The Maryland Institute for Emergency Medical Services Systems (MIEMSS), the State agency responsible for coordinating Maryland's emergency medical services (EMS) designated Holy Cross Hospital as a "Cardiac Interventional Center." This designation means Holy Cross Hospital complies with state standards to receive patients transported by EMS who are experiencing the most common type of heart attack called an ST-elevation myocardial infarction (STEMI). As a result of this designation, effective April 1, 2011, EMS providers who have identified a STEMI patient may transport those patients to the closest designated Cardiac Interventional Center, which may be Holy Cross Hospital, bypassing non-designated hospitals in accordance with the Maryland Medical Protocols for EMS Providers. The American Hospital Association estimates annually, approximately 400,000 patients experience a STEMI in the United States. In Maryland, it is estimated that approximately 5,600 patients experience a STEMI.