Nursing care During Primary Angioplasty Essay
Nursing care During Primary Angioplasty Essay
Details to be collected typically include – onset duration progress of cardiac symptoms, similar complaints in the past, any other major illnesses like diabetes, hypertension, medicines with dosage, previous surgeries, any allergies, etc. Details are provided to the respective physician and orders noted accordingly. Meanwhile the patient and the relatives are provided counseling and assurance. Coronary Angioplasty is planned in this patient to widen the occluded coronary artery. These arteries supply blood and oxygen to the heart muscles. Nursing care During Primary Angioplasty Essay .These arteries get occluded due to fatty tissue or atheroma resulting in reduced blood supply to the heart causing chest pain. Angioplasty is performed to open up the blocked vessels by compressing fatty tissue against anterior coronary vessel wall. This procedure helps to improve blood flow through the vessels to the heart muscles and helps in relieving chest pain. Also, this procedure is advised when – a. Medicines like calcium channel blocker, beta adnergic blockers or nitrates fail to correct coronary heart disease symptoms (NICE technology appraisal guidance 71) or b. There is recurrence of chest pain post CABG (Coronary Artery Bypass Graft surgery). Coronary angioplasty can be planned procedure or an emergency procedure in the case of heart attack and unstable chest pain with acute myocardial infarction. (Coronary Angioplasty and Stents) This operation is performed either through radial artery or femoral artery. Radial route is more popular in recent times because radial artery is easily accessible and palpable. Its superficial location makes it easy to compress to achieve homeostasis later on. Normal Allen’s test ensures dual blood supply to hand. So in case of bruise to radial artery or radial blood flow shunt, hands will still receive perfusion through Ulnar artery without feeling any damage. There is less chance of nerve injury in radial method. This approach provides comfort to the patient as it allows them ability to mobilize. It is easier for the patient to notice and control any bleeding from the radial incision, the femoral artery lies deeper in leg, so compressing the artery is difficult and by the time hematoma is noted bleeding would be significant. Radial artery method is cost effective too. (Radial Approach to Cardiac Catheterisation). Nursing care During Primary Angioplasty Essay .Coronary Angiography is performed with the Angioplasty in an emergency. Angiogram allows doctor to look inside coronary arteries and find out how severe and where the narrowed areas are. (Coronary Angioplasty and Stents) Patient is advised what medicines to be avoided on the day of the procedure, such as aspirin or any anti coagulant, which medicines should be stopped few days before the procedure and what additional medicines need to be taken. He/she is also informed about the details of the procedure along with the effect of anesthetic drugs during and after the procedure. Doctor explains about the nature of pain the patient may have. Nursing staff ensures that patient would not eat or drink anything 4 -5 hours before the procedure. Proper consent is taken from the patient and relatives informing them about the complication involved in it. Nursing staff prepares the patient for the procedure by checking .
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One of the longest running debates in cardiology is about the best reperfusion therapy for patients with evolving acute myocardial infarction (MI). Percutaneous transluminal coronary angioplasty (ANGIOPLASTY) is a surgical treatment to reopen a blocked coronary artery to restore blood flow. It is a type of percutaneous (through-the-skin) coronary intervention (PCI) also known as balloon angioplasty. When performed on patients with acute myocardial infarction, it is called primary angioplasty. Primary angioplasty is an alternative to thrombolysis, clot-dissolving drug therapy, for patients with acute MI associated with ST-segment elevation (STEMI), a change recorded with an electrocardiogram (ECG) during chest pain. Nursing care During Primary Angioplasty Essay .
This review of the clinical benefits and policy implications of primary angioplasty was requested by the Ontario Health Technology Advisory Committee and prompted by the recent publication of a randomized controlled trial (RCT) in the New England Journal of Medicine (1) that compared referred primary angioplasty with on-site thrombolysis. The Medical Advisory Secretariat reviewed the literature comparing primary angioplasty with thrombolysis and other therapies (pre-hospital thrombolysis and facilitated angioplasty, the latter approach consisting of thrombolysis followed by primary angioplasty irrespective of response to thrombolysis) for acute STEMI.
