Clinical Experience with Diltiazem in the Treatment of Cardiovascular Diseases

Serious Bleeding in Patients With Atrial Fibrillation Using Diltiazem With Apixaban or Rivaroxaban

Importance

Diltiazem, a commonly prescribed ventricular rate-control medication for patients with atrial fibrillation, inhibits apixaban and rivaroxaban elimination, possibly causing overanticoagulation.

Objective

To compare serious bleeding risk for new users of apixaban or rivaroxaban with atrial fibrillation treated with diltiazem or metoprolol.

Design, Setting, and Participants

This retrospective cohort study included Medicare beneficiaries aged 65 years or older with atrial fibrillation who initiated apixaban or rivaroxaban use and also began treatment with diltiazem or metoprolol between January 1, 2012, and November 29, 2020. Patients were followed up to 365 days through November 30, 2020. Data were analyzed from August 2023 to February 2024.

Exposures

Diltiazem and metoprolol.

Main Outcomes and Measures

The primary outcome was a composite of bleeding-related hospitalization and death with recent evidence of bleeding. Secondary outcomes were ischemic stroke or systemic embolism, major ischemic or hemorrhagic events (ischemic stroke, systemic embolism, intracranial or fatal extracranial bleeding, or death with recent evidence of bleeding), and death without recent evidence of bleeding. Hazard ratios (HRs) and rate differences (RDs) were adjusted for covariate differences with overlap weighting.

Results

The study included 204 155 US Medicare beneficiaries, of whom 53 275 received diltiazem and 150 880 received metoprolol. Study patients (mean [SD] age, 76.9 [7.0] years; 52.7% female) had 90 927 person-years (PY) of follow-up (median, 120 [IQR, 59-281] days). Patients receiving diltiazem treatment had increased risk for the primary outcome (RD, 10.6 [95% CI, 7.0-14.2] per 1000 PY; HR, 1.21 [95% CI, 1.13-1.29]) and its components of bleeding-related hospitalization (RD, 8.2 [95% CI, 5.1-11.4] per 1000 PY; HR, 1.22 [95% CI, 1.13-1.31]) and death with recent evidence of bleeding (RD, 2.4 [95% CI, 0.6-4.2] per 1000 PY; HR, 1.19 [95% CI, 1.05-1.34]) compared with patients receiving metoprolol. Risk for the primary outcome with initial diltiazem doses exceeding 120 mg/d (RD, 15.1 [95% CI, 10.2-20.1] per 1000 PY; HR, 1.29 [95% CI, 1.19-1.39]) was greater than that for lower doses (RD, 6.7 [95% CI, 2.0-11.4] per 1000 PY; HR, 1.13 [95% CI, 1.04-1.24]). For doses exceeding 120 mg/d, the risk of major ischemic or hemorrhagic events was increased (HR, 1.14 [95% CI, 1.02-1.27]). Neither dose group had significant changes in the risk for ischemic stroke or systemic embolism or death without recent evidence of bleeding. When patients receiving high- and low-dose diltiazem treatment were directly compared, the HR for the primary outcome was 1.14 (95% CI, 1.02-1.26).

Conclusions and Relevance

In Medicare patients with atrial fibrillation receiving apixaban or rivaroxaban, diltiazem was associated with greater risk of serious bleeding than metoprolol, particularly for diltiazem doses exceeding 120 mg/d.

Repurposing Diltiazem for Its Neuroprotective Anti-Dementia Role against Intra-Cerebroventricular Streptozotocin-Induced Sporadic Alzheimer's Disease-Type Rat Model

Alzheimer's disease (AD) is an age-related neuropsychiatric disorder and a common cause of progressive dementia. Diltiazem (DTZ), the non-dihydropyridine benzothiazepine class of calcium channel blocker (CCB), used clinically in angina and other cardiovascular disorders, has proven neurological benefits. In the present study, the neuroprotective anti-dementia effects of DTZ against intra-cerebroventricular-streptozotocin (ICV-STZ)-induced sporadic AD (SAD)-type rat model was investigated. ICV-STZ-induced cognitive impairments were measured via passive avoidance and Morris water maze tasks. Anti-oxidative enzyme status, pro-inflammatory markers, and amyloid-beta (Aβ) protein expression in rat brain tissues were measured using ELISA kits, Western blotting, and immunostaining techniques. The data revealed that ICV-STZ injection in rats significantly induced cognitive deficits and altered the levels of oxidative and pro-inflammatory markers (p < 0.05~p < 0.001). Treatment with DTZ (10 mg/kg, 20 mg/kg, and 40 mg/kg, p.o.) daily for twenty-one days, 1 h before a single ICV-STZ (3 mg/kg) injection, significantly improved cognitive impairments and ameliorated the ICV-STZ-induced altered nitrite, pro-inflammatory cytokines (TNF-α, and IL-1β) and anti-oxidative enzyme levels (superoxide dismutase, lipid peroxidation, and glutathione). Further, DTZ restored the increased Aβ protein expression in ICV-STZ-induced brain tissue. Considering the results obtained, DTZ might have a potential therapeutic role in treating and managing AD and related dementia pathologies due to its anti-dementia activity in SAD-type conditions in rats induced by ICV-STZ.

