Recurrent myocardial ischemia following thrombolytic therapy: guidelines for practicing clinicians.

The natural history of patients with acute myocardial infarction treated with thrombolytic therapy includes two distinct phases: the initial or acute phase is characterized pathologically by atheromatous plaque rupture and thrombotic coronary arterial occlusion, and clinically by the abrupt onset of symptoms. Prompt restoration of coronary blood flow and myocardial reperfusion during this phase, achieved in a majority of patients given thrombolytic therapy, limits myocardial necrosis, preserves ventricular function, and lowers mortality. Although the thrombus can be pharmacologically removed, an unstable anatomic substrate persists. Therefore following thrombolytic therapy, a subacute phase occurs, during which patients are at risk for recurrent ischemic events. More than a theoretical concept, experience has shown that recurrent ischemia and reinfarction develop in 20% to 30% and 5% of patients, respectively. Morbidity and mortality are elevated considerably in these patients, dictating an aggressive diagnostic and treatment approach.