Single-arm, Multi-center Study Evaluating the Acceptance and Feasibility of a Digital Remote Monitoring Tool Configured for Patients With ATTR-CM: ACO-Monitor

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a heart condition caused by a protein called transthyretin (TTR) building up as amyloid in the heart muscle. This build-up makes the heart stiff and can lead to symptoms of heart failure, such as difficulty breathing, tiredness, swelling in the legs, and reduced ability to be physically active. ATTR-CM occurs in two forms: a hereditary (variant) type caused by changes in genes, and a wild-type form that usually develops with aging. People living with ATTR-CM are usually cared for at specialist centers, which may require them to travel long distances for appointments. Because of this, visits may be infrequent, and sometimes people only see their doctor once a year. This can make it harder to notice if the disease is getting worse or if there are problems with following their treatment plan. As a result, important changes in health may go unnoticed for several months, which can be risky. Remote monitoring offers a way for people living with ATTR-CM and their healthcare professionals to stay connected between clinic visits. Recent studies have shown that remote monitoring can help by making it easier to share health information, spot problems earlier, and support people to follow their treatment plans. This can lead to fewer hospital visits and better health outcomes. Luscii is a digital remote monitoring tool designed to help people living with ATTR-CM and their healthcare professionals stay connected between clinic visits. Luscii has two main parts: Luscii contact, a smartphone app that allows secure messaging and video calls, and Luscii vitals, a clinical software system that organizes health data and can alert the healthcare team if there are changes that need attention. Luscii vitals is a CE-marked medical device used within its approved purpose and does not replace a doctor's judgement. By making it easier to communicate and share information, Luscii aims to support earlier detection of problems, better management of ATTR-CM, and a more positive experience for people living with this condition. The main purpose of this observational study, called ACO-MONITOR, is to learn how acceptable and practical Luscii is for people living with ATTR-CM and their healthcare professionals. The study will take place in Austria, Germany, and Italy at three specialist centers. About 60 adults with a diagnosis of hereditary or wild-type ATTR-CM will be invited to take part. There will be no treatments given as part of this study. Instead, participants will use the Luscii app and devices at home to track their health and share information with their healthcare professionals. The study team will provide training on how to use Luscii and will help participants get started. The study team will look at: * How quickly and how often participants and healthcare professionals use Luscii * How long Luscii is used by each person * How many times participants use Luscii after being reminded * How easy Luscii is to use, based on questionnaires for both participants and healthcare professionals The study will last about 18 months in total, including a 6-month period to invite participants and a 12-month follow-up period. During the study, the study team will: * Support participants in using Luscii to share health information from home * Monitor how often and how easily Luscii is used * Ask participants and healthcare professionals about their experiences using Luscii, including what worked well and what could be improved * Record any problems or technical issues with using Luscii By collecting this information, the researchers hope to learn if Luscii can help improve communication, support earlier detection of health problems, and make it easier for people living with ATTR-CM to manage their condition between clinic visits.

Inclusion Criteria: * Adult (≥18 years at the date of signing the informed consent form (ICF)). * Diagnosis of either wild-type or variant ATTR-CM. * Treatment with a drug approved for ATTR-CM, including newly prescribed therapy at the initial visit. * Signed ICF. * Access to and basic ability to use a personal smartphone with internet connectivity sufficient to install and operate the Luscii contact application. Exclusion Criteria: * Participation in an investigational program with interventions outside of routine clinical practice. * Patients who are unable to provide consent, including those whose consent would need to be given by a legal representative.