Coronary Flow Slows as Renal Function Worsens
Background: Slow coronary flow in patients without obstructive coronary artery disease is an angiographic finding that could easily be detected by thrombolysis in myocardial infarction (TIMI) frame counts. On the other hand, impaired renal function is a frequent problem. We searched the association between the 2 entities. Hypothesis: We evaluated the impact of impaired renal function on slow coronary flow. Methods: In this study, 105 patients with normal coronary arteries and impaired renal function in the form of a calculated glomerular filtration rate (GFR) < 90 mL/min/1.73 m(2) were enrolled and compared with 102 age-and sex-matched controls who had normal a GFR. Results: Calculated GFR was found to be negatively correlated with TIMI frame count in LAD (r = -0.579, p < 0.001), in CX (r = -0.499, P < 0.001), and in RCA (r = -0.491, P < 0.001) in patients with impaired renal function. After adjusting for systolic and diastolic blood pressure and high-density lipoprotein (HDL) cholesterol, multiple regression analysis demonstrated a statistically significant and independent relationship between TIMI frame count for 3 vessels and calculated GFR. Conclusions: Impaired renal function seems to denote slower coronary flow in patients with normal coronary arteries compared with those with normal renal function, and there seems to be an independent association between GFR and TIMI frame count in those with impaired renal function.