The association between renal atherosclerotic plaque characteristics and renal function before and after renal artery intervention

The renal artery-aorta angle associated with renal artery plaque: a retrospective analysis based on CT

PURPOSE

To investigate the relationship between renal artery anatomical configuration and renal artery plaque (RAP) based on 320-row CT.

METHODS

The abdominal contrast-enhanced CT data from 210 patients was retrospectively analyzed. Among 210 patients, there were 118 patients with RAP and 92 patients with no RAP. The anatomical parameters between lesion group and control group were compared and analyzed by using t-test, χ2-test and logistic regression analysis.

RESULTS

(1) There were statistical differences on age, hypertension, diabetes, hypertriglyceridemia and hypercholesterolemia between lesion group and control group. (2) The differences on the distribution and type and of RAP between lesion group and control group were statistically significant. The most common position was the proximal, and the most common type was calcified plaque. (3)There were significant statistical differences on the proximal diameter of renal artery and renal artery-aorta angle A between lesion group and control group. The differences on the other anatomical factors between two groups were not statistically significant. (4) The result of logistic regression analysis showed that right RAP was related to age, hypertension and right renal artery angle A (the AUC of ROC = 0.82), and left RAP was related to high serum cholesterol, age and left renal artery angle A(the AUC of ROC = 0.83). (5) The RAP was associated with renal artery-aorta angle A, but the differences on distribution, type stability of RAP between R1 (L1) group and R2 (L2) group were not statistically significant.

CONCLUSIONS

The RAP was associated with age, hypertension, hypercholesterolemia and renal artery-aorta angle A. Adults which had the greater renal artery-aorta angle A and the other above risk factors may be at increased risk for RAP.

Can lercanidipine improve renal function in patients with atherosclerotic renal artery stenosis undergoing renal artery intervention?

OBJECTIVE

To investigate the renal-protective effect of lercanidipine in patients undergoing renal artery intervention.

METHODS

A prospective, single-center, cohort study was conducted and patients, 30-75 years of age, with atherosclerotic renal artery stenosis were consecutively enrolled between September 2011 and October 2012. Lercanidipine (10-20 mg/day) was regularly taken after the intervention. Follow up visits were performed at 3 and 6 months after the intervention. Serum creatinine, clinical blood pressure, 24 hour ambulatory blood pressure, pulse wave velocity, and 24 hour urine protein were assessed. Adverse events were recorded.

RESULTS

In total, 55 patients (mean age 63.5 ± 8.9 years) were enrolled and 52 completed the study. Renal function, estimated glomerular filtration rate (eGFR) and 24 hour urine protein at 3 months after the intervention were not statistically different compared with the baseline. At 6 months after the intervention eGFR significantly increased versus baseline (78 ± 23 ml/min/1.73 m(2) vs 71 ± 21 ml/min/1.73 m(2), p = 0.021); 24 hour urine protein decreased significantly (0.02 g [IQR, 0.01-0.1] vs 0.03 g [IQR, 0.01-0.28], p = 0.042). Blood pressure control improved at 3 months and 6 months after the intervention. The need for antihypertensive drugs decreased; clinical systolic blood pressure, diastolic blood pressure and 24 hour average systolic blood pressure and diastolic blood pressure decreased. The pulse wave velocity decreased after 3 and 6 months. At the end of follow-up, none of the following adverse events occurred: death, dialysis, myocardial infarction or stroke. Mild lower extremity edema occurred in only one patient. No other side effects occurred.

CONCLUSIONS

This study showed that lercanidipine can improve renal function in patients undergoing renal artery intervention.

Technical discussion of diagnostic angiography and intervention of atherosclerotic renal artery stenosis

Renal artery stenting remains an important adjuvant treatment for true-resistant hypertension, although recent disappointing randomized trials highlight the importance of careful patient selection. Safe and successful renal interventions begin with critical core knowledge regarding renal artery anatomy and understanding the often hostile nature of the parent vessel (pararenal aorta). Armed with fundamental knowledge about anatomy and renal ostial disease pathology, it becomes easier to understand the advantages of less traumatic access techniques and how low-profile contemporary flexible stents have enhanced outcomes. In addition to suggested techniques based on detailed understanding of the vessel architecture and pathology, we will review the current available US Food and Drug Administration-approved balloon-expandable on-label renal stents and discuss the role of intravascular ultrasound for definition of lesion severity, stent sizing, and stent apposition. The durability of renal stenting will also be discussed, as will the velocity criteria for duplex surveillance. Lastly, the current empirical data related to renal embolic protection is provided, along with insight into technical issues in this domain.

