A novel external counterpulsation system for coronary artery disease and heart failure: pilot studies and initial clinical experiences.

External counterpulsation (ECP) is a beneficial and noninvasive treatment for coronary artery disease or heart failure; however, it still has a lot of limitations. We used a novel ECP system, Compact CP, the main feature of which is the double-lumen cuff that reduces the impact of cuff inflation and the size of the air compressor. The first lumen was a contact cuff that was attached to the legs with a constant pressure (8 kPa). The second lumen was a main cuff that was inflated and deflated with a driving pressure and synchronized to the cardiac cycle. In this report, we describe the results of four pilot studies in a total number of 39 healthy volunteers and initial clinical experiences of this system in three patients. The pilot studies demonstrated that the ECP system provided significant diastolic augmentation and systolic unloading. It also achieved a satisfactory diastolic/systolic pressure ratio (1.00 ± 0.06) with a high comfort level at a driving pressure of 40 kPa. Higher pressure (50-70 kPa) increased the assist performance but decreased the comfort level. ECP was also applied with a patient with chronic refractory angina and two patients with postoperative heart failure following cardiac surgery. The clinical conditions improved. No adverse effect was observed. Our novel ECP system is safe, effective, and promising in the treatment of coronary artery disease or heart failure. Further clinical investigations are needed to support the significance of this system.