There have been many RCTs and meta-analyses of these RCTs comparing primary angioplasty with thrombolysis and these were the subject of this analysis. Results showed a statistically significant reduction in mortality, reinfarction, and stroke for patients receiving primary angioplasty. Although the individual trials did not show significant improvements in mortality alone, they did show it for the outcomes of nonfatal reinfarction and stroke, and for an end point combining mortality, reinfarction, and stroke. However, researchers have raised concerns about these studies.
A main concern with the large RCTs is that they lack consistency in methods. Furthermore, there is some question as to their generalizability to practice in Ontario. Across the RCTs, there were differences in the type of thrombolytic drug, the use of stenting versus balloon-only angioplasty, and the use of the newer antiplatelet glycoprotein IIb/IIIa. The largest trial did not offer routine follow-up angioplasty for patients receiving thrombolysis, which is the practice in Ontario, and the meta-analysis included trials with streptokinase, an agent seldom used in hospitals in Ontario. Thus, the true magnitude of mortality benefit can only be surmised from head-to-head comparisons of current standard therapies for primary angioplasty and for thrombolysis.
By taking a more restrictive sample of the available studies, the Medical Advisory Secretariat conducted a review that was more consistent with patterns of practice in Ontario and selected trials that used accelerated alteplase as the thrombolytic agent.
Results from this meta-analysis suggest that the rates for primary angioplasty are significantly better for mortality, reinfarction, and stroke, in the short term (30 days), and for mortality, reinfarction, and the combined end point at 6 months. Nursing care During Primary Angioplasty Essay .When primary angioplasty was compared with in-hospital thrombolysis, results showed a significant reduction in adverse event rates associated with primary angioplasty. However, 1 large RCT of pre-hospital thrombolysis (i.e., thrombolysis given by paramedics before arriving at the hospital) compared with primary angioplasty documented that pre-hospital thrombolysis is an equivalent intervention to primary thrombolysis in terms of survival. Furthermore, a meta-analysis of studies that compared pre-hospital thrombolysis with in-hospital thrombolysis showed a reduction in all hospital mortality rates in favour of pre-hospital thrombolysis, supporting the findings of the pre-hospital thrombolysis study. (2)
Clinical trials to date have reported that hospital stay is often reduced for patients who receive primary angioplasty compared with thrombolysis. Using a cost-analysis performed alongside the only study from Ontario, the Medical Advisory Secretariat concluded that there might be savings associated with primary angioplasty. These savings may partly offset the investment the provincial government would have to make to increase access to this technology. These savings should also be shown outside of a clinical trial protocol if the overall efficiencies of primary angioplasty are to be verified.
Based on this health technology policy analysis, the Medical Advisory Secretariat concludes that primary angioplasty has advantages with respect to mortality and combined end points compared with in-hospital thrombolysis (Level 1 evidence). However, pre-hospital thrombolysis improves survival compared with in-hospital thrombolysis (Level 1 evidence) and is equivalent to primary angioplasty (Level 1 evidence). Nursing care During Primary Angioplasty Essay .
Results from the literature review raise concerns about the loss of therapeutic advantage due to treatment delays, time lapse from symptom onset to revascularization, time-of-day variations, the hospital volume of procedures, and the ability of hospitals to achieve in practice what RCTs have shown.
Furthermore, questions relevant to applying primary angioplasty widely, involve the diagnosis by paramedics, ambulance diversion protocols, paramedic training, and inter-hospital transfer protocols. These logistical considerations need to be addressed to realise the potential to improve patient outcomes. In its analysis, the Medical Advisory Secretariat concludes that it is unrealistic to reorganise the emergency medical services across Ontario to fully implement a primary angioplasty program.
