Ivabradine in patients with acute ST-elevation myocardial infarction: a meta-analysis of randomized controlled trials

BACKGROUND

Elevated resting heart rate (HR) predicts poor outcomes in patients with coronary artery disease. Ivabradine has been recommended as a second-line anti-anginal agent in chronic coronary syndrome, while there are no clear indications for acute ST-elevation myocardial infarction (STEMI).

RESULTS

We systematically searched PubMed, Medline, EMBASE, Clinical Trials.gov, and the Cochrane Central Register of Controlled Trials with search terms Ivabradine and Acute myocardial infarction. There are two study outcomes from this study: therapeutic and safety effects. Therapeutic effects include the efficacy of Ivabradine on HR, all-cause mortality, heart failure incidence, left ventricular function and remodeling. Safety effects include troponin levels and ischemic events (recurrent angina pectoris). A total of 6 RCTs was included and showed that Ivabradine was associated with greater resting HR reduction [MD - 5.40; 95%CI - 8.60, - 2.20], improvement of left ventricular ejection fraction [MD 2.98; 95%CI 0.44, 5.51], and left ventricular end systolic volume [MD - 3.81; 95%CI - 6.88, - 0.75]. However, Ivabradine had no impact on all-cause mortality [OR 0.76; 95%CI 0.35, 1.67], heart failure incidence [OR 0.61; 95%CI 0.21, 1.80], and recurrent angina pectoris [OR 0.71; 95%CI 0.50, 1.00].

CONCLUSIONS

Ivabradine is safe and effective for resting HR reduction in patients with STEMI; however, it has no significant influence on mortality. These results suggest that an elevated HR is only a marker of risk but not a modifiable determinant of outcomes in patients who have suffered an acute myocardial infarction.

Integrated Bioinformatics and Validation of lncRNA-Mediated ceRNA Network in Myocardial Ischemia/Reperfusion Injury

Background

Myocardial ischemia/reperfusion (MI/R) injury is a common pathology in ischemia heart disease. Long noncoding RNAs (lncRNAs) are significant regulators related to many ischemia/reperfusion conditions. This study is aimed at exploring the molecule mechanism of lncRNA-mediated competing endogenous RNA (ceRNA) network in MI/R.

Methods

The dataset profiles of MI/R and normal tissues (GSE130217 and GSE124176) were obtained from the GEO database. Integrated bioinformatics were performed to screen out differentially expressed genes (DEGs). Thereafter, an lncRNA-mediated ceRNA network was constructed by the starBase database. The GO annotations and KEGG pathway analysis were conducted to study action mechanism and related pathways of DEGs in MI/R. A model of hypoxia/reoxygenation- (H/R-) treated HL-1 cell was performed to verify the expression of lncRNAs through qRT-PCR.

Results

2406 differentially expressed- (DE-) mRNAs, 70 DE-lncRNAs, and 156 DE-miRNAs were acquired. These DEGs were conducted to construct an lncRNA-mediated ceRNA network, and a subnetwork including lncRNA Xist/miRNA-133c/mRNA (Slc30a9) was screen out. The functional enrichment analyses revealed that the lncRNAs involved in the ceRNA network might functions in oxidative stress and calcium signaling pathway. The lncRNA Xist expression is reduced under H/R conditions, followed by the increased level of miRNA-133c, thus downregulating the expression of Slc30a9.

Conclusion

In sum, the identified ceRNA network which included the lncRNA Xist/miR-133c/Slc30a9 axis might contribute a better understanding to the pathogenesis and development of MI/R injury and offer a novel targeted therapy way.

Clinical use of ivabradine in the acute coronary syndrome: A systematic review and narrative synthesis of current evidence

