Recommendations have developed to help ensure that patients suffering from a myocardial infarction receive a prompt diagnosis and revascularization in order to minimize the damage that occurs before treatment is initiated. The "door-to-balloon" time is one measure, and requires the patient to have restoration of blood flow down the culprit vessel within 90 minutes of presentation to the hospital. This holds true whether the patient presents in the middle of the day or the middle of the night, and most hospitals have spent countless hours developing plans, revising protocols, and monitoring their progress to ensure that they meet the standards set.
The established goal in the treatment of myocardial infarction is early time to reperfusion, defined as within 90 minutes from the patient’s arrival in the emergency room. The most effective way to accomplish this goal is primary percutaneous coronary intervention (PCI). The “Door to Balloon Time (D2B) initiative” was launched by the American College of Cardiology in 2006, to encourage hospitals with PCI capability to comply with this standard.
Any delay in reperfusion greater than 90 minutes increases myocardial damage and mortality. Early reperfusion, i.e., less than 60 minutes, results in the most favorable outcomes for patients with ST segment elevation myocardial infarction.
There may, however, be reasons why a patient is a not candidate for PCI. An anatomical reason, such as a blockage in the left main artery, if severe enough, may prevent the physician from reaching the lesion causing the myocardial infraction downstream in the left anterior descending or circumflex vessel. A severely tortuous artery may prevent delivery of a balloon or stent. A wire may fail to cross a lesion if it is severely narrowed or the plaque causing the heart attack is severely disrupted. There may be reasons unrelated to coronary anatomy that would favor surgical revascularization over percutaneous intervention, such as concomitant valve disease requiring emergent correction or the patient’s inability to take antiplatelet therapy after PCI.
Catheter-based early revascularization saves heart muscle placed at risk by acutely occluded vessels. Emergent coronary bypass surgery is not the appropriate treatment because there is delayed reperfusion time associated with mobilization of a surgical team, as well as increased risk of bleeding related to Plavix use, and increased risk of other serious complications (for example, the necrotic digits). Delay in revascularization results in progressive and irreversible myocardial damage.
Treatment of myocardial ischemia medical expert witness specialties include cardiology interventional, cardiology, emergency medicine, EMT, emergency nursing, cardiac anesthesiology, internal medicine, family medicine, and cardiovascular surgery.