OPTImizing Lead Placement in Patients Requiring Pacemaker After Cardiac Surgery (OPTI-PACS)

OPTIMIZING LEAD PLACEMENT IN PATIENTS REQUIRING PACEMAKER AFTER CARDIAC SURGERY

Conventional right ventricular pacing has been associated with ventricular dyssynchrony and an increased risk of pacing-induced cardiomyopathy, which may lead to worse clinical outcomes. To lessen the burden of pacing-induced cardiomyopathy, the adoption of conduction system pacing has increased in recent years. In patients with normal cardiac function, measured as left ventricular ejection fraction, the superiority of conduction system pacing is less clear. As a result, both pacing strategies remain in widespread clinical use.

Patients undergoing cardiac surgery represent a vulnerable cohort for pacing-induced cardiomyopathy, given their established structural heart disease, and postoperative atrioventricular block remains a common occurrence in these patients.

This multicenter randomized trial aims to evaluate the use of conduction system pacing, in the form of left bundle branch area pacing, versus conventional pacing in patients with normal left ventricular ejection fraction after cardiac surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Cardiac Surgery; Atrioventricular Block
• Intervention / Treatment: Device: Conventional pacing strategy; Device: Left bundle branch area pacing

Detailed Description

A high percentage of ventricular pacing increases the risk of pacing-induced cardiomyopathy. Pacing-induced cardiomyopathy is a syndrome defined by left ventricular dysfunction secondary to chronic right ventricular pacing, resulting in impaired outcomes. Pacing-induced cardiomyopathy is estimated to affect approximately 10-20% of patients with a high proportion of right ventricular pacing (>20%), a population that mainly consists of patients with atrioventricular block (AVB). The abnormal activation leads to prolonged electrical and mechanical activation, which results in ventricular dyssynchrony. Other important risk factors for pacing-induced cardiomyopathy include structural heart disease and reduced ejection fraction, male sex and wide, paced QRS.

Clinical practice guidelines support pacemaker implantation following cardiac surgery only for severe and non-transient bradyarrhythmias, as pacemaker implantation increases the risk of severe infections and device-related long-term complications. Evidence suggests that a substantial proportion of patients who receive a pacemaker following cardiac surgery have limited need for pacing at long-term follow-up. Thus, the risk/benefit ratio for patients following cardiac surgery differs from that of the general population, while these patients also form a vulnerable population at high risk for pacing-induced cardiomyopathy.

Over the last decade, a conduction system pacing strategy called left bundle branch area pacing (LBBAP) has been developed. In LBBAP, the pacemaker lead is inserted deep into the interventricular septum from the right ventricle to the left ventricular endocardium, targeting the left bundle and its resulting fascicles. As the current understanding of the development of pacing-induced cardiomyopathy suggests that the electrical dyssynchrony introduced by right ventricular pacing plays a crucial role, our hypothesis is that its incidence could be reduced by the favorable electrical activation achieved with LBBAP.

There are ongoing randomized controlled trials of conduction system pacing in the general population; however, none are investigating cardiac surgery patients. These patients differ substantially from the general population in age, expected long-term survival, and cardiovascular health. This increases their risk of pacing-induced cardiomyopathy and could influence the feasibility of conduction system pacing due to their otherwise impaired cardiovascular health. At the same time, their long-term pacing dependence could differ from that of the general population.

Therefore, the aim of the present multicenter randomized controlled trial is to evaluate the long-term outcomes of LBBAP versus right ventricular pacing after cardiac surgery in patients with normal left ventricular ejection fraction. A secondary aim is to assess the feasibility of LBBAP after cardiac surgery with regard to implantation success and long-term electrical parameters. The results of this trial are anticipated to provide clinically meaningful evidence to guide pacing strategy selection in this patient cohort.

• Study Type: Interventional
• Enrollment (Estimated): 110
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Andreas S Martinsson, MD, PhD; Phone Number: +46313427717; Email: andreas.s.martinsson@vgregion.se
• Study Contact Backup: Name: Alice David, MD; Phone Number: +313429684; Email: laura.david@vgregion.se

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• High degree atrioventricular block
• Cardiac surgery within 30 days of pacemaker implantation
• Written informed consent
• Current left ventricular ejection fraction at or above 50%

Exclusion Criteria:

• Any concomitant condition that results in a life expectancy of less than 1 year
• Planned for heart transplant or left ventricular assist device
• Current dialysis
• Not suitable according to the opinion of the investigators due to characteristics that interfere with the adherence to the study protocol.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Conventional pacing strategy; This arm will receive a conventional pacemaker lead if they have atrioventricular block after cardiac surgery	Device: Conventional pacing strategy; Conventional pacing strategy
Experimental: Left bundle branch area pacing strategy; This arm will receive a left bundle branch area pacing pacemaker lead if they have atrioventricular block after cardiac surgery	Device: Left bundle branch area pacing; Conventional pacing strategy versus conduction system pacing strategy in the form of left bundle branch area pacing

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in left ventricular ejection fraction	Change in left ventricular ejection fraction between enrollment and end of follow-up	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
All-cause mortality	All-cause mortality	1 year
Change in left ventricular end-diastolic diameter	Change in LVEDD from enrollment to end of study follow-up	1 year
Clinical endpoints - composite	Composite of all-cause mortality, heart failure hospitalization, device-related hospitalization	1 year
Heart failure hospitalization	Heart failure hospitalization	1 year
Device-related hospitalization	Device-related hospitalization	1 year
Quality-of-life measurement	Quality-of-life measurement by standardized questionnaire	1 year

Collaborators and Investigators

• Sponsor: Sahlgrenska University Hospital
• Investigators: Principal Investigator: Andreas S Martinsson, MD, PhD, Sahlgrensa university hospital

Study record dates

Study Major Dates

• Study Start (Estimated): September 10, 2026
• Primary Completion (Estimated): December 1, 2030
• Study Completion (Estimated): December 1, 2030

Study Registration Dates

• First Submitted: August 26, 2026
• First Submitted That Met QC Criteria: August 26, 2026
• First Posted (Actual): August 31, 2026

Study Record Updates

• Last Update Posted (Actual): August 31, 2026
• Last Update Submitted That Met QC Criteria: August 26, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Atrioventricular block; Conduction system pacing; Left bundle branch area pacing; After cardiac surgery
• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Heart Block; Pathological Conditions, Signs and Symptoms; Atrioventricular Block
• Other Study ID Numbers: 2025-08652-01; 2025 (U.S. NIH Grant/Contract: Faculty of Social Sciences Scientific Grant at the University of Gdańsk); 20241208 (Other Grant/Funding Number: Swedish Heart- Lung Foundation); ALFGBG-977905 (Other Grant/Funding Number: ALF Agreement (Swedish state)); ALFGBG-1029431 (Other Grant/Funding Number: ALF Agreement (Swedish state))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No