Heart rate (HR) lowering during acute coronary syndrome (ACS) is beneficial as it reduces myocardial oxygen consumption. However, the role of ivabradine as an HR-lowering agent in the setting of ACS is not clear. We aimed to systematically review and synthesize the current evidence on the role of ivabradine use in the ACS. A systematic review was conducted for eligible randomized clinical trials and quasi-experimental studies, between 2009 and 2020, that investigated the use of ivabradine in ACS. Various clinical endpoints were evaluated such as major adverse cardiovascular events, efficacy in HR control, impact on left ventricular (LV) dimensions and function, and overall safety. Eleven publications were included encompassing a total of 1833 patients. The mean age of the examined cohort was 57 ± 11 years and 80 % were men. Seven studies were in the setting of ST-segment elevation myocardial infarction (MI) while the remaining studies also included patients with unstable angina and non-ST-segment elevation MI. Ivabradine was administered as a peroral drug with dosing from 2.5 to 7.5 mg b.i.d. Overall, the addition of ivabradine was superior to the control arm concerning HR control with a good safety profile. Beneficial effects on LV function and potential impact on infarct size reduction were observed as well. The use of ivabradine appeared to not affect short-term mortality. In conclusion, the use of ivabradine for HR control is safe, feasible, and efficacious for HR control in the ACS. Further studies are required to elucidate other potentially beneficial effects of ivabradine.

THE IMPACT OF VALVULAR PATHOLOGIES ON HEART RATE, THE SECOND HEART SOUND SPLIT, AND SYSTOLIC PULMONARY ARTERIAL PRESSURE

The heart rate increases during inspiration and decreases during expiration; the study of this variation and the change of the second heart sound split (a change related to inspiration and expiration) can determine at what time in a cardiac cycle is the inspiration and the expiration. It would also be interesting to study the variation in systolic pulmonary artery pressure (SPAP) estimated over several cardiac cycles and to understand its evolution as its variation is related to the pulmonary valve, on the one hand, and inspiration and expiration, on the other hand. The algorithm developed based on the Hilbert transform and the energy of Shannon gives the second heart sound split. The SPAP will be estimated from spectral parameters of the second heart S2. The results show an excellent performance of the algorithm proposed to extract different information on the variation of heart rate. The results of the change in pressure and split are encouraging and promising for the use of the proposed method in a clinical context of hypertension in non-invasive pulmonary pathways, for example.

Progressive development of cardiomyopathy following altered autonomic activity in status epilepticus

Seizures are associated with altered autonomic activity, which has been implicated in the development of cardiac dysfunction and structural damage. This study aimed to investigate the involvement of the autonomic nervous system in seizure-induced cardiomyopathy. Male Sprague-Dawley rats (320–350 g) were implanted with EEG/ECG electrodes to allow simultaneous telemetric recordings during seizures induced by intrahippocampal (2 nmol, 1 μl/min) kainic acid and monitored for 7 days. Seizure activity occurred in conjunction with increased heart rate (20%), blood pressure (25%), and QTc prolongation (15%). This increased sympathetic activity was confirmed by the presence of raised plasma noradrenaline levels at 3 h post-seizure induction. By 48 h post-seizure induction, sympathovagal balance was shifted in favor of sympathetic dominance, as indicated by both heart rate variability (LF/HF ratio of 3.5 ± 1.0) and pharmacological autonomic blockade. Functional cardiac deficits were evident at 7 and 28 days, as demonstrated by echocardiography showing a decreased ejection fraction (14% compared with control, P < 0.05) and dilated cardiomyopathy present at 28 days following seizure induction. Histological changes, including cardiomyocyte vacuolization, cardiac fibrosis, and inflammatory cell infiltration, were evident within 48 h of seizure induction and remained present for up to 28 days. These structural changes most probably contributed to an increased susceptibility to aconitine-induced arrhythmias. This study confirms that prolonged seizure activity results in acute and chronic alterations in cardiovascular control, leading to a deterioration in cardiac structure and function. This study further supports the need for modulation of sympathetic activity as a promising therapeutic approach in seizure-induced cardiomyopathy.

Relationship of resting heart rate and physical activity with insulin sensitivity in a population-based survey

BACKGROUND

Resting heart rate (RHR) has been identified as an independent risk factor for cardiovascular disease and mortality, contributing to atherosclerosis, the progression of heart failure, and myocardial ischemia and infarction. This study examines the association RHR and physical activity has with insulin resistance and insulin secretion in a multiethnic cohort from North Kohala, Hawai'i.

METHODS

Cross-sectional data from 1,440 participants of Native Hawaiian, Japanese, Filipino, Caucasian, and mixed ethnic ancestries were analyzed for the study to include anthropometric measurements, and biochemical markers. Body fat was estimated by calculating body mass indices (BMI); body fat distribution by waist-hip ratios (WHR); and fasting plasma glucose and insulin levels were used to calculate insulin resistance using the Homeostasis Model (HOMA-IR). First phase insulin response was estimated using the insulin secretion ratio (ISR). Associations were estimated using general linear models (GLM).

