Time to treatment of acute myocardial infarction revisited.

Time to treatment in acute myocardial infarction (MI) has been of great interest since the advent of thrombolytic therapy. The paradigm that has emerged is that rapid achievement of reperfusion, with either thrombolysis or primary angioplasty, minimizes infarct size, reduces the degree of left ventricular dysfunction, and improves survival. Recent studies have confirmed the benefit of reducing time to treatment with thrombolysis (between onset of pain to initiation of thrombolysis) and that of more rapid drug reperfusion time with more aggressive thrombolytic regimens (between initiation of thrombolytic therapy and actual achievement of reperfusion). Furthermore, their effects are additive (and in some cases synergistic), confirming the benefit of rapid reperfusion. For primary angioplasty, the same relationship has been observed: More rapid treatment seems to be associated with improved outcome. The "door-to-balloon" time is a major determinant of overall time to reperfusion and, as such, is a crucial component of the overall strategy. This paradigm can also be extended to the prehospital phase of treating acute MI in two ways: 1) for patients to rapidly identify the symptoms of acute MI and to present earlier to the hospital is critical in reducing overall time to treatment and 2) in emergency medical care, rapid identification of MI patients, electrocardiographic monitoring, and defibrillation as needed for ventricular arrhythmias has been shown to be lifesaving. Thus, time to treatment in the current era of aggressive management of acute MI extends far beyond the original description to every aspect of acute MI care.