Page 542 - Cardiac Nursing

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518 PA R T IV / Pathophysiology and Management of Heart Disease

Table 22-3 ■ AMERICAN COLLEGE OF CARDIOLOGY/AMERICAN HEART ASSOCIATION GUIDELINES FOR SELECTING A
REPERFUSION STRATEGY
Step 1: Assess time and risk
• Time since onset of symptoms
• Risk of STEMI
• Risk of fibrinolysis
• Time required for transport to a skilled PCI laboratory
Step 2: Determine if fibrinolysis or invasive strategy is preferred
If presentation is less than 3 hours and there is no delay to an invasive strategy, there is no preference for either strategy
Fibrinolysis is generally preferred if: An invasive strategy is generally preferred if:
• Early presentation (3 hours from symptom onset and delay to • Skilled PCI laboratory available with surgical backup
invasive strategy) (see below) Medical contact-to-balloon or door-to-balloon time is 90 minutes
• Invasive strategy is not an option (Door-to-balloon)-(door-to-needle) time is 1 hour
Catheterization laboratory occupied/not available
Vascular access difficulties • High risk from STEMI
Lack of access to a skilled PCI laboratory Cardiogenic shock
• Delay to invasive strategy Killip class is 3
Prolonged treatment • Contraindications to fibrinolysis including increased risk of bleeding and
intracranial hemorrhage
(Door-to-balloon)-(door-to-needle) is 1 hour • Late presentation
Medical contact-to-balloon or door-to-balloon is 90 minutes Symptom onset was 3 hours ago
• Diagnosis of STEMI is in doubt

From Boden, W. E., Eagle, K., & Granger, C. B. (2007). Reperfusion strategies in acute ST-segment elevation myocardial infarction: A comprehensive review of contemporary man-
agement options. Journal of American College of Cardiology, 50(10), 917–929.
From Antman, J. L., Anbe, D. T., Armstrong, P. W., et al. (2004). ACC/AHA Guidelines for the Management of Patients with ST-elevation Myocardial Infarction: A report of the
American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients
with Acute Myocardial Infarction). Journal of American College of Cardiology, 44, 671–719.4 4

3
Optimizing Door-to-Balloon or trical stability, and encourage collateral vessel growth. However, in
Medical Contact-to-Needle Time patients with persistent total occlusion of the infarct-related artery
3 to 28 days after the acute event, there was no delayed benefit of
2
The current ACC/AHA STEMI Guidelines are based on clinical PCI over optimal medical therapy alone (aspirin, -blockers,
data that support the time-dependent nature of myocardial necro- ACEI, and statins), and therefore no support for PCI outside the
21
sis. A delay in time-to-treatment (PCI or fibrinolysis) translates therapeutic window in an asymptomatic patient following
directly to increased mortality. 11 To improve the quality of STEMI. 3,12
STEMI care, there has been increased focus on strategies that both
increase access to primary PCI and improve time-to-treatment Pharmacological
with particular emphasis on door-to-balloon time. Strong clinical Reperfusion/Fibrinolytic Therapy
evidence supports the early-open-artery hypothesis 12 of the im-
portant relation between achieving prompt antegrade blood flow The development of pharmacological fibrinolytic agents to restore
of the infarct artery and improved clinical outcomes for both fib- coronary blood flow was based on the science and clinical research
rinolysis 13–15 and primary PCI. 16–20 Door-to-balloon time is one that identified the pathogenesis of STEMI. DeWood et al. who
of the performance measures regarding quality of care for performed coronary angiography in patients with STEMI found
STEMI. 2,3 The goal of EMS is to facilitate rapid recognition and that 85% had thrombotic coronary artery occlusion in the early
treatment of patients with STEMI and implement quickly the hours of transmural MI. 22 Rentrop et al. demonstrated acute
most appropriate reperfusion strategy. Thus, the ACC/AHA reperfusion of occluded infarct arteries with streptokinase. 23 The
2
Guidelines recommend that all hospitals have established multi- Western Washington randomized trial of intracoronary streptoki-
disciplinary teams to develop guideline-based, institution-specific nase 24 and the Netherlands Interuniversity Cardiology Institute
written protocols for triaging and managing patients who present trial 25 stimulated the intense interest in fibrinolytic therapy. Fib-
with symptoms suggestive of myocardial ischemia. Specific goals rinolytic therapy has been developed over the last two decades and
are to implement door-to-needle time (or medical contact-to- shown to restore infarct artery patency, reduce infarct size, pre-
needle time) of 30 minutes for initiation of fibrinolytic therapy, or serve LV function, and decrease mortality in patients with
door-to-balloon time (or medical contact-to-balloon time) within STEMI. 26 Patients with STEMI who receive fibrinolytic therapy
90 minutes for primary PCI. STEMI patients presenting to a fa- have better short- and long-term survival when treatment is insti-
cility without the capability for expert, prompt intervention with tuted rapidly, with early reestablishment of flow within 2 to
primary PCI within 90 minutes of first medical contact should 3 hours after onset of symptoms. Little benefit is seen with fibri-
undergo fibrinolysis within 30 minutes unless contraindicated. nolytic therapy after 12 hours, which is theorized to be related to
(Class I, level of evidence: B) 3 thrombus organization within the coronary artery over time and
The late-open-artery hypothesis proposed that late reestablish- loss of an opportunity for restoration of blood flow and myocar-
ment of antegrade flow would improve LV function, enhance elec- dial salvage. 27