RESULTS

Caucasians had lower mean RHR than all other ethnic groups; there were no statistically significant differences between other ethnic groups on mean RHR. HOMA-IR was associated with ethnic group, BMI and WHR, PA and RHR, while ISR was associated with age, ethnic group and BMI, but none of the primary risk factors. Both RHR and physical activity level remained significant for insulin resistance.

CONCLUSIONS

In a multiethnic cohort from a rural community in Hawai'i, increased RHR and a lower level of physical activity were both independently associated with increased risk for the development of insulin resistance, suggesting cardiovascular fitness may be as important as physical activity in preventing insulin resistance.

Ivabradine therapy effectiveness in patients with chronic heart failure, Functional Class III

Aim. To assess the effectiveness of ivabradine-including therapy, as well as the effects of ivabradine on regulatoryadaptive status (RAS), in patients with chronic heart failure (CHF), Functional Class (FC) III. Material and methods. The study included 100 patients with FC III CHF and coronary heart disease (CHD) and/ or Stage III arterial hypertension (AH). The participants were previously prescribed a complex treatment regime. After randomisation, Group I included 56 patients (mean age 62,9±1,8 years), who were additionally administered metoprolol succinate extended-release (mean dose 59,1±4,5 mg/day). Group II (n=44; mean age 59,4±1,3 years) was additionally administered an If channel inhibitor ivabradine, when beta-adrenoblocker (BAB) therapy was not possible. At baseline and 6 months later, participants underwent treadmill test (with VO2max assessment), echocardiography, 24-hour blood pressure monitoring, and the measurement of plasma levels of N-terminal probrain natriuretic peptide (NT-proBNP). RAS status was qualitatively assessed in a cardio-respiratory synchronism test. Results. Ivabradine-including therapy improved myocardial structure and function, increased exercise capacity, and demonstrated positive effects on plasma NT-proBNP levels, VO2мах during treadmill test, and RAS status.

Conclusion. Ivabradine could be an alternative medication when BAB therapy is not possible in patients with FC III CHF and CHD and/or Stage III AH.

Treatment of stable angina pectoris by ivabradine in every day practice: the REDUCTION study

BACKGROUND

The antianginal efficacy of ivabradine was studied in controlled clinical trials. Strict patient selection criteria may cause a discrepancy between the results of highly controlled clinical trials and everyday routine practice. The objective of this study was to evaluate the efficacy and safety of ivabradine in everyday routine practice.

METHODS

In this multicenter study, 4,954 patients with stable angina pectoris received ivabradine in everyday routine practice and underwent follow-up for 4 months. The heart rate (HR), angina pectoris attacks, nitrate consumption, overall efficacy, and tolerance were evaluated.

RESULTS

Within 4 months of treatment with ivabradine, HR was reduced by 12.4 +/- 12.2 beat/min from 82.9 +/- 15.3 to 70.4 +/- 9.2 beat/min (P < .0001). Angina pectoris attacks were reduced from 2.4 +/- 3.1 to 0.4 +/- 1.5 per week (P < .0001). Consumption of short-acting nitrates was reduced from 3.3 +/- 4.4 to 0.6 +/- 1.6 U/wk (P < .0001). Seventy-eight cases of adverse drug reactions were reported. The most common adverse drug reactions were nausea (n = 11, 0.22%) and dizziness (n = 9, 0.18%). Efficacy and tolerance were graded by physicians as being "excellent/very good" for 97% and 98% of the patients treated.

CONCLUSION

Ivabradine reduces the HR and is highly effective and well tolerated in the treatment of patients with symptomatic coronary artery disease. The results confirm the findings of controlled clinical trials in a broad patient population in everyday routine practice.

Resting heart rate: a modifiable prognostic indicator of cardiovascular risk and outcomes?

A growing body of evidence from clinical trials and epidemiological studies has identified elevated resting heart rate as a predictor of clinical events. Proof of direct cause and effect is limited, because current drugs that lower heart rate (eg, beta-blockers) have multiple mechanisms of action. A new class of drug, selective I(f) inhibitors, is under investigation as a 'pure' heart rate-reducing medication and will help confirm if there is a causal link between elevated heart rate and cardiovascular outcomes. The present paper reviews the evidence for elevated heart rate as a cardiovascular risk factor and some of the current clinical trials testing this hypothesis.