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Management of Acute Myocardial Infarction

Nitroglycerin

Mononitrates alone and in combination with other agents (Captopril and Mg) on mortality in the thrombolytic era. GISSI 3 examined the impact of IV and transdermal nitrates alone and in combination with lisinopril on mortality.

There was no difference in mortality between treated and control patients in these two large mycardial studies.

In ISIS-4 the small benefit of 2.5 lives saved per 1,000 patients treated with nitrates was maintained by 6 months. There was no difference in the incidence of reinfarction, post MI angina, CHF and stroke in the control.

Previous meta-analytic data showing a benefit for nitrates was seen in the pre-thrombolytic era.

Clearly there is no large mortality benefit of nitrates in the thrombolytic era, but a small benefit on the order of 2.5 lives/1,000 cannot be excluded.

Nitrates remain useful in the treatment of refractory chest pain, in lowering the wedge pressure, and in lowering peripheral vascular resistance.

Magnesium: heart attack

Potential mechanism of benefits:

Reduced incidence of arrhythmias

Decreased peripheral vascular resistance

Dilates coronary arteries in vivo and in vitro

Decreases platelet aggregation

Protects against catecholamine induced myocardial necrosis

May protect against reperfusion injury and heart attack

Meta-analytic data had shown a 25% reduction in mortality in patients treated with Mg, benefit thought to be independent of thrombolytic therapy.

Benefit of Mg tested in two recent trials:

Pooled Results of Recent Large Magnesium Trials Heart Attack