Chemistry and Pharmacological diversity of Benzothiazepine - Excellent pathway to drug discovery

In this era of sporadic advancement in science and technology, a substantial amount of intervention is being set in motion to reduce health-related diseases. Discoveries from researchers have pinpointed the usefulness of heterocyclic compounds, amongst which benzothiazepine (BTZ) derivatives have been synthesized for their various pharmacological activities. This also contributes to their undeniable application in therapeutic medicine for the development of efficacious drugs. BTZs are compounds with a benzene ring fused with a thiazepine ring. This work contains several methods that have been used to synthesize 1,3-, 1,4-, 1,5-, and 4-1-benzothiazepine derivatives. In addition, up-to-date information about the crucial pharmacological activities of BTZ derivatives has been reviewed in this present study to appreciate their druggable potential in therapeutic medicine for drug development. Drug design and development have further been simplified with the implementation of computer aided approaches to predict biological interactions which can help in the design of several derivatives. Hence, the structural activity relationship (SAR), ADMET and the molecular docking studies of BTZ derivatives were discussed to further establish their interactions and safety in biological systems. This present work aims to expound on the reported chemistry and pharmacological propensity of BTZ moiety in relation to other relevant moieties to validate their potential as excellent pharmacophores in drug design and development.

Mitochondrial Effects of Common Cardiovascular Medications: The Good, the Bad and the Mixed

Mitochondria are central organelles in the homeostasis of the cardiovascular system via the integration of several physiological processes, such as ATP generation via oxidative phosphorylation, synthesis/exchange of metabolites, calcium sequestration, reactive oxygen species (ROS) production/buffering and control of cellular survival/death. Mitochondrial impairment has been widely recognized as a central pathomechanism of almost all cardiovascular diseases, rendering these organelles important therapeutic targets. Mitochondrial dysfunction has been reported to occur in the setting of drug-induced toxicity in several tissues and organs, including the heart. Members of the drug classes currently used in the therapeutics of cardiovascular pathologies have been reported to both support and undermine mitochondrial function. For the latter case, mitochondrial toxicity is the consequence of drug interference (direct or off-target effects) with mitochondrial respiration/energy conversion, DNA replication, ROS production and detoxification, cell death signaling and mitochondrial dynamics. The present narrative review aims to summarize the beneficial and deleterious mitochondrial effects of common cardiovascular medications as described in various experimental models and identify those for which evidence for both types of effects is available in the literature.

Influence of Diversity Nursing on Patients' Rehabilitation in Cardiology Treatment

With the improvement of living standards, people have more and more physical health problems. Among them, high-risk cardiovascular diseases such as hypertension, diabetes, and coronary heart disease are the most prominent. The number of cardiology patients is increasing year by year. Effectively improving the treatment of cardiology patients and speeding up the recovery of cardiology patients have become a social problem. This article aims to explore the impact of diverse nursing care on patients in cardiology treatment. This article first gives a detailed introduction to the treatment of diverse nursing and cardiology diseases, then takes 300 cardiology patients in our hospital as experimental subjects, and conducts a controlled experiment of nursing intervention, which is categorized into an experimental group of 150 cases (including 35 cases of hypertension, 46 cases of diabetes, 28 cases of coronary heart disease, 24 cases of angina pectoris, and 17 cases of multiple complications) and a control group of 150 cases (including 30 cases of hypertension, 47 cases of diabetes, 39 cases of coronary heart disease, 21 cases of angina pectoris, and 13 cases of multiple complications). The experimental results showed the following: the general information of the two groups of patients was not statistically different (P > 0.05); after the nursing intervention, the blood glucose levels of the two groups of patients decreased, but the experimental group decreased more significantly and the blood glucose control effect was more obvious; after the intervention, in the experimental group that implemented diversified nursing interventions, the patient's condition management effect was better and their scores were between 8 and 10; the mental state self-evaluation of the two groups of patients was significantly different from the domestic reference value (P < 0.05), and there is a very significant statistical difference between the two groups after nursing intervention (P < 0.01); after nursing intervention, compared with the control group, the quality of life of the experimental group improved more significantly and the highest score reached about 70; the overall satisfaction of the experimental group with nursing work reached 92%, while the satisfaction of the control group with nursing work was only 44.67%. Studies have shown that diversified care has a positive impact on the rehabilitation of patients in cardiology treatment.

