1. The patients suspected coronary artery disease or those needing an angiography as per the inclusion criteria would be included after a 2d echocardiography and treadmill test/ stress myocardial stress imaging (if indicated) after a written and informed consent.

2. Anthropometric and lab paraments would be recorded.

3. Study will have 2 arms. I. A study arm 1 - baseline comparative arm of patients having undergone angiography with standard dose/ old low dose angiography.

   II. A study arm 2 - a comparative arm where the patients being once eligible for the study; would undergo angiography using the new low dose protocol.

4. Post completion of the sample size the data of each angiographic view would be noted in both the study arms

INTRODUCTION

The increasing prevalence of cardiovascular diseases has led to a surge in the use of diagnostic angiography procedures. While these procedures are crucial for diagnosing and treating heart conditions, they also involve significant exposure to ionizing radiation. Excessive radiation exposure can pose serious health risks, including an increased risk of cancer and other adverse effects.

The RADRED study aims to address the critical issue of radiation exposure in cardiology catheterization labs. By comparing the radiation dose received by patients undergoing diagnostic angiography with and without a new low dose exposure protocol, the study seeks to evaluate the effectiveness of this protocol in reducing radiation exposure.

Several factors contribute to the need for such research. Firstly, the growing number of patients undergoing diagnostic angiography, particularly elderly individuals and those with multiple comorbidities, increases the cumulative radiation exposure to the population. Secondly, advancements in imaging technology have led to more complex procedures, often requiring longer fluoroscopy times, which can result in higher radiation doses. Finally, there is a growing awareness of the potential long-term health consequences of radiation exposure, particularly for vulnerable populations.

The RADRED study has the potential to make a significant contribution to the field of cardiology by demonstrating the feasibility and benefits of implementing a low dose exposure protocol in catheterization labs. By reducing radiation exposure, this protocol can help to protect the health of patients and healthcare providers, while also improving the overall efficiency and cost-effectiveness of diagnostic angiography procedures AIM To study determine the difference in the radiation exposure in diagnostic angiography with and without a new low dose exposure protocol

OBJECTIVES Primary objective To determine the difference in the radiation exposure levels received by patients undergoing diagnostic angiography with and without the new low dose exposure protocol.

Secondary objectives

1. To evaluate the diagnostic image quality obtained with the new low dose exposure protocol compared to the standard protocol.
2. To assess any potential limitations associated with the new low dose exposure protocol.

STUDY DESIGN:

Observational analytical cohort study

PARTICIPANTS:

Inclusion criteria:

Adult patients who qualify for a need of diagnostic angiography and are finally found to have normal epicardial coronaries, e.g.:

• Pre aortic or mitral valve replacement angiography
• TMT positive for inducible ischemia
• SPECT MPI positive patients
• Cradiologically symptomatic patients with ECG abnormalities, who cannot be subjected to stress test
• High risk pre transplant patients

Exclusion criteria:

• Those who are unwilling for study
• Patients who come with STEMI or NSTEMI

STUDY METHOD:

1. The patients suspected coronary artery disease or those needing an angiography as per the inclusion criteria would be included after a 2d echocardiography and treadmill test/ stress myocardial stress imaging (if indicated) after a written and informed consent.

2. Anthropometric and lab paraments would be recorded.

3. Study will have 2 arms. I. A study arm 1 - baseline comparative arm of patients having undergone angiography with standard dose/ old low dose angiography.

   II. A study arm 2 - a comparative arm where the patients being once eligible for the study; would undergo angiography using the new low dose protocol.

4. Post completion of the sample size the data of each angiographic view would be noted in both the study arms

PERIOD OF STUDY: till completion of sample in study arm 2 (each successive patient would be enrolled - cluster sample)

PATIENT CONSENT:

Appropriate approval will be obtained from IEC of the institute.

STATISTCAL ANALYSIS Data will be compiled in an excel sheet for all the variables of interest and presented in the form of tables and graphs as appropriate.

Measures of central tendency (mean or median) would be calculated for all quantitative variables along with measures of dispersion (standard deviation or interquartile range). Qualitative or categorical variables will be described as frequencies and proportions. The investigators will use a t-test for independent samples to compare the means of radiation exposure All the statistical analysis will be carried out using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, version 22.0 for Windows) at 5% level of significance i.e., p≤0.05 will be considered significant

ETHICAL JUSTIFICATION This study aims to evaluate the efficacy of a new low-dose radiation protocol for diagnostic angiography in cardiology Cath labs. By comparing patient radiation exposure with and without the protocol, the study seeks to reduce the cumulative radiation burden on patients, especially those at higher risk due to age or underlying health conditions. The increasing frequency of diagnostic angiography, coupled with advancements in imaging technology leading to more complex procedures, has resulted in a growing concern about the potential long-term health risks associated with radiation exposure. This study addresses this critical issue by exploring the effectiveness of a new protocol designed to minimize radiation dose during these procedures

. As, such low dose protocol has never been used earlier, there is a need for evaluating the same as to set new standards and protocols

The patients involved in the research project will be informed of the methods, anticipated benefits and potential risks of the study and the discomfort it may cause and the remedies thereof.

Written informed consent will be obtained. Every precaution will be taken to respect the privacy and confidentiality of the patient.

The parent has right to abstain from the study or to withdraw consent to participate at any time of the study without reprisal.

Due care and caution will be taken at all stages to ensure that the patient is put to minimum risk or suffer from irreversible side effects and probably benefit from study

DISCLOSURES/ CONFLICT OF INTEREST: NIL

Inclusion Criteria:

Adult patients who qualify for a need of diagnostic angiography and are finally found to have normal epicardial coronaries, e.g.:

• Pre aortic or mitral valve replacement angiography
• TMT positive for inducible ischemia
• SPECT MPI positive patients
• Cradiologically symptomatic patients with ECG abnormalities, who cannot be subjected to stress test
• High risk pre transplant patients

Exclusion Criteria:

• Those who are unwilling for study
• Patients who come with STEMI or NSTEMI

Patients undergoing diagnostic angiography (age ≥18 years) will be included in the study.

Currently there is no plan to share the IPD data due to government hospital data sharing restrictions. though anonymous data can be shared with a fellow researcher if a combined study is planned