Five-year results of heart rate control with ivabradine or metoprolol succinate in patients after heart transplantation

Efficacy of metoprolol plus atorvastatin for carotid atherosclerosis and its influence on carotid intima-media thickness and homocysteine level

OBJECTIVE

To analyze the effects of metoprolol (MET) plus atorvastatin (ATO) on carotid intima-media thickness (IMT) and homocysteine (Hcy) level in carotid atherosclerosis (CAS) patients.

METHODS

In this retrospective study, 90 patients with CAS admitted to the Hangzhou Ninth People's Hospital between January 2019 and July 2021 were enrolled, including 40 cases (control group, the Con) treated with MET and 50 cases treated with the combination therapy of MET plus ATO (Research group, the Res). The efficacy and related influencing factors were observed and compared. The clinical effects (IMT, plaque score), Hcy level, inflammatory cytokines (ICs; matrix metalloproteinase-9 [MMP-9], high-sensitivity C-reactive protein [hs-CRP]), blood lipid indices (low-/high- density lipoprotein cholesterol [LDL-C/HDL-C], total cholesterol [TC], triglyceride [TG]) and coagulation markers (thrombin time [TT], prothrombin time [PT], activated partial thromboplastin time [APTT], fibrinogen [FIB]) of the two groups were observed and compared.

RESULTS

The results identified a statistically higher overall response rate in the Res group. Age, coronary heart disease, cerebral infarction and plaque score were confirmed to be closely related to the efficacy of CAS. In addition, statistically lower post-treatment IMT, plaque score, MMP-9, hs-CRP, LDL-C, TG, TC and FIB while higher PT, TT and APTT were determined in the Res group compared with the pre-treatment values and the Con group.

CONCLUSIONS

MET plus ATO can significantly improve efficacy, reduce IMT and plaque score of patients with CAS, as well as improve inflammatory factors, blood lipid indices and coagulation markers, for which it deserves clinical promotion.

Successful use of ivabradine in a 10-year-old patient with graft failure after heart transplantation

We encountered a paediatric case of graft failure due to antibody-mediated rejection after heart transplantation in which ivabradine was effective. Inappropriate sinus tachycardia in denervated transplanted hearts is a good indication for ivabradine administration as beta-blockers have a limited efficacy. To our knowledge, this is the first report on the effectiveness of ivabradine in a paediatric heart transplant rejection case.

The Bradycardic Agent Ivabradine Acts as an Atypical Inhibitor of Voltage-Gated Sodium Channels

Background and purpose: Ivabradine is clinically administered to lower the heart rate, proposedly by inhibiting hyperpolarization-activated cyclic nucleotide-gated cation channels in the sinoatrial node. Recent evidence suggests that voltage-gated sodium channels (VGSC) are inhibited within the same concentration range. VGSCs are expressed within the sinoatrial node and throughout the conduction system of the heart. A block of these channels thus likely contributes to the established and newly raised clinical indications of ivabradine. We, therefore, investigated the pharmacological action of ivabradine on VGSCs in sufficient detail in order to gain a better understanding of the pro- and anti-arrhythmic effects associated with the administration of this drug.

Experimental Approach: Ivabradine was tested on VGSCs in native cardiomyocytes isolated from mouse ventricles and the His-Purkinje system and on human Na_v1.5 in a heterologous expression system. We investigated the mechanism of channel inhibition by determining its voltage-, frequency-, state-, and temperature-dependence, complemented by a molecular drug docking to the recent Na_v1.5 cryoEM structure. Automated patch-clamp experiments were used to investigate ivabradine-mediated changes in Na_v1.5 inactivation parameters and inhibition of different VGSC isoforms.

Key results: Ivabradine inhibited VGSCs in a voltage- and frequency-dependent manner, but did not alter voltage-dependence of activation and fast inactivation, nor recovery from fast inactivation. Cardiac (Na_v1.5), neuronal (Na_v1.2), and skeletal muscle (Na_v1.4) VGSC isoforms were inhibited by ivabradine within the same concentration range, as were sodium currents in native cardiomyocytes isolated from the ventricles and the His-Purkinje system. Molecular drug docking suggested an interaction of ivabradine with the classical local anesthetic binding site.

Conclusion and Implications: Ivabradine acts as an atypical inhibitor of VGSCs. Inhibition of VGSCs likely contributes to the heart rate lowering effect of ivabradine, in particular at higher stimulation frequencies and depolarized membrane potentials, and to the observed slowing of intra-cardiac conduction. Inhibition of VGSCs in native cardiomyocytes and across channel isoforms may provide a potential basis for the anti-arrhythmic potential as observed upon administration of ivabradine.

COVID-19 among heart transplant recipients in Germany: a multicenter survey

Aims

Heart transplantation may represent a particular risk factor for severe coronavirus infectious disease 2019 (COVID-19) due to chronic immunosuppression and frequent comorbidities. We conducted a nation-wide survey of all heart transplant centers in Germany presenting the clinical characteristics of heart transplant recipients with COVID-19 during the first months of the pandemic in Germany.

Methods and results

A multicenter survey of all heart transplant centers in Germany evaluating the current status of COVID-19 among adult heart transplant recipients was performed. A total of 21 heart transplant patients with COVID-19 was reported to the transplant centers during the first months of the pandemic in Germany. Mean patient age was 58.6 ± 12.3 years and 81.0% were male. Comorbidities included arterial hypertension (71.4%), dyslipidemia (71.4%), diabetes mellitus (33.3%), chronic kidney failure requiring dialysis (28.6%) and chronic-obstructive lung disease/asthma (19.0%). Most patients received an immunosuppressive drug regimen consisting of a calcineurin inhibitor (71.4%), mycophenolate mofetil (85.7%) and steroids (71.4%). Eight of 21 patients (38.1%) displayed a severe course needing invasive mechanical ventilation. Those patients showed a high mortality (87.5%) which was associated with right ventricular dysfunction (62.5% vs. 7.7%; p = 0.014), arrhythmias (50.0% vs. none; p = 0.012), and thromboembolic events (50.0% vs. none; p = 0.012). Elevated high-sensitivity cardiac troponin T- and N-terminal prohormone of brain natriuretic peptide were significantly associated with the severe form of COVID-19 (p = 0.017 and p < 0.001, respectively).

Conclusion

Severe course of COVID-19 was frequent in heart transplanted patients. High mortality was associated with right ventricular dysfunction, arrhythmias, thromboembolic events, and markedly elevated cardiac biomarkers.