Faculty Bibliography

BACKGROUND: Individuals with chronic kidney disease (CKD) have high rates of myocardial infarction (MI), but whether the nature of coronary lesions susceptible to plaque rupture is altered and whether the high rate of MI is related to a greater burden of atherosclerotic lesions in individuals with CKD is uncertain. METHODS: We used quantitative coronary angiography to assess atherosclerotic plaque location and characteristics at baseline and at the time of MI in 62 patients with and without CKD. Univariate and multivariable conditional logistic regression models were used to assess whether the association between pre-MI angiographic findings and MI differs in individuals with and without CKD. RESULTS: The risk of MI rose as the distance from the coronary ostium decreased both in patients with CKD (odds ratio per 10 mm 0.92 [95 % CI 0.87-0.99]) and in those without CKD (odds ratio 0.83 [95 % CI 0.75-0.93]). Although tighter degrees of coronary stenosis were associated with increased risks of MI in patients with and without CKD, the majority of MIs (70.9 % in patients with CKD and 89.5 % in those without CKD) occurred in segments with <50 % diameter stenosis at baseline. CONCLUSIONS: The characteristics of lesions progressing to MI are similar in individuals with and without CKD and the majority of events occur in areas with <50 % stenosis at baseline. Given the high burden of non-stenotic lesions in patients with CKD, an interventional strategy aimed solely at sites with high-grade stenosis is unlikely to markedly reduce the risk of MI in patients with CKD.

Patients with chronic kidney disease have high rates of myocardial infarction and death following an initial attack. Proximal location of coronary atherosclerotic lesions has been linked to the risk of acute myocardial infarction and to infarction-associated mortality. To examine if the spatial distribution of lesions differs in patients with and without chronic kidney disease, we used quantitative coronary angiography to measure this in patients with acute coronary thromboses who were having angiography following acute myocardial infarction. Multivariable linear regression was used to adjust for differences in baseline characteristics. Among 82 patients with stage 3 or higher chronic kidney disease, 55.6% of lesions were located within 30 mm and 87.7% were within 50 mm of the coronary ostia. This compared to 34.7 and 71.8%, respectively, among 299 patients without significant kidney disease. Chronic kidney disease was independently and significantly associated with a 7.0 mm decrease in the distance from the coronary ostia to the problem lesion. Our study suggests that a causal link between a more proximal culprit lesion location in patients with chronic kidney disease and their high mortality rates after myocardial infarct is possible and may have important implications for interventions to prevent infarction.