This is a prospective and retrospective multicentre study conducted under the scientific coordination of the IRCCS Fondazione Don Gnocchi and funded by the Italian Ministry of Health (PNRR-MCNT2-2023-12377767). Using the Altshock registry, the largest multicentre Cardiogenic Shock (CS) registry in Italy, which currently has registered more than 1,000 CS patients across Italy, we will recruit patients to: (1) provide a granular assessment of post-acute phase programmes, patients' functional disability, return to work and quality of life, including specific reference to gender; (2) implement specific pathways of care in the post-acute phase; (3) provide a multidimensional assessment, thus validating an innovative model in comparison with the traditional pathway, defining the potential benefits to and impact on economic efficiency and the general sustainability of this therapeutic trajectory.

Study Population: The study will include all consecutive Cardiogenic Shock (CS) patients from the Altshock registry. The primary outcome is all-cause death and readmission-free survival at 6 months and 1 year post-ICU discharge. Secondary outcomes include functional recovery measured by illness severity (using the Medical Research Council Scale and electromyography if needed), disease-specific PROM (Kansas City Cardiomyopathy Questionnaire), and a chronic condition PROM (Long-Term Conditions Questionnaire) at 6 months.

Sample Size: An estimated cohort of 2000 CS patients, with around 1240 survivors, will be studied. This sample allows us to detect a 10% difference in death and readmission-free survival rates between those receiving post-acute care services and those who do not, with 80% power and a 5% significance level.

Validation and Assessment: A mixed-method approach will validate the innovative care model, incorporating clinical data, health economics, and professional perceptions. Key performance indicators and a RACI matrix will guide the implementation, with a focus on short- and long-term organizational impacts, economic benefits, and healthcare professional perceptions.

Data Analysis: Quantitative variables will be analyzed using standard statistical methods, and survival analysis will compare groups using Kaplan-Meier curves and log-rank tests. Multivariable Cox models will assess the impact of post-acute care services on outcomes. Economic analyses will involve cost-effectiveness and budget impact assessments.

Rehabilitation Intervention: Post-acute care, including cardiac and neuromotor rehabilitation, is critical for CS patients to prevent complications and rehospitalization. The rehabilitation program will include respiratory physiotherapy, muscle strengthening, endurance training, cardiovascular exercises, and secondary prevention strategies. Neuromotor rehabilitation will address sarcopenia and polyneuropathies with targeted exercises and advanced technologies like robotics and FES.

Expected Outcomes: The ENIGMA project aims to improve CS patient outcomes by transforming post-acute care, reducing mortality, enhancing quality of life, and proving the cost-effectiveness and sustainability of innovative care pathways.

Inclusion Criteria:

• All consecutive patients with a clinical diagnosis of Cardiogenic Shock.

Exclusion Criteria:

• Refusal to give informed consent.

All consecutive patients with Cardiogenic Shock (CS) will be included. The deferred consent is admitted for non-competent patients.