Door-to-balloon is a time measurement in emergency cardiac care (ECC), specifically in the treatment of ST segment elevation myocardial infarction (or STEMI). The interval starts with the patient's arrival in the emergency department, and ends when a catheter guidewire crosses the culprit lesion in the cardiac cath lab. Because of the adage that "time is muscle", meaning that delays in treating a myocardial infarction increase the likelihood and amount of cardiac muscle damage due to localised hypoxia, [1] [2] [3] [4] ACC/AHA guidelines recommend a door-to-balloon interval of no more than 90 minutes. [5] As of 2006 in the United States, fewer than half of STEMI patients received reperfusion with primary percutaneous coronary intervention (PCI) within the guideline-recommended timeframe. [6] It has become a core quality measure for the Joint Commission on Accreditation of Healthcare Organizations (TJC). [7] [8] [9]
The benefit of prompt, expertly performed primary percutaneous coronary intervention over thrombolytic therapy for acute ST elevation myocardial infarction is now well established. [10] Few hospitals can provide PCI within the 90 minute interval, [11] which prompted the American College of Cardiology (ACC) to launch a national Door to Balloon (D2B) Initiative in November 2006. The D2B Alliance seeks to "take the extraordinary performance of a few hospitals and make it the ordinary performance of every hospital." [12] Over 800 hospitals have joined the D2B Alliance as of March 16, 2007. [13]
The D2B Alliance advocates six key evidence-based strategies and one optional strategy to help reduce door-to-balloon times: [12] [14]
On May 30, 2007, the American Heart Association launched 'Mission: Lifeline', a "community-based initiative aimed at quickly activating the appropriate chain of events critical to opening a blocked artery to the heart that is causing a heart attack." [15] It is seen as complementary to the ACC's D2B Initiative. [16] The program will concentrate on patient education to make the public more aware of the signs of a heart attack and the importance of calling 9-1-1 for emergency medical services (EMS) for transport to the hospital. [15] In addition, the program will attempt to improve the diagnosis of STEMI patients by EMS personnel. [15] According to Alice Jacobs, MD, who led the work group that addressed STEMI systems, [17] when patients arrive at non-PCI hospitals they will stay on the EMS stretcher with paramedics in attendance while a determination is made as to whether or not the patient will be transferred. [17] For walk-in STEMI patients at non-PCI hospitals, EMS calls to transfer the patient to a PCI hospital should be handled with the same urgency as a 9-1-1 call. [17]
Although incorporating a prehospital 12 lead ECG into critical pathways for STEMI patients is listed as an optional strategy by the D2B Alliance, the fastest median door-to-balloon times have been achieved by hospitals with paramedics who perform 12 lead ECGs in the field. [18] EMS can play a key role in reducing the first-medical-contact-to-balloon time, sometimes referred to as EMS-to-balloon (E2B) time, [19] by performing a 12 lead ECG in the field and using this information to triage the patient to the most appropriate medical facility. [20] [21] [22] [23]
Depending on how the prehospital 12 lead ECG program is structured, the 12 lead ECG can be transmitted to the receiving hospital for physician interpretation, interpreted on-site by appropriately trained paramedics, or interpreted on-site by paramedics with the help of computerized interpretive algorithms. [24] Some EMS systems utilize a combination of all three methods. [19] Prior notification of an inbound STEMI patient enables time saving decisions to be made prior to the patient's arrival. This may include a "cardiac alert" or "STEMI alert" that calls in off duty personnel in areas where the cardiac cath lab is not staffed 24 hours a day. [19] The 30-30-30 rule takes the goal of achieving a 90-minute door-to-balloon time and divides it into three equal time segments. Each STEMI care provider (EMS, the emergency department, and the cardiac cath lab) has 30 minutes to complete its assigned tasks and seamlessly "hand off" the STEMI patient to the next provider. [19] In some locations, the emergency department may be bypassed altogether. [25]
Bradley et al. (Circulation 2006) performed a qualitative analysis of 11 hospitals in the National Registry of Myocardial Infarction that had median door-to-balloon times = or < 90 minutes. They identified 8 themes that were present in all 11 hospitals: [6]
Granger et al. (Circulation 2007) identified the following criteria of an ideal primary PCI center. [24]
Granger et al. (Circulation 2007) identified the following barriers to timely access to primary PCI. [24]
Cardiac markers are biomarkers measured to evaluate heart function. They can be useful in the early prediction or diagnosis of disease. Although they are often discussed in the context of myocardial infarction, other conditions can lead to an elevation in cardiac marker level.
