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Objectives: A randomized trial was done to compare single-chamber atrial (AAI) and dual-chamber (DDD) pacing in patients with sick sinus syndrome (SSS). Primary end points were changes in left atrial (LA) size and left ventricular (LV) size and function as measured by M-mode echocardiography.Background: In patients with SSS and normal atrioventricular conduction, it is still not clear whether the optimal pacing mode is AAI or DDD pacing.Methods: A total of 177 consecutive patients (mean age 74 +/- 9 years, 73 men) were randomized to treatment with one of three rate-adaptive (R) pacemakers: AAIR (n = 54), DDDR with a short atrioventricular delay (n = 60) (DDDR-s), or DDDR with a fixed long atrioventricular delay (n = 63) (DDDR-l). Before pacemaker implantation and at each follow-up, M-mode echocardiography was done to measure LA and LV diameters. Left ventricular fractional shortening (LVFS) was calculated. Analysis was on an intention-to-treat basis.Results: Mean follow-up was 2.9 +/- 1.1 years. In the AAIR group, no significant changes were observed in LA or LV diameters or LVFS from baseline to last follow-up. In both DDDR groups, LA diameter increased significantly (p < 0.05), and in the DDDR-s group, LVFS decreased significantly (p < 0.01). Atrial fibrillation was significantly less common in the AAIR group, 7.4% versus 23.3% in the DDDR-s group versus 17.5% in the DDDR-l group (p = 0.03, log-rank test). Mortality, thromboembolism, and congestive heart failure did not differ between groups.Conclusions: During a mean follow-up of 2.9 +/- 1.1 years, DDDR pacing causes increased LA diameter, and DDDR pacing with a short atrioventricular delay also causes decreased LVFS. No changes occur in LA or LV diameters or LVFS during AAIR pacing. Atrial fibrillation is significantly less common during AAIR pacing. [ABSTRACT FROM AUTHOR]

Background and Aims: Risk stratification of sudden cardiac death after myocardial infarction and prevention by defibrillator rely on left ventricular ejection fraction (LVEF). Improved risk stratification across the whole LVEF range is required for decision-making on defibrillator implantation., Methods: The analysis pooled 20 data sets with 140 204 post-myocardial infarction patients containing information on demographics, medical history, clinical characteristics, biomarkers, electrocardiography, echocardiography, and cardiac magnetic resonance imaging. Separate analyses were performed in patients (i) carrying a primary prevention cardioverter-defibrillator with LVEF ≤ 35% [implantable cardioverter-defibrillator (ICD) patients], (ii) without cardioverter-defibrillator with LVEF ≤ 35% (non-ICD patients ≤ 35%), and (iii) without cardioverter-defibrillator with LVEF > 35% (non-ICD patients >35%). Primary outcome was sudden cardiac death or, in defibrillator carriers, appropriate defibrillator therapy. Using a competing risk framework and systematic internal-external cross-validation, a model using LVEF only, a multivariable flexible parametric survival model, and a multivariable random forest survival model were developed and externally validated. Predictive performance was assessed by random effect meta-analysis., Results: There were 1326 primary outcomes in 7543 ICD patients, 1193 in 25 058 non-ICD patients ≤35%, and 1567 in 107 603 non-ICD patients >35% during mean follow-up of 30.0, 46.5, and 57.6 months, respectively. In these three subgroups, LVEF poorly predicted sudden cardiac death (c-statistics between 0.50 and 0.56). Considering additional parameters did not improve calibration and discrimination, and model generalizability was poor., Conclusions: More accurate risk stratification for sudden cardiac death and identification of low-risk individuals with severely reduced LVEF or of high-risk individuals with preserved LVEF was not feasible, neither using LVEF nor using other predictors., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Purpose To assess long-term geometric changes of the mitral valve apparatus using cardiac CT in individuals who underwent cardiac resynchronization therapy (CRT). Materials and Methods Participants from a randomized controlled trial with cardiac CT examinations before CRT implantation and at 6 months follow-up (Clinicaltrials.gov identifier NCT01323686) were invited to undergo an additional long-term follow-up cardiac CT examination. The geometry of the mitral valve apparatus, including mitral valve annulus area, A2 leaflet angle, tenting height, and interpapillary muscle distances, were assessed. Geometric changes at the long-term follow-up examination were reported as mean differences (95% CI), and the Pearson correlation test was used to assess correlation between statistically significant geometric changes and left ventricular (LV) volumes and function. Results Thirty participants (mean age, 68 years ± 9 [SD]; 25 male participants) underwent cardiac CT imaging after a median long-term follow-up of 9.0 years (IQR, 8.4-9.4). There were reductions in end-systolic A2 leaflet angle (-4° [95% CI: -7, -2]), end-systolic tenting height (-1 mm [95% CI: -2, -1]), and end-systolic and end-diastolic interpapillary muscle distances (-4 mm [95% CI: -6, -2]) compared with pre-CRT implantation values. The mitral valve annulus area remained unchanged. LV end-diastolic and end-systolic volumes decreased (-68 mL [95% CI: -99, -37] and -67 mL [95% CI: -96, -39], respectively), and LV ejection fraction increased (13% [95% CI: 7, 19]) at the long-term follow-up examination. Changes in interpapillary muscle distances showed moderate to strong correlations with LV volumes ( r = 0.42-0.72; P < .05), while A2 leaflet angle and tenting height were not correlated to LV volumes or function. Conclusion Among the various geometric changes in the mitral valve apparatus after long-term CRT, the reduction in interpapillary muscle distances correlated with LV volumes while the reduced A2 leaflet angle and tenting height did not correlate with LV volumes. Keywords: Mitral Valve Apparatus, Cardiac Resynchronization Therapy, Cardiac CT Supplemental material is available for this article. © RSNA, 2024.