Focus on the Lymphatic Route to Optimize Drug Delivery in Cardiovascular Medicine

While oral agents have been the gold standard for cardiovascular disease therapy, the new generation of treatments is switching to other administration options that offer reduced dosing frequency and more efficacy. The lymphatic network is a unidirectional and low-pressure vascular system that is responsible for the absorption of interstitial fluids, molecules, and cells from the peripheral tissue, including the skin and the intestines. Targeting the lymphatic route for drug delivery employing traditional or new technologies and drug formulations is exponentially gaining attention in the quest to avoid the hepatic first-pass effect. The present review will give an overview of the current knowledge on the involvement of the lymphatic vessels in drug delivery in the context of cardiovascular disease.

Drug release from magnesium aluminium silicate-polyethylene oxide (PEO) nanocomposite matrices: An investigation using the USP III apparatus

This work investigated the use of the USP III apparatus in discriminating simulated fed and fasted conditions as well as ionic strength on veegum-polyethylene (PEO) (called clay-PEO matrices hereafter) matrices. The successful formulations were characterised using differential scanning calorimetry (DSC) and evaluated for their physical properties. Isothermal calorimetry (ITC) was used to evaluate the thermodynamics of the complexation processes. The effect of agitation sequences on the matrices as evaluated from the USP III suggested an increase in polymer content to significantly decrease the burst release experienced using diltiazem hydrochloride (DILT) as a model cationic drug. The manufacturing methods showed superior performance in relation to a decrease in burst release over the physical manufactured counterparts. The clay-PEO matrices also showed robustness (no matrix failure) in up to 0.2 M ionic strength solutions mimicking the upper limit experienced in the GI tract. ITC results revealed that the binding between DILT and PEO was enthalpy and entropy-driven. Furthermore, the binding between veegum and DILT in the presence of PEO was shown to be enthalpy-driven and entropically unfavourable, which was also the case for the binding between veegum and PEO thus giving insights to how the matrices were performing on a molecular level.

Everolimus Rescues the Phenotype of Elastin Insufficiency in Patient Induced Pluripotent Stem Cell-Derived Vascular Smooth Muscle Cells

Supplemental Digital Content is available in the text.

Objective:

Elastin gene deletion or mutation leads to arterial stenoses due to vascular smooth muscle cell (SMC) proliferation. Human induced pluripotent stem cells–derived SMCs can model the elastin insufficiency phenotype in vitro but show only partial rescue with rapamycin. Our objective was to identify drug candidates with superior efficacy in rescuing the SMC phenotype in elastin insufficiency patients.

Approach and Results:

SMCs generated from induced pluripotent stem cells from 5 elastin insufficiency patients with severe recurrent vascular stenoses (3 Williams syndrome and 2 elastin mutations) were phenotypically immature, hyperproliferative, poorly responsive to endothelin, and exerted reduced tension in 3-dimensional smooth muscle biowires. Elastin mRNA and protein were reduced in SMCs from patients compared to healthy control SMCs. Fourteen drug candidates were tested on patient SMCs. Of the mammalian target of rapamycin inhibitors studied, everolimus restored differentiation, rescued proliferation, and improved endothelin-induced calcium flux in all patient SMCs except one Williams syndrome. Of the calcium channel blockers, verapamil increased SMC differentiation and reduced proliferation in Williams syndrome patient cells but not in elastin mutation patients and had no effect on endothelin response. Combination treatment with everolimus and verapamil was not superior to everolimus alone. Other drug candidates had limited efficacy.

Conclusions:

Everolimus caused the most consistent improvement in SMC differentiation, proliferation and in SMC function in patients with both syndromic and nonsyndromic elastin insufficiency, and offers the best candidate for drug repurposing for treatment of elastin insufficiency associated vasculopathy.

Thermodynamics of clay-drug complex dispersions: Isothermal titration calorimetry and high-performance liquid chromatography

An understanding of the thermodynamics of the complexation process utilized in sustaining drug release in clay matrices is of great importance. Several characterisation techniques as well as isothermal calorimetry were utilized in investigating the adsorption process of a model cationic drug (diltiazem hydrochloride, DIL) onto a pharmaceutical clay system (magnesium aluminium silicate, MAS). X-ray powder diffraction (XRPD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and optical microscopy confirmed the successful formation of the DIL-MAS complexes. Drug quantification from the complexes demonstrated variable behaviour in the differing media used with DIL degrading to desacetyl diltiazem hydrochloride (DC-DIL) in the 2 M HCl media. Here also, the authors report for the first time two binding processes that occurred for DIL and MAS. A competitor binding model was thus proposed and the thermodynamics obtained suggested their binding processes to be enthalpy driven and entropically unfavourable. This information is of great importance for a formulator as care and consideration should be given with appropriate media selection as well as the nature of binding in complexes.

