Background: Recent reports have evidenced an increased mortality rate in hypertensive patients with electrocardiographic left ventricular hypertrophy (ECG-LVH) achieving systolic blood pressure (SBP) <130mmHg. However, to the best of our knowledge, the actual effects of BP reduction to the {less than or equal to}130/80mmHg target on the incidence of cardiovascular events in hypertensive patients with a diagnosis of LVH based on echocardiographic-criteria (Echo-LVH) have never been determined. Methods: In order to fill this long-standing knowledge gap, we harnessed a population of 9511 hypertensive patients, followed-up for 33.6 [IQR 7.9-72.7] months. The population was divided into six groups according to the average SBP achieved during the follow-up ({less than or equal to}130, 130-to-139, and {greater than or equal to}140mmHg) and absence/presence of Echo-LVH. The primary endpoint was a composite of fatal or non-fatal myocardial infarction and stroke, sudden cardiac death, heart failure requiring hospitalization, revascularization, and carotid stenting. Secondary endpoints included atrial fibrillation and transient ischemic attack. Results: During the follow-up, achieved SBP and diastolic BP (DBP) were comparable between patients with and without Echo-LVH. Strikingly, the rate of primary and secondary endpoints was significantly higher in patients with Echo-LVH and SBP>130mmHg, reaching the highest rate in the Echo-LVH group with SBP{greater than or equal to}140mmHg. By separate Cox multivariable regressions, after adjusting for potential confounders, both primary and secondary endpoints were significantly associated with SBP{greater than or equal to}140mmHg and Echo-LVH. Instead, DBP reduction {less than or equal to}80mmHg was associated with a significant increased rate of secondary events. Conclusions: In hypertensive patients with Echo-LVH, achieving an average in-treatment SBP target {less than or equal to}130mmHg has a beneficial prognostic impact on incidence of cardiovascular events. Significance Statement In contrast with recent reports, achieving in-treatment SBP≤130mmHg reduces the incidence of CV events in hypertensive patients with Echo-LVH. Reducing DBP≤80mmHg is instead associated with a higher rate of CV complications. By Cox multivariable regression models, adjusting for potential confounders, the rate of hard and soft CV events was significantly associated with Echo-LVH and SBP≥140mmHg. Our data indicate that therapeutic strategies in patients with Echo-LVH should aim at reducing SBP≤130mmHg paying attention to not reducing DBP≤80mmHg.

Aryl hydrocarbon receptor (AhR) is a multifunctional receptor that regulate cytochrome P450 1A1 (CYP1A1), an arachidonic acid (AA) metabolizing enzyme producing 19-hydroxyeicosatetraenoic acid (HETE). 6-formylindolo[3,2-b]carbazole (FICZ) demonstrates great-affinity toward the AhR. Recently, we have shown that 19(S)-HETE is preferentially cardioprotective. This study investigates the role of FICZ on AhR and CYP1A1 mediated AA metabolism and whether it attenuate angiotensin (Ang) II-induced cardiac hypertrophy. Adult human ventricular cardiomyocytes cell line (AC16) treated with FICZ in the presence and absence of Ang II 10 μM. Protein levels of AhR and CYPs were determined by Western blot analysis and the mRNA expression of cardiac hypertrophic markers and CYPs were determined by real time-PCR. CYP1A1 enzyme activity and proteasomal degradation were determined by 7-ethoxyresorufin O-deethylase (EROD) and proteasome 20S activity assays, respectively. LC-MS/MS was used to measure AA metabolites. Our results show that Ang II-induced cardiac hypertrophy modulates AA metabolites in an enantioselective manner, and that FICZ activates AhR in a time dependent manner, inhibits AhR proteasomal degradation, induces CYP1A1, increases the concentration of 19(S)-HETE and attenuate Ang II-induced cardiac hypertrophy by inhibiting the hypertrophic markers and decreasing cell surface area through midchain-HETEs dependent mechanism. In conclusion, the results demonstrate the ability of FICZ to protects against Ang II-induced cardiac hypertrophy by increasing the concentration of 19(S)-HETE through AhR regulated enzyme induction and inhibition of midchain-HETEs metabolites. Significance Statement This study shows that FICZ attenuate Ang II-induced cellular hypertrophy. The novel findings of our investigation are in characterizing the AhR involvement and the enantioselective differences in AA metabolism in cardiac hypertrophy, which opens a new pathway to tackle and eventually treat heart failure.

