Introduction Evidence of telehealth for chronic disease management is scarce and contradictory. Objectives We aimed to evaluate the safety and efficacy of teleconsultations as support in the care transition of patients with stable coronary artery disease (CAD) from tertiary to primary care. Methods A randomized noninferiority clinical trial was undertaken in patients with CAD from a tertiary hospital in a middle-income country. Patients with functional angina class 1 or 2 and meeting discharge criteria were randomized to remain in the cardiology outpatient clinic for 12 months (control group, CG) or continue follow-up in a primary care unit with clinical support via telemedicine (intervention group, IG). The primary outcome was the maintenance of the functional angina class after 12 months. Secondary outcomes included control of risk factors and clinical outcomes. Results In total 271 patients (mean age, 66 years) were included; 81.1% and 91% of the IG and CG, respectively, maintained stable angina symptoms, thus noninferiority could not be shown between the groups. Regarding emergency room visits at 1 year, the IG (7.6%) was noninferior to the CG (6.0%) (absolute difference, 1.6%; noninferiority margin (NIM), –4.8% to 8.2%). For control of risk factors, 30.7% and 29.6% of the IG and CG, respectively, had blood pressure <130/80 mmHg (absolute difference, 1.1%; NIM, –10.5% to 12.8%), and 48.9% and 33.3% of diabetic patients in the IG and CG, respectively, had glycated haemoglobin <7% (absolute difference, 15.6%; NIM, –6.8% to 36%). Conclusions In our study, the difference in the patients’ angina functional class did not result in greater seeking of emergency care, supporting that discharge from the outpatient clinic with telemedicine is safe for patients with stable CAD treated at the tertiary level. The control of risk factors in these patients was noninferior to patients followed up in primary care. ClinicalTrials.gov (NCT02489565).