OLD AND EMERGING OPTIONS FOR TREATMENT OF REFRACTORY ANGINA: A CRITICAL APPRAISAL
Udho Thadani, M.D.,
University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, OK, USA
Patients with refractory angina are considered to be not suitable candidates for a revascularization procedure, and remain symptomatic despite good medical therapy. However, some patients with refractory angina, experience a marked symptomatic relief after adjustment of their antianginal drugs and lifestyle modifications, including regular exercise. External Enhanced Counter Pulsation (EECP) has also proved useful in these patients and improves CCS angina class in registry data. But randomized sham controlled studies are lacking with EECP. Percutaneous transmyocardial revascularization, initially thought to be effective, is not superior to a sham procedure. And surgical laser transmyocardial revascularization may be effective in selected patients, but is not subjected to a sham procedure, and is used infrequently at present. Spinal cord stimulation is used in European countries with good results in open label trials, but needs to be subjected to randomized studies. Newer antianginal agents (ranolazine, ivabradine and trimetazidine), and older medications (allopurinol and colchicine), look promising, but placebo controlled studies are lacking in this patient group. Patients considered to be poor candidates for a revascularization procedure, are now undergoing stenting of the total coronary occlusions and or of occluded venous graft, with good initial results. But randomized sham controlled studies are needed to establish their long term effectiveness. Gene based therapy, has produced conflicting results, and pilot studies using cell based therapy look promising. A recent report of coronary sinus occlusion devise to increase coronary venous pressure and thus coronary subendocardial blood flow is under active investigation. If all else fails heart transplant remains a last resort in selected patients.