Evaluation of Beta-Blockers with Alpha Activity and Nitric Oxide Liberation in Takotsubo Syndrome: A Randomized Controlled Trial

The primary objective of this study is to evaluate the clinical efficacy of **beta-blockers** in patients with Takotsubo Syndrome (TT), an acute cardiac condition. The study aims to assess the role of beta-blockers with alpha activity or nitric oxide liberation in facilitating the recovery of left ventricular function as observed through echocardiography in TT patients. The clinical relevance of this objective lies in determining the effectiveness of a widely used pharmacological strategy in improving cardiac function in TT, potentially guiding therapeutic decisions in clinical practice. The consistency of the treatment effect will be examined across several predefined clinical subgroups, with adjustments made for multiple comparisons.

Secondary objectives will be addressed through predefined ancillary studies, including:

• Assessment of other relevant echocardiographic outcome measures of left ventricular function (LVEF, GLS) at different time points post-index event.
• Coronary angiographic assessment (visual and QCA).
• Magnetic resonance imaging (MRI).
• Intracoronary imaging using optical coherence tomography (OCT) and intravascular ultrasound (IVUS).
• Invasive and noninvasive coronary physiological indexes.
• Cardiac CT.
• Pharmacogenetics.
• Inflammatory, immunologic, genetic, and micro-RNA analyses.
• Quality of life (QoL) analyses using well-accepted questionnaires.

The clinical trial involves participants diagnosed with **Takotsubo Syndrome**, an acute cardiac condition. The study population includes both male and female subjects, with an age range spanning from adults to the elderly. Participants were selected based on specific inclusion criteria, including a confirmed diagnosis of Takotsubo Syndrome and the exclusion of significant culprit coronary artery disease through invasive angiography. The trial does not focus on a vulnerable population. Lifestyle considerations such as diet, physical activity, or habits are not specified. The sponsor has not provided information regarding the total number of participants in this study.

The clinical trial is designed to evaluate the **clinical efficacy** of beta-blockers in patients with **Takotsubo Syndrome** (TT), an acute cardiac condition. This study is a randomized, double-blind, controlled trial, ensuring that neither the participants nor the researchers know which treatment the participants are receiving, thus minimizing bias. The trial will span approximately two years, with an estimated recruitment start date of March 15, 2024, and an estimated end date of February 2, 2026.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to confirm eligibility based on criteria such as a diagnosis of TT and exclusion of significant coronary artery disease. Following the screening, participants will be randomly assigned to receive either a beta-blocker with alpha activity or a selective or non-selective beta-blocker, administered orally. The primary endpoint is the comparison of left ventricular systolic function recovery, assessed by the echocardiographic left ventricular wall motion score index (WMSI) at 7 days. Secondary endpoints include changes in left ventricular function by other methods and comparison of clinical outcomes.

Participants are expected to be involved in the trial for a maximum treatment period of 24 weeks. Follow-up visits will be scheduled to monitor the participants' health and the efficacy of the treatment. The end-of-study visit will conclude the trial for each participant, where final assessments will be conducted. Conditions that may lead to early termination from the study include withdrawal of consent or any adverse events that compromise the safety of the participant. The trial is categorized as a Phase IV, low-intervention study, as it involves drugs already on the market used within their approved indications, without additional procedures beyond standard clinical care.

The clinical trial involves the administration of three different **beta-blockers** to evaluate their efficacy in patients with Takotsubo Syndrome. The first experimental medication is a **beta-blocker with alpha activity**, classified under the ATC code C07AG. This group includes medications such as carvedilol and labetalol. The pharmaceutical form is coded as PHF00009MIG, and the medication is administered orally. The maximum daily dose is 25 mg, with a total maximum dose of 25 mg over a treatment period of 24 weeks. The medication is not a pediatric formulation and is not classified as an orphan drug.

The second experimental medication is a **selective beta-blocker**, classified under the ATC code C07AB. This category includes drugs such as nebivolol, metoprolol, and atenolol. The pharmaceutical form is coded as PHF00082MIG, and the medication is administered orally. The maximum daily dose is 5 mg, with a total maximum dose of 5 mg over a treatment period of 24 weeks. Similar to the first medication, it is not a pediatric formulation and is not classified as an orphan drug.

The third experimental medication is a **non-selective beta-blocker**, classified under the ATC code C07AA. This group includes medications such as propranolol, oxprenolol, and pindolol. The pharmaceutical form is also coded as PHF00082MIG, and the medication is administered orally. The maximum daily dose is 40 mg, with a total maximum dose of 40 mg over a treatment period of 24 weeks. This medication is also not a pediatric formulation and is not classified as an orphan drug.

All medications are administered orally, and participant compliance is monitored throughout the trial. The trial does not include any non-experimental treatments such as standard-of-care therapy, placebo, or comparator treatment. The primary objective is to assess the role of these beta-blockers in facilitating left ventricular function recovery in patients with Takotsubo Syndrome, with treatment effects examined across several predefined clinical subgroups.

The clinical trial titled "Beta-Blockers in Takotsubo Syndrome: A Randomized Clinical Trial" aims to evaluate the clinical efficacy of beta-blockers in patients with **Takotsubo Syndrome**. The primary endpoint for assessing efficacy is the comparison of left ventricular systolic function recovery, which will be measured using the echocardiographic left ventricular wall motion score index (WMSI) at 7 days. Secondary endpoints include changes in left ventricular function assessed by other methods such as left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS), as well as the comparison of clinical outcomes, including adverse clinical events.

The trial will utilize echocardiography as the primary tool for efficacy assessment, focusing on the recovery of left ventricular function. Measurements will be collected at specific timepoints, with the primary assessment occurring at 7 days post-treatment initiation. The study will also explore the consistency of treatment effects across several predefined clinical subgroups, adjusting for multiple comparisons to ensure robust analysis. The trial is categorized as a low-intervention Phase IV study, involving drugs already on the market and used within their approved indications, without additional procedures beyond standard clinical care.