS, 77.1 [interquartile range, 58.3-91.7]). The effects of dapagliflozin vs placebo on reducing cardiovascular death or worsening heart failure were consistent across the range of KCCQ-TSS (lowest to highest tertile: hazard ratio, 0.70 [95% CI, 0.57-0.86]; hazard ratio, 0.77 [95% CI, 0.61-0.98]; hazard ratio, 0.62 [95% CI, 0.46-0.83]; P for heterogeneity=0.52). Patients treated with dapagliflozin had greater improvement in mean KCCQ-TSS, clinical summary score, and overall summary score at 8 months (2.8, 2.5 and 2.3 points higher versus placebo; P<0.0001 for all). Fewer patients treated with dapagliflozin had a deterioration in KCCQ-TSS (odds ratio, 0.84 [95% CI, 0.78-0.90]; P<0.0001); and more patients had at least small, moderate, and large improvements (odds ratio, 1.15 [95% CI, 1.08-1.23]; odds ratio, 1.15 [95% CI, 1.08-1.22]; odds ratio, 1.14 [95% CI, 1.07-1.22]; number needed to treat=14, 15, and 18, respectively; P<0.0001 for all; results consistent for KCCQ clinical summary score and overall summary score). CONCLUSIONS: Dapagliflozin reduced cardiovascular death and worsening heart failure across the range of baseline KCCQ, and improved symptoms, physical function, and quality of life in patients with heart failure and reduced ejection fraction. Furthermore, dapagliflozin increased the proportion of patients experiencing at least small, moderate, and large improvements in health status; these effects were clinically important. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03036124.

In vivo real-time ATP imaging in zebrafish hearts reveals G0s2 induces ischemic tolerance.

Most eukaryotic cells generate adenosine triphosphate (ATP) through the oxidative phosphorylation system (OXPHOS) to support cellular activities. In cultured cell-based experiments, we recently identified the hypoxia-inducible protein G0/G1 switch gene 2 (G0s2) as a positive regulator of OXPHOS, and showed that G0s2 protects cultured cardiomyocytes from hypoxia. In this study, we examined the in vivo protective role of G0s2 against hypoxia by generating both loss-of-function and gain-of-function models of g0s2 in zebrafish. Zebrafish harboring transcription activator-like effector nuclease (TALEN)-mediated knockout of g0s2 lost hypoxic tolerance. Conversely, cardiomyocyte-specific transgenic zebrafish hearts exhibited strong tolerance against hypoxia. To clarify the mechanism by which G0s2 protects cardiac function under hypoxia, we introduced a mitochondrially targeted FRET-based ATP biosensor into zebrafish heart to visualize ATP dynamics in in vivo beating hearts. In addition, we employed a mosaic overexpression model of g0s2 to compare the contraction and ATP dynamics between g0s2-expressing and non-expressing cardiomyocytes, side-by-side within the same heart. These techniques revealed that g0s2-expressing cardiomyocyte populations exhibited preserved contractility coupled with maintained intra-mitochondrial ATP concentrations even under hypoxic condition. Collectively, these results demonstrate that G0s2 provides ischemic tolerance in vivo by maintaining ATP production, and therefore represents a promising therapeutic target for hypoxia-related diseases.

Esm1 and Stc1 as Angiogenic Factors Responsible for Protective Actions of Adipose-Derived Stem Cell Sheets on Chronic Heart Failure After Rat Myocardial Infarction.

BACKGROUND: Although adipose-derived stem cell (ADSC) sheets improve the cardiac function after myocardial infarction (MI), underlying mechanisms remain to be elucidated. The aim of this study was to determine the fate of transplanted ADSC sheets and candidate angiogenic factors released from ADSCs for their cardiac protective actions.Methods and Results:MI was induced by ligation of the left anterior descending coronary artery. Sheets of transgenic (Tg)-ADSCs expressing green fluorescence protein (GFP) and luciferase or wild-type (WT)-ADSCs were transplanted 1 week after MI. Both WT- and Tg-ADSC sheets improved cardiac functions evaluated by echocardiography at 3 and 5 weeks after MI. Histological examination at 5 weeks after MI demonstrated that either sheet suppressed fibrosis and increased vasculogenesis. Luciferase signals from Tg-ADSC sheets were detected at 1 and 2 weeks, but not at 4 weeks, after transplantation. RNA sequencing of PKH (yellow-orange fluorescent dye with long aliphatic tails)-labeled Tg-ADSCs identified mRNAs of 4 molecules related to angiogenesis, including those of Esm1 and Stc1 that increased under hypoxia. Administration of Esm1 or Stc1 promoted tube formation by human umbilical vein endothelial cells. CONCLUSIONS: ADSC sheets improved cardiac contractile functions after MI by suppressing cardiac fibrosis and enhancing neovascularization. Transplanted ADSCs existed for >2 weeks on MI hearts and produced the angiogenic factors Esm1 and Stc1, which may improve cardiac functions after MI.

