Risks (theoretical):•Coronary sinus dissection at the time of implantation. •Coronary sinus perforation and acute cardiac tamponade requiring drainage. •Device migration and embolization. •Late coronary sinus occlusion These risk were not reported in patients who receieved the device. Benefits: •Reduce angina severity. •Improve quality of life. •Reduction in the intensity of medical therapy with decrease side effects. •Reduced incidence of hospital admissions, emergency room visits and outpatient clinic visits for refractory angina. •Improved left ventricular function, and reduced LV end diastolic pressure. These patients have poor quality of life. They are disable and unable to work or to perform basic daily activities. Cannulation of the coronary sinus presents procedural risks similar to that of pacemaker electrode insertion, a procedure which is frequently performed in Interventional cardiology. For these particular patients with poor quality of life, the offered technology can potentially make them more active, more productive, and less dependent on medication and the health system.