Renal artery stenosis: epidemiology and treatment

Renal artery stenosis (RAS) is a frequently encountered problem in clinical practice. The disease encompasses a broad spectrum of pathophysiologies and is associated with three major clinical syndromes: ischemic nephropathy, hypertension, and destabilizing cardiac syndromes. The two most common etiologies are fibromuscular dysplasia and atherosclerotic renal artery disease with atherosclerotic disease accounting for the vast majority of cases. Atherosclerotic renovascular disease has considerable overlap with atherosclerotic disease elsewhere and is associated with a poor prognosis. A wide range of diagnostic modalities and treatment approaches for RAS are available to clinicians, and with the advent of endovascular interventions, selecting the best course for a given patient has only grown more challenging. Several clinical trials have demonstrated some benefit with revascularization but not to the extent that many had hoped for or expected. Furthermore, much of the existing data is only marginally useful given significant flaws in study design and inherent bias. There remains a need for further identification of subgroups and appropriate indications in hopes of maximizing outcomes and avoiding unnecessary procedures in patients who would not benefit from treatment. In recent decades, the study of RAS has expanded and evolved rapidly. In this review, we will attempt to summarize the amassed body of literature with a focus on the epidemiology of RAS including prevalence, overlap with other atherosclerotic disease, and prognosis. We will also outline existing diagnostic and treatment approaches available to clinicians as well as summarize the findings of several major clinical trials. Finally, we will offer our perspective on future directions in the field.

Time-trend analysis on the Framingham risk score and prevalence of cardiovascular risk factors in patients undergoing percutaneous coronary intervention without prior history of coronary vascular disease over the last 17 years: a study from the Mayo Clinic PCI registry

BACKGROUND

There is a paucity of data on the temporal trends of cardiovascular risk factors in patients undergoing percutaneous coronary intervention (PCI). We investigated the secular trends of risk profiles of patients undergoing PCI without prior history of cardiovascular disease (CVD).

HYPOTHESIS

CVD risk factors are changed over time.

METHODS

This time-trend analysis from 1994 to 2010 was performed within the Mayo Clinic PCI Registry. Outcome measures were prevalence of CVD risk factors, including the Framingham risk score (FRS), at the time of admission for PCI.

RESULTS

During this period, 12,055 patients without a history of CVD (mean age, 65.0 ± 12.4 years, 67% male) underwent PCI at the Mayo Clinic. Age distribution slightly shifted toward older age (P for trend <0.05), but sex did not change over time. Despite a higher prevalence of hypertension, hypercholesterolemia, and diabetes mellitus over time, actual blood pressure and lipid profiles improved (P for trend <0.001). Over time, FRS and 10-year CVD risk improved significantly (7.3 ± 3.2 to 6.5 ± 3.3, P for trend <0.001; and 11.0 to 9.0, P for trend <0.001, respectively). Body mass index, not included in the FRS, increased significantly (29.0 ± 5.2 to 30.1 ± 6.2 kg/m(2) , P for trend <0.001), whereas smoking prevalence did not change.

CONCLUSIONS

The current study demonstrates that although traditional FRS and its associated predicted 10-year cardiovascular risk declined over time, the prevalence of risk factors increased in patients undergoing PCI. The study suggests the need for a new risk-factor assessment in this patient population.

Plaque characteristics and arterial remodeling in coronary and peripheral arterial systems

BACKGROUND

Few studies have examined plaque characteristics among multiple arterial beds in vivo. The purpose of this study was to compare the plaque morphology and arterial remodeling between coronary and peripheral arteries using gray-scale and radiofrequency intravascular ultrasound (IVUS) at clinical presentation.

METHODS AND RESULTS

IVUS imaging was performed in 68 patients with coronary and 93 with peripheral artery lesions (29 carotid, 50 renal, and 14 iliac arteries). Plaques were classified as fibroatheroma (VH-FA) (further subclassified as thin-capped [VH-TCFA] and thick-capped [VH-ThCFA]), fibrocalcific plaque (VH-FC) and pathological intimal thickening (VH-PIT). Plaque rupture (13% of coronary, 7% of carotid, 6% of renal, and 7% of iliac arteries; P = NS) and VH-TCFA (37% of coronary, 24% of carotid, 16% of renal, and 7% of iliac arteries; P = 0.02) were observed in all arteries. Compared with coronary arteries, VH-FA was less frequently observed in renal (P < 0.001) and iliac arteries (P < 0.006). Lesions with positive remodeling demonstrated more characteristics of VH-FA in coronary (84% vs. 25%, P < 0.001), carotid (72% vs. 20%, P = 0.001), and renal arteries (42% vs. 4%, P = 0.001) compared with those with intermediate/negative remodeling. There was positive relationship between remodeling index and percent necrotic area in all four arteries.

CONCLUSIONS

Atherosclerotic plaque phenotypes were heterogeneous among four different arteries; renal and iliac arteries had more stable phenotypes compared with coronary artery. In contrast, the associations of remodeling pattern with plaque phenotype and composition were similar among the various arterial beds.