Effects of Early Vagus Nerve Stimulation on Infarct Damage and Functioning After Acute STEMI

The goal of this clinical trial is to investigate whether early non-invasive vagus nerve stimulation (nVNS) can reduce infarct damage and improve functioning after acute ST-elevation myocardial infarction (STEMI). It will assess the safety and effectiveness of nVNS in improving cardiac outcomes. The main questions it aims to answer are:

* Does nVNS improve short-term prognosis post-STEMI by enhancing heart rate variability (HRV) and reducing inflammation?
* Does nVNS reduce infarct size, improve left ventricular function, and lower inflammatory markers compared to sham stimulation?

Participants will be randomly assigned to one of two groups:

* Experimental group: Receive standard care plus nVNS for 60 minutes at the right ear using the Parasym device under ECG monitoring.
* Control group: Receive standard care plus sham nVNS (placebo-like procedure without stimulation).

Participants will undergo stimulation once for 60 minutes post-percutaneous coronary intervention (PCI), and be monitored for adverse reactions like bradycardia, with immediate cessation if needed.

Key study details:

* Inclusion criteria: Adults aged 25-75 years with confirmed STEMI (clinical signs and elevated troponin).
* Exclusion criteria: Bradycardia (HR \< 50 bpm), extensive anterior MI, hypotension, or severe cardiac/medical conditions.
* Intervention parameters: Stimulation targeting the auricular branch of the vagal nerve with 200µs pulse width, 20Hz frequency, and adjustable intensity (10-50mA), remaining below the pain threshold.

Outcomes measured:

* Primary outcomes: Wall motion score index (WMSI) and left ventricular ejection fraction (LVEF).
* Secondary outcomes: HRV metrics, troponin levels, inflammatory markers (CRP, NLR), atrial fibrillation events, hospitalization duration, one-month survival, quality of life (HeartQOL scale), and one-year survival.

Statistical analysis: Researchers will compare baseline characteristics using t-tests and chi-square tests. Main analyses will involve repeated measures mixed-design ANOVA and multivariate ANOVA. Moderation analysis will assess the influence of the experimental condition on inflammation and clinical outcomes.

Ethical considerations: The study complies with Israeli Ministry of Health guidelines for emergency clinical trials. Participants will provide verbal consent followed by written consent. Ethical approval was granted by the IRB of Bnai Zion Medical Center, Haifa, Israel (Approval No. 0169-21-BNZ).


Eligibility Criteria:
Inclusion Criteria:

* Having had an MI verified by clinical signs (e.g., pain in the chest, left arm, left shoulder), ST-elevation MI (STEMI) and clinically significant elevations of troponin values (cut-off value 19 ng/l or using sex-specific cut-off values of 14ng/l for women and 22ng/l for men.
* Between 25-75 years of age.
* Patients with Intra-Aortic Balloon.

Exclusion Criteria:

* Heart rate (HR) \< 50 bpm (bradycardia)
* Extensive anterior MI: According to infarct size criteria: KILLIP III \& KILLIP IV of Heart Failure following MI is defined as Extensive anterior MI.
* Hypotension (systolic blood pressure \< 90mmHg).
* Sildenafil treatment.
* Diagnosed with Atrial Fibrillation.
* Diagnosed with Ventricular arrythmias not including Accelerated Idio Ventricular Rhythm (AIVR).
* Anaesthetize patient.
* Mechanical ventilated patient.
* Participation in another trial