Finally, it is important to evaluate the potential of this technology in the context of Ontario’s health system. This includes urban and rural considerations, the ability to expand access to primary angioplasty and to minimize symptom-to-assessment time through a diverse strategy including public awareness. Therefore, a measured, evaluative approach to adopting this technology is warranted.
Furthermore, the alternative approach to pre-hospital or early thrombolysis, especially within 120 minutes from onset of symptoms, should be considered when developing the approach to improving outcomes for acute MI. This could include efforts to decrease the symptom-to-thrombolysis time through strategies such as a concerted public education program to expedite presentation to emergency rooms after onset of symptoms, a pre-hospital ECG and thrombolysis checklist in ambulances to reduce door-to-needle time on arrival at emergency rooms, and, especially in remote areas, access to pre-hospital thrombolysis.
The Medical Advisory Secretariat therefore recommends that this analysis of primary angioplasty be viewed in the overall context of all interventions for the management of acute MI and, in particular, of improving access to primary angioplasty and maximising the use of early thrombolysis.
Outcomes for patients with acute MI can be improved if efforts are made to optimise the interval from symptom onset to thrombolysis or angioplasty. Nursing care During Primary Angioplasty Essay .This will require concerted efforts, including public awareness through education to reduce the symptom-to-emergency room time, and maximising efficiencies in door-to-intervention times for primary angioplasty and for early thrombolysis.
Primary angioplasty and early thrombolysis cannot be considered in isolation from one another. For example, patients who have persistent STEMI 90 minutes after receiving thrombolysis should be considered for angioplasty (“rescue angioplasty”). Furthermore, for patients with acute MI who are in cardiac shock, primary angioplasty is considered the preferred intervention. The concomitant use of primary angioplasty and thrombolysis (“facilitated angioplasty”) is considered experimental and has no place in routine management of acute MI at this time. In remote parts of the province, consideration should be given to introducing pre-hospital thrombolysis as the preferred intervention through upgrading a select number of paramedics to advanced care status.
Objective
Percutaneous transluminal coronary angioplasty (ANGIOPLASTY) is a surgical treatment to reopen a blocked coronary artery to restore blood flow. It is a type of percutaneous (through-the-skin) coronary intervention (PCI). When performed on patients with acute myocardial infarction (MI), it is called primary angioplasty. Primary angioplasty is an alternative to thrombolysis, clot-dissolving drug therapy, for patients with acute MI associated with ST-segment elevation (STEMI), a change recorded with an electrocardiogram (ECG) during chest pain. This review of the clinical benefits and policy implications of primary angioplasty was requested by the Ontario Health Technology Advisory Committee and prompted by the recent publication of a randomized controlled trial (RCT) in the New England Journal of Medicine (1) that compared referred primary angioplasty with on-site thrombolysis in Denmark. Nursing care During Primary Angioplasty Essay .
Background
Clinical Need: Target Population
MI is an acute coronary syndrome caused by the blockage of 1 or more coronary arteries, usually by an atherosclerotic plaque, which results in a thrombus (blood clot). Unstable angina, chest pain not caused by a thrombus, is another type of acute coronary syndrome. An ECG differentiates patients with acute coronary syndrome from those with noncoronary chest pain or stable angina. An ECG also determines if an acute MI is associated with ST-segment elevation.
