<International Circulation>: Could you tell us something about Cardiac Syndrome X and what its causes might be? And what is the newest information on the subject?
　　Dr Bairey Merz: Cardiac Syndrome X is a term for patients with chest discomfort and abnormal stress tests but no obstructive coronary disease on their angiogram. Investigators presented here at this meeting， that a majority (over 50% of these patients) have some form of microvascular or variant angina. We are now saying we should not call it Syndrome X; we actually know what the cause is and in over half of the patients we have been able to identify what we call mechanistic pathways which are either in variant angina dysfunction of the smooth muscle or in the microvascular angina dysfunction of either the endothelial or the non-endothelial pathways of the little arterioles. That is clear now. It is an important problem. Reassurance does not make the pain go away. It does appear to be associated with an intermediate at-risk for heart attack and death. So we are now a bit at equipoise as to how to treat them. There were a lot of opinions at this meeting about how to treat patients – nitrates， calcium channel blockers， beta-blockers， ranolazine， ivabradine (not enough information available) and so on. I think we would conclude after the session here that we need to do some good clinical trials in patients who are well characterized， not Cardiac Syndrome X which includes people who don’t have a genuine ischemic problem. Variant angina is one category and microvascular angina is another category. We need randomized controlled trials in those well-characterized populations about what are the most effective treatments.