The AHA Guidelines and Scientific Statements Handbook

The AHA Guidelines and Scientifi c Statements Handbook

The recommendation for beta-blockade in these

new guidelines now is counterbalanced with a state-

ment on the potential for harm, especially with

acute IV administration in those at risk of heart

failure or cardiogenic shock (COMMIT Study) [10].

Nonsteroidal anti-infl ammatory drugs (NSAIDs)

other than aspirin should be avoided in UA/NSTEMI

patients because of the recent recognition of poten-

tial harm [11,12]. Contemporary thienopyridine

use (primarily with clopidogrel) is emphasized,

including higher loading-dose options [13], earlier

(upstream) administration, and longer duration

administration (especially after drug-eluting stent

placement) (see Figure 2.3) [14].

Two new anticoagulants, fondaparinux [15] and

bivalirudin [16], are recommended as alternatives to

unfractionated heparin (UFH) and low-molecular-

weight heparins (LMWHs) for specifi c applications

(see Figures 2.4–2.7). Special emphasis is placed on

dosing adjustment (e.g., for anticoagulants and anti-

platelet agents) based on creatinine clearance, espe-

cially in the elderly, in women, and in patients with

baseline renal insuffi ciency, to prevent dosing errors

leading to increased bleeding risk [17]. The guide-

lines also incorporate recent updates for secondary

and primary prevention (Table 2.3) [18]. An

Table 2.1 TIMI risk score for unstable angina/non-ST elevation MI

TIMI risk score

All-cause mortality, new or recurrent MI, or severe recurrent ischemia requiring urgent

revascularization through 14 d after randomization

0–1 4.7%
2 8.3%
3 13.2%
4 19.9%
5 26.2%
6–7 40.9%

The TIMI risk score is determined by the sum of the presence of seven variables present at admission; one point is given for each of the following variables:

• Age 65 y or older


• At least 3 risk factors for CAD


• Prior coronary stenosis of 50% or more*


• ST segment deviation on ECG presentation


• At least 2 anginal events in prior 24 h


• Use of aspirin in prior 7 d


• Elevated serum cardiac biomarkers

• Variable remained relatively insensitive to missing information and remained a signifi cant predictor of events.
  From Antman EM, Cohen M, Bernink PJ, et al. The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision
  making. JAMA. 2000;284:835–42.

50

20

10

5

(^2) A
D
C
Multiples of the upper
reference limit
B
1
(^0) 12 3
Days after onset of acute MI
4567
Upper reference limit
8
Fig. 2.1 Timing of release of biomarkers following acute
myocardial infarction. Peak A, early release of myoglobin after acute
MI; peak B, cardiac troponin after “classic” acute MI (frequently
seen with ST-elevation MI); peak C, CK-MB after acute MI; peak D,
cardiac troponin after “microinfarction” (typically seen after
NSTEMI). Data are plotted on a relative scale, where 1.0 is set at
the upper reference limit. AMI, acute myocardial infarction; CAD,
coronary artery disease; CK, creatine kinase. Modifi ed from WU AH,
et al. Clin Chem. 1999;45:1104–121 and Antman EM. Decision
making with cardiac troponin tests. N Engl J Med.
2002;346:2079–82.
events. An overview of emerging data suggests that
an initial conservative strategy may be considered in
low-risk ACS patients, and is preferred in particular
in low-risk women [7–9].