In 1999, there were 25,775 cases of acute MI and 7,628 deaths in Ontario.(3) The estimated number of patients with STEMI annually in Ontario as of 2003 was 11,100. Cardiovascular disease is the leading cause of death among residents of Ontario. Most cardiovascular disease mortality is due to acute MI. (4) The economic burden of cardiovascular disease is severe. It costs the government of Ontario about $5.5 billion annually, about 2% of the provincial gross domestic product. (4)
The risk factors for acute MI are hypertension, diabetes, smoking, obesity, a high fat diet, and a sedentary lifestyle. Ontario’s acute MI mortality rates have been declining steadily since 1979.Nursing care During Primary Angioplasty Essay . However, as Ontario’s population grows and ages, the number of deaths from cardiovascular disease is expected to double by 2018.(4)
The determination that patients with STEMI may benefit from revascularization depends on their timely arrival at a hospital. Patients may take themselves to emergency departments or may be transported by ambulance. About 25% to 45% of patients with acute MI that arrive at emergency departments within 12 hours of experiencing symptoms have ST-segment elevation on ECG and no other contraindications to primary angioplasty or thrombolysis (Figure 1). (5)
Existing Treatments Other Than Technology Being Reviewed
Treatment for acute STEMI aims to restore coronary blood flow through the blocked artery promptly. Rapid restoration is associated with better rates of survival, limitation of infarction size, and improved left ventricular function. Primary angioplasty and thrombolytic therapy each are used to treat STEMI.
Treatment of acute MI has improved in the last 10 to 20 years. The adoption of β-blockers, thrombolytic agents, aspirin, statins, and angiotensin-converting enzyme inhibitors are seen as advances. These treatments are being adopted and are benefiting people generally. (6) Population-based studies (7-9) continue to show that acute MI mortality rates are dropping in the short-term (30 days) and in the long-term (1 year). Nursing care During Primary Angioplasty Essay .
Thrombolysis
Among treatments, thrombolysis is the reference standard of care. (10) Thrombolytic therapy is widely available, easily and quickly administered, and highly effective at improving survival in patients with evolving infarctions. Furthermore, it does not require a catheterization laboratory and can be given by a physician, nurse, or technician in the hospital or even before a patient arrives at the hospital. The magnitude of benefit is related to the promptness of the drug’s administration.
The benefits of thrombolytic therapy in patients with acute MI have been well established. (11;12) Furthermore, a retrospective analysis (8) associated thrombolysis with 17% of the total 71% reduction in acute MI mortality rates from 1975 to 1995, although using thrombolytic agents increased the risk of cerebral bleeding and stroke. Four thrombolytic agents are marketed in Canada: reteplase, tenecteplase, alteplase, and streptokinase. The risk of cerebral bleeding varies slightly among these agents, but streptokinase may present a lower risk. (13-16)
Streptokinase was the first thrombolytic in widespread use, and several trials of close to 100,000 patients were required before the medical community embraced it. Then, as recombinant alteplase was developed and studied, the question arose as to which agent was better. Another series of trials, the largest recruiting almost 45,000 patients, established that small differences could be measured, and alteplase had better mortality outcomes. (14) Due to these studies, and to the marketing of the companies involved, alteplase has become a dominant choice for patients treated and, more importantly, in total market dollars. Nursing care During Primary Angioplasty Essay .The 1.1% difference in absolute risk of mortality translated into 0.14 expected life years gained. This comes at an incremental cost of $2845 (US) per patient ($32,678/life-year gained (US), after discounts). (17)
Alteplase and alteplase derivatives account for 90% of all patient treatments in Canada and is regarded as the standard of care for thrombolysis in Canada. For this review, excluding trials that did not use accelerated alteplase is justifiable for modelling current practice standard in Ontario. Their exclusion also is recognition of the difference between alteplase and streptokinase, and between nonaccelerated alteplase and accelerated alteplase. (14)
The noteworthy difference between thrombolytic therapy and PCI has to do with achieving reperfusion (the restoration of blood flow). Thrombolytic trials have shown that the best clinical outcomes are associated with timely reperfusion. (18) To quantify the reperfusion achieved, the Thrombolysis in Myocardial Infarction (TIMI) trials groups developed an index to measure improvement in blocked arteries. In one study, (18) the accelerated alteplase protocol was the most successful thrombolytic regimen to establish reperfusion. It resulted in the best-grade revascularization, called TIMI 3 flow, in 54% of the patients and TIMI 2 flow in 27% more of the patients within 90 minutes of infusion, for a total reperfusion response of 81%. This alteplase regimen is now the most commonly used. It is a combined bolus (single intravenous injection) and infusion over 90 minutes. As summarized in Figure 1, success rates of thrombolysis in STEMI range from 55% to 81%. Nursing care During Primary Angioplasty Essay .
