Sacubitril/valsartan decreases mortality in the rat model of the isoprenaline-induced takotsubo-like syndrome

Animal models of Takotsubo syndrome: bridging the gap to the human condition

Modelling human diseases serves as a crucial tool to unveil underlying mechanisms and pathophysiology. Takotsubo syndrome (TS), an acute form of heart failure resembling myocardial infarction, manifests with reversible regional wall motion abnormalities (RWMA) of the ventricles. Despite its mortality and clinical similarity to myocardial infarction, TS aetiology remains elusive, with stress and catecholamines playing central roles. This review delves into current animal models of TS, aiming to assess their ability to replicate key clinical traits and identifying limitations. An in-depth evaluation of published animal models reveals a variation in the definition of TS among studies. We notice a substantial prevalence of catecholamine-induced models, particularly in rodents. While these models shed light on TS, there remains potential for refinement. Translational success in TS research hinges on models that align with human TS features and exhibit the key features, including transient RWMA. Animal models should be comprehensively evaluated regarding the various systemic changes of the applied trigger(s) for a proper interpretation. This review acts as a guide for researchers, advocating for stringent TS model standards and enhancing translational validity.

Takotsubo syndrome: unravelling the enigma of the broken heart syndrome?-a narrative review

Background and Objective

Takotsubo syndrome (TTS) is a condition characterized by transient ventricular regional wall motion abnormalities, without causative coronary artery disease, typically triggered by emotional or physical stress. TTS is more common in post-menopausal women, closely resembling acute coronary syndrome (ACS) in its clinical presentation, with multiple proposed underlying pathophysiological mechanisms and no evidence-based treatments. This review aims to provide a comprehensive summary of the latest research, encompassing the pathophysiology, diagnostic findings, prognosis, and treatment options for TTS patients.

Methods

Relevant literature from 1990 to June 2023 on TTS epidemiology, physiopathology, diagnosis, clinical manifestations, treatment, and prognosis was retrieved through PubMed research. Only English publications were included.

Key Content and Findings

TTS is an increasingly recognized cardiovascular disorder, a significant release of catecholamines is thought to be a key contributing element, yet its exact mechanism remains unclear. Notably, TTS poses significant short and long-term risks akin to ACS. Initial treatment should focus on ruling out ACS and providing standard care for subsequent left ventricular dysfunction and complications. Research hints at a potential role for Angiotensin-converting enzyme inhibitors and Angiotensin II receptor blockers in improving long-term prognosis in TTS patients.

Conclusions

Significant knowledge gaps still exist in our understanding of the pathophysiology, treatment options, and areas for improvement in diagnosing and prognosticating this intriguing condition. Further research is therefore needed.

Sacubitril/valsartan cardioprotective effect against cisplatin-induced cardiotoxicity via modulation of VEGF/eNOS and TLR4/TNFα/IL6 signalling pathways

OBJECTIVES

Drug-induced cardiac injury is a potentially preventable cause of heart failure. Cisplatin (CIS) is a widely used chemotherapeutic agent complicated with cardiotoxicity that limits its clinical application so we aimed to evaluate the suspected cardioprotective effect of sacubitril/valsartan (Sac/Val) against CIS cardiotoxic injury.

METHODS

Forty male rats of Wistar albino species were divided into four groups. group I received the vehicle; group II was given the vehicle plus CIS (10 mg/kg) single i.p. on fifth day; group III was given Sac/Val (30 mg/kg/d) orally for 7 days plus CIS (10 mg/kg) single i.p. on fif5th day; group IV was given the same as group III plus nitro-ω-L-arginine (L-NNA) (25 mg/kg/d) orally for 7 days.

KEY FINDINGS

CIS-induced cardiotoxicity and L-NNA co-administered group showed significant increases in cardiac enzymes, toxic histopathological features, elevated heart weights, angiotensin II (Ang II), neprilysin, malondialdehyde (MDA), inflammatory mediators, blood pressure (BP) and caspase 3 expressions, but there are significant decreases in the antioxidant parameters, vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS). However, the co-administration of Sac/Val could ameliorate these changes of CIS.

CONCLUSION

Sac/Val has an important cardioprotective effect against CIS cardiotoxicity with the involvement of eNOS.

Acute stress induces long-term metabolic, functional, and structural remodeling of the heart

Takotsubo cardiomyopathy is a stress-induced cardiovascular disease with symptoms comparable to those of an acute coronary syndrome but without coronary obstruction. Takotsubo was initially considered spontaneously reversible, but epidemiological studies revealed significant long-term morbidity and mortality, the reason for which is unknown. Here, we show in a female rodent model that a single pharmacological challenge creates a stress-induced cardiomyopathy similar to Takotsubo. The acute response involves changes in blood and tissue biomarkers and in cardiac in vivo imaging acquired with ultrasound, magnetic resonance and positron emission tomography. Longitudinal follow up using in vivo imaging, histochemistry, protein and proteomics analyses evidences a continued metabolic reprogramming of the heart towards metabolic malfunction, eventually leading to irreversible damage in cardiac function and structure. The results combat the supposed reversibility of Takotsubo, point to dysregulation of glucose metabolic pathways as a main cause of long-term cardiac disease and support early therapeutic management of Takotsubo.

Sacubitril/valsartan decreases mortality in the rat model of the isoprenaline-induced takotsubo-like syndrome

Aims

Takotsubo syndrome (TTS) is an acute potentially reversible cardiac syndrome characterized by variable regional myocardial akinesia that cannot be attributed to a culprit coronary artery occlusion. TTS is an important differential diagnosis of acute heart failure where brain natriuretic peptides are elevated. Sacubitril/valsartan is a novel and effective pharmacological agent for the treatment of patients with heart failure. Our aim was to explore whether treatment with sacubitril/valsartan could prevent isoprenaline‐induced takotsubo‐like phenotype in rats.

Methods and results

A total number of 186 Sprague–Dawley male rats were randomized to receive pretreatment with water (CONTROL, n = 62), valsartan (VAL, n = 62), or sacubitril/valsartan (SAC/VAL, n = 62) before receiving isoprenaline for induction of TTS. We recorded heart rate and blood pressure invasively. Cardiac morphology and function were evaluated by high‐resolution echocardiography 90 min after the administration of isoprenaline. We documented the survival rate at the time of echocardiography. Compared with the CONTROL group, the SAC/VAL group had less pronounced TTS‐like cardiac dysfunction and lower mortality rate, while the VAL group did not differ. Heart rate and blood pressure were not significantly different between the groups. Analysis of cardiac lipids was performed with mass spectrometry. The VAL and SAC/VAL groups had significantly higher levels of lysophosphatidylcholine (LPC), in particular LPC 18:1 and LPC 16:0.

Conclusions

Pretreatment with sacubitril/valsartan but not with valsartan reduces mortality and attenuates isoprenaline‐induced apical akinesia in the TTS‐like model in rats. Sacubitril/valsartan could be a potential treatment option in patients with TTS in humans.