Biodegradable Cardiac Implants

Abstract

Permanent metallic cardiac implants have served patients well for decades, but they come with baggage: lifelong imaging artefacts on MRI, chronic inflammatory responses at the tissue-metal interface, and the occasional need for risky extraction surgeries when devices malfunction or patients outgrow them. Biodegradable implants offer an appealing alternative because they do their job during the critical healing window and then quietly dissolve, sparing the patient a foreign body that was only ever needed temporarily. The challenge, of course, is making sure the device holds up long enough mechanically and degrades at a rate that the surrounding tissue can handle without triggering an excessive inflammatory cascade. We examined 220 biodegradable cardiac implant programmes across five material families - magnesium alloys, zinc alloys, iron-based composites, polylactic acid blends, and silk-fibroin hybrids -- collected from partner laboratories in Italy, Spain, and Sweden between 2019 and 2023. A Biodegradable Cardiac Implant Quality Index (BCIQI) was constructed from five weighted sub-scores: mechanical retention, controlled degradation rate, biocompatibility profile, therapeutic delivery capacity, and imaging compatibility. Regression-derived weights tied each sub-score to observed translational success. BCIQI predicted successful clinical translation with r = +0.84 and an AUC of 0.882. Magnesium alloy programmes scored highest (mean BCIQI 0.821), while iron-based composites lagged at 0.594. Only 36.4 percent of programmes exceeded a BCIQI of 0.75, highlighting considerable room for material and design optimisation across the field.