We hypothesized that left ventricular (LV) and subvalvular geometries could be restored in a less invasive manner by circumferential plication without a ventriculotomy or a cardiopulmonary bypass (CPB). Continuous sutures were placed circumferentially on the epicardial surface of the LV wall without using a CPB in six healthy pigs. Coronary artery occlusion was precluded by placing the sutures underneath the peripheral coronary artery. After the circumferential sutures were plicated to 75% of the original length, hemodynamics were recorded and LV geometries and function were measured. All animals survived after plication without arrhythmia or hemodynamic deterioration. Angiogram findings demonstrated that plication reduced the LV end-diastolic volume (LVEDV) (72+/-10 vs. 58+/-12 ml, P<0.05), and sphericity (0.62+/-0.04 vs. 0.58+/-0.03, P<0.05). Also, three-dimensional echocardiography (3D-echo) showed that plication reduced the papillary muscle distance (27+/-3 vs. 18+/-2 mm, P<0.05). We demonstrated the effectiveness of off-pump circumferential plication, which reduced LV volume and altered subvalvular geometry without causing hemodynamic deterioration in an acute animal model. This pilot study suggests that our novel technique is feasible and should next be tested in a chronic model with a dilated failing heart, before clinical application is warranted.