Decentralized digital ledger technology (DLT) archives data transparent and immutable with a trustless encrypted protocol and a consensus mechanism. It allows secure, public or private transactions with or without anonymity, depending on the blockchain. Smart contracts consist of code that can be executed in a DLT environment. The smart contracts technology enables the development of decentralized apps (DApps) who can interact directly with the blockchain and support on-chain storage. DLT with smart contracts and DApps could solve key challenges in healthcare ecosystems, i.e. healthcare interoperability, multi-center-studies with automatic patient acquisition by smart contracts, patient-centric identification and authentication, pharmacovigilance.