Planken, R. Nils

Abstract Background Left atrial appendage (LAA) closure or amputation is commonly performed in atrial fibrillation (AF) patients undergoing cardiac surgery to reduce stroke risk. It has been shown that LAA closure or amputation results in persistent blood pressure (BP) decrease, which may be due to a surge in atrial natriuretic peptide (ANP) and by suppression of sympathetic activity due to activation of mechanoreceptors by atrial distention. We hypothesize that size of the LAA, a compliant structure, affects atrial distension. Consequently, patients with smaller LAA remnants (i.e. more complete amputation) have more distension of the atrium and a more pronounced BP response upon LAA amputation. Methods We analyzed 33 patients with persistent AF from the MARK AF registry who underwent LAA amputation concomitant to thoracoscopic AF ablation. Systolic BP was measured at baseline, 12 hours (h), 24h, and 48h, 1 month, 1 year, and 2 years postoperatively. Complete amputation was defined as LAA remnant depth <10mm and a remnant LAA was defined as depth ≥ 10 mm on contrast enhanced CT 6 months post surgery. The postoperative LAA remnant/LA volume ratio was calculated by segmenting the atria and quantifying the volume of the contrast pools. T-tests and linear regression analyzed BP changes by remnant size and LAA remnant/LA volume ratio. Results were visualized using a boxplot and scatter plots with regression lines. Results 25/33 Patients had a LAA remnant. Baseline systolic BP was similar with 147 ± 31 mmHg in the complete amputation group vs. 137 ± 23 mmHg in the remnant group, p=0.389. Complete amputation correlated with greater systolic BP reductions in relation to baseline at 12h (-18%, p=0.018), 24h (-14%, p=0.025), 48h (-15%, p=0.028), 1 month (-20%, p=0.024), and 1 year (-16%, p=0.001), Figure 1. BP returned to baseline by 2 years in both groups. Lower LAA remnant/LA volume ratios were significantly associated with greater systolic BP reductions at 12h (β=7.4, p=0.005), 24h (β=9.9, p<0.001), 48h (β=10.1, p=0.002), and 1 month (β=11.1, p=0.01), Figure 2. However, this association was not observed at 1 and 2 years. Conclusion Patients with smaller LAA remnants after LAA amputation experienced a more pronounced transient reduction in blood pressure. Our findings suggest that increased atrial distension—due to the loss of compliant LAA tissue—could play a key role in modulating hemodynamics via sympathoinhibition and suppression of the Renin-Angiotensin-Aldosterone System (RAAS). Further investigation is needed to confirm these results and explore the neurohumoral effects of LAA amputation.Figure 1 Figure 2

Background: Cardiac CT acquired during the acute stroke imaging protocol is an emerging diagnostic modality to detect cardiac thrombi. We aimed to determine its diagnostic yield in a large, international, multicenter study. Methods: We performed an individual patient data meta-analysis by pooling prospective and retrospective observational data of patients with acute ischemic stroke (AIS) who underwent cardiac CT (ECG-gated or non-ECG-gated) as part of the acute imaging protocol between May 2018 and June 2024. We excluded patients with a TIA or stroke mimic. The primary outcome was the proportion of patients with a cardiac thrombus detected on cardiac CT. Secondary outcomes were additional scan time and radiation dose, comparison of yield with echocardiography, and 90-day mortality and recurrent ischemic stroke rates. Results: We included 3940 patients from 4 hospitals (median age 74 [IQR 63-82], 58.0% male, median NIHSS 6 [IQR 3-12], median time onset to hospital arrival 100 minutes [IQR 62-185]). Atrial fibrillation at baseline was present in 23.1% patients, and 29.6% had a large vessel occlusion. Cardiac CT was non-diagnostic in 17 (0.4%) patients. In total, cardiac CT detected 254 cardiac thrombi in 243/3923 (6.2%) patients. Thrombi were located in the left atrial appendage (n=193), left atrium (n=19), and left ventricle (n=42). Of 95/243 (39.1%) patients with a cardiac thrombus that underwent echocardiography (median interval cardiac CT-echocardiography: 2 days), transthoracic echocardiography detected a thrombus in 18/92 (19.6%) patients and transesophageal echocardiography in 2/5 (40.0%) patients. The diagnostic yield in patients that underwent both modalities was higher for cardiac CT (OR 7.5 [CI 4.0-15.3], p<0.001). Median additional scan time was 6 minutes (IQR 5-7) for ECG-gated and 17 seconds (IQR 15-63) for non-ECG-gated cardiac CT. Median additional radiation dose was 5.4mSv (IQR 3.0-7.6). Patients with a cardiac thrombus on cardiac CT had higher 90-day mortality than those without a thrombus (33.3% vs 14.6%, p<0.001). We found no difference in 90-day recurrent stroke rate (5.4% vs 4.4%, p=0.50). Conclusion: Routine cardiac CT performed during the acute stroke imaging protocol detects a cardiac thrombus in 1 out of 16 patients with AIS, with a 7-times higher yield than routine echocardiography. Mortality rate was doubled in patients with a cardiac thrombus, but 90-day stroke recurrence risk did not differ.