Prasugrel, sold under the brand name Effient in the US, Australia and India, and Efient in the EU) is a medication used to prevent formation of blood clots. It is a platelet inhibitor and an irreversible antagonist of P2Y12 ADP receptors and is of the thienopyridine drug class. It was developed by Daiichi Sankyo Co. and produced by Ube and marketed in the United States in cooperation with Eli Lilly and Company.
Acute coronary syndrome (ACS) is a syndrome due to decreased blood flow in the coronary arteries such that part of the heart muscle is unable to function properly or dies. The most common symptom is centrally located pressure-like chest pain, often radiating to the left shoulder or angle of the jaw, and associated with nausea and sweating. Many people with acute coronary syndromes present with symptoms other than chest pain, particularly women, older people, and people with diabetes mellitus.
Unstable angina is a type of angina pectoris that is irregular or more easily provoked. It is classified as a type of acute coronary syndrome.
Percutaneous coronary intervention (PCI) is a minimally invasive non-surgical procedure used to treat narrowing of the coronary arteries of the heart found in coronary artery disease. The procedure is used to place and deploy coronary stents, a permanent wire-meshed tube, to open narrowed coronary arteries. PCI is considered 'non-surgical' as it uses a small hole in a peripheral artery (leg/arm) to gain access to the arterial system, an equivalent surgical procedure would involve the opening of the chest wall to gain access to the heart area. The term 'coronary angioplasty with stent' is synonymous with PCI. The procedure visualises the blood vessels via fluoroscopic imaging and contrast dyes. PCI is performed by an interventional cardiologists in a catheterization laboratory setting.
P2Y12 is a chemoreceptor for adenosine diphosphate (ADP) that belongs to the Gi class of a group of G protein-coupled (GPCR) purinergic receptors. This P2Y receptor family has several receptor subtypes with different pharmacological selectivity, which overlaps in some cases, for various adenosine and uridine nucleotides. The P2Y12 receptor is involved in platelet aggregation and is thus a biological target for the treatment of thromboembolisms and other clotting disorders. Two transcript variants encoding the same isoform have been identified for this gene.
Bivalirudin (Bivalitroban), sold under the brand names Angiomax and Angiox and manufactured by The Medicines Company, is a specific and reversible direct thrombin inhibitor (DTI).
Myocardial rupture is a laceration of the ventricles or atria of the heart, of the interatrial or interventricular septum, or of the papillary muscles. It is most commonly seen as a serious sequela of an acute myocardial infarction.
Cardiac monitoring generally refers to continuous or intermittent monitoring of heart activity to assess a patient's condition relative to their cardiac rhythm. Cardiac monitoring is usually carried out using electrocardiography, which is a noninvasive process that records the heart's electrical activity and displays it in an electrocardiogram. It is different from hemodynamic monitoring, which monitors the pressure and flow of blood within the cardiovascular system. The two may be performed simultaneously on critical heart patients. Cardiac monitoring for ambulatory patients is known as ambulatory electrocardiography and uses a small, wearable device, such as a Holter monitor, wireless ambulatory ECG, or an implantable loop recorder. Data from a cardiac monitor can be transmitted to a distant monitoring station in a process known as telemetry or biotelemetry.
A coronary stent is a tube-shaped device placed in the coronary arteries that supply blood to the heart, to keep the arteries open in patients suffering from coronary heart disease. The vast majority of stents used in modern interventional cardiology are drug-eluting stents (DES) It is used in a medical procedure called percutaneous coronary intervention (PCI). Coronary stents are divided into two broad types - drug-eluting and bare metal stents, as of 2023 drug-eluting stents were used in more than 90% of all PCI procedures. Stents reduce angina and have been shown to improve survival and decrease adverse events after a patient has suffered a heart attack - medically termed an acute myocardial infarction.
