Nonpharmacological approaches to refractory angina

An increasing number of patients have advanced coronary artery disease with ischemic symptoms that are refractory to medical therapy and revascularization. With the increasing adoption of percutaneous revascularization of chronic total occlusions, previously nonrevascularizable vessels may now be targets for revascularization, which may change the landscape of refractory angina. Several nonpharmacological approaches to refractory angina have emerged, including novel interventional, noninvasive, neuromodulatory, and angiogenic approaches. Enhanced external counterpulsation remains the mainstay of noninvasive therapy, increasing time to exercise-induced ischemia and reducing frequency of angina episodes. Cardiac shockwave therapy is a promising noninvasive therapy, but randomized data remain limited. Neuromodulatory approaches include spinal cord stimulation, which has demonstrated a reduction in frequency of angina episodes; however, randomized, double-blind clinical trials have yielded conflicting results. Cell-based therapies have shown a reduction in angina and an improvement in exercise tolerance, but advancement of such therapies awaits adequately powered phase 3 trials. Coronary sinus reduction is a novel interventional approach in which an hourglass-shaped device is implanted in the coronary sinus, creating a narrowing that increases upstream pressure, relieving angina. The recently reported COSIRA phase 2 randomized trial showed improvements in angina class and quality of life metrics, setting the stage for a larger definitive trial. In summary, novel nonpharmacological therapies are emerging as promising options for the growing population of formerly "no-option" patients.