Cardiovascular effects of DWORF (dwarf open reading frame) peptide in normal and ischaemia/reperfused isolated rat hearts

The novel peptide dwarf open reading frame (DWORF), highly conserved across species and expressed almost exclusively in cardiac ventricular muscle, may play a role in cardiac physiology and pathophysiology. The effect of direct administration of DWORF in the intact heart has not previously been examined. Accordingly, we investigated the cardiac effects of DWORF (1-30 nM) in normal isolated perfused rat hearts and hearts undergoing ischaemia/reperfusion (I/R) injury, and evaluated potential mechanisms of action. Exogenous DWORF at the top dose (30 nM) increased perfusion pressure (PP) in normal hearts, which indicates coronary vasoconstriction; and during post-ischaemic reperfusion, DWORF increased PP in a dose-dependent manner. In I/R hearts, DWORF at the top dose also increased left ventricular end-diastolic pressure and maximum and minimum derivatives of left ventricular pressure noted dP/dt(max) and dP/dt(min), respectively, without affecting developed pressure (DP). Co-infusion of DWORF with Diltiazem, an l-type Ca²⁺ channel blocker (1μM), in I/R hearts attenuated the falls in DP, dP/dt(max) and dP/dt(min) observed with Diltiazem alone. DWORF co-infusion with both Diltiazem and Y27632 (1μM) (a Rho-Kinase inhibitor) reversed the coronary vasodilator effect of the inhibitors administered alone. In conclusion, we provide the first evidence that DWORF has coronary vasoconstrictor actions in normal hearts and when administered during reperfusion in an ex-vivo model of cardiac I/R injury, and also exhibits positive cardiac inotropic activity in the latter setting. DWORF's effect on ventricular contractile function appears to be dependent on the l-type Ca²⁺ channel, whereas Rho-Kinase activity may be related to the coronary vasoconstrictor effects of DWORF.

Pathophysiology of Calcium Mediated Ventricular Arrhythmias and Novel Therapeutic Options with Focus on Gene Therapy

Cardiac arrhythmias constitute a major health problem with a huge impact on mortality rates and health care costs. Despite ongoing research efforts, the understanding of the molecular mechanisms and processes responsible for arrhythmogenesis remains incomplete. Given the crucial role of Ca²⁺-handling in action potential generation and cardiac contraction, Ca²⁺ channels and Ca²⁺ handling proteins represent promising targets for suppression of ventricular arrhythmias. Accordingly, we report the different roles of Ca²⁺-handling in the development of congenital as well as acquired ventricular arrhythmia syndromes. We highlight the therapeutic potential of gene therapy as a novel and innovative approach for future arrhythmia therapy. Furthermore, we discuss various promising cellular and mitochondrial targets for therapeutic gene transfer currently under investigation.

Arrhythmogenic Substrates for Atrial Fibrillation in Obesity

Global obesity rates have nearly tripled since 1975. This obesity rate increase is mirrored by increases in atrial fibrillation (AF) that now impacts nearly 10% of Americans over the age of 65. Numerous epidemiologic studies have linked incidence of AF and obesity and other obesity-related diseases, including hypertension and diabetes. Due to the wealth of epidemiologic data linking AF with obesity-related disease, mechanisms of AF pathogenesis in the context of obesity are an area of ongoing investigation. However, progress has been somewhat slowed by the complex phenotype of obesity; separating the effects of obesity from those of related sequelae is problematic. While the initiation of pathogenic pathways leading to AF varies with disease (including increased glycosylation in diabetes, increased renin angiotensin aldosterone system activation in hypertension, atrial ischemia in coronary artery disease, and sleep apnea) the pathogenesis of AF is united by shared mediators of altered conduction in the atria. We suggest focusing on these downstream mediators of AF in obesity is likely to yield more broadly applicable data. In the context of obesity, AF is driven by the interrelated processes of inflammation, atrial remodeling, and oxidative stress. Obesity is characterized by a constant low-grade inflammation that leads to increased expression of pro-inflammatory cytokines. These cytokines contribute to changes in cardiomyocyte excitability. Atrial structural remodeling, including fibrosis, enlargement, and fatty infiltration is a prominent feature of AF and contributes to the altered conduction. Finally, obesity impacts oxidative stress. Within the cardiomyocyte, oxidative stress is increased through both increased production of reactive oxygen species and by downregulation of scavenging enzymes. This increased oxidative stress modulates of cardiomyocyte excitability, increasing susceptibility to AF. Although the initiating insults vary, inflammation, atrial remodeling, and oxidative stress are conserved mechanisms in the pathophysiology of AF in the obese patients. In this review, we highlight mechanisms that have been shown to be relevant in the pathogenesis of AF across obesity-related disease.