The APOLLO Trial

About the trial

The APOLLO Trial evaluates the safety and effectiveness of an investigative treatment for patients with symptomatic mitral regurgitation.

CAUTION: The Intrepid™ transcatheter mitral valve replacement system is an investigational device. Limited by federal (United States) law to investigational use. Exclusively for clinical investigations. Not approved by FDA and not for sale in the United States.

CAUTION: Investigational device. To be used by qualified investigators only. Exclusively for clinical investigations.

Mitral regurgitation (MR)

  • MR affects an estimated four million people in the U.S.1,2
  • Mitral valve leaflets become damaged or stretched out where they don’t close properly, which allows blood to flow backward, causing MR.
  • Prior heart attacks and heart disease increases the risk of developing MR.
  • If left untreated, MR may lead to chronic heart failure (HF), the leading cause of hospitalization in the U.S. and Europe.
    • Approximately 50% of HF patients will die within five years.
    • Approximately 10% of HF patients have symptoms, such as shortness of breath at rest. 

Mitral annular calcification (MAC)

  • MAC is a chronic degenerative process of the mitral valve that has been found to increase the incidence of mitral valve disease and arrhythmias and influence the outcomes of cardiac surgery.3
  • MAC is estimated to affect approximately 9% of Americans4 and reaches about 42% in elderly patients who suffer from cardiovascular disease.5
  • Presence of MAC is associated with a significant increased risk of cardiovascular death and all-cause death, compared to patients without MAC.6
  • Severe MAC presents significant technical challenges during surgical mitral valve repair or replacement7 and presence of MAC, regardless of severity, is independently associated with increased operative mortality and adverse postoperative outcomes in patients undergoing surgical mitral valve replacement.8

Trial design

Evaluating the safety and efficacy of the Intrepid transcatheter mitral valve replacement system for patients with moderate-to-severe to severe symptomatic mitral regurgitation (MR), with or without MAC, who are unsuitable for TEER or surgical mitral valve interventions.

Diagram illustrating how the APOLLO clinical trial is designed

Study synopsis: primary cohort and MAC

Primary endpoint

  • Primary cohort: The rate of all-cause mortality, or heart failure hospitalization post 30-days, or KCCQ improvement < 10 as evaluated at one year
  • MAC cohort: The rate of all-cause mortality or heart failure hospitalization at one year

Secondary endpoint

  • Composite of all-cause mortality, disabling stroke, acute kidney injury (stage three or with renal replacement), prolonged ventilation, deep wound infection, reoperation or reintervention, or ≥ major bleeding at 30 days or at hospital discharge, whichever is longer
  • Change in NYHA at 30 days
  • Change in Quality of Life (QoL) at 30 days (SF-12) 
  • Change in QoL at three months as assessed by KCCQ
  • Degree of mitral regurgitation at one year as assessed by echo core lab
  • Cardiovascular hospitalization through one year

Intrepid TMVR system overview

The Intrepid transcatheter mitral valve replacement system (TMVR) integrates self-expanding stent technology with a tissue heart valve to facilitate minimally invasive, catheter-based implantation.

The prosthesis is compressed inside a hollow delivery catheter and implantation is completed through transfemoral access. It is designed to engage and conform to the native annulus without need for additional sutures, tethers, or anchors.

Diagram of the Intrepid TMVR system with numbered callouts showing the location of outer stent, inner stent, and brim

The device design features:

  1. A conformable outer stent designed to engage the annulus and leaflets, providing fixation while isolating the inner stent from the dynamic anatomy.
  2. A flexible brim designed to aid imaging during implantation and subsequent tissue in-growth.
  3. The circular inner stent houses a 27 mm tri-leaflet bovine pericardium valve.

Find out if your patients are eligible.

Read through the inclusion/exclusion criteria and view more resources to help you determine if you have patients who are eligible to participate in the trial.

Share APOLLO Trial details.

Use the button below to send an email to your colleagues about the trial. This email template is prepopulated with basic information about the trial and a link to the website where your colleagues can learn more.



U.S. Census Bureau. Statistical Abstract of the U.S.: 2006, Table 12.


Nkomo VT, Gardin JM, Skelton TN, Gottdiener JS, Scott CG, Enriquez-Sarano M. Burden of valvular heart diseases: a population-based study. Lancet. September 16, 2006;368(9540):1005–1011.


Abramowitz Y, Jilaihawa H, Chakravarty T, Mack MJ, Makkar RR. Mitral Annulus Calcification. J Am Coll Cardiol. October 27, 2015;66(17):1934–1941.


Vergeer M, Cohn DM, Boekholdt SM, et al. Lack of association between common genetic variation in endothelial lipase (LIPG) and the risk for CAD and DVT. Atherosclerosis. August 2010;211(2):558–564.


Barasch E, Gottdiener JS, Marino Larsen EK, Chaves PHM, Newman AB, Manolio TA. Clinical significance of calcification of the fibrous skeleton of the heart and aortosclerosis in community dwelling elderly. The Cardiovascular Health Study (CHS). Am Heart J. January 2006;151(1):39–47.


Fox CS, Vasan RS, Parise H, et al. Mitral annular calcification predicts cardiovascular morbidity and mortality: the Framingham Heart Study. Circulation. March 25, 2003;107(11):1492–1506.


Bedeir K, Kaneko T, Aranki S. Current and evolving strategies in the management of severe mitral annular calcification. J Thorac Cardiovasc Surg. February 2019;157(2):555–566.


Kaneko T, Hirji S, Percy E, et al. Characterizing Risks Associated With Mitral Annular Calcification in Mitral Valve Replacement. Ann Thorac Surg. December 2019;108(6):1761–1767.