Circadian rhythms in pump parameters of patients on contemporary left ventricular assist device support

BACKGROUND

Algorithms to monitor pump parameters are needed to further improve outcomes after left ventricular assist device (LVAD) implantation. Previous research showed a restored circadian rhythm in pump parameters in patients on HeartWare (HVAD) support. Circadian patterns in HeartMate3 (HM3) were not studied before, but this is important for the development of LVAD monitoring algorithms. Hence, we aimed to describe circadian patterns in HM3 parameters and their relation to patterns in heart rate (HR).

METHODS

18 HM3 patients were included in this study. HM3 data were retrieved at a high frequency (one sample per 1 or 2 h) for 1-2 weeks. HR was measured using a wearable biosensor. To study overall patterns in HM3 parameters and HR, a heatmap was created. A 24-h cosine was fitted on power and HR separately. The relationship between the amplitude of the fitted cosines of power and HR was calculated using Spearman correlation.

RESULTS

A lower between patient variability was found in power compared with flow and PI. 83% of the patients showed a significant circadian rhythmicity in power (p < 0.001-0.04), with a clear morning increase. All patients showed significant circadian rhythmicity in HR (p < 0.001-0.02). The amplitudes of the circadian rhythm in power and HR were not correlated (Spearman correlation of 0.32, p = 0.19).

CONCLUSIONS

A circadian rhythm of pump parameters is present in the majority of HM3 patients. Higher frequency pump parameter data should be collected, to enable early detection of complications in the future development of predictive algorithms.

[Cardioband®: Where do we stand, who are suitable patients?]

Functional mitral regurgitation (FMR) is characterized by a dilatation of the mitral valve annulus resulting in an insufficient adaptation of the anterior and posterior mitral valve leaflets and/or severe tethering of the leaflets due to dilatation of the left ventricle. The Cardioband® system was introduced in 2015 and is a catheter-based direct mitral valve annuloplasty procedure for treatment of FMR. In the European CE approval study 60 patients with moderate or severe FMR were analyzed per protocol. There were no device or procedure-related deaths. The technical success rate of the procedure, defined as successful implantation and tightening was 97%. At 1 year, the overall survival and survival free of hospital readmission for heart failure were 87% and 66%, respectively. Currently, various interventional treatment procedures are available, such as the edge-to-edge technique as well as direct and indirect annuloplasty. In summary, patients with FMR as a result of a dilatation of the mitral valve annulus appear to be suitable for direct annuloplasty with the Cardioband® system.