Stenting for renal-artery stenosis

Is there still a role for renal artery stenting in the management of renovascular hypertension - A single-center experience and where do we stand?

BACKGROUND

Renal artery (RA) stenosis has been implicated in the pathophysiological mechanism for resistant hypertension. Despite the increasingly diagnosed frequency of hemodynamically significant lesions, the value of RA revascularization remains controversial. Our group had previously demonstrated significant blood pressure (BP) reduction in a retrospective cohort of appropriately selected patients undergoing RA stenting up to 18-months of follow-up. We herein present long-term clinical outcomes data 5-years post revascularization on 26 subjects who continued follow-up at our institution.

METHODS

Retrospective analysis was performed on subjects who underwent RA stenting at our institution for hemodynamically significant (≥70%) RA stenosis and systolic hypertension on ≥3 antihypertensive agents. Clinical outcome data for systolic blood pressure (SBP), diastolic blood pressure (DBP), creatinine level and number of antihypertensive drugs was assessed prior to and then later at 6-12 months and 3-5 years post RA stenting.

RESULTS

Mean age was 69 ± 9 years; 27% (7/26) were male. Median follow-up was 5.1 years. Blood pressure reduction was sustained at long-term follow-up (135/70 ± 18/11 mmHg) compared to initial reduction noted at 6-months (136/69 ± 16/8 mmHg; p ≤0.01 for both) and from baseline (162/80 ± 24/18 mmHg; p ≤0.001 for both). The number of antihypertensive agents also decreased from 4.1 ± 1.0 to 2.7 ± 2.1 (p = 0.002) at 6-months and was sustained at long-term follow-up, 3.4 ± 1.2 (p = 0.03) with no difference in renal function between short- and long-term follow-up compared to baseline.

CONCLUSIONS

This study shows sustained benefit of RA stenting in BP reduction in an appropriately selected cohort with significant stenosis ≥70% and uncontrolled hypertension on multiple medications on long-term follow-up.

Non-hemodynamically significant renal artery stenosis predicts cardiovascular events in persons with ischemic heart disease

BACKGROUND/AIMS

Recently, we reported that small renal arteries, defined by a low reference diameter (RD) or minimal luminal diameter (MD), are independently associated with a low GFR, resistant hypertension, and onset of contrast-induced nephropathy and suggested a post-hoc analysis of CORAL trial based on RD categories. Here we hypothesized that RD and MD are markers of nontraditional cardiovascular risk factors and tested whether low RD and MD could impact the prognosis of patients with ischemic heart disease.

METHODS

Prospective cohort study. We used proportional hazards models to analyze the first onset of cardiovascular events in relation with RD, MD, or percentage of renal artery stenosis (RAS) in those with low-to-moderate RAS (10-70%) (n = 181).

RESULTS

During the median follow-up of 4.5 (range, 0.1-5) years, 27.8% participants (n = 623; mean age, 64 years; 29% women) experienced a cardiovascular event (35.4% in those with RAS 10-70%). The presence of low-to-moderate RAS was associated with cardiovascular events. In these subjects, those with low MD were associated with a higher risk of cardiovascular events (MD >4.2 mm, HR: 1; MD 3.2-4.2 mm, HR: 1.66, 95% CI: 0.74-3.72, p = 0.22; MD <3.2 mm, HR: 3.72, 95% CI: 1.65-8.40, p = 0.002). When MD was added to a standard risk-factor model, risk prediction improvement was by 4.1%. Results were qualitatively similar if MD was replaced by RD or percentage of stenosis, but with smaller improvement of risk prediction and model fit.

CONCLUSIONS

In patients with ischemic heart disease and low-to-moderate RAS, MD is a significant predictor of cardiovascular events, improves risk prediction, and may represent a valuable biomarker of cardiovascular disease risk.