Effect of renal function on ultrasonic coronary plaque characteristics in patients with acute myocardial infarction.

We used intravascular ultrasonography to assess plaque morphology and morphometry in 310 patients with acute myocardial infarction (125 with ST-segment elevation and 185 with non-ST-segment elevation myocardial infarction) with varying degrees of renal dysfunction according to the creatinine clearance (CrCl): CrCl >70 ml/min in 153, CrCl of 30 to 69 ml/min in 103, and CrCl of <30 ml/min in 54 patients, including 20 patients requiring dialysis). The lesion site plaque burden was greatest (77.4 +/- 11.0% vs 79.8 +/- 12.5% vs 82.0 +/- 10.3%, p = 0.031) and the lesion was longest (20.9 +/- 9.1 vs 23.1 +/- 9.5 vs 26.3 +/- 9.6 mm, p = 0.038) in the lowest CrCl group. Infarct-related artery plaque rupture (31.4% vs 34.0% vs 53.7%, p = 0.011) and multiple plaque ruptures (11.1% vs 12.6% vs 33.3%, p <0.001) were the most common, the ruptured plaque cavities were the largest (1.98 +/- 0.89 vs 2.20 +/- 1.45 vs 3.06 +/- 1.70 mm(2), p = 0.002), and the ruptured plaque was longest (2.33 +/- 0.93 vs 2.59 +/- 1.50 vs 3.33 +/- 1.76 mm, p = 0.008) in the lowest CrCl group (<30 ml/min). Intravascular ultrasound-detected thrombus was observed most frequently in the lowest CrCl group (22.9% vs 23.3% vs 40.7%, p = 0.027). CrCl was the one of the independent predictors of culprit lesion plaque rupture (odds ratio 0.979, 95% confidence interval 0.963 to 0.994, p = 0.008). During 1 year of follow-up, the incidence of nonfatal myocardial infarction (2.6% vs 4.9% vs 11.1%, p = 0.044) and cardiac death (3.9% vs 6.8% vs 14.8%, p = 0.024) was greatest in the lowest CrCl group. Also, a strong trend was found toward the greatest incidence of stent thrombosis (2.0% vs 3.9% vs 9.3%, p = 0.057) in the lowest CrCl group. In conclusion, patients with acute myocardial infarction and significant renal dysfunction had more plaque vulnerability compared to those with normal renal function. This might be associated with poor clinical outcomes in patients with acute myocardial infarction and renal dysfunction.