Background: Angina and no obstructive coronary artery disease (ANOCA) is associated with poor outcomes and limited treatment options. Enhanced external counterpulsation (EECP) is a non-invasive treatment that involves applying external inflatable cuffs to the lower extremities to increase blood flow during diastole (diastolic augmentation and increased preload), followed by deflation during systole (decreased afterload). Although EECP is indicated in refractory angina patients, its effectiveness in treating refractory angina in ANOCA patients is relatively unknown and limited to small case series. Objective: Assess the efficacy of EECP treatment in ANOCA patients using Canadian Cardiovascular Society (CCS) angina class, 6-minute walk test (6MWT), Duke Activity Status Index (DASI), Seattle Angina Questionnaire (SAQ), and weekly anginal episodes. Methods: We examined ANOCA patients (defined as £50% stenosis in any major epicardial vessels) with CCS class 3 or 4 angina that completed EECP treatment at 2 large centers. CCS class, 6MWT, DASI, SAQ, and weekly anginal episodes were evaluated pre- and post- EECP treatment, as data was available. A paired Student’s t-test, Wilcoxon signed-rank test, and McNemar’s test were utilized as appropriate. Results: 65 ANOCA patients (63% female; 60±11 years) that completed 35±2 EECP sessions were included. Patients were on 4±2 cardiac medications pre-EECP (78% statin, 52% ACEI/ARB, 62% BBs, 34% CCBs, 48% nitrates, and 53% ranolazine). Post-EECP, 42 patients (65%) had an improvement of 3 1 CCS angina class with 16 (25%) improving by 3 2 classes. Significant improvements in CCS angina severity, 6MWT, DASI, SAQ, and weekly anginal episodes were evident post-EECP ( Table ). Conclusion: In ANOCA patients, EECP therapy reduces CCS angina class and improves exercise tolerance. EECP should be considered in ANOCA patients with refractory angina CCS class 3 or 4 as a part of optimal medical therapy.