In silico methods for enhanced design optimization and durability testing of left ventricular expanders in heart failure

Abstract

Left ventricular (LV) expanders are spring-like devices that are specifically dedicated to the treatment of heart failure with preserved ejection fraction (HFpEF). They are intended to mechanically facilitate outward ventricular expansion during cardiac relaxation, thus enhancing the LV filling. This study demonstrates how in-silico models can be used to explore device capabilities to improve cardiac performance and optimize their design. Various configurations of shape, size, and material of an LV expander device implanted in a human heart model with hypertrophy and cardiac stiffening that was modified from the living heart project. The devices’ effects on cardiac function were quantified by physiological parameters, and fatigue analyses were performed on the optimal design to assess the long-term device durability. All designs showed a positive impact on the heart function. The results also revealed that cobalt-chromium alloy is more appropriate than nickel-titanium for this type of application. The fatigue analysis of the optimized configuration revealed that the device is capable of withstanding at least 2.5 years with hardened alloy, with the potential to last for 10 years. This study demonstrates that the use of LV expanders may be used with caution in HFpEF and other diseases of cardiac stiffening. Interestingly, even devices with reduced longevity may still offer significant benefits to patients with severe cardiac stiffening, who typically have a shorter life expectancy. Further patient-specific analysis is needed to check the device in the context of clinical needs and can also be utilized to tailor and optimize the expander device for each pathology.