A Study of Metformin to Improve Cardiac Function After LVAD Implantation

Starting soon · Phase 1/Phase 2 · Has a placebo group

Conditions studied: Heart Failure, Left Ventricular Assist Device

In brief

This study investigates whether metformin, compared with placebo, improves cardiac function in patients after Left Ventricular Assist Device (LVAD) implantation. Metformin is a widely used oral medication for type 2 diabetes, but emerging evidence suggests it may have beneficial effects on cardiac metabolism and function independent of its glucose-lowering effects. This is a prospective, multicenter, randomized, double-blind, placebo-controlled trial. A total of 108patients undergoing LVAD implantation will be enrolled from 5 centers in China. Eligible participants will be randomly assigned in a 1:1 ratio to receive either metformin or placebo for 12 months. The primary outcome is the incidence of Full Responder at 12 months post-implantation. A Full Responder is defined as meeting all of the following four criteria: (1) left ventricular ejection fraction (LVEF) ≥40% and left ventricular end-diastolic diameter (LVEDD) ≤6.0 cm (Utah-Inova Responder criteria); (2) soluble ST2 (sST2) ≤100 ng/mL at both 6 months and 12 months post-implantation; (3) absolute value of left ventricular global longitudinal strain (GLS) ≥12% at 12 months post-implantation. Secondary outcomes include clinical events, cardiac function status, blood biomarker results, global functional status and quality of life, medication safety, and exploratory measures. Clinical events assessed up to 24 months post-implantation include: heart failure rehospitalization rate, all-cause mortality, LVAD explantation rate, cardiovascular mortality, major bleeding, cardiac structural damage, thromboembolic events, systemic inflammatory dissemination, sepsis, and other serious adverse events. Cardiac function status is evaluated by echocardiographic parameters (LVEF, LVEDD, GLS) and hemodynamic measures. Blood biomarkers include sST2, NT-proBNP, cardiac troponin, and inflammatory cytokines. Global functional status and quality of life are measured using the 6-minute walk test (6MWT), peak oxygen consumption (VO₂max), and the Kansas City Cardiomyopathy Questionnaire (KCCQ). Safety outcomes include the incidence and severity of adverse events, serious adverse events, and adverse events of special interest. Exploratory outcomes include pre-implantation right ventricular myocardial biopsy (obtained only when clinically indicated for temporary pacemaker lead placement) to assess insulin receptor substrate (IRS)/Akt phosphorylation, G6PD activity, NADPH/NADP⁺ ratio, and oxidative stress markers (malondialdehyde, 4-hydroxynonenal). The study aims to provide evidence on whether adjunctive metformin therapy can improve post-LVAD cardiac outcomes and reduce adverse clinical events.

Key facts

Study ID: NCT07666698
Run by: The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School
People needed: 108
Starts: 2026-07-01
Expected to finish: 2029-09-01
Last updated by the study team: 2026-06-24

Who can join

Age: 18 and older, up to 75. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

Age 18-75 years
Receiving continuous-flow LVADs, such as HeartMate 3, HVAD, Core-Heart 6, Brio-Heart
Presence of insulin resistance
HbA1c ≤ 6.5%

You may not qualify if…

Diagnosed type 1 diabetes mellitus, or type 2 diabetes mellitus with HbA1c > 6.5% (patients with prior type 2 diabetes who are currently off therapy and have HbA1c ≤ 6.5% may be enrolled; such patients may still have insulin resistance but have achieved glycemic control)
History of diagnosed diabetic ketoacidosis or hyperosmolar hyperglycemic state
Currently using any glucose-lowering medications (including insulin, oral hypoglycemic agents, GLP-1 receptor agonists, SGLT2 inhibitors, etc.)
History of diagnosed polycystic ovary syndrome (PCOS) and currently undergoing treatment
Estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m² (CKD-EPI equation)
History of acute kidney injury (KDIGO criteria) with incomplete renal recovery
Receiving any form of renal replacement therapy (hemodialysis, peritoneal dialysis)
Post-kidney transplantation or awaiting kidney transplantation
Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 3× the upper limit of normal, total bilirubin > 2× upper limit of normal, or Child-Pugh class B or C cirrhosis
Active viral hepatitis
History of alcoholic liver disease or drug-induced liver injury currently in the active phase
Concurrent right ventricular assist device (RVAD) or total artificial heart implantation
LVAD-related complications requiring surgical intervention within 30 days postoperatively, including but not limited to: pump thrombosis requiring LVAD exchange or thrombolysis, driveline infection requiring debridement or replacement, hemorrhagic complications requiring re-sternotomy, device malfunction requiring urgent intervention
Acute kidney injury requiring ongoing renal replacement therapy (CRRT) within 30 days postoperatively
Preoperative severe right heart failure (on echocardiography: right ventricular fractional area change < 35%, or tricuspid annular plane systolic excursion < 14 mm; or right heart catheterization showing central venous pressure > 15 mmHg and cardiac index < 2.0 L/min/m²)
Preoperative severe pulmonary arterial hypertension (mean pulmonary arterial pressure ≥ 40 mmHg and pulmonary vascular resistance ≥ 4 Wood units)
Within 30 days postoperatively, occurrence of severe low cardiac output syndrome requiring extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pump (IABP) support
Significant prosthetic valve dysfunction or severe prosthetic valve infectious endocarditis
Severe unrepaired valvular disease
Active systemic infection or sepsis requiring ongoing intravenous antibiotics or antifungal therapy
Active infectious endocarditis (modified Duke criteria) or high clinical suspicion
Human immunodeficiency virus (HIV) infection with CD4 count < 200/μL or not on regular antiretroviral therapy
Active tuberculosis or non-tuberculous mycobacterial infection
Active cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infection
Known active inflammatory diseases (e.g., systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease) currently requiring immunosuppressive therapy

Where it is running

Dong-Jin Wang — Nanjing, Jiangsu, China

Full record on ClinicalTrials.gov

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