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction to the heart muscle. The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck or jaw. Often it occurs in the center or left side of the chest and lasts for more than a few minutes. The discomfort may occasionally feel like heartburn. Other symptoms may include shortness of breath, nausea, feeling faint, a cold sweat, feeling tired, and decreased level of consciousness. About 30% of people have atypical symptoms. Women more often present without chest pain and instead have neck pain, arm pain or feel tired. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure, an irregular heartbeat, cardiogenic shock or cardiac arrest.
ST elevation refers to a finding on an electrocardiogram wherein the trace in the ST segment is abnormally high above the baseline.
Reperfusion therapy is a medical treatment to restore blood flow, either through or around, blocked arteries, typically after a heart attack. Reperfusion therapy includes drugs and surgery. The drugs are thrombolytics and fibrinolytics used in a process called thrombolysis. Surgeries performed may be minimally-invasive endovascular procedures such as a percutaneous coronary intervention (PCI), which involves coronary angioplasty. The angioplasty uses the insertion of a balloon and/or stents to open up the artery. Other surgeries performed are the more invasive bypass surgeries that graft arteries around blockages.
Electrocardiography in suspected myocardial infarction has the main purpose of detecting ischemia or acute coronary injury in emergency department populations coming for symptoms of myocardial infarction (MI). Also, it can distinguish clinically different types of myocardial infarction.
Francis Miller Fesmire was an American emergency physician and a nationally recognized expert in myocardial infarction. He authored numerous academic articles and assisted in the development of clinical guidelines on the standard of care in treating patients with suspected myocardial infarction by the American College of Emergency Physicians and the American Heart Association/American College of Cardiology. He performed numerous research investigations in chest pain patients, reporting the usefulness of continuous 12-lead ECG monitoring, two-hour delta cardiac marker testing, and nuclear cardiac stress testing in the emergency department. The culmination of his studies was The Erlanger Chest Pain Evaluation Protocol published in the Annals of Emergency Medicine in 2002. In 2011 he published a novel Nashville Skyline that received a 5 star review by ForeWord Reviews. His most recent research involved the risk stratification of chest pain patients in the emergency department.
A diagnosis of myocardial infarction is created by integrating the history of the presenting illness and physical examination with electrocardiogram findings and cardiac markers. A coronary angiogram allows visualization of narrowings or obstructions on the heart vessels, and therapeutic measures can follow immediately. At autopsy, a pathologist can diagnose a myocardial infarction based on anatomopathological findings.
Management of acute coronary syndrome is targeted against the effects of reduced blood flow to the affected area of the heart muscle, usually because of a blood clot in one of the coronary arteries, the vessels that supply oxygenated blood to the myocardium. This is achieved with urgent hospitalization and medical therapy, including drugs that relieve chest pain and reduce the size of the infarct, and drugs that inhibit clot formation; for a subset of patients invasive measures are also employed. Basic principles of management are the same for all types of acute coronary syndrome. However, some important aspects of treatment depend on the presence or absence of elevation of the ST segment on the electrocardiogram, which classifies cases upon presentation to either ST segment elevation myocardial infarction (STEMI) or non-ST elevation acute coronary syndrome (NST-ACS); the latter includes unstable angina and non-ST elevation myocardial infarction (NSTEMI). Treatment is generally more aggressive for STEMI patients, and reperfusion therapy is more often reserved for them. Long-term therapy is necessary for prevention of recurrent events and complications.
Sgarbossa's criteria are a set of electrocardiographic findings generally used to identify myocardial infarction in the presence of a left bundle branch block (LBBB) or a ventricular paced rhythm.
Protected percutaneous coronary intervention, abbreviated as Protected PCI, is a heart procedure that involves a ventricular assist device that is used to treat patients with cardiovascular disease, including advanced heart failure.
Remote ischemic conditioning (RIC) is an experimental medical procedure that aims to reduce the severity of ischaemic injury to an organ such as the heart or the brain, most commonly in the situation of a heart attack or a stroke, or during procedures such as heart surgery when the heart may temporary suffer ischaemia during the operation, by triggering the body's natural protection against tissue injury. Although noted to have some benefits in experimental models in animals, this is still an experimental procedure in humans and initial evidence from small studies have not been replicated in larger clinical trials. Successive clinical trials have failed to identify evidence supporting a protective role in humans.