Pre-hospital Thrombolysis
Ideally, thrombolytic therapy should be started as soon as possible after symptoms appear. In comparing the best practices of thrombolysis and primary angioplasty, researchers have explored the option of pre-hospital thrombolysis – treating patients in the ambulance before or during transport to hospital. In a meta-analysis (19)of trials comparing pre-hospital fibrinolysis (a therapy to dissolve fibrin, a clot-forming insoluble protein) to in-hospital thrombolysis, the pre-hospital strategy was significantly associated with lower total mortality rates: 9.7% versus 11.1% (P=.03), respectively, but none of the trials used the thrombolytic alteplase or the bolus-type recombinants. The safety of pre-hospital or ambulance thrombolysis was also demonstrated in the ASSENT-3 PLUS study. (20) In that study, patients received the thrombolytic tenecteplase and either enoxaparin (an anticoagulant to prevent blood clots in the legs of patients) or unfractionated heparin (also an anticoagulant). To date, however, only 1 study (21) has compared primary angioplasty with pre-hospital thrombolysis.
Pre-hospital thrombolysis is not the practice standard in Ontario now.
New Technology Being Reviewed
Primary balloon angioplasty was developed as an alternative to thrombolysis, because it can be used where thrombolysis is contraindicated. In balloon or coronary angioplasty, a balloon catheter is inserted under the skin to reopen blocked coronary arteries and to maintain the patency with the subsequent placement of a coronary stent in a procedure called stenting. Since the advantages of angioplasty plus stenting over angioplasty alone have been established in randomized controlled trials (RCTs) (22-24), primary angioplasty at the time of MI is currently assumed to include the placement of a stent.
Primary angioplasty improves on 2 serious complications of thrombolytic therapy: the risk of reinfarction (having another MI) and the risk of intracranial hemorrhage (bleeding in the brain). During the procedure, the patient with STEMI is admitted to the cardiac catheterization lab without any prior thrombolysis, often bypassing the emergency department. In contrast to thrombolysis, primary angioplasty requires specialized training (interventional cardiology), specialized facilities (catheterization laboratories), and rapid referral systems from emergency departments.
Primary angioplasty results in higher rates of coronary patency and substantially less intracranial hemorrhage than thrombolysis.Nursing care During Primary Angioplasty Essay . It results in TIMI 3 flow in 46% to 97% of treated arteries. (25;26). The disadvantages of primary angioplasty are its geographical (i.e., access) constraints, its dependence on highly trained specialists, and its requirement for dedicated facilities.
There is also a well-documented relationship between procedure volume and patient outcomes, including mortality, with higher volume centres having better outcomes. (27-30) This is not the situation with thrombolysis, because no volume-outcome relationship has been shown. (29)
From these RCTs, researchers have concluded that primary angioplasty is the best reperfusion strategy for most patients with acute STEMI. However, some researchers (31) have argued that these studies have limited bearing on routine practice. These arguments are based on the wide variability in service delivery documented in registry studies and on variations between the ideal setting of clinical trials and the realities of practice. Modern trials of mechanical reperfusion strategies have had to account for logistics, transfer times, and adjunctive drug treatments during transfer. These complex issues pose questions as to the generalizability of these trials into standard practice so that primary angioplasty protocols need to be judged against earliest possible thrombolysis with modern agents.
Furthermore, researchers have noted that any delay in the decision to treat patients with thrombolysis as opposed to transferring them for primary angioplasty also affects outcomes. The terms “time to needle” or “door to needle” describe the time lapse between when a patient presents at a hospital emergency room and when he or she receives thrombolysis parenterally (by needle). This elapsed time measures the performance standard for thrombolysis: a door-to-needle time of 30 minutes or less is optimal.Nursing care During Primary Angioplasty Essay . The corresponding variable for primary angioplasty is “time to balloon.” Clinical trials (32;33) have shown better or similar rates of survival with primary angioplasty compared with thrombolysis for patients with STEMI who present early after symptom onset and who can receive angioplasty within 60 minutes of presenting. A recent study (34) reported that delays between symptom onset and treatment were associated with poorer mortality and morbidity in a large cohort of patients receiving angioplasty.
