Randomized Study of Ataciguat to Slow Progression of Moderate Calcific Aortic Valve Stenosis in Adults

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What is this study about?

The trial focuses on Moderate Calcific Aortic Valve Stenosis, a condition where calcium builds up on the aortic valve, making it harder for the heart to pump blood forward. The study evaluates an oral capsule of Ataciguat, compared with a matching inactive tablet, to determine whether the medication can slow the narrowing of the valve and improve the ability to exercise. The purpose of the study is to assess whether Ataciguat can reduce the rate at which the valve opening diminishes and improve physical fitness.

Participants will take the assigned tablet every day for about 48 weeks, with regular clinic visits. At each visit, a heart ultrasound called an echocardiogram will be used to measure how wide the valve opens, and a breathing‑exercise test will assess peak VO2, which reflects the maximum amount of oxygen the body can use during intense activity. A low‑dose CT scan without contrast will look at the amount of calcium on the valve. The study also tracks whether participants need a valve replacement procedure, either a catheter‑based approach (TAVR) or open‑heart surgery (SAVR), or experience any serious health events.

1 enrollment and randomization

after joining the study you are assigned to receive either ataciguat or a matching placebo in a double‑blind manner, meaning neither you nor the study staff know which one you receive.

2 baseline assessments

initial measurements are performed before starting medication, including an echocardiogram to measure the aortic valve area, a cardiopulmonary exercise test (cpet) to determine peak vo2, and a non‑contrast ct scan to assess calcification.

these results serve as the reference point for later comparisons.

3 start of study medication

you begin taking one 200 mg oral capsule of the assigned product each day.

the capsule is taken by mouth with water, typically at the same time each day.

treatment continues for a total of 48 weeks.

4 regular safety visits

throughout the 48‑week period you attend scheduled clinic visits where vital signs, symptoms, and any side effects are reviewed.

blood samples may be taken to monitor safety, but no additional study medication adjustments are made.

5 mid‑study check (optional)

if required by the protocol, an interim echocardiogram or other test may be performed around the middle of the treatment period to ensure continued safety.

6 final assessments at week 48

at the end of the 48‑week treatment you undergo the same set of tests as at baseline: echocardiogram, cardiopulmonary exercise test, and ct scan.

the changes from baseline are used to evaluate the effect of the study medication on valve function and exercise capacity.

7 study completion

after the final assessments you stop taking the study medication.

the study team will provide information about the overall results once the analysis is finished.

Who Can Join the Study?

Be an adult man or woman who is at least 50 years old.
Have moderate calcific aortic valve stenosis (CAVS), which means:
- The opening of the aortic valve (called the aortic valve area, AVA) is between 1.0 and 1.5 cm².
- A heart CT scan shows calcium buildup in the valve (measured in Agatston units) that is:
  - 600 to 1,200 AU for women, or
  - 600 to 2,000 AU for men.
Have a left ventricular ejection fraction (EF) of 45% or higher, which is a measure of how well the main pumping chamber of the heart squeezes blood.
If you are taking beta blockers (medicines that slow the heart), the dose must have been steady for at least 90 days before the screening visit and should not be expected to change during the study.
Agree to any other requirements that are listed in the study protocol.

Who Cannot Join the Study?

You have already had or are planning to have surgery or a procedure to replace or fix your aortic valve within the next six months.
You have moderate or worse narrowing (mitral stenosis) or leaking (mitral regurgitation) of the mitral valve, or leaking (aortic regurgitation) of the aortic valve.
You were born with an abnormal aortic valve (a condition called congenital disease), such as a bicuspid aortic valve that has two flaps instead of three.
You have severe heart‑failure symptoms that limit daily activities (Class III) or symptoms that occur even while at rest (Class IV), according to the NYHA classification.
The main reason for your heart failure is something other than a problem with the aortic valve.
You have coronary artery disease (narrowing of the heart’s blood vessels) or you expect to have a procedure called stenting to open those vessels.
Your heart’s electrical timing (the QTc interval) is 480 milliseconds or longer, or you have risk factors for a dangerous rhythm called torsades de pointes, such as low potassium, a family history of long QT syndrome, medicines that prolong the QT interval, an abnormal ECG result, or ongoing irregular heartbeat (atrial fibrillation).
You have a medical or physical condition (for example, lung disease, joint, leg, hip, or back problems, or any other condition) that would prevent you from safely completing the required CPET (cardiopulmonary exercise test).
Other study rules not listed here may also exclude you from participating.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country
Unidade Local De Saúde De Santa Maria, E.P.E.	Lisbon	Portugal
4 Wojskowy SzpitaKliniczny Z Polikliniką Samodzielny Publiczny ZakładOpieki ZdrowotneWe Wrocławiu	Wroclaw	Poland
Uniwersytecki Szpital Kliniczny Im Jana Mikulicza Radeckiego We Wroclawiu	Wroclaw	Poland
Centre Hospitalier Universitaire De Lille	Lille	France
Medical University Of Graz	Graz	Austria
Samodzielny Publiczny Zaklad Opieki Zdrowotnej Centralny Szpital Kliniczny Uniwersytetu Medycznego W Lodzi	Lodz	Poland
Unidade Local De Saude De Lisboa Ocidental E.P.E.	Carnaxide	Portugal
Hospor Hospitais Portugueses S.A.	Setubal	Portugal
CHU Grenoble Alpes	La Tronche	France

