THE RELATİONSHİP BETWEEN BLOOD GAS PARAMETERS OBTAİNED FROM THE CORONARY SİNUS DURİNG THE PROCEDURE AND CRT RESPONSE İN PATİENTS WİTH HEART FAİLURE WHO UNDERWENT CRT IMPLANTATİON

Heart failure (HF) is one of the clinical syndromes with the highest morbidity and mortality rates among cardiovascular diseases. Despite pharmacological treatments, symptoms persist in a significant proportion of patients, and mortality cannot be prevented. Therefore, device-based therapies, particularly cardiac resynchronisation therapy (CRT), have gained an important place in the treatment algorithm.CRT aims to correct mechanical dyssynchrony by enabling simultaneous contraction of the left and right ventricles. It also aims to reduce sudden cardiac death rates with its defibrillator feature. Current guidelines emphasise that CRT provides significant benefits in terms of symptomatic improvement and long-term survival when appropriate patient selection is made. However, not all patients who meet the criteria have benefited equally from CRT. It is difficult to predict in advance which heart failure patients will benefit from CRT.The aim of the study is to analyse blood gas parameters obtained from the coronary sinus during the procedure in cases of symptomatic heart failure with low ejection fraction despite optimal medical treatment and in patients with indications for CRT according to current guidelines. This analysis aims to contribute to the prior identification of patients who may benefit.

Study Overview

• Status: Active, not recruiting
• Conditions: Heart Failure; Cardiac Resynchronization Therapy; Coronary Sinus
• Intervention / Treatment: Diagnostic test: coronary sinus blood sampling

• Study Type: Observational
• Enrollment (Actual): 65

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Edirne, Turkey (Türkiye), 22100
    • Trakya University Faculty of Medicine Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Heart failure patients with an ejection fraction below 35, NYHA physical capacity of 2-3, and QRS duration longer than 135 ms on ECG, whose symptoms persist despite optimal medical treatment.

Description

Inclusion Criteria:

1. Patients diagnosed with heart failure, with an EF <35, and in heart failure stages 2-3-4 despite optimal medical therapy.
2. Those who agree to participate in the study.
3. Patients aged 18 years and older.
4. Patients with a QRS duration of 135 ms or more on ECG.

Exclusion Criteria:

1. Patients with EF 35 or higher.
2. QRS duration on ECG less than 130 milliseconds.
3. Not receiving the maximum tolerable dose of medication for KY.
4. Absence of left bundle branch block morphology on ECG.
5. History of acute myocardial infarction within the last 3 months.
6. Estimated life expectancy of less than 1 year.
7. History of cardiac surgery within the last 3 months.
8. Elective cardiac surgery planned.
9. Patients scheduled for CRT prior to nodal ablation.
10. Patients with intracardiac shunts.
11. Those who refuse to participate in the study.
12. Chronic lung diseases (COPD, emphysema, bronchitis, etc.). -

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
The group that benefits from CRT; At the sixth-month visit, patients' ECG findings, NYHA classification, echocardiography parameters, history of hospitalization due to heart failure, need for intravenous (IV) diuretic therapy, need for diuretic dose increase, mortality, device pacing, and intensive care unit admission were evaluated. At the end of follow-up, patients who showed at least a 5-point or 15% increase in ejection fraction and at least a one-grade improvement in NYHA class, and who did not develop heart failure-related death, hospitalization, or IV diuretic requirement during the same period, were classified as the "responsive" group to CRT treatment. Other patients were classified as the "non-responsive" group.	Diagnostic test: coronary sinus blood sampling; Blood gas analysis by drawing blood from the coronary sinus
The group that benefits from CRT and the group that does not; At the sixth-month visit, patients' ECG findings, NYHA classification, echocardiography parameters, history of hospitalization due to heart failure, need for intravenous (IV) diuretic therapy, need for diuretic dose increase, mortality, device pacing, and intensive care unit admission were evaluated. At the end of follow-up, patients who showed at least a 5-point or 15% increase in ejection fraction and at least a one-grade improvement in NYHA class, and who did not develop heart failure-related death, hospitalization, or IV diuretic requirement during the same period, were classified as the "responsive" group to CRT treatment. Other patients were classified as the "non-responsive" group.	Diagnostic test: coronary sinus blood sampling; Blood gas analysis by drawing blood from the coronary sinus

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Combined endpoint of hospitalization for heart failure, death, need for IV diuretics, change in ejection fraction, and change in NYHA classification	6 months

Collaborators and Investigators

• Sponsor: Trakya University

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2022
• Primary Completion (Actual): September 1, 2024
• Study Completion (Estimated): March 15, 2026

Study Registration Dates

• First Submitted: February 20, 2026
• First Submitted That Met QC Criteria: February 20, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 20, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Heart Diseases; Heart Failure
• Other Study ID Numbers: TÜTF-GOBAEK 2022/174

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual patient data will be added to the data system with the written consent of the patients and will be destroyed after statistical analysis. Other researchers are not involved in this process; therefore, these data will not be shared with other researchers.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No