Generally, the use of stents and antiplatelet glycoprotein (GP) IIb/IIIa therapy in primary angioplasty has been supported by evidence from clinical trials (22;35-38) and by registry studies. (39) Adding GP IIb/IIIa to stenting in acute MI has also been supported by RCTs (40;41), to the extent that these are recognized standards of care. These 2 technologies are not always combined, however, because of the anatomy or morphology of the target arteries. To date, the benefits of including stents in acute MI procedures have been limited to the restenosis and revision rates, and have not affected the primary outcomes of mortality, reinfarction, and stroke, compared with balloon angioplasty alone
A Canadian database in British Columbia (42) that collected data from 1994 to 1997 documented improved clinical outcome after widespread use of coronary artery stenting for all angioplasty indications. The study showed that the use of stenting increased to 58.7% by the end of the study period, and it is likely to be significantly higher than this now.
Combined Thrombolysis and Angioplasty
There are different ways to combine angioplasty and thrombolysis to treat acute MI. Primary angioplasty is a special case of immediate or direct angioplasty to restore blood flow to a blocked artery. Nursing care During Primary Angioplasty Essay .Angioplasty can also be performed after thrombolytic therapy, either immediately (as soon as possible), a procedure called facilitated angioplasty, or a bit later in the post-MI period. These post-MI angioplasty procedures are classified as follows:
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Early angioplasty (within several hours or a few days after thrombolysis)
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Delayed angioplasty (within 4 or more days after thrombolysis)
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Rescue angioplasty (for persistent blockage of the infarct-related artery after thrombolysis) (43)
In rescue angioplasty, patients are catheterized only after thrombolysis is considered to have failed based on persistent STEMI. Usually, under these circumstances, patients are not rechallenged with thrombolysis, and patients are “crossed over” to angioplasty. Two trials examining the benefit of a second course of thrombolysis did not yield significant results. (44;45) These trials were performed in centres with emergency PCI services, and the thrombolytic drug was given upon presentation and diagnosis of the patient in the emergency department. Generally, facilitated angioplasty protocols may refer patients receiving thrombolysis for catheterization as soon as the thrombolytic administration is complete.
The term facilitated angioplasty has been used to refer to any version of primary angioplasty combined with thrombolysis, but it is precisely defined as treatment with low-dose thrombolytic drugs, platelet GP IIb/IIIa inhibitors, or both, prior to primary angioplasty. (46) The rationale for this approach is to provide the earliest possible pharmacologic reperfusion before attempting definitive mechanical revascularization of the infarct-related artery. Nursing care During Primary Angioplasty Essay .Four RCTs have compared facilitated angioplasty with primary angioplasty. (32;33;47;48) In a separate review, Keeley et al. (49) summarized these trials. They concluded that there has been no demonstrated benefit and noted increased bleeding complications.
O’Neill et al. (47) randomized patients either to primary angioplasty or to streptokinase (1.5 million units [MU]) administered intravenously over 30 minutes with facilitated primary angioplasty. The authors found no difference in mortality rates. Patients receiving facilitated angioplasty required fewer subsequent revascularization procedures (83% versus 92%) since these patients with sufficient reperfusion did not receive angioplasty after they underwent angiography. However, the group receiving facilitated angioplasty needed more emergency coronary artery bypass graft (CABG) surgery, had more vascular complications, and received more blood transfusions. Based on these events, and the difference in hospital costs associated with about 60 patients per arm, the authors did not recommend further study of the combination.
