The role of long-term mechanical circulatory support in patients with advanced heart failure

Left ventricular assist device implantation and clinical outcomes in the Netherlands

BACKGROUND

Left ventricular assist device (LVAD) therapy is an established treatment for advanced heart failure with reduced ejection fraction. We evaluated the characteristics and clinical outcomes of patients implanted with an LVAD in the Netherlands.

METHODS

Patients implanted with an LVAD in the Netherlands between 2016 and 2020 were included in the analysis. Baseline characteristics entered into this registry, as well as clinical outcomes (death on device, heart transplantation) and major adverse events (device dysfunction, major bleeding, major infection and cerebrovascular event), were evaluated.

RESULTS

A total of 430 patients were implanted with an LVAD; mean age was 55 ± 13 years and 27% were female. The initial device strategy was bridge to transplant (BTT) in 50%, destination therapy (DT) in 29% and bridge to decision (BTD) in the remaining 21%. After a follow-up of 17 months, 97 (23%) patients had died during active LVAD support. Survival was 83% at 1 year, 76% at 2 years and 54% at 5 years. Patients implanted with an LVAD as a BTT had better outcomes compared with DT at all time points (1 year 86% vs 72%, 2 years 83% vs 59% and 5 years 58% vs 33%). Major adverse events were frequently observed, most often major infection, major bleeding and cerebrovascular events (0.84, 0.33 and 0.09 per patient-year at risk, respectively) and were similar across device strategies. Patients supported with HeartMate 3 had a lower incidence of major adverse events.

CONCLUSIONS

Long-term survival on durable LVAD support in the Netherlands is over 50% after 5 years. Major adverse events, especially infection and bleeding, are still frequently observed, but decreasing with the contemporary use of HeartMate 3 LVAD.

Hyperpolypharmacy is a predictor of mortality after left ventricular assist device (LVAD) implantation

Background

The prevalence of (hyper)polypharmacy in patients on left ventricular assist device (LVAD) support and its effect on clinical outcomeis unknown. Therefore, we aimed to determine the prevalence of (hyper)polypharmacy in LVAD patients and evaluate its association with mortality and complications.

Materials and methods

210 patients aged ≥40 years who received a primary LVAD implantation between 2011 and 2019 were included for analysis. Polypharmacy and hyperpolypharmacy were defined as the concomitant use of 5-9 and ≥10 medications at discharge after LVAD implantation, respectively. Cause specific cox regression was used to assess the association of ≥10 medications with mortality, cardiac arrhythmia, driveline infection and major bleeding.

Results

The median age of the patients was 57.5 years, and 35.7 % were female. The average number of discharge medications was 8.8 ± 2.3 per patient. The prevalence of patients with 5-9 medications and ≥10 medications was 62.9 % and 34.8 %, respectively. The median follow-up duration was 948 days (interquartile range 874 days). The prescription of ≥10 medications was significantly associated with a higher risk of mortality (HR 2.03; 95 % CI 1.15-3.6, p-value 0.02) adjusted for sex, age, comorbidity and stratified for device type. The prescription of ≥10 medications was not associated with a higher risk of major bleeding, cardiac arrhythmia or driveline infection.

Conclusions

(Hyper)polypharmacy is highly prevalent in LVAD patients and is independently associated with a higher risk of mortality. Future research is needed to assess the efficacy of individual risk-benefit profiling of (cardiovascular) medication to ensure appropriate polypharmacy and to decrease negative health outcomes.

A Flow Sensor-Based Suction-Index Control Strategy for Rotary Left Ventricular Assist Devices

Rotary left ventricular assist devices (LVAD) have emerged as a long-term treatment option for patients with advanced heart failure. LVADs need to maintain sufficient physiological perfusion while avoiding left ventricular myocardial damage due to suction at the LVAD inlet. To achieve these objectives, a control algorithm that utilizes a calculated suction index from measured pump flow (SIMPF) is proposed. This algorithm maintained a reference, user-defined SIMPF value, and was evaluated using an in silico model of the human circulatory system coupled to an axial or mixed flow LVAD with 5–10% uniformly distributed measurement noise added to flow sensors. Efficacy of the SIMPF algorithm was compared to a constant pump speed control strategy currently used clinically, and control algorithms proposed in the literature including differential pump speed control, left ventricular end-diastolic pressure control, mean aortic pressure control, and differential pressure control during (1) rest and exercise states; (2) rapid, eight-fold augmentation of pulmonary vascular resistance for (1); and (3) rapid change in physiologic states between rest and exercise. Maintaining SIMPF simultaneously provided sufficient physiological perfusion and avoided ventricular suction. Performance of the SIMPF algorithm was superior to the compared control strategies for both types of LVAD, demonstrating pump independence of the SIMPF algorithm.