Most of us have seen or heard the statistics so many times that we are inured to their affect. Acute myocardial infarction (AMI) strikes approximately 1.5 million individuals in the United States each year and of these, about 500,000 die.1 Myocardial infarction is the major killer of both women and men in the United States, and it retains this dubious distinction despite reductions over the past decades in its incidence and mortality. As these statistics indicate, there are still substantial improvements to be made in AMI outcomes. Rapidly emerging knowledge about the spectrum of acute coronary syndromes and the opportunity to interrupt the process leading to AMI has increased clinicians' appreciation of the importance of early and definitive treatment. In this environment, it is imperative that cardiovascular nurses keep abreast of the latest research and innovations in AMI care. This issue of The Journal of Cardiovascular Nursing (13:3) covers the spectrum of AMI care and provides important information for all nurses who care for AMI patients.
The first article in the issue is Doering's comprehensive article on the pathophysiology of acute coronary syndromes leading to AMI. Acute myocardial infarction is now recognized not as a discrete coronary event, but as one end of the continuum of acute coronary syndromes. This recognition sets the stage for many of the current innovations in pharmacologic and interventional treatment of AMI. Readers of Doering's article will gain a thorough understanding of atherosclerotic plaque progression and disruption, acute event triggering, tissue necrosis, Q-wave and non-Q-wave infarction and ventricular remodeling.
Hospital mortality during AMI is about 14%, but 50%-60% of people who die after suffering AMI do so in the hour after the onset of symptoms before they ever reach the hospital.1 Most of these deaths are thought to be primary arrhythmic deaths that could be successfully treated with defibrillation and appropriate pharmacologic therapy. This is one reason that it is imperative patients experiencing AMI symptoms promptly make the decision to seek hospital treatment for their symptoms. Another reason for seeking prompt treatment is that the use of thrombolytic therapy is associated with an overall 21% reduction in 1-month mortality compared with therapy without thrombolytic medication. Thrombolytic therapy translates to a saving of 21 lives for every 1,000 AMI patients treated. The benefits from thrombolytic therapy diminish as time to treatment from symptom onset increase. The greatest benefits are seen when patients are treated within the first hour of symptom onset. Unfortunately, the average patient delays far longer than an hour before seeking treatment. Zerwic explores reasons why patients delay, specific factors associated with patient delay in seeking treatment for AMI symptoms, and results of educational campaigns designed to reduce delay and suggests avenues for future research. Alonzo discusses the intriguing thesis that posttraumatic stress disorder in response to AMI may affect coping and contribute to delays in appropriate care-seeking among some AMI patients who experience subsequent cardiac events.
In some centers, primary angioplasty may be an effective alternative to thrombolytic therapy for providing reperfusion in the context of AMI. McErlean compares thrombolysis and primary angioplasty and discusses the controversies surrounding comparison of these therapies. She also discusses the current and future roles of additional therapies, such as IIb/IIIa platelet inhibitors, as possible adjuncts to thrombolysis or primary angioplasty.
A variety of psychosocial factors play a major role determining outcomes after AMI. Depression, anxiety, and social support all have been demonstrated to have an effect on AMI morbidity and mortality that is independent of the effect of other traditional risk factors. Nonetheless, psychosocial factors often receive significantly less attention than physical factors. Nurses caring for AMI patients must have a complete understanding of the most current findings related to psychosocial factors so that they can provide optimal care to their patients. In this issue of the journal, Buselli and Stuart present a thorough review of the influence of psychosocial factors and biopsychosocial interventions on AMI outcomes. Another under-appreciated area in AMI care is the family. Fleury and Moore discuss the effect that AMI can have on the entire family and the importance to future physical and psychologic well-being of delivering family-centered care during AMI.
Halm, Penque, Doll, and Beahrs present data demonstrating that even though women may be eligible in greater proportions for Phase II cardiac rehabilitation, more men receive referrals from their physicians. Furthermore, men complete Phase II programs at greater rates than do women. These authors discuss possible reasons for these findings and implications for nurses caring for AMI patients.
Pulmonary artery catheterization with measurement of cardiac output is indicated in AMI patients who experience cardiogenic shock, progressive hypotension, pulmonary edema, severe congestive heart failure, or mechanical complications.2 The continuous thermodilution technique is a new method of measuring cardiac output that may ultimately replace the traditional intermittent bolus technique. Several factors can extraneously influence the measurement of cardiac output and the concurrence between these two techniques. Two such factors are ambient temperature and the stability of cardiac output measurements. Cathelyn and Glenn report data that will be useful for interpreting cardiac output from their study of the effect of these two factors on agreement between the continuous thermodilution technique and the intermittent bolus technique.
Glenn, Ramsey, and Alley carefully studied the cost and duration of cardiovascular care (including AMI) for 4,804 episodes of hospitalization to determine whether length of stay and cost of care were different according to gender, type of insurance, hospital location as either urban or rural, and type of services. Their data provide important insights regarding gender and hospital location differences that may contribute to understanding the considerable differences in outcomes from cardiovascular hospitalizations.
In the Dysrhythmia Department, McCauley, Schanne, and Wilensky present a case of AMI in a 16-year-old with familial hypercholesterolemia. As this interesting case illustrates, nurses should maintain a high index of suspicion for acute cardiac events in individuals who normally are unlikely to suffer AMI when those individuals have significant risk factors for cardiovascular disease.
In 1996, the American College of Cardiology and the American Heart Association jointly published guidelines for the management of patients with AMI.2 These guidelines offer recommendations based on the latest research findings for prehospital care through long-term management. All clinicians caring for AMI patients should be familiar with the recommendations contained in the guidelines and work within their institutions to ensure that all AMI patients receive care that reflects the latest clinical research so that they can achieve optimal outcomes. Each nurse who cares for AMI patients should periodically consider the following questions related to their care3:
* Are ACC/AHA guidelines followed? Specifically, are AMI patients treated promptly and if not, why not?
* Do all AMI patients receive currently recommended pharmacologic therapy such as aspirin, angiotensin-converting enzyme inhibitors, [beta]-blockers, combination thrombolytic, and antiplatelet therapy?
* Does the institution use early serum markers (ie, cardiac troponin I or T) in the assessment of patients with AMI symptoms?
* Are all clinicians caring for AMI patients current on latest treatments and are there plans to educate them as AMI care changes?
Some of the strategies that nurses can use to ensure optimal care include initiating a multidisciplinary team approach if one is not in use or actively participating if one is in use, creating and implementing AMI critical pathways, and conducting and using AMI patient care research.3 Nurses are not passive bystanders in the delivery of care to AMI patients, but active participants who can, with the requisite knowledge, substantially improve AMI patient outcomes.
Debra K. Moser, DNSc, RN
Issue Editor
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