Mobile Heart Rate Variability Biofeedback as a Complementary Intervention After Myocardial Infarction: a Randomized Controlled Study

Anja Limmer,Astrid Schütz,Martin Laser

doi:10.1007/s12529-021-10000-6

Abstract

BackgroundTo enhance effective prevention programs after myocardial infarction (MI), the study examined the effects and feasibility of mobile biofeedback training on heart rate variability (HRV-BF).MethodsForty-six outpatients aged 41 to 79 years with a documented MI were randomized to HRV-BF versus usual care. Generalized estimating equation (GEE) analyses were performed to test improvements in measures of short- and long-time HRV, namely, the standard deviation of the normal-to-normal intervals (SDNN) and well-being after 12 weeks of HRV-BF.ResultsThere were intervention effects for short-time HRV (d > 0.4, p < 0.04), which were partly replicated in the GEE models that accounted for control variables: In the HRV-BF group, the high-frequency HRV (group × time interaction: β = 0.59, p = 0.04) compensated for significantly lower baseline levels than the group with usual care. In an optimal dose sample (on average two HRV-BF sessions a day), SDNN significantly increased after HRV-BF (p = 0.002) but not in the waitlist control group. Compensatory trends of HRV-BF were also found for high-frequency HRV and self-efficacy. No adverse effects of the intervention were found but neither were effects on long-time HRV measures.ConclusionThe results showed the feasibility of self-guided HRV-BF for almost all post-MI patients. HRV-BF as an adjunctive behavioral treatment increased HRV, which is an indicator of lower cardiovascular risk, and self-efficacy, which suggests heightened psychological resilience. These benefits warrant confirmation and tests of sustainability in larger studies.Trial RegistrationThe trial has not been registered due to its starting point in 2017 predating the publication of the applicable CONSORT extension for reporting social and psychological intervention trials in 2018.

Highlights

Diseases of the circulatory system, most notably coronary heart disease, remain the major cause of death in Europe and beyond [1]
The importance of Heart rate variability (HRV) for cardiovascular health was made evident in Kleiger et al.’s [11] study, which showed that a quantification of HRV was an independent predictor of mortality after acute myocardial infarction (MI)
One participant of the HRV-BF group had to be excluded because of a lack of self-guided training. These individuals were predominantly female in contrast to those retained in the analysis (55% versus 15%, p < 0.01) but did not differ in any other variable at preintervention

Summary

Introduction

Diseases of the circulatory system, most notably coronary heart disease, remain the major cause of death in Europe and beyond [1]. To enhance effective prevention programs after myocardial infarction (MI), the study examined the effects and feasibility of mobile biofeedback training on heart rate variability (HRV-BF). Generalized estimating equation (GEE) analyses were performed to test improvements in measures of short- and long-time HRV, namely, the standard deviation of the normal-to-normal intervals (SDNN) and well-being after 12 weeks of HRV-BF. HRV-BF as an adjunctive behavioral treatment increased HRV, which is an indicator of lower cardiovascular risk, and self-efficacy, which suggests heightened psychological resilience. These benefits warrant confirmation and tests of sustainability in larger studies. Trial Registration The trial has not been registered due to its starting point in 2017 predating the publication of the applicable CONSORT extension for reporting social and psychological intervention trials in 2018

Methods

Results

Discussion

Conclusion