During the study, participants will undergo several tests to measure how well their heart is working and how much chest pain they experience. These tests include treadmill exercise tests where participants walk on a treadmill to see how long they can exercise before chest pain starts, imaging scans using PET (a type of scan that creates pictures of the heart) to measure blood flow in the heart, and keeping a daily diary to record chest pain episodes and use of nitroglycerin medication. The treatment will be delivered directly into the heart muscle using a special catheter called an Extroducer Infusion Catheter System, which is a thin flexible tube that is inserted through blood vessels to reach the heart. The main study period lasts 26 weeks, with an additional 26-week extension period to continue monitoring participants.

Throughout the study, doctors will check for any side effects and monitor the safety of the treatment. They will measure changes in exercise ability, frequency and severity of chest pain episodes, blood flow to the heart muscle, and overall quality of life using questionnaires. Blood tests will be done to check general health and to measure the body’s response to the treatment. The study will also track serious heart-related events such as heart attacks, hospitalizations for heart problems, or the need for additional heart procedures. Participants will need to continue taking their regular heart medications during the study and use effective birth control methods for six months after receiving the treatment.

The purpose of the study is to confirm the anti-anginal effect of T89 in patients with stable angina. Participants in the study will be randomly assigned to one of three groups: one group will receive T89, another will receive Nitroglycerin, and the third group will receive a placebo. The study is designed to be double-blind, meaning neither the participants nor the researchers will know who is receiving which treatment until the study is completed. This helps ensure that the results are not biased. The study will take place over a period of several weeks, during which participants will be monitored for changes in their symptoms and any side effects they may experience.

Throughout the study, participants will undergo various assessments to track their progress. These assessments will include measuring the duration of exercise they can perform before experiencing symptoms, as well as monitoring the frequency of angina episodes. The study will also evaluate the safety of T89 by recording any adverse events or notable changes in laboratory tests. The ultimate goal is to determine whether T89 can effectively reduce the symptoms of stable angina and improve the quality of life for those affected by this condition.

Participants in the study will be given either diltiazem or a placebo, which is a substance with no active medication. The study will last for a period of up to six months. During this time, the effects of diltiazem on the heart’s small blood vessels will be closely monitored. The goal is to determine if diltiazem can help normalize the function of these vessels without causing any of the normal parameters to become abnormal.

The study will assess the success of the treatment by checking if at least one of the abnormal heart function parameters returns to normal. These parameters include measures like the Index of Microcirculatory Resistance (IMR) and the Coronary Flow Reserve (CFR). A successful treatment would mean that patients experience fewer symptoms of angina and improved heart function. The trial is expected to continue until 2026, providing valuable insights into the potential benefits of diltiazem for patients with coronary microvascular dysfunction.