Читать книгу Practical Cardiovascular Medicine - Elias B. Hanna - Страница 35

Table 1.3 Summary of antithrombotic therapy in ACS.

Antiplatelet therapy

1.Aspirin 325mg on admission to all, then 81 mg daily (after a 325mg first dose)

2.Clopidogrel 300mg or ticagrelor 180mg may be used on admission, but in the era of expedite catheterization <24 hours, ADP receptor antagonists are best reserved for downstream use, during PCI

3. After coronary angiography, if PCI is to be performed:

Add 300 mg of clopidogrel if 300 mg has already been given

or load with 600 mg of clopidogrel in the lab if no clopidogrel has been given

or load with prasugrel 60 mg (even if clopidogrel has been given)

or load with ticagrelor 180 mg (even if clopidogrel has been given)

or infuse IV cangrelor for 2 hours, not if patient already received P2Y12-antagonist, then load with oral P2Y12-antagonist as infusion finishes

GPI if PCI complications or heavy thrombus burden (bailout use of GPI)

Anticoagulant therapy

UFH pre-catheterization and during PCI

or UFH pre-catheterization and switch to bivalirudin during PCI

or Fondaparinux 2.5mg SQ once daily pre-catheterization, with standard-dose UFH or bivalirudin during PCI

or Enoxaparin pre-catheterization. If patient received 1 mg/kg SQ within 8h of PCI and has already received two doses of enoxaparin, no additional anticoagulation is needed during PCI (if enoxaparin was used 8–12 h ago or only one SQ dose was given, add 0.3 mg/kg IV during PCI; if enoxaparin was used >12h ago, give 0.5–0.75mg/kg IV bolus)

Note: Avoid switching between UFH and enoxaparin. The switch to bivalirudin is, however, appropriate.

1 β -Blocker, such as oral metoprolol, is administered at a dose of 25 mg Q8–12 h and titrated to 50 mg Q8–12 h if tolerated. In the COMMIT-CCS trial, the initiation of β-blockers on the first day of ACS (mainly STEMI) was associated with an increased risk of cardiogenic shock during that first day, the benefit from β-blockers on reinfarction and VF emerging gradually beyond the second day.⁷³ Overall, β-blockers significantly reduced the endpoint of death/MI/cardiac arrest between day 2 and day 15, but increased this endpoint in the first day and in unstable patients, making the overall β-blocker effect neutral. Therefore, β-blockers should be avoided on the first day if there are any HF signs or features predictive of cardiogenic shock: SBP < 120 mmHg, heart rate > 110 bpm, or age > 70 years.^* Counterintuitively, β-blockers are avoided in sinus tachycardia, which is often a pre-shock state. Moreover, intravenous β-blockers are preferably avoided in all patients, as this was the formulation used in COMMIT-CCS on the first day, but may still be used in a patient with active ischemia and none of the previous features (IV metoprolol, 5 mg Q10 min up to 3 times).

2 ACE-Is or ARBs are recommended in ACS patients with HF, LV dysfunction, hypertension, or diabetes (class I indication). They may also be used in ACS patients who do not have these features (class IIa indication). They are avoided in acute renal failure or when SBP is < 100 mmHg or 30 mmHg below baseline.

3 Statin therapy should be started during ACS hospitalization regardless of the baseline LDL. Statin’s benefit is not usually immediate but may become evident within 1 month.⁷⁴ A more immediate benefit is seen in patients undergoing PCI, as high-dose statin reduces peri-PCI MI.⁷⁴ The high doses used in secondary prevention trials, such as atorvastatin 80 mg in the PROVE-IT trial, are preferred as they further reduce cardiovascular events (including death/MI) and peri-PCI MI, possibly through superior stabilization of vulnerable plaques. Note that, for patients receiving chronic statin therapy, the harm from statin withdrawal is immediate, with an early cardiac risk that is higher than that of statin non-users.⁷⁵

4 Nitroglycerin (NTG) is administered sublingually for chest pain (as needed, Q5 min up to three times if tolerated). NTG should be avoided if SBP < 100 mmHg or 30 mmHg below baseline, or bradycardia < 50 bpm. Acutely in ACS, one can give NTG at a lower BP level than one can give β-blockers. Later on, in case of borderline BP, the priority is given to β-blocker administration.IV NTG is indicated for frequently recurrent angina, ongoing angina, or ischemia associated with hypertension or HF. Angina that is not relieved by 400 mcg of sublingual NTG may not be relieved by the smaller infusion dose of IV NTG (10–200 mcg/min); the latter may however be tried, in conjunction with β-blockers and antithrombotic therapy. IV NTG is initiated at 10 mcg/min and increased by 10 mcg/min every 3–5 minutes until symptoms are relieved or a limiting reduction of SBP < 100–110 mmHg occurs. Oral or topical nitrates (patch, paste) are acceptable alternatives in the absence of ongoing angina. After stabilization, IV NTG may be converted to an oral or topical nitrate, with a dosing that prevents tolerance and leaves a 12-hour nitrate-free interval (e.g., isosorbide dinitrate 10–40 mg or nitropaste 0.5–2 inches at 8 a.m., 2 p.m. and 8 p.m.).

5  Morphine may be given for angina that is refractory to the above after a decision is made as to whether emergent revascularization will be performed or not. Thus, morphine should not be used to mask “refractory angina,” and resolution of a true angina only after morphine administration should not defer the emergent performance of coronary angiography ± PCI.

6 Calcium channel blockers. Dihydropyridines (DHPs) are vasodilators (nifedipine, amlodipine). Non-dihydropyridines are vasodilators that also have negative ino- and chronotropic effects (verapamil, diltiazem). Short-acting DHPs, such as nifedipine, lead to reflex tachycardia and should be avoided in ACS; long-acting DHPs may be used in ACS in combination with β-blockers. Non-DHPs may be used in ACS if β-blockers are contraindicated and LV systolic function is normal; as opposed to DHPs, they should generally not be combined with β-blockers.

7 Aldosterone antagonist reduces short-term (30 days) and long-term mortality when initiated in MI patients with EF<40%, at 3-7 days (EPHESUS trial). However, its acute initiation in the emergency department in MI with EF>40% was not beneficial (ALBATROSS trial).⁷⁶