Vermeer et al. (32) justified adding a combined angioplasty and thrombolysis arm to their trial by stating that studies had not included a combined “rescue angioplasty” arm. Patients in the combined arm of this trial received thrombolysis with accelerated alteplase followed by transfer and rescue if indicated. All patients presented to a non-PCI centre and were either given thrombolysis on-site, given thrombolysis and transferred, or only transferred.
Scheller et al. (48) compared thrombolysis and immediate stenting with thrombolysis and delayed stenting. They found immediate stenting was associated with reduced rates of reinfarction and fewer complications. It also eliminated the need for unplanned angiography. The study was designed to accommodate centres that would treat acute MI by thrombolysis first and then refer patients to a PCI centre. The immediate referral came from hospitals within 35 kilometres of the PCI centre. After 6 months, rates of mortality were 4.9% for immediate PCI compared with 11.1% for delayed PCI. Rates of reinfarction were 2.4% for immediate PCI compared with 2.5% for delayed PCI. Rates of stroke were 2.4% for immediate PCI compared with 2.5% for delayed PCI. Because this was a small study, these rates were only significant when a combined end point that included ischemic events was used. Nonetheless, it suggests data supporting the combined approach of thrombolysis and referral to PCI are accumulating. Nursing care During Primary Angioplasty Essay .
A special case of facilitated angioplasty is when thrombolysis is combined with transfer for primary angioplasty. Several studies have evaluated this combination. The original PRAGUE study in the Czech republic (33) included a third arm of patients given thrombolytic agents and then transferred. Results showed patients randomized to thrombolysis before transfer for angioplasty bled more.
The guidelines of the American College of Cardiology/American Heart Association (50;51) require that a hospital perform 200 or more PCIs per year, that each physician perform 75 or more PCIs per year, and that door-to-balloon time be less than 120 minutes. The volume-provider relationships have been summarized by Boersma et al. (52)
Literature Review on Effectiveness
Objective
This literature search aimed to summarize existing health technology assessments, meta-analyses, and RCTs comparing primary angioplasty with thrombolysis to determine the absolute benefits of each for patient survival, adverse effects, and reinfarction. The secondary purpose, using this summary, was to model current practice in Ontario and to do a cost-benefit analysis, that is, to determine the benefits and costs that may accrue for the policy choices to expand primary angioplasty services in the province. The analysis was undertaken to assist the Ontario Health Technology Advisory Committee in making its recommendation to the Ministry of Health and Long-term Care regarding the use of primary angioplasty in the management of acute MI
RCTs are the evidence standard to determine the superiority of different therapeutic interventions to treat acute MI. Publications based on the provincial MI registry, data collected and maintained by ICES, and guidelines for acute MI comprise the evidence base to determine the model of practice in Ontario. Nursing care During Primary Angioplasty Essay .
Ontario, with its large mass, makes optimizing time to treatment for acute MI geographically challenging. This health technology assessment aimed to identify opportunities for real-world selection of patients for optimal treatment with angioplasty, and various types of thrombolysis. The search also sought to address studies that transported patients after randomization, as did Andersen et al. (1)
Questions Asked
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What is the pooled efficacy of primary angioplasty compared with thrombolysis to treat patients with acute STEMI?
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What is the status quo in Ontario?
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What incremental costs and patient outcome benefits are expected if access to the more effective technology is increased?
Methods: Literature Review
The methods used in this report were similar to those used in other reports of the Medical Advisory Secretariat. Existing health technology assessments and meta-analyses retrieved from an initial review of the literature were used to determine the starting point for subsequent formal searches for new evidence from RCTs. The literature review was also used to identify studies that characterized current practice patterns and emergent therapies targeted at the same patient population. Nursing care During Primary Angioplasty Essay .Overall, the methods comprised a formal search to update the list of RCTs, a meta-analysis of retrieved studies to estimate treatment differences, and a synthesis of practice reports and clinical guidelines to document the normative and consensus standards of care.
