Novel drugs for heart rate control in heart failure

Association of cumulative resting heart rate exposure with rapid renal function decline: a prospective cohort study with 27,564 older adults

OBJECTIVE

To evaluate the prospective association between cumulative resting heart rate (cumRHR) and rapid renal function decline (RRFD) in a cohort of individuals aged 60 and older.

METHODS

In the Tianjin Chronic Kidney Disease Cohort Study, the individuals who underwent three consecutive physical examinations between 2014 and 2017, with estimated glomerular filtration rate (eGFR) greater than 60 mL/min per 1.73 m2 and aged 60 years or older were enrolled. A total of 27,564 patients were prospectively followed up from January 1, 2017 to December 31, 2020. The 3-year cumRHR was calculated. The primary outcome was RRFD, defined as an annualized decline in eGFR of 5 mL/min per 1.73 m2 or greater. Logistic and restricted spline regression models and subgroup analysis were used to investigate the association of cumRHR with RRFD after adjusting for all confounders.

RESULTS

During a median follow-up of 3.2 years, a total of 4,347 (15.77%) subjects developed RRFD. In fully-adjusted models, compared with the lowest quartile of cumRHR, the odds ratio (OR) for the highest was 1.44 (1.28-1.61), P < 0.001. Furthermore, each 1-standard deviation (27.97 beats/min per year) increment in cumRHR was associated with a 17% (P < 0.001) increased risk of RRFD, with a linear positive correlation (P for non-linear = 0.803). Participants with a 3-year cumRHR ≥ 207 (beats/min) * year (equivalent to ≥ 69 beats/min per year in 3 years) were found to be at a higher risk of RRFD.

CONCLUSIONS

The cumRHR is significantly associated with a higher risk of RRFD among older adults. These results might provide an effective goal for managing and delaying the decline of renal function in the older adults.

Minimum heart rate and mortality after cardiac surgery: retrospective analysis of the Multi-parameter Intelligent Monitoring in Intensive Care (MIMIC-III) database

Low heart rate is a risk factor of mortality in many cardiovascular diseases. However, the relationship of minimum heart rate (MHR) with outcomes after cardiac surgery is still unclear, and the association between optimum MHR and risk of mortality in patients receiving cardiac surgery remains unknown. In this retrospective study using the Multi-parameter Intelligent Monitoring in Intensive Care (MIMIC-III) database, 8243 adult patients who underwent cardiac surgery were included. The association between MHR and the 30-day, 90-day, 180-day, and 1-year mortality of patients undergoing cardiac surgery was analyzed using multivariate Cox proportional hazard analysis. As a continuous variable, MHR was evaluated using restricted cubic regression splines, and appropriate cut-off points were determined. Kaplan-Meier curve was used to further explore the relationship between MHR and prognosis. Subgroup analyses were performed based on age, sex, hypertension, diabetes, and ethnicity. The rates of the 30-day, 90-day, 180-day, and 1-year mortalities of patients in the low MHR group were higher than those in the high MHR group (4.1% vs. 2.9%, P < 0.05; 6.8% vs. 5.3%, P < 0.05; 8.9% vs. 7.0%, P < 0.05, and 10.9% vs. 8.8%, P < 0.05, respectively). Low MHR significantly correlated with the 30-day, 90-day, 180-day, and 1-year mortality after adjusting for confounders. A U-shaped relationship was observed between the 30-day, 90-day, 180-day, and 1-year mortality and MHR, and the mortality was lowest when the MHR was 69 bpm. Kaplan-Meier curve analysis also indicated that low MHR had poor prognosis in patients undergoing cardiac surgery. According to subgroup analyses, the effect of low MHR on post-cardiac surgery survival was restricted to patients who were < 75 years old, male, without hypertension and diabetes, and of White ethnicity. MHR (69 bpm) was associated with better 30-day, 90-day, 180-day, and 1-year survival in patients after cardiac surgery. Therefore, effective HR control strategies are required in this high-risk population.

