New ACS Rules
A brief overview of the newest guidelines for treatment of ACS in the elderly, as put forth by the AHA and the ACC.
When it comes to the care of the elderly with acute coronary syndrome, there have been a few impediments in providing them with the most up-to-date therapies. Most trials have been geared toward the younger than 65-year-old group, with men as the main subjects. The patients enrolled in trials are different from the heterogeneous community elderly, who tend to have more co-morbidities. Physicians have been slow in their aggressiveness to treat the elderly because of their atypical presentations (chief complaints other than chest pain), non-diagnostic ECG’s, delay in presentation, co-morbidities, polypharmacy, decreased renal function, and age-related changes in the cardiovascular system and their higher morbidity and mortality from ACS. Yet, the evidence points toward aggressive treatment for the elderly as they have the most to gain in the first place.
The following is a summary of the latest AHA/ACC recommendations for the care of the elderly with Non-ST-Segment-Elevation Acute Coronary Syndromes (NSTE ACS) and ST-Segment-Elevation Myocardial infarction (STEMI). The elderly patient with either NSTE ACS or STEMI must be taken in the perspective of their altered physiology, pharmacodynamics, co-morbidities and the atypical presentations of their ACS symptoms.
For the management of NSTE ACS, aspirin (ASA) 81mg to 325mg remains a central theme (22% reduction in non-fatal MI; 22% lower death rate after an MI). Clopidogrel 75mg (Class I recommendation) in addition to ASA has added a 20% reduction in cardiovascular mortality, nonfatal MI, and stroke at 1 year). Patients undergoing percutaneous coronary intervention (PCI) benefit more from Clopidogrel. The elderly, being a high-risk group, enjoy a higher benefit from the use of aspirin. In patients 63 years old and younger, Antithrombin therapy in the form of weight-based unfractionated heparin (UFH) has shown a 34% reduction in mortality or MI rate and Low-molecular-weight-heparins (LMWH) have resulted in a 61% decline in mortality. However, the efficacy of UFH and LMWH has not been established in the elderly. The glycoprotein (GP) IIb/IIIa inhibitors, which prevent recurrent coronary events, are favorably added to aspirin and heparin in patients undergoing cardiac catherization and PCI (Class I recommendation). Monitor creatinine clearance and beware of bleeding, especially in the older than 75 group since most of the elderly thus treated receive an excess dosage. The current guidelines favor an early invasive approach to ACS in those at risk for recurrent angina, ischemia with mild activity despite treatment, elevated cardiac markers, CHF, a low ejection fraction (<40%), prior coronary revascularization or PCI in the last 6 months. The elderly subgroup benefits the most, however, patient selection, patient preference and risk/benefit ratio (bleeding versus therapeutic improvement) must be weighed in such difficult cases.
The AHA guidelines for STEMI as well as for NSTE ACS recognize the same factors that negatively affect the elderly. Fibrinolytic therapy and PCI reduce mortality and should be provided within 12 hours of symptom onset if no contraindications exist. Fibrinolytic therapy is useful up to the age of 85. The guidelines favor PCI over fibrinolytic therapy as being safer when compared to half-dose thrombolytics. It is encouraged especially in the setting of shock, past 6 hours the onset of symptoms, and it salvages myocardium even past 12 hours of symptoms. PCI is a good alternative in the absence of ST elevation or persistent chest pain. Within 3 hours of symptom onset, the results are similar for PCI and fibrinolytic therapy. Adjunctive therapy calls for oral beta blockers while intravenous beta blockers need to be used with caution in the elderly because of higher incidence of CHF and shock. The evidence supports the long use of beta blockers up to the age of 90 years old.
ACE-inhibitors and angiotensin receptor blockers are useful especially in the elderly with CHF and low ejection fraction. Statins help reduce recurrent MI regardless of age and are more beneficial in the elderly than the younger population at risk. Nitrates have been found to be beneficial in the >/70 years old especially if accompanied by persistent or recurrent ischemia, pulmonary congestion or hypertension.
The AHA/ACC guidelines conclude that trials need to incorporate more elderly community participants in subgroups, with specific end points. Age should not be the sole criterion for exclusion from trials. The potential candidate must be evaluated in terms of comorbidities, frailty, and cognitive status. Patient and family preferences must be taken into account during care for ACS. Many questions still remain regarding the oldest old (>85 years old). One must keep in mind that the elderly are not just older adults, just like children are not little adults. They are a unique group with unique problems.
Fitzgerald Alcindor, MD, is a clinical assistant professor at the NYU School of Medicine and the assistant ED director at North Shore University Hospital, Forest Hills, New York.