Association of Beta-Blocker Therapy With Cardiovascular Outcomes in Patients With Stable Ischemic Heart Disease

Oral mitochondrial transplantation using nanomotors to treat ischaemic heart disease

Mitochondrial transplantation is an important therapeutic strategy for restoring energy supply in patients with ischaemic heart disease (IHD); however, it is limited by the invasiveness of the transplantation method and loss of mitochondrial activity. Here we report successful mitochondrial transplantation by oral administration for IHD therapy. A nitric-oxide-releasing nanomotor is modified on the mitochondria surface to obtain nanomotorized mitochondria with chemotactic targeting ability towards damaged heart tissue due to nanomotor action. The nanomotorized mitochondria are packaged in enteric capsules to protect them from gastric acid erosion. After oral delivery the mitochondria are released in the intestine, where they are quickly absorbed by intestinal cells and secreted into the bloodstream, allowing delivery to the damaged heart tissue. The regulation of disease microenvironment by the nanomotorized mitochondria can not only achieve rapid uptake and high retention of mitochondria by damaged cardiomyocytes but also maintains high activity of the transplanted mitochondria. Furthermore, results from animal models of IHD indicate that the accumulated nanomotorized mitochondria in the damaged heart tissue can regulate cardiac metabolism at the transcriptional level, thus preventing IHD progression. This strategy has the potential to change the therapeutic strategy used to treat IHD.

Tolerability and effectiveness of beta-blockers in patients with cardiac amyloidosis: A systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to assess the tolerability of patients with cardiac amyloidosis (CA) to beta-blockers (BBs) and evaluate its association with adverse outcomes.

METHODS

We performed a comprehensive search from January 1, 2000 to October 20, 2023. Studies examining BB use and tolerance or the relationship between BB use and outcomes in patients with CA were included. Pooled adjusted hazard ratios (aHRs) for all-cause mortality were calculated using random- and fixed-effects models.

RESULTS

Eight observational studies involving 4002 patients with CA (87.5% with transthyretin CA [ATTR-CA] and 12.5% with immunoglobulin light chain CA [AL-CA]) were assessed. BBs were used by 52.5% of the patients. However, 26.3% of the patients discontinued BBs because of hypotension, bradycardia, or fatigue. Regarding the association between BB use and all-cause death, four studies were identified that included 2874 patients with ATTR-CA and 16 patients with AL-CA. The meta-analysis revealed no apparent relationship between BB use and all-cause mortality (pooled aHR = 0.78, 95% confidence interval (CI) = 0.40-1.51). Two studies on patients with ATTR-CA found no impact of BB use on all-cause mortality in the subgroup with left ventricular ejection fraction (LVEF) > 40%, but conflicting results exist for those with LVEF ≤40% (pooled aHR = 0.78, 95% CI = 0.40-1.54).

CONCLUSION

The limited number of observational studies that predominantly enrolled patients with ATTR-CA showed that BBs were used in almost half of the patients with CA, with varying tolerability. However, no significant association was observed between BB use and all-cause mortality.

Beta Blockers in Contemporary Cardiology: Is It Better to Cast Them Out?

Beta blockers are one of the commonest prescription drugs in medicine and they have been thought to revolutionize the treatment of heart failure (HF) with reduced ejection fraction (HFrEF) in the last century. In addition to HFrEF, they are prescribed for a variety of diseases in cardiology from hypertension to HF, angina, and stable coronary artery disease (CAD). The increased prescription of beta blockers in conditions like HF with preserved ejection fraction (HFpEF), and stable CAD may be doing more harm than good as per the data we have so far. The available data shows that beta blockers are associated with increased stroke risk and atrial fibrillation (AF) in hypertension and in patients with HFpEF, they have been associated with decreased exercise capacity. In patients with stable CAD and patients with myocardial infarction with normal systolic functions, beta blockers don't offer any mortality benefit. In this article, we critically review the common indications and the uses of beta blockers in patients with HFpEF, CAD, hypertension and AF and we propose that beta blockers are over-prescribed under the shadow of their beneficial effects in patients with HFrEF.

Association of β-blocker use at discharge and prognosis of oldest old with acute myocardial infarction: a prospective cohort study

PURPOSE

It is uncertain whether β-blockers are beneficial for long-term prognosis in older patients following acute myocardial infarction (AMI). Thus, this study sought to examine the effect of β-blockers on long-term cardiovascular mortality (CVM) in the oldest old (≥ 80 years) with AMI.

METHODS

In this prospective, consecutive, non-randomized study, a total of 1156 patients with AMI admitted within 24 h after onset of symptoms were enrolled from January 2012 to February 2020. Univariate and multivariate Cox regression analyses were performed to examine the impact of β-blocker use on prognosis. Furthermore, one-to-one propensity score matching (PSM) and inverse probability treatment weighting (IPTW) analyses were used to control for systemic differences between groups. The primary outcome was long-term CVM.

RESULTS

Among the enrolled subjects, 972 (85.9%) were prescribed with β-blockers at discharge. Over a mean follow-up of 26.3 months, 224 cardiovascular deaths were recorded. Both univariate [hazard ratio (HR), 1.41, 95% confidence interval (CI) 0.93-2.13] and multivariate (HR, 1.29, 95% CI 0.79-2.10) Cox regression analyses showed that β-blocker use had no significant association with the long-term CVM, which was further demonstrated by PSM (HR, 1.31, 95% CI 0.75-2.28) and IPTW (HR, 1.41, 95% CI 0.73-2.69) analyses. Subgroup analyses according to sex, heart rate, hypertension, diabetes, revascularization, left ventricular ejection fraction, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers use showed consistent results as well.

CONCLUSION

Our findings first suggested that the use of β-blockers at discharge in oldest old with AMI was not useful for reducing post-discharge CVM, which need to be further verified by randomized controlled trials.

Traditional Therapeutics and Potential Epidrugs for CVD: Why Not Both?

Cardiovascular disease (CVD) is the leading cause of death worldwide. In addition to the high mortality rate, people suffering from CVD often endure difficulties with physical activities and productivity that significantly affect their quality of life. The high prevalence of debilitating risk factors such as obesity, type 2 diabetes mellitus, smoking, hypertension, and hyperlipidemia only predicts a bleak future. Current traditional CVD interventions offer temporary respite; however, they compound the severe economic strain of health-related expenditures. Furthermore, these therapeutics can be prescribed indefinitely. Recent advances in the field of epigenetics have generated new treatment options by confronting CVD at an epigenetic level. This involves modulating gene expression by altering the organization of our genome rather than altering the DNA sequence itself. Epigenetic changes are heritable, reversible, and influenced by environmental factors such as medications. As CVD is physiologically and pathologically diverse in nature, epigenetic interventions can offer a ray of hope to replace or be combined with traditional therapeutics to provide the prospect of addressing more than just the symptoms of CVD. This review discusses various risk factors contributing to CVD, perspectives of current traditional medications in practice, and a focus on potential epigenetic therapeutics to be used as alternatives.