A Model for the Prediction of Mortality and Hospitalization in Chinese Heart Failure Patients

Background: Although many risk prediction models have been released internationally, the application of these models in the Chinese population still has some limitations.

Aims: The purpose of the study was to establish a heart failure (HF) prognosis model suitable for the Chinese population.

Methods: According to the inclusion criteria, we included patients with chronic heart failure (CHF) who were admitted to the Department of Cardiac Rehabilitation of Tongji Hospital from March 2007 to December 2018, recorded each patient's condition and followed up on the patient's re-admission and death. All data sets were randomly divided into derivation and validation cohorts in a ratio of 7/3. Least absolute shrinkage and selection operator regression and Cox regression were used to screen independent predictors; a nomogram chart scoring model was constructed and validated.

Results: A total of 547 patients were recruited in this cohort, and the median follow-up time was 519 days. The independent predictors screened out by the derivation cohort included age, atrial fibrillation (AF), percutaneous coronary intervention (PCI), diabetes mellitus (DM), peak oxygen uptake (peak VO₂), heart rate at the 8th minute after the cardiopulmonary exercise peaked (HR8min), C-reaction protein(CRP), and uric acid (UA). The C indexes values of the derivation and the validation cohorts were 0.69 and 0.62, respectively, and the calibration curves indicate that the model's predictions were in good agreement with the actual observations.

Conclusions: We have developed and validated a multiple Cox regression model to predict long-term mortality and readmission risk of Chinese patients with CHF.

Registration Number: ChicTR-TRC-00000235.

Heart rate modulates the relationship of augmented systolic blood pressure with the blood natriuretic peptide levels

AIMS

Augmented central systolic blood pressure (cSBP), which is known to affect the cardiac afterload, is an independent risk factor for cardiovascular disease. While an inverse relationship is known to exist between the heart rate (HR) and the cSBP, it has not yet been clarified if the HR also modulates the association between the cSBP and the cardiac afterload. The present study was conducted to clarify whether the association of the cSBP with the serum levels of the N-terminal fragment B-type natriuretic peptide (NT-proBNP) differs between subjects with high and low HRs, using data obtained from the same subjects on two occasions (2009 and 2012) so as to confirm their consistency.

METHODS AND RESULTS

The radial augmentation index, systolic pressure at the second peak of the radial pressure waveform (SBP2), and serum NT-proBNP levels were measured and analysed in a worksite cohort of 2000 middle-aged men in 2009 and in 2012. The subjects were divided into three groups by the HR (i.e. ≤69, 70-79, and ≥80 b.p.m.). While the serum NT-proBNP levels were similar among the three groups, the radial augmentation index increased (from 61 ± 12% to 72 ± 13%, P < 0.01 in 2009 and from 61 ± 13% to 73 ± 12%, P < 0.01 in 2012) and the SBP1-2 decreased (from 18 ± 7 to 13 ± 7 mmHg, P < 0.01 in 2009 and from 19 ± 7 to 13 ± 6 mmHg, P < 0.01 in 2012) significantly with decreasing HR. After the adjustment, the SBP2 showed a significant association with the serum NT-proBNP levels in the overall study population [non-standardized coefficient (B) = 0.005, standard error (SE) = 0.001, P < 0.01 in 2009 (n = 2257) and B = 0.004, SE = 0.001, P < 0.01 in 2012 (n = 1986)]. In subgroup analyses, the SBP2 showed a significant association with the serum NT-proBNP levels [B = 0.004, SE = 0.002, P = 0.02 in 2009 (n = 1291) and B = 0.005, SE = 0.001, P < 0.01 in 2012 (n = 1204)] only in the subject group with an HR of ≤69 b.p.m.

CONCLUSIONS

In middle-aged Japanese men, the relationship between the cSBP and the cardiac afterload appears to differ depending on the HR; the results of our analysis showed that the relationship between the cSBP and the cardiac overload may be more pronounced and strongly significant in patients with low HRs as compared with patients with high HRs.

