A Textbook of Clinical Pharmacology and Therapeutics

MANAGEMENT OFSTAB LEANGINA 197

order to prevent pain. Alternatively, long-acting nitrates (e.g.
isosorbide mononitrate) may be taken regularly to reduce the
frequency of attacks. Beta-blockers (usually of the ‘cardiose-
lective’ type, e.g. atenolol, metoprolol or bisoprolol) or
calcium-channel blockers (most commonly diltiazem, less
commonlyverapamilor one of the dihydropyridine drugs,
such as nifedipineoramlodipine) are also useful for chronic
prophylaxis (see below). Nicorandil combines nitrate-like
with K-channel-activating properties and relaxes veins and
arteries. It is used in acute and long-term prophylaxis of
angina, usually as an add-on to nitrates, beta-blockers and/or
calcium-channel blockers where these have been incompletely
effective, poorly tolerated or contraindicated. Statins (e.g. sim-
vastatinoratorvastatin) should be prescribed routinely for
cholesterol lowering unless there is a contraindication, regard-
less of serum cholesterol (unless it is already very low: total
cholesterol 4 mmol/L and/or LDL cholesterol 2 mmol/L), as
numerous large studies have shown prognostic benefit in terms
of prevention of cardiac events and reduction in mortality.

CONSIDERATION OF SURGERY/ANGIOPLASTY

Cardiac catheterization identifies patients who would benefit
from coronary artery bypass graft (CABG) surgery or percu-
taneous coronary intervention (PCI, which most commonly
involves balloon angioplasty of the affected coronary arteries
with concomitant stent insertion). Coronary artery disease is
progressive and there are two roles for such interventions:

1. symptom relief;
   2.to improve outcome.

CABG and PCI are both excellent treatments for relieving the

symptoms of angina, although they are not a permanent cure

and symptoms may recur if there is restenosis, if the graft

becomes occluded, or if the underlying atheromatous disease

progresses. Restenosis following PCI is relatively common,

occurring in 20–30% of patients in the first four to six months

following the procedure, and various strategies are currently

under investigation for reducing the occurrence of restenosis;

one very promising strategy involves the use of ‘drug-eluting’

stents (stents which are coated with a thin polymer containing a

cytotoxic drug, usually sirolimusorpaclitaxel, which sup-

presses the hypertrophic vascular response to injury). PCI as

currently performed does not improve the final outcome in

terms of survival or myocardial infarction, whereas CABG can

benefit some patients. Those with significant disease in the left

main coronary artery survive longer if they are operated on and

so do patients with severe triple-vessel disease. Patients with

strongly positive stress cardiograms have a relatively high inci-

dence of such lesions, but unfortunately there is no foolproof

method of making such anatomical diagnoses non-invasively,

so the issue of which patients to subject to the low risks of inva-

sive study remains one of clinical judgement and of cost.

Surgical treatment consists of coronary artery grafting with

saphenous vein or, preferably, internal mammary artery (and

sometimes other artery segments, e.g. radial artery) to bypass

diseased segment(s) of coronary artery. Arterial bypass grafts

have a much longer patency life than vein grafts, the latter

usually becoming occluded after 10–15 years (and often after

much shorter periods). PCI has yet to be shown to prolong life

in the setting of stable angina, but can be valuable as a less

demanding alternative to surgery in patients with accessible

Assess risk factors

Investigations: full blood count (exclude polycythaemia, either primary or secondary

to smoking, thrombocythaemia), plasma glucose and lipid profile

Aspirin 75 mg daily

Statin therapy

Modification of risk factors

Trial of anti-anginal medication

No significant improvement in symptoms

REFER TO CARDIOLOGIST

OR CHEST PAIN CLINIC

Adequate control of symptoms

Adequate control of risk factors

ANNUAL REVIEW

(Assessment of pain, risk factors)

Worsening of symptoms

or risk factors Figure 29.1:General management of stable

angina.