Diabetes is associated with increased cardiac injury and sudden death. Nicotinamide phosphoribosyltransferase (Nampt) is an essential enzyme for the NAD⁺ salvage pathway and dysregulated in diabetes. Hypothesis: Nampt activation results in rescued NADH/NAD⁺ ratios and provides pharmacological changes necessary for diabetic cardioprotection. Computer docking shows that P7C3 allows for enhanced Nampt dimerization and association. Methods: To test the pharmacological application, we utilized male leptin receptor-deficient (db/db) mice and treated with Nampt activator P7C3 (1-(3,6-Dibromo-carbazol-9-yl)-3-phenylamino-propan-2-ol). The effects of four-week P7C3 treatment on cardiac function were evaluated along with molecular signaling changes for p-AKT, p-eNOS, and SiRT-1. Results: The cardiac function evaluated by ECG and Echo were significantly improved after four-weeks of P7C3 treatment. Biochemically, higher NADH/NAD⁺ ratio in diabetic heart were rescued by P7C3 treatment. Moreover, activities of Nampt and Sirt1 were significantly increased in P7C3 treated diabetic hearts. P7C3 treatment significantly decreased the blood glucose in diabetic mice with 4-week treatment as noted by glucose tolerance test and fasting blood glucose measurements compared with vehicle treated mice. P7C3 activated Nampt enzymatic activity both in vitro and in the 4-week diabetic mouse hearts demonstrates the specificity of the small molecule. P7C3 treatment significantly enhanced the expression of cardioprotective signaling; p-AKT, p-eNOS, and Beclin 1 in diabetic hearts. Nampt activator P7C3 allows for decreased infarct size with decreased Troponin I and LDH release, which is beneficial to the heart. Conclusions: Overall, the present study shows that P7C3 activates Nampt and Sirt1 activity, decreases NADH/NAD⁺ ratio, resulting in improved biochemical signaling providing cardioprotection. Significance Statement We show that P7C3 is effective in the treatment of diabetes and cardiovascular diseases. The novel small molecule is anti-arrhythmic and improves the ejection fraction in diabetic hearts. The study demonstrates that P7C3 decreases the infarct size in heart during myocardial infarction and ischemia-reperfusion injury. Biochemical and cellular signaling show increased NAD⁺ levels, along with Nampt activity involved in upregulating protective signaling in the diabetic heart. Based on the cardioprotective properties P7C3 has high therapeutic potential.

Cardiac rehabilitation (CR) following acute myocardial infarction (AMI) improves physical capacities and decreases hospitalizations and cardiovascular mortality. L-Arginine is the substrate used by nitric oxide (NO) synthase (NOS) to generate NO and it has been shown to exert its beneficial effects on endothelium driving vasodilatation, reducing inflammation, and ameliorating physical function. We hypothesized that L-Arginine could enhance physical capacities in patients who underwent CR after AMI. We designed a study aimed to assess the effects of L-arginine administration on the physical capacity of patients who underwent coronary revascularization after AMI. The trial was carried out amid the COVID-19 pandemic. Patients were assigned, with a 2:1 ratio, to add to their standard therapy 1 bottle containing 1.66 g of L-arginine or 1 bottle of identical aspect apart from not containing L-arginine, twice a day orally for 3 weeks. Patients performed a 6-minute walking test (6MWT) and were assessed their Borg modified 0-10 rating of perceived exertion (BRPE) before starting and at the end of the treatment. Seventy-five patients receiving L-Arginine, and thirty-five receiving placebo successfully completed the study. The 6MWT distance increased significantly in the L-Arginine group compared to both baseline and placebo (p<0.0001). Additionally, we observed a significant improvement in the BRPE in patients treated with L-arginine but not in the placebo group. Taken together, our data indicate that L-arginine potentiates the response to CR, independently of age, sex, baseline functional capacity, and comorbid conditions. Significance Statement This study shows for the first time that oral supplementation of L-arginine potentiates the response to cardiac rehabilitation after myocardial infarction and cardiac revascularization. Indeed, we observed a significant improvement in two fundamental parameters, namely, the 6-minute walking test and the Borg modified 0-10 rating of perceived exertion. Strikingly, the beneficial effects of L-arginine were independent from age, sex, comorbid conditions, and baseline functional capacity.

