HEART DOCTORS IN YELAHANKA NEWTOWN, BANGALORE
Management of ACS (NSTEACS)
Patients with this diagnosis represent a rather heterogeneous group. Some have had the recent
onset of angina at the extremes of exercise, others have angina at rest associated with ECG
changes. This variation has made attempts to study the effects of different treatment rather
difficult. Although the majority of patients with myocardial infarction have a preceding period
of unstable angina, only about 5% of all patients admitted to hospital with a diagnosis of an
ACS go on to infarct during that admission. The in-hospital mortality for these patients is low.
Mortality rates of less than 2% are usual. Nevertheless, there is a real short-term and longerterm
risk of infarction, recurrent admission with unstable symptoms and death which is higher
than that of patients with stable angina. The diagnosis should therefore lead to admission to
a CCU. The cardiac enzymes are, by definition, not elevated in these patients but the newer,
more sensitive tests for troponin T and troponin I may be abnormal and indicate a worse
In the CCU, bed rest, oxygen and ECG monitoring are routinely enforced and any mobile
phones taken away (allegedly to protect the monitoring equipment). Recurrence of chest pain
can be assessed quickly and ECGs performed to look for changes suggesting infarction. The
cardiac biomarkers can be checked regularly.
All patients should receive aspirin (300 mg) unless there is a contraindication. Patients
with an intermediate or a higher risk should also be given clopidogrel (usually a 300–600 mg
The use of intravenous heparin has become standard treatment. A typical starting dose is
5000 units as a bolus followed by 24, 000 units over 24 hours. The activated partial thromboplastin
time (APPT) should be measured after about six hours of treatment and the infusion
rate of heparin adjusted to maintain this at about twice normal. Heparin is generally safe when
used in this way. Bleeding problems may sometimes occur and the platelet count should be
checked every few days so that heparin-induced thrombocytopenia (HITS), a rare but serious
complication, can be detected early.
Low molecular weight heparins are at least as effective as unfractionated heparin.
These drugs have some advantages over heparin. Their dose response effect is more predictable
and they cause less thrombocytopenia. They are effective given subcutaneously without
APPT monitoring and are now cheaper than IV heparin when savings on APPT monitoring
and the use of infusion sets are considered. A standard twice-daily dose is given according to
the patient’s weight—1 mg/kg for enoxaparin (Clexane). The dose is reduced by half for those
with moderate or severe renal impairment and for those over the age of 75.
Additional treatment should include beta-blockers unless these are contraindicated.
These drugs reduce the number of ischaemic episodes and probably the risk of myocardial
Nitrates can be a useful adjunctive treatment. They may be given orally, topically or
intravenously. The IV dose can be titrated up or down depending on the amount of pain the
patient is experiencing and the severity of side effects such as hypotension and headache. The
problem of tachyphylaxis with nitrates can be overcome by steady increases in the IV dose
Calcium antagonists are appropriate treatment for patients intolerant of beta-blockers and may
sometimes be added to beta-blockers. Nifedipine, especially in its short-acting form, should not be
used for patients with acute coronary syndromes unless they are already taking beta-blockers.
Thrombolytic drugs have been disappointing when used for NSTEACS. In trials where
they have been used for patients with ischaemic chest pain but without ST elevation there has
been a trend towards an adverse outcome. This may be related to the rebound hypercoagulable
state that can occur after their use. In general they should not be used for the treatment
Glycoprotein IIb/IIIa inhibitors (p. 198) should be given for high-risk patients,