Minimum heart rate and mortality in critically ill myocardial infarction patients: an analysis of the MIMIC-III database

Background

Low minimum heart rate (MHR) is common in critically ill myocardial infarction (MI) patients. However, the association between MHR and the mortality of critically ill MI patients remains unclear.

Methods

In this retrospective cohort study, a total of 2,031 critically ill MI patients were enrolled from the Medical Information Mart for Intensive Care (MIMIC)-III database. Patients were divided into a low MHR group [MHR <60 beats per minute (bpm)] and a high MHR group (MHR ≥60 bpm). A Cox proportional hazard model was used to elucidate the association between these two groups and the mortality of MI patients. The association between mortality and MHR as a continuous variable was analyzed non-parametrically using restricted cubic splines. Sensitivity analyses were conducted to determine the impact of different admission heart rate, hypertension, atrial fibrillation, and vasopressor use on our results.

Results

MI patients in the low MHR group had higher 30-day and 1-year mortality than those in the high MHR group (20.59% vs. 10.91%, P<0.001 and 29.76% vs. 19.31%, P<0.001, respectively). After adjustment, the low MHR group was significantly correlated with 30-day mortality [hazard ratio, 1.779, 95% confidence interval (CI), 1.400-2.261, P<0.001] and 1-year mortality (hazard ratio, 1.537, 95% CI, 1.272-1.859, P<0.001). This correlation remained remarkable in patients with low or high admission heart rate, with or without hypertension, and with or without atrial fibrillation. An apparent L-curve relationship was observed between the 30-day mortality or 1-year mortality and MHR as a continuous variable.

Conclusions

MHR under 60 bpm may be associated with a higher risk for both 30-day and 1-year mortality in critically ill MI patients. These findings highlight the possibility of MHR as an early risk indicator and potential therapeutic target for mortality in critically ill MI patients, which warrants further investigation.

Pharmacology of Ivabradine and the Effect on Chronic Heart Failure

Chronic Heart Failure (CHF) is a complex clinical syndrome with a high incidence worldwide. Although various types of pharmacological and device therapies are available for CHF, the prognosis is not ideal, for which, the control of increased Heart Rate (HR) is critical. Recently, a bradycardic agent, ivabradine, is found to reduce HR by inhibiting the funny current (If). The underlying mechanism states that ivabradine can enter the Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels and bind to the intracellular side, subsequently inhibiting the If. This phenomenon can prolong the slow spontaneous phase in the diastolic depolarization, and thus, reduce HR. The clinical trials demonstrated the significant effects of the drug on reducing HR and improving the symptoms of CHF with fewer adverse effects. This review primarily introduces the chemical features and pharmacological characteristics of ivabradine and the mechanism of treating CHF. Also, some expected therapeutic effects on different diseases were also concluded. However, ivabradine, as a typical If channel inhibitor, necessitates additional research to verify its pharmacological functions.

EC18 as a Tool To Understand the Role of HCN4 Channels in Mediating Hyperpolarization-Activated Current in Tissues

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are membrane proteins encoded by four genes (HCN1-4) and widely distributed in the central and peripheral nervous system and in the heart. HCN channels are involved in several physiological functions, including the generation of rhythmic activity, and are considered important drug targets if compounds with isoform selectivity are developed. At present, however, few compounds are known, which are able to discriminate among HCN channel isoforms. The inclusion of the three-methylene chain of zatebradine into a cyclohexane ring gave a compound (3a) showing a 5-fold preference for HCN4 channels, and ability to selectively modulate I_h in different tissues. Compound 3a has been tested for its ability to reduce I_h and to interact with other ion channels in the heart and the central nervous system. Its preference for HCN4 channels makes this compound useful to elucidate the contribution of this isoform in the physiological and pathological processes involving hyperpolarization-activated current.