Study Proposal: Change in Albumin Levels After Cardiac Operations

Prospective, two-arm, unblinded, randomized mono-centric trial

Study Overview

The trial titled  "Change in Albumin Levels After Cardiac Operations Through Essential Amino Acid Supplementation"  investigates the impact of amino acid supplementation on serum albumin levels in patients undergoing cardiac surgery.

Hypotheses

The primary hypothesis posts that patients receiving nutritional supplementation with amino acids will exhibit higher postoperative serum albumin levels compared to those who do not receive the supplement.

The secondary hypothesis suggests that these patients will experience fewer adverse events after surgery.

Design

This is a prospective, two-arm, unblinded, randomized mono-centric trial involving 100 subjects.

Participants will be randomly assigned in a 1:1 ratio to either the amino acid supplement (AAS) group or the no supplement (NS) group. Permuted block randomization will ensure balanced treatment distribution.

Outcomes

The primary outcome of the study is the measurement of serum albumin levels. The secondary outcomes will focus on the incidence of adverse events following cardiac surgery, with primary safety measures including serum creatinine, blood urea nitrogen, and blood ammonia levels.

Subject Enrollment and Intervention

A total of 100 subjects will be enrolled in the study. Data collection will occur solely during the patients' hospital stays, with no follow-up post-discharge. All participants will undergo standard heart surgery. Those in the AAS group will receive two protein drinks daily, beginning the day before surgery and continuing until the seventh postoperative day, while the NS group will receive standard care.

Inclusion/Exclusion Criteria

Inclusion criteria specify that subjects must be scheduled for open-heart surgery. Key exclusion criteria include pregnancy, age under 18, emergency operations, recent previous cardiac surgeries, severe end-organ dysfunction, liver cirrhosis, significant lactose intolerance, and participation in another clinical trial within the last three months.

Sample Size and Statistical Analysis

Given the lack of comparable studies, the sample size is set at 50 participants per trial arm. The primary outcome will be analyzed per protocol, with results presented using line charts and boxplots, including treatment as a covariate, and reported with 95% confidence intervals and p-values.

The perioperative assessment of blood parameters will occur in the morning before surgery and conclude at the end of the procedure. Following surgery, daily blood parameter assessments will be conducted. Any postoperative adverse events will be documented in the patient’s case file and subsequently transferred to the case report form once the patient’s medical care is completed. All collected data will be meticulously recorded in this case report form.

The assessment schedule will include daily screenings from Day 1 through Day 9. Key elements include informed consent, the surgical operation, documentation of adverse events, and the collection of blood parameters.Outcome Measures:

1. Primary Outcome: The primary focus will be on serum albumin levels.

2. Secondary Outcomes: This includes monitoring for adverse events such as: Revision due to bleeding

Perioperative and postoperative myocardial infarctions

Any incidence of stroke Requirements for dialysis or tracheostomy Surgical site and sternal wound complications Unplanned re-operations Prolonged mechanical ventilation (>24 hours) New rhythm disturbances Acute renal failure Nosocomial infections Shock All-cause mortality

Safety Considerations 

Discharge to a location other than home will be noted, along with any safety concerns such as elevated serum creatinine (>2.5 mg/dL), blood urea nitrogen (>45 mg/dL), or blood ammonia levels (>150 μg/dL).

Follow-Up

There will be no follow-up after discharge, as data collection is confined to the hospital stay.

Sample Size

The study aims for 50 participants in each treatment group, as there are no existing studies on essential amino acid supplementation for cardiac surgery patients.

Statistical Analysis

Representativeness of the study sample will be illustrated through a CONSORT flow diagram, with demographic and clinical characteristics compared across randomized groups. Outcomes will be analyzed per-protocol, utilizing Chi-squared and Student’s t-tests as appropriate, with non-parametric tests for non-normally distributed variables. Primary and Secondary Outcomes The primary outcome data will be visually represented using a line chart and box plots, incorporating the treatment arm as a covariate. Secondary outcomes will be analyzed both individually and in combination. All outcomes will be reported with a 95% confidence interval and associated p-values. It is important to note that this analysis will not adjust for clustering of patients within surgeons.

Trial Organization

The study will be coordinated by …....... Data Monitoring and Safety Monitoring of the trial will be conducted by …..., a medical student from …....., under the supervision of …......... and …......., both of whom are members of the cardiac surgery team at the study center. There will be no interim efficacy analysis due to the trial's small scale and short duration. However, if a participant experiences an adverse reaction to the amino acid supplements (AAS) or violates safety measures, they will be withdrawn from the study.

Trial Location

This trial will be conducted at the Department of Cardiac Surgery..........

Ethics and Funding

This trial will adhere to the MRG Guidelines for Good Clinical Practice and the Declaration of Helsinki. Approval from the …... Ethics Committee and the Ethics Committee of ….......... will be obtained prior to commencement. This is an academic study, and protein supplements will be provided at no cost.

Registration and Publication

The trial is yet to be registered.

Publication of study results will occur after the trial's completion and all data collection is finalized. Approval from the Ethics Committee of the City of Vienna will be sought for publication.

References

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