The formal literature search was designed to build and supplement the literature search conducted by Keeley et al. (53) In that report, the authors identified all published and unpublished randomized trials done up to 2002 that compared primary angioplasty with thrombolysis for acute STEMI. Their index search was limited to the MEDLINE database, supplemented by reviews of specific cardiology journals and contact with the principal investigators directly. For this analysis, MEDLINE, EMBASE, INAHTA, Cochrane, and NICE were searched.
The search was designed to include all randomized trials comparing primary angioplasty with thrombolysis, all meta-analyses of such studies, and all health technology assessments about primary angioplasty. The search excluded non-systematic reviews, commentaries, and letters.
Methods: Meta-Analysis
The literature search was designed to identify all trials published since the search by Keeley et al.(53) Published in Lancet early in 2003, that meta-analysis included citations up to 2002. This literature search began from there to include all publications published in 2002 and 2003. Because entire calendar years were specified, there were likely overlaps with the period used by Keeley and colleagues. Nursing care During Primary Angioplasty Essay .
Departing from the methods of those investigators, this meta-analysis excluded the 23rd study cited by them, the cardiac SHOCK trial (54) that enrolled high-risk patients with acute MI. High-risk patients were excluded from most trials in the entire sample, therefore this review excluded them too. This analysis also used a random-effects model, which assumes that, given a world of conditions, the effects of a study are only a sample, ideally random, of possible effects. It is considered more conservative and is recommended when trial protocols differ moderately, as these trials do.
For example, the 22 trials included in the sample had different cut-off points from time to presentation of between 6 and 12 hours. Some trials had age group restrictions. In some, different thrombolytic agents were used. The trials also differed over time: later trials tended to use newer thrombolytic agents, to include stenting in the primary angioplasty arms, and to include GP IIb/IIIa to varying degrees.
To confirm the adverse event rates reported in meta-analyses to date, the original articles of the selected studies were retrieved, and the event rates were checked. Where discrepancies appeared, the rates in the original publication were used. If the original paper could not be found, then the event rates used in at least 2 subsequent meta-analyses had to agree for the results to be included.
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From there, the authors of this review were able to specify what trials would be included in the Medical Advisory Secretariat’s meta-analysis. It’s worth noting that understanding the degree to which study populations reflect real patients and their outcomes is vital to determine how, or if, results are generalizable. Nursing care During Primary Angioplasty Essay .Therefore, the focus was on identifying trials with factors that best represent normative practice standards in Ontario and provincial clinical guidelines. Parameters to define the status quo for residents of Ontario were taken from the design elements of the RCTs identified. Thus, it was determined that trials had to have included, for the primary angioplasty arm, primary coronary stenting and the option of using GP IIb/IIIa. For the group receiving thrombolysis, patients had to have received the accelerated regimen of alteplase in the hospital and have been offered rescue angioplasty. Heparin and aspirin had to be have been offered to all patients as a matter of protocol, and antiplatelet agents had to be administered for at least 1 month after the MI. These parameters were consistent with the trial characteristics summarized by Keeley et al. (53)
Results of Literature Review
As noted in the methods, the Keeley et al. (53) meta-analysis was the starting point for the literature search to identify all trials that had been published since that study and that would otherwise have been included in a meta-analysis. An electronic search of the MEDLINE database (1966 to week 3, October 2003 yielded 140 citations. The details of the search strategy, with the keywords, are in Appendix 1. Similar searches of EMBASE and PREMEDLINE yielded 167 and 27 citations, respectively. Combining all results and eliminating duplicate citations yielded 289 citations that were then reviewed manually by reading their abstracts to identify RCTs comparing angioplasty with thrombolysis.
Only evidence from RCTs is summarized (Table 1). Trials with fewer than 100 patients per group, on average, were considered small RCTs. Consistent with the Keeley et al. meta-analysis, trials that included pre-hospital thrombolysis (e.g., the CAPTIM study) (21) were included if the group for comparison was primary angioplasty (or primary stenting). Nursing care During Primary Angioplasty Essay.
