Big data analysis from Sweden confirms that resting heart rate in late adolescence is significantly associated with incident heart failure and all-cause mortality

Levosimendan Can Improve the Level of B-Type Natriuretic Peptide and the Left Ventricular Ejection Fraction of Patients with Advanced Heart Failure: A Meta-analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

Levosimendan, a calcium (Ca²⁺)-sensitizing cardiotonic agent, is mainly used in patients with advanced heart failure. However, no research could explain how levosimendan reduces the mortality in advanced heart failure patients. We aim to illustrate the efficacy of levosimendan through clinical indexes.

METHODS

We searched PubMed, Embase, and CENTRAL from 1994 to August 2019 to compare the efficacy of levosimendan infusion for the treatment of advanced heart failure with that of other agents (placebo, dobutamine, furosemide, and prostaglandin E1). Levels of B-type natriuretic peptide (BNP) and N-terminal pro BNP (NT-proBNP), and left ventricular ejection fraction (LVEF) and heart rate (HR) were analyzed. The count data were analyzed by the standardized mean difference (SMD) and its 95% confidence interval (CI) to determine the effect size. We chose the random effect model or the fixed effect model according to the heterogeneity.

RESULTS

Nine randomized controlled trials with 413 patients were ultimately enrolled. Compared with other agents (placebo, dobutamine, furosemide, and prostaglandin E1), levosimendan significantly reduced the BNP level (SMD - 0.91; 95% CI - 1.44 to - 0.39; p = 0.001; I² = 74.3%) and improved the LVEF (SMD 0.74; 95% CI 0.22-1.25; p = 0.005; I² = 79.7%). However, levosimendan did not significantly change the HR (SMD 0.09; 95% CI - 0.24 to 0.42; p = 0.592; I² = 51.5%). Meanwhile, we found that the main source of heterogeneity was the use of loaded or unloaded levosimendan.

CONCLUSION

Our meta-analysis suggests that intravenous levosimendan can reduce BNP level and increase LVEF in patients with advanced heart failure to reduce the mortality at the shortest follow-up available.

Heart Rate Is a Better Predictor of Cardiorespiratory Fitness Than Heart Rate Variability in Overweight/Obese Children: The ActiveBrains Project

Cardiac autonomic function can be quantified through mean heart rate (HR) or heart rate variability (HRV). Numerous studies have supported the utility of different HRV parameters as indicators of cardiorespiratory fitness (CRF). However, HR has recently shown to be a stronger predictor of CRF than HRV in healthy young adults, yet these findings need to be replicated, in other age groups such as children. Therefore, this study aimed: (1) to study the associations between indicators of cardiac autonomic function (HR, standard and corrected HRV parameters) and CRF in overweight/obese children; and (2) to test which of the two indicators (i.e., HR or HRV) is a stronger predictor of CRF. This study used cross-sectional baseline data of 107 overweight/obese children (10.03 ± 1.13 years, 58% boys) from the ActiveBrains project. Cardiac autonomic indicators were measured with Polar RS800CX®. CRF was assessed using a gas analyzer while performing a maximal incremental treadmill test. Correlations and stepwise linear regressions were performed. Mean HR and standard HRV parameters (i.e., pNN50, RMSSD, and SDNN) were associated with CRF (r coefficients ranging from -0.333 to 0.268; all p ≤ 0.05). The association of HR with CRF persisted after adjusting for sex, peak height velocity (PHV), adiposity moderate-to-vigorous physical activity, energy intake and circadian-related variable intradaily variability of activity patterns whilst for HRV parameters (i.e., pNN50, RMSSD, and SDNN) disappeared. Stepwise linear regression models entering HR and all HRV parameters showed that mean HR was the strongest predictor of CRF (β = -0.333, R 2 = 0.111, p < 0.001). Standard and corrected HRV parameters did not provide additional value to the coefficient of determination (all p > 0.05). Our findings suggest that HR is the strongest indicator of CRF. It seems that quantification of HRV parameters in time and frequency domain do not add relevant clinical information about the cardiovascular health status (as measured by CRF) in overweight/obese children beyond the information already provided by the simple measure of HR.