Objective: The aim of the present study was to demonstrate the relationship between hypertension stages according to JNC-8 classification and mean renal frame count (RFC), which is an indicator of renal perfusion.
Methods: In this retrospective study, 100 hypertensive patients without obstructive renal artery disease, who had been evaluated with renal artery angiography for hypertension, were allocated into 2 groups (Stage 1 and Stage 2 hypertension). During coronary angiography, the patients were evaluated by selective renal angiography using 6F Judkins catheter. Cineangiographic images were evaluated by the same clinician and mean RFC was estimated for both renal arteries. Injections during renal angiography were performed with power injector and same amount of radiopaque media with same speed was used for all patients.
Results: There was no significant difference between the groups in terms of age, sex, duration of hypertension, and laboratory markers. Stage 2 hypertensive patients (Group 2) had a significantly higher mean RFC than Stage 1 hypertensive patients (Group 1) (p<0.001). The mean RFC of both kidneys in Group 2 was significantly higher than that of Group 1 (p<0.001 and p=0.023, respectively).
Conclusions: This study showed that the mean RFC increased with increases in hypertension levels and it could be used as an indicator of renal perfusion, which is an indirect marker of renal function. If renal artery flow gets slower, blood pressure levels increase and there is a proportional relationship between these two variables (mean RFC and blood pressure levels). This study also demonstrated that there was a statistically significant correlation between mean RFC and JNC-8 hypertension stages.
Keywords: Hypertension; Hypertension stages; Renal angiography; Renal artery; Renal frame count.