Acute myocardial infarction and renal dysfunction: A high-risk combination

Background: Survival is poor in patients with acute myocardial infarction (MI) who also have severe renal disease. Less is known about the outcome of acute MI in patients with mild to moderate renal insufficiency. Objective: To compare outcomes after acute MI in patients with varying levels of renal disease and in patients without renal failure. Design: Retrospective cohort study. Setting: Academic medical center. Patients: 3106 total patients admitted with acute MI and end-stage renal disease (n = 44), severe renal insufficiency (creatinine clearance < 0.59 mL/s [<35 mL/min]) (n = 391), moderate renal dysfunction (creatinine clearance ≥ 0.59 mL/s [<35 mL/min] but ≤0.84 mL/s [≤50 mL/min]) (n = 491), mild chronic renal insufficiency (creatinine clearance > 0.84 mL/s [>50 mL/min] but ≤1.25 mL/s [≤75 mL/min]) (n = 860), or no renal disease (n= 1320). Measurements: Clinical characteristics, treatment strategies, and short- and long-term survival were compared after patients were stratified by creatinine clearance. Results: In-hospital mortality rates were 2% in patients with normal renal function, 6% in those with mild renal failure, 14% in those with moderate renal failure, 21% in those with severe renal failure, and 30% in those with end-stage renal disease (P< 0.001). Compared with patients without renal disease, similar adjusted trends were present for postdischarge death in patients with end-stage renal disease (hazard ratio, 5.4 [95% Cl, 3.0 to 9.7]; P < 0.001), severe renal insufficiency (hazard ratio, 1.9 [Cl, 1.2 to 3.0]; P = 0.006), moderate renal dysfunction (hazard ratio, 2.2 [Cl, 1.5 to 3.3]; P < 0.001), and mild chronic renal insufficiency (hazard ratio, 2.4 [Cl, 1.7 to 3.3]; P < 0.001). Patients with renal failure received adjunctive and reperfusion therapies less frequently than those with normal renal function (P < 0.001). Postdischarge death was less likely in patients who received acute reperfusion therapy (odds ratio, 0.7 [Cl, 0.6 to 0.9]), aspirin (odds ratio, 0.7 [Cl, 0.5 to 0.8]), and β-blocker therapy (odds ratio, 0.7 [Cl, 0.6 to 0.9]). Conclusion: Patients with renal failure are at increased risk for death after acute MI and receive less aggressive treatment than patients with normal renal function.