Thiamine After Cardiac Arrest Study

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Thiamine After Cardiac Arrest (THACA): a randomized, double-blind, placebo-controlled trial of thiamine to decrease lactate and improve outcomes after cardiac arrest:

Study Team:

Michael W. Donnino MD (Principal Investigator)

Katherine M. Berg MD

Michael N. Cocchi MD

Anne V. Grossestreuer PhD

Xiaowen Liu PhD

Mathias J. Holmberg MD

Why are we doing this study?

Cardiac arrest is an emergent condition in which the heart completely stops. The chances of survival are low, even with CPR. Over 200,000 people per year experience an out-of-hospital cardiac arrest in the United States. Survival rates are low, and even those who survive often have significant brain injury. Unfortunately there are no medicines available to treat this condition. Our prior work suggests that a simple vitamin (Vitamin B1, or thiamine) may help improve outcomes in these patients. Based on our work, the National Institutes of Health has funded a study to test whether thiamine decreases lactate (a chemical that increases in the blood when a patient is in shock from lack of blood flow or inability to process oxygen). We will also test whether thiamine improves the ability of patient’s cells to use oxygen normally, and other blood tests that are markers for brain and other organ injury.

This is a randomized, double-blind, placebo-controlled study. This means that when a patient starts the study neither the patient, family nor the research team will know if the patient is getting thiamine or a placebo (an inactive substance, in this case simple salt water).

Who is eligible to be in this study?

We will include adult patients who are brought to the hospital after a cardiac arrest requiring CPR.

How is this study different from many research studies?

Because of the importance of administering Vitamin B1 (Thiamine) as soon as possible after cardiac arrest in order to maximize the chance of finding a benefit, this study will be conducted under exception from informed consent (EFIC) in accordance with the federal Food and Drug Administration (FDA) regulations. EFIC is allowed only when testing possible treatments for life-threatening conditions for which there is no alternative proven treatment, when obtaining consent is not possible because the study treatment must be administered quickly and family or healthcare proxy is not reachable.

When someone is reachable to provide consent, research staff will obtain consent prior to enrollment.  For participants enrolled under EFIC, they or their representatives will be notified of enrollment as soon as possible and asked if they would like to continue participation, with the option to withdraw from the study at any time. All patients will receive standard post-cardiac arrest care per their clinical team, whether or not they enroll in the study.

When research is done under EFIC, the study must conduct outreach to the surrounding community to inform them of the study, get feedback on the proposed study and EFIC, and provide a way for individuals to opt out of the study.  Based on this response, the IRB has determined that we can move forward. We will continue to take feedback and questions from anyone in the community leading up to and during the trial.

Opting out: Any member of the community has the right to opt out if they do not wish to be enrolled in the event that they suffer a cardiac arrest. In order to opt out, a person simply needs to contact our team at, or (617) 754-2885, and provide their name and date of birth. A bracelet indicating their wish to opt out of the BIDMC THACA trial will be provided either by being mailed to their home or picked up at the medical center, according to their preference.

Results: The THACA study is now complete. Results can be found at ( and in the manuscript.

Improving patient lives by advancing the field of resuscitation medicine