UNSTABLE ANGINA

Definition: a change in anginal pattern typically characterized by one of the following: 1) CP at rest, 2) new onset, 3) acceleration of sxs (crescendo angina).

Spectrum of disease: acute coronary syndromes are a spectrum ranging from 1) chronic stable angina, to 2) unstable angina, to 3) NQWMI, to 4) QWMI.

Pathogenesis: vascular biology explains this spectrum

CSA USA MI

Risk assessment: prognostic factors guide aggressiveness of management

1. Pathogenetic grading

A. LOW risk- identifiable extracardiac cause

B. INTERMEDIATE risk- primary USA

C. HIGH risk- post-infarct angina

2. Severity grading

I. LOW risk- no rest pain

II. INTERMIDIATE risk- no pain in 48hrs

III. HIGH risk- pain w/in 48hrs

Quantitative risk assessment for USA

Path/Severity	A. Extracardiac	B. Primary	C. Post-MI
I. Exertional	1	4	7
II. Resting, >48hrs	2	5	8
III. Resting, <48hrs	3	6	9

3. Other risk factors

a. likelihood of disease

b. severity/duration

c. EKG

d. enzymes

e. LV function

Treatment: (“Supply and Demand”)

1. Anti-ischemics: bedrest, nitrates, beta-blockers, CaCB

2. Antithrombotics

a. ASA- decr MI 70%

b. Ticlid- decr MI 46%

c. Heparin- decr MI 3-7(0.8%

d. GP IIb/IIIa antagonists (abciximab, eptifibutide, lamfiban, tirofiban)- additional 9% decr MI

3. Angiography/revascularization

a. TIMI-3b: 1473 pts randomized to early intervention vs. medical management.

b. No difference in outcome, BUT 64% cross-over. Cross-over criteria: 1) recurrent CP w/ ST changes, 2) >20 min isch ST changes on holter, 3) +sub-max ETT.

Therapies for USA

RISK	HIGH (7-9)	INTERMED (6)	LOW (1-5)
THERAPIES	IV TNG Beta-blockers CaCB ASA Heparin GPIIb/IIIa Cath	Nitrates Beta-blockers ASA Heparin GPIIb/Iia ?Cath	Nitrates Beta blockers ASA ?Cath

Theroux, Fuster. Circulation. 97:1195-1206, 1998.