Background: The rate of intracardiac thrombus detection in the hyperacute phase of stroke varies from 5% to 12% between studies. Our aim was to compare the thrombus detection rate between ECG-gated and non-ECG-gated cardiac CT protocols in acute stroke patients, using data from a large, international, multicentre registry. Methods: We conducted an individual patient data meta-analysis by pooling prospective and retrospective observational data from stroke patients assessed at four comprehensive stroke centres who underwent either ECG-gated or non-ECG-gated cardiac CT (extended CT angiography or two-phase non-ECG-gated cardiac CT) as part of the acute stroke imaging protocol between May 2018 and June 2024. The primary outcome was the proportion of patients with a cardiac thrombus in gated vs non gated techniques. Results: Of 3,940 patients, 1,474 (37.4%) underwent ECG-gated and 2,466 (62.6%) non-ECG-gated cardiac CT. Patients in the ECG-gated group were younger (median age 72 [IQR 62–81] vs. 74 [IQR 64–82] years, p = 0.000) and had a lower NIHSS at baseline (median 5 [IQR 2–12] vs. 6 [IQR 3–13], p < 0.00). There was a higher rate of thrombus detection with ECG-gated CT compared to non-gated CT (7.5% vs. 5.5%, p = 0.011. The association remained significant after adjusting for age, sex, baseline NIHSS score, and baseline atrial fibrillation (adjusted OR 1.87, 95% CI 1.42–2.47, p = 0.000). ECG-gated CT was associated with lower radiation dose (3.6 vs. 6.3 mSv, p = 0.000) but longer acquisition time (5.8 vs. 0.28 min, p = 0.000). Conclusion: ECG-gated cardiac CT has a higher detection rate for intracardiac thrombus detection compared to non-ECG-gated CT in patients with acute ischemic stroke.

Abstract Introduction Cardiac CT is increasingly used to screen for cardioembolism in stroke patients. We assessed the frequency and management of non-cardiac incidental findings on prospective ECG-gated cardiac CT in patients with a suspected stroke. Patients and methods This was a post-hoc analysis of the Mind the Heart study, a prospective single-centre cohort study including consecutive adult patients with acute ischaemic stroke (AIS), transient ischaemic attack (TIA), or a stroke mimic who underwent cardiac CT as part of an acute stroke imaging protocol. Endpoints were pre-defined non-cardiac incidental findings that were detected on cardiac CT: pulmonary embolism (PE), potential malignant lesions, pulmonary consolidations or ground-glass densities, bone fractures, lymphadenopathy, focal liver lesions, and ascending aortic or pulmonary artery dilatation. Change of management was defined as additional treatment or follow-up. Results We included 654 patients (57% men, median age 71 [IQR 59–80] years) of whom 451 (69%) had AIS, 48 had TIA (7%), and 155 had a stroke mimic (24%). Overall, 58 non-cardiac incidental findings were found in 55 (8%; 95%CI, 6–11) patients. The most frequent incidental findings were consolidations or ground-glass densities (n = 17, 3%), liver cysts or non-specific hypodensