CLINICAL GUIDELINE .2. RISK STRATIFICATION AFTER MYOCARDIAL-INFARCTION

Purpose: To review the literature on risk stratification after acute m yocardial infarction in the reperfusion era and to propose an algorith m for early and continual risk assessment. Data Sources: A MEDLINE sea rch of the English-language literature on humans was done using the te rms myocardial infarction, prospective studies, and prognosis. This se arch was supplemented by narrowed searches for subheadings (such as ca rdiogenic shock, thrombolytic therapy, and stress testing) and surveys of references cited in review articles and book chapters. Study Selec tion: Literature on prognosis and myocardial infarction published from 1981 to 1996 was considered. From the literature on stress testing me thods, studies that enrolled patients before 1980, enrolled patients f or indications other than myocardial infarction, tested patients more than 6 weeks after infarction, were missing outcome data, or had inade quate follow-up were excluded. Data Extraction: Because too few random ized trials were available to allow the cross-comparison of risk strat ification methods, the available observational data were synthesized a nd supplemented with clinical judgments to produce recommendations. Da ta Synthesis: Risk stratification must begin when acute myocardial inf arction is diagnosed. High-risk patients (such as those with cardiogen ic shock) and candidates for reperfusion therapy must be identified qu ickly if ideal emergency care is to be given. At specific points durin g hospitalization, specialized tests may be useful if they add increme ntal information to the results of clinical evaluations. High-risk pat ients who have complications after infarction or significant left vent ricular dysfunction probably benefit from early angiography; patients without these conditions are at low risk for recurrent events and shou ld have noninvasive stress testing for further risk stratification. Co nclusions: Physicians should continually reappraise risk throughout ho spitalization to optimize both patient outcomes and cost containment.