We tested the hypothesis that isoform shifts in sarcomeres of the immature heart modify the effect of cardiac myosin-directed sarcomere inhibitors and activators. Omecamtiv mecarbil (OM) activates tension and is in clinical trials for the treatment of adult acute and chronic heart failure. Mavacamten (Mava) inhibits tension and is in clinical trials to relieve hyper-contractility and outflow obstruction in advanced genetic hypertrophic cardiomyopathy (HCM) linked commonly to mutations in sarcomeric proteins. To address the effect of these agents in developing sarcomeres we isolated heart fiber bundles, extracted membranes with Triton X-100, and measured tension developed over a range of Ca²⁺ concentrations with and without OM or Mava treatment. We made measurements in fiber bundles from hearts of adult non-transgenic controls (NTG) expressing cardiac troponin I (cTnI), and from hearts of transgenic mice (TG-ssTnI) expressing the fetal/neonatal form, slow skeletal troponin I (ssTnI). We also compared fibers from 7+14-day-old NTG mice expressing ssTnI and cTnI. These studies were repeated with 7+14-day old transgenic mice (TG-cTnT-R92Q) expressing a mutant form of cardiac TnT (cTnT) linked to HCM. OM increased Ca²⁺-sensitivity and decreased cooperative activation in both ssTnI- and cTnI- regulated myofilaments with a similar effect reducing sub-maximal tension in immature and mature myofilaments. Although Mava decreased tension similarly in cTnI- and ssTnI-regulated myofilaments controlled either by cTnT or cTnT-R92Q, its effect involved a depressed Ca²⁺-sensitivity in the mature cTnT-R92-myofilaments. Our data demonstrate an influence of myosin and thin filament-associated proteins on the actions of myosin-directed agents such as OM and Mava. Significance Statement The effects of myosin-targeted activators and inhibitors on Ca²⁺-activated tension in developing cardiac sarcomeres presented here provide novel, ex-vivo evidence as to their actions in early-stage cardiac disorders. These studies advance understanding of the molecular mechanisms of these agents that is important in pre-clinical studies employing sarcomere Ca²⁺-response as a screening approach. The data also inform the use of commonly immature cardiac myocytes generated from human inducible pluripotent stem cells in screening for sarcomere activators and inhibitors.

The (pro)renin receptor (PRR) is a single-transmembrane protein that regulates the local renin-angiotensin system and participates in various intracellular signaling pathways, thus exhibiting a significant physio-pathological relevance in cellular homeostasis. A soluble form of PRR (sPRR) is generated through proteases-mediated cleavage of the full-length PRR and secreted into extracellular spaces. Accumulating evidence indicates pivotal biological functions of sPRR in various physiopathological processes. sPRR may be a novel biomarker for multiple diseases. Significance Statement Circulating sPRR concentrations are elevated in patients and animals under various physiopathological conditions. Here we highlight recent advances in sPRR functions in health and pathophysiological conditions. Results suggest that sPRR may be a novel biomarker for multiple diseases, but further studies are needed to determine the diagnostic value of sPRR.