Other Sites

Site Name	City	Country
Landeskrankenanstalten-Betriebsgesellschaft Kabeg	Klagenfurt am Wörthersee	Austria
Sørlandet sykehus Kristiansand	Kristiansand	Norway
Centrum Medyczne Zdrowa	Cracow	Poland
Nemocnice Ceske Budejovice a.s.	Ceske Budejovice	Czechia
Fakultni Nemocnice Brno	Brno	Czechia
University Clinical Hospital Virgen De La Arrixaca	Murcia	Spain
Fakultni Nemocnice U Sv Anny V Brne	Brno-Stred	Czechia
Sykehuset Oestfold HF Kalnes	Graalum	Norway
Centre Hospitalier Universitaire De Nantes	Nantes	France
Vojenska Nemocnice Brno	Brno-Zidenice	Czechia
Vseobecna Fakultni Nemocnice V Praze	Prague	Czechia
Uniwersytecki Szpital Kliniczny W Poznaniu	Poznan	Poland
Centre Hospitalier Universitaire De Rennes	Rennes	France
Hopital Beaujon	Clichy	France
Unidade Local De Saude De Gaia/Espinho E.P.E.	Vila Nova De Gaia	Portugal
St. Olavs Hospital HF	Trondheim	Norway
Helse Stavanger HF	Stavanger	Norway
Narodowy Instytut Kardiologii Stefana Kardynala Wyszynskiego Panstwowy Instytut Badawczy	Warsaw	Poland
Wojewodzki Specjalistyczny Szpital Im Dr Wl Bieganskiego	Lodz	Poland
Santa Sp. z o.o.	Lodz	Poland
Stadt Wien Wiener Gesundheitsverbund	Vienna	Austria
CCAB Centro Clinico Academico Braga Associacao	Braga	Portugal
Wojewodzki Szpital Zespolony Im.L.Rydygiera W Toruniu	Torun	Poland
Unidade Local De Saude Do Alto Ave E.P.E.	Guimaraes	Portugal
Wojewodzki Szpital Specjalistyczny We Wroclawiu	Wroclaw	Poland
Linden Sp. z o.o. sp.k.	Cracow	Poland
Kardio Brynow Sp. z o.o.	Katowice	Poland
Hlrojpff Vrut duybevzx	Barcelona	Spain
Atphvhh Sux z oalz	Poznan	Poland
Hbeovrum Ulohtweqsfiah dq A Cpdfwp	A Coruna Galicia	Spain
Auqajkxo Ukdhampdyv Hizyfkme	Lorenskog	Norway
Uisxbyaaysmrlh Cvslwbp Kfmdttcmc	Gdansk	Poland
Cbchydqp Howhfvmdblin Ubusuxsgrbyxj Di Vfwv	Vigo	Spain

Trial status

Country	Status	Recruitment Start
Austria	Not yet recruiting	01.10.2026
Czechia	Not yet recruiting	01.10.2026
France	Not yet recruiting	01.10.2026
Norway	Not yet recruiting	01.10.2026
Poland	Not yet recruiting	01.10.2026
Portugal	Not yet recruiting	01.10.2026
Spain	Not yet recruiting	01.10.2026

Trial locations

Ataciguat is an oral medication taken in capsule form that is being tested to see if it can slow down the worsening of the heart valve problem called calcific aortic valve stenosis. In this study, participants will take Ataciguat regularly while researchers measure how the size of the valve opening changes over time and how well the participants can perform physical activity, such as their peak oxygen use during exercise. The goal is to find out whether Ataciguat can help keep the valve from narrowing faster and improve overall heart function.

Moderate calcific aortic valve stenosis – It is a condition where calcium deposits build up on the aortic valve, making the valve stiff and narrowed. The narrowing reduces the amount of blood that can flow from the heart to the rest of the body. As the valve opening becomes smaller, the heart must work harder to push blood through. Over time the valve area continues to shrink, leading to increasing difficulty with activities that require effort. This progression often results in breathlessness and reduced ability to exercise.

Trial ID:

2025-522176-86-01

Protocol code:

ATA-301

NCT ID:

NCT07001800

Trial Phase:

Therapeutic confirmatory (Phase III)

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Randomized Study of Ataciguat to Slow Progression of Moderate Calcific Aortic Valve Stenosis in Adults

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?