Background: Staphylococcus aureus bacteremia (SAB) is a high-risk condition associated with high morbidity and mortality. In the presence of cardiac implantable electronic devices (CIEDs), SAB may cause or clinically indicate device infection. We aimed to estimate the 10-year absolute risk of SAB in adult Danish first-time CIED carriers. Secondary aims included identification of risk factors associated with SAB., Methods: A registry-based study utilizing Danish nationwide registers and including consecutive Danish patients undergoing first CIED implantation between 2000 and 2020 was conducted. The primary outcome was first-time SAB after CIED implantation., Results: A total of 87 257 patients with first CIED implantation in the study period were identified (median age, 75 years; 62.6% were male; median follow-up, 3.8 years). Patients with pacemakers (PMs) were older and with more noncardiovascular comorbidities compared to patients with implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy devices with or without defibrillator capacity (CRTs). In total, 1366 patients (1.6%) developed SAB. The 10-year absolute risk (95% confidence interval) of SAB was 2.0% (1.9%-2.1%) for PM, 2.6% (2.2%-3.1%) for ICD, and 3.7% (3.0%-4.5%) for CRT. A multivariable Cox analysis identified hemodialysis (hazard ratio [HR], 8.51), SAB before CIED (HR, 2.76), liver disease (HR, 2.35), and carrying a CRT device (HR, 1.68) among the covariates associated with increased risk of SAB., Conclusions: The absolute risk of SAB in Danish CIED carriers increased with more advanced CIED systems. The risk was highest within the first 3 months after CIED implantation and increased with the presence of certain covariates including renal dialysis, SAB before CIED, male sex, and advancing age., Competing Interests: Potential conflicts of interest. N. E. B. reports grants/contracts not related to this study from the Novo Nordisk Foundation and Health Insurance Denmark, and participation on a data and safety monitoring board or advisory board in the Heart Runner Project. E. F. reports grants/contracts not related to this study from the Novo Nordisk Foundation. J. B. J. reports payment or honoraria for lectures, presentations, speaker’s bureaus, manuscript writing, or educational events not related to this project from Medtonic and Merit Medical. J. C. N. reports a role as executive editor for Europace. S. R. reports grants/contracts not related to this study from the Novo Nordisk Foundation. A. C. R. reports payment or honoraria for lectures, presentations, speaker’s bureaus, manuscript writing, or educational events nor related to this project from Novartis, Bristol-Myers Squibb, and AstraZeneca. L. Ø. reports grants/contracts not related to this study from the Novo Nordisk Foundation. All other authors report no potential conflicts., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Background: In the ARTESiA trial (Apixaban for the Reduction of Thromboembolism in Patients With Device-Detected Subclinical Atrial Fibrillation), apixaban, compared with aspirin, reduced stroke or systemic embolism in patients with device-detected subclinical atrial fibrillation (SCAF). Clinical guidelines recommend considering SCAF episode duration when deciding whether to prescribe oral anticoagulation for this population., Methods: We performed a retrospective cohort study in ARTESiA. Using Cox regression adjusted for CHA 2 DS 2 -VASc score and treatment allocation (apixaban or aspirin), we assessed frequency of SCAF episodes and duration of the longest SCAF episode in the 6 months before randomization as predictors of stroke risk and of apixaban treatment effect., Results: Among 3986 patients with complete baseline SCAF data, 703 (17.6%) had no SCAF episode ≥6 minutes in the 6 months before enrollment. Among 3283 patients (82.4%) with ≥1 episode of SCAF ≥6 minutes in the 6 months before enrollment, 2542 (77.4%) had up to 5 episodes, and 741 (22.6%) had ≥6 episodes. The longest episode lasted <1 hour in 1030 patients (31.4%), 1 to <6 hours in 1421 patients (43.3%), and >6 hours in 832 patients (25.3%). Higher baseline SCAF frequency was not associated with increased risk of stroke or systemic embolism: 1.1% for 1 to 5 episodes versus 1.2%/patient-year for ≥6 episodes (adjusted hazard ratio, 0.89 [95% CI, 0.59-1.34]). In an exploratory analysis, patients with previous SCAF but no episode ≥6 minutes in the 6 months before enrollment had a lower risk of stroke or systemic embolism than patients with at least one episode during that period (0.5% versus 1.1%/patient-year; adjusted hazard ratio, 0.48 [95% CI, 0.27-0.85]). The frequency of SCAF did not modify the reduction in stroke or systemic embolism with apixaban ( P interaction =0.1). The duration of the longest SCAF episode in the 6 months before enrollment was not associated with the risk of stroke or systemic embolism during follow-up (<1 hour: 1.0%/patient-year [reference]; 1-6 hours: 1.2%/patient-year [adjusted hazard ratio, 1.27 (95% CI, 0.85-1.90)]; >6 hours: 1.0%/patient-year [adjusted hazard ratio, 1.02 (95% CI, 0.63-1.66)]). SCAF duration did not modify the reduction in stroke or systemic embolism with apixaban ( P trend =0.1)., Conclusions: In ARTESiA, baseline SCAF frequency and longest episode duration were not associated with risk of stroke or systemic embolism and did not modify the effect of apixaban on reduction of stroke or systemic embolism., Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01938248.