**Background:** Cardiovascular diseases are the leading cause of mortality in Europe, with over 60 million deaths per year. Cardiac rehabilitation (CR) is essential for secondary prevention after acute cardiovascular events, but access is limited. The COVID-19 pandemic further disrupted center-based CR programs. The vCare project (EU Horizon 2020, grant no 769807) developed a virtual rehabilitation assistant for elderly patients to support home-based recovery. This study evaluated the vCare system's effectiveness, feasibility, and usability in heart failure (HF) and ischemic heart disease (IHD) patients in Romania.
**Methods:** This prospective interventional pilot study was conducted at Carol Davila University of Medicine and Pharmacy, Bucharest. Recruitment occurred over 6–12 weeks at Bagdasar–Arseni Emergency Clinical Hospital. Thirty HF patients (17M/13F; mean age 61.53±9.41 years) were randomized into three subgroups of 10 each: vCare experimental group (EG) using the vCare app at home, ambulatory group (AG) undergoing conventional center-based CR, and control group (CG) receiving only discharge advice. Twenty IHD patients (16M/4F; mean age 58.1±7.12 years) were randomized into two subgroups of 10 each: vCare EG and CG. The study duration was three months. Assessments at baseline (T₀) and post-intervention (T₁) included clinical examination, blood tests, echocardiography, cardiopulmonary exercise testing (VO₂max), 24h blood pressure and ECG monitoring, and standardized questionnaires (Minnesota MLHFQ for HF only, HADS, Fagerström, EuroQol-5D, EQ-VAS). Usability was assessed with the User Experience Questionnaire (UEQ), System Usability Scale (SUS), and Technology Acceptance Model (TAM). The vCare system included components for exercise training, medical education, medication adherence, vital sign monitoring (blood pressure, heart rate, weight, SpO₂), and smoking cessation; alcohol reduction was included only for IHD. Statistical analysis used t-tests comparing T₀ and T₁ values.
**Key Results:** In the HF group, VO₂max improved in EG (19.21 to 21.32 mL/kg/min) and AG (19.18 to 21.98 mL/kg/min), while CG decreased (18.46 to 17.04 mL/kg/min). LDL-cholesterol decreased approximately 30% from baseline in EG, with improvement also in AG but no significant change in CG. Quality of life (MLHFQ) and anxiety/depression (HADS) improved in EG and AG but not CG; depression severity increased in CG (p=0.4). Smoking reduction of 50% was observed in EG. In the IHD group, VO₂max improved in EG (16.58 to 20.7 mL/kg/min) while CG decreased by 1.75 mL/kg/min. LDL-cholesterol decreased in both groups (CG: 165.34 to 132.42 mg/dL; EG: decrease of 21.05 mg/dL from baseline). Depression improved more in EG than CG; anxiety showed no change in CG and a slight increase in EG. Quality of life (EQ-VAS) showed a 15% increase in EG with no change in CG. SUS scores exceeded 68 (acceptability threshold) in both study groups. TAM results for HF EG: perceived usefulness 30.5±4.08, perceived ease of use 28.6±3.35, total 59.1±7.43. For IHD EG: perceived usefulness 29.8±4.82, perceived ease of use 29.6±5.46, total 59.1±7.43. Technical errors and COVID-19 restrictions affected some patients' rehabilitation duration.
**Clinical Implications:** The vCare virtual assistant demonstrated effectiveness comparable to center-based cardiac rehabilitation for improving exercise capacity, reducing cardiovascular risk factors (LDL-cholesterol, smoking), and enhancing quality of life in HF and IHD patients. The system was particularly valuable during the COVID-19 pandemic when access to center-based CR was restricted. Usability scores indicated good patient acceptance. These findings support virtual cardiac rehabilitation as a viable alternative for patients unable to attend in-person programs. Limitations include small sample size and tablet-only platform. Future research should evaluate the system on larger populations and develop cross-platform mobile compatibility.