Effect of dapagliflozin according to baseline systolic blood pressure in the Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure trial (DAPA-HF).

AIMS: Concern about hypotension often leads to withholding of beneficial therapy in patients with heart failure and reduced ejection fraction (HFrEF). We evaluated the efficacy and safety of dapagliflozin, which lowers systolic blood pressure (SBP),according to baseline SBP in Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure trial (DAPA-HF). METHODS AND RESULTS: Key inclusion criteria were: New York Heart Association Class II-IV, left ventricular ejection fraction ≤ 40%, elevated N-terminal pro-B-type natriuretic peptide level, and SBP ≥95 mmHg. The primary outcome was a composite of worsening heart failure or cardiovascular death. The efficacy and safety of dapagliflozin were examined using SBP as both a categorical and continuous variable. A total of 1205 patients had a baseline SBP <110 mmHg; 981 ≥ 110 < 120; 1149 ≥ 120 < 130; and 1409 ≥ 130 mmHg. The placebo-corrected reduction in SBP from baseline to 2 weeks with dapagliflozin was -2.54 (-3.33 to -1.76) mmHg (P < 0.001), with a smaller between-treatment difference in patients in the lowest compared to highest SBP category. Patients in the lowest SBP category had a much higher rate (per 100 person-years) of the primary outcome [20.6, 95% confidence interval (95% CI) 17.6-24.2] than those in the highest SBP category (13.8, 11.7-16.4). The benefit and safety of dapagliflozin was consistent across the range of SBP; hazard ratio (95% CI) in each SBP group, lowest to highest: 0.76 (0.60-0.97), 0.76 (0.57-1.02), 0.81 (0.61-1.08), and 0.67 (0.51-0.87), P interaction = 0.78. Study drug discontinuation did not differ between dapagliflozin and placebo across the SBP categories examined. CONCLUSION: Dapagliflozin had a small effect on SBP in patients with HFrEF and was superior to placebo in improving outcomes, and well tolerated, across the range of SBP included in DAPA-HF. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT03036124.

Mutant KCNJ3 and KCNJ5 Potassium Channels as Novel Molecular Targets in Bradyarrhythmias and Atrial Fibrillation.

BACKGROUND: Bradyarrhythmia is a common clinical manifestation. Although the majority of cases are acquired, genetic analysis of families with bradyarrhythmia has identified a growing number of causative gene mutations. Because the only ultimate treatment for symptomatic bradyarrhythmia has been invasive surgical implantation of a pacemaker, the discovery of novel therapeutic molecular targets is necessary to improve prognosis and quality of life. METHODS: We investigated a family containing 7 individuals with autosomal dominant bradyarrhythmias of sinus node dysfunction, atrial fibrillation with slow ventricular response, and atrioventricular block. To identify the causative mutation, we conducted the family-based whole exome sequencing and genome-wide linkage analysis. We characterized the mutation-related mechanisms based on the pathophysiology in vitro. After generating a transgenic animal model to confirm the human phenotypes of bradyarrhythmia, we also evaluated the efficacy of a newly identified molecular-targeted compound to upregulate heart rate in bradyarrhythmias by using the animal model. RESULTS: We identified one heterozygous mutation, KCNJ3 c.247A>C, p.N83H, as a novel cause of hereditary bradyarrhythmias in this family. KCNJ3 encodes the inwardly rectifying potassium channel Kir3.1, which combines with Kir3.4 (encoded by KCNJ5) to form the acetylcholine-activated potassium channel ( IKACh channel) with specific expression in the atrium. An additional study using a genome cohort of 2185 patients with sporadic atrial fibrillation revealed another 5 rare mutations in KCNJ3 and KCNJ5, suggesting the relevance of both genes to these arrhythmias. Cellular electrophysiological studies revealed that the KCNJ3 p.N83H mutation caused a gain of IKACh channel function by increasing the basal current, even in the absence of m2 muscarinic receptor stimulation. We generated transgenic zebrafish expressing mutant human KCNJ3 in the atrium specifically. It is interesting to note that the selective IKACh channel blocker NIP-151 repressed the increased current and improved bradyarrhythmia phenotypes in the mutant zebrafish. CONCLUSIONS: The IKACh channel is associated with the pathophysiology of bradyarrhythmia and atrial fibrillation, and the mutant IKACh channel ( KCNJ3 p.N83H) can be effectively inhibited by NIP-151, a selective IKACh channel blocker. Thus, the IKACh channel might be considered to be a suitable pharmacological target for patients who have bradyarrhythmia with a gain-of-function mutation in the IKACh channel.