Covered vs Bare Metal Stents for Atherosclerotic Renal Artery Stenosis (COMBAT)

Endovascular Treatment of Atherosclerotic Renal Artery Stenosis: A Prospective Randomized Controlled Study Comparing Covered Stents and Bare Metal Stents

Atherosclerotic renal artery stenosis is the most common cause of secondary hypertension , increasing the risk of cardiovascular and kidney-related complications. Some small-scale studies have suggested that covered stents are effective and safe, but high-quality evidence from large-scale studies in atherosclerotic renal artery stenosis remains limited.

This study aims to evaluate whether covered stents are more effective than bare metal stents in patients with atherosclerotic renal artery stenosis. Eligible participants will be randomly assigned to receive either a covered stent or a bare metal stent. Patients will be followed for 12 months to assess Changes in eGFR, 24-hour systolic blood pressure, and 24-hour diastolic blood pressure from baseline to 12 months were compared among the groups.

The results of this study may help improve treatment strategies and guide the selection of stent type for patients with this condition.

Study Overview

• Status: Not yet recruiting
• Conditions: Hypertension; Renal Artery Stenosis; Atherosclerotic Renal Artery Stenosis
• Intervention / Treatment: Device: Bare Metal Stent; Device: Covered Stent

• Study Type: Interventional
• Enrollment (Estimated): 150
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Xiongjing Jiang; Phone Number: 86-010-88322387; Email: jiangxiongjing@163.com
• Study Contact Backup: Name: Hui Dong; Phone Number: 86-010-88322385; Email: donghui666@sina.com

Study Locations

• China
  • Beijing, China
    • Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037
    • Contact: Hui Dong; Phone Number: 15810161393; Email: donghui666@sina.com
  • Chongqing, China, 400016
    • Department of Cardiovascular Medicine, Cardiovascular Research Center , The First Affiliated Hospital of Chongqing Medical University
  • Harbin, China
    • The Second Affiliated Hospital of Harbin Medical University, Ha'erbin
    • Contact: Shuo Zhang; Phone Number: 18645056661; Email: zhangshuoemail@163.com
  • Jilin, China, 130033
    • China-Japan Union Hospital of Jilin University, Changchun, Lilin
    • Contact: Yuquan He; Phone Number: 13944145413; Email: liuxueyan@jlu.edu.cn
  • Guangdong
    • Guangzhou, Guangdong, China, 510000
      • The First Affiliated Hospital of Sun Yat-Sen University
      • Contact: Wenhao Xia; Phone Number: 020-87755766; Email: xiawhao@mail.sysu.edu.cn
  • Heilongjiang
    • Harbin, Heilongjiang, China, 150086
      • The Second Affiliated Hospital of Harbin Medical University
      • Contact: Zhiyu Shi; Phone Number: 18645056661; Email: zhangshuoemail@163.com
  • Henan
    • Zhengzhou, Henan, China, 450000
      • Fuwai Central China Cardiovascular Hospital
    • Zhengzhou, Henan, China, 450007
      • Zhengzhou Central Hospital Affiliated to Zhengzhou University
      • Contact: Shuhua Yu; Phone Number: 0371-67690941; Email: 13613716677@139.com
  • Jiangsu
    • Nanjing, Jiangsu, China, 211800
      • Nanjing Pukou People's Hospital(Liangjiang Hospital Southeast University)
  • Jiangxi
    • Nanchang, Jiangxi, China, 330038
      • Jiangxi Provincial People's Hospital (The First Affiliated Hospital of Nanchang Medical College)
  • Liaoning
    • Dalian, Liaoning, China, 116001
      • Affilated Zhongshan Hospital of Dalian University
    • Dalian, Liaoning, China
      • Frist Aiffiliated Hospital of Dalian Medical University
  • Shandong
    • Jinan, Shandong, China, 250012
      • Qilu Hospital of Shandong University
    • Qingdao, Shandong, China
      • Qingdao Hospital University of Health and Rehabilitation Sciences (Qingdao Municipal Hospital)
  • Sichuan
    • Chengdu, Sichuan, China, 610031
      • The Affiliated Hospital of Southwest Jiaotong University, The Third People's Hospital of Chengdu
      • Contact: Zhen Zhang; Phone Number: 13708042927; Email: 31350377@qq.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 1) Renal artery diameter stenosis ≥60%; 2) Office systolic blood pressure ≥ 160 mmHg and/or office diastolic blood pressure ≥ 100 mmHg on at least two separate days without antihypertensive medication, or office systolic blood pressure ≥ 140 mmHg and/or office diastolic blood pressure ≥ 90 mmHg while on three antihypertensive drugs at conventional doses; 3) Serum creatinine < 264 μmol/L (3.0 mg/dL); 4) Affected kidney length ≥ 7.0 cm, with residual glomerular filtration rate (GFR) ≥ 10 mL/min;

Exclusion Criteria:

• 1) Unstable clinical condition rendering the patient intolerant to revascularisation therapy; 2) Urinary protein ≥2+; 3) Contrast medium allergy; 4) Renal artery anatomy unsuitable for revascularisation therapy; 5) Reference vessel diameter <3.5mm or >8mm. 6)Patients with non-atherosclerotic renal artery stenosis (such as fibromuscular dysplasia or Takayasu arteritis); 7)Reference vessel diameter < 3.5 mm or > 8 mm

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: bare metal stents group	Device: Bare Metal Stent; Endovascular implantation of a bare metal stent in the renal artery.
Experimental: covered stents group	Device: Covered Stent; Endovascular implantation of a covered stent in the renal artery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in eGFR	Change in estimated glomerular filtration rate (eGFR) at 12 months compared with baseline	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in 24-Hour Ambulatory Systolic Blood Pressure	Change in 24-Hour Ambulatory Systolic Blood Pressure Compared With Baseline	12 months
Change in 24-Hour Ambulatory Diastolic Blood Pressure	Change in 24-Hour Ambulatory Diastolic Blood Pressure Compared With Baseline	12 months
Change in Office Systolic Blood Pressure	Change in Office Systolic Blood Pressure Compared With Baseline	12 months
Change in Office Diastolic Blood Pressure	Change in Office Diastolic Blood Pressure Compared With Baseline	12 months
Change in Home Systolic Blood Pressure	Change in Home Systolic Blood Pressure Compared With Baseline	12 months
Change in Home Diastolic Blood Pressure	Change in Home Diastolic Blood Pressure Compared With Baseline	12 months
Change in antihypertensive medication burden	Change in antihypertensive medication burden at 12 months compared with pre-procedure levels	12 months
Stent patency	Stent patency at 12 months	12 months
Incidence of perioperative complications		1 month
MACE	Major adverse cardiovascular events (MACE) include cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and hospitalization for heart failure.	12 months
Renal Adverse Events	Renal adverse events include a sustained decline in renal function (≥30% decrease in eGFR from baseline confirmed on repeat measurement), doubling of serum creatinine, initiation of renal replacement therapy (dialysis or kidney transplantation), or progression to end-stage renal disease.	12 months

Collaborators and Investigators

• Sponsor: Chinese Academy of Medical Sciences, Fuwai Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): April 30, 2026
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): April 30, 2028

Study Registration Dates

• First Submitted: April 27, 2026
• First Submitted That Met QC Criteria: April 27, 2026
• First Posted (Actual): May 4, 2026

Study Record Updates

• Last Update Posted (Actual): May 4, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: bare metal stents; covered stents; atherosclerotic renal artery stenosis
• Additional Relevant MeSH Terms: Urogenital Diseases; Vascular Diseases; Cardiovascular Diseases; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Arterial Occlusive Diseases; Hypertension; Renal Artery Obstruction
• Other Study ID Numbers: 2026-0427

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No