Pacemaker implantation after cardiac surgery: a contemporary, nationwide perspective

Background: Cardiac surgery entails an increased risk for brady-arrhythmias. Currently known rates for permanent pacemaker (PPM) implantation after cardiac surgery are derived from non-contemporary studies. This study aimed to explore the incidence and indications for PPM implantation at 30 days and one year after different cardiac surgical procedures in a modern cohort. Methods: All first-time coronary artery bypass grafting (CABG) and/or valvular surgery patients in Sweden 2006 - 2020 without previous PPM or implantable cardioverter-defibrillator (ICD) (n= 76,447) were included in this nationwide population-based study using data from four national registries. Patients undergoing heart transplantation and those who subsequently received an ICD were excluded. Results: A PPM was implanted in 8.2% (n= 6,271) of the patients, 35% (n= 2,196) within the first 30 days and 46.3% (n= 2,647) at one year following surgery. The main indication of PPM implantation was atrioventricular block. Tricuspid valve surgery exhibited the highest cumulative incidence for PPM both at 30 days (6.8% (95% confidence interval 4.3 ? 10.0)) and one year (8.8% (95% CI 6.0-12.0)) surpassing mitral valve surgery (30-day 5.3% (95% CI 4.7-6.0); one-year 6.5% (95% CI 5.8-7.3)), aortic valve surgery (30-day 4.8% (95% CI 4.5-5.1); one-year 6.0% (95% CI 5.6-6.3)) and CABG (30-day 0.74% (95% CI 0.66-0.83); one-year 1.3% (95% CI 1.2-1.35)). The incidence following combined operations (multiple valves and/or coronary surgery) was 6.5% (95% CI 6.0-6.9) and 8.1% (95% CI 7.7-8.6) at 30 days and one year respectively. Concomitant ablation surgery increased the risk even further (adjusted Hazard Ratio 9.20 (95% CI 7.96-10.64), p<0.001). Conclusions: The need for PPM after cardiac surgery is common, primarily due to atrioventricular block. Tricuspid valve surgery is associated with the highest risk for PPM implantation amongst isolated procedures. Combined procedures and concomitant surgical ablation further increase that risk. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial The study was not registered due to the retrospective and observational nature of the study. ### Funding Statement This work was funded by the Swedish state under the agreement between the Swedish government and the county councils concerning economic support of research and education of doctors (ALF agreement, ALFGBG-977905 to AM) ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by the Swedish Ethical Review Authority (registration number 2021-00122, approved March 31, 2021). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data used in this study will be provided upon reasonable request and following approval by the SWEDEHEART Registry, the Swedish National Board of Health and Welfare, and the Ethical Review Authority.