ABSTRACT
ST-segment elevation myocardial infarction The fundamental work of Herzog et al5 was the initial observation that revealed the poor prognosis faced by patients with endstage renal disease (ESRD) who suffer from acute myocardial infarction (AMI). Using the US Renal Data System data base, the investigators examined the outcome of 34 189 patients on long-term dialysis after a first episode of AMI, and documented an in-hospital mortality of 26% and a dismal long-term survival. The 1-year and 2-year mortality rates for the entire cohort were 59% and 73%, respectively. It is noteworthy that most patients on dialysis, who had AMI, died of heart disease.These observations were confirmed by Chertow et al,6 who reported a 30-day mortality rate of 20% and a 1-year mortality rate of 53%, after AMI, in 640 patients with ESRD. Interestingly, 88% of the patients were treated with pharmacologic therapy alone, 7% with PCI, and 5% with coronary artery bypass grafting (CABG). Multivariate analysis showed only a trend toward a reduced risk of death in patients who underwent surgical revascularization. Thus, it is not possible to determine from this study whether percutaneous or surgical interventions are clearly superior or not to medical therapy alone in patients with ESRD after AMI. Beattie et al7 extended the investigation to patients with advanced renal dysfunction who were not on dialysis therapy. They analyzed a prospective coronary care unit registry of 1724 patients with STEMI admitted over an 8-year period at a single tertiary-care center. Patients were stratified into groups based on different corrected creatinine clearance (CrCl) values. A graded rise in in-hospital complications and death rate, as well as a reduction in long-term survival, were observed across increasing renal dysfunction strata. This study, as well as another by McCullough et al,8 showed a similar graded increase in the relative risk of atrial and ventricular arrhythmias, heart block, asystole, pulmonary congestion, and cardiogenic shock in parallel with progressive renal impairment. Moreover, the use of mortality-reducing treatments, including primary angioplasty, thrombolysis, and beta-blockers, decreased with the progressive decline of renal function, suggesting a treatment bias in favor of patients with less advanced renal dysfunction (Figure 5.1).While the lower rates of PCI may be rationally explained by the fear of an increased risk of CIN and of the associated high mortality rate, the potential risk of bleeding and hemodynamic complications constitutes only a partial justification for the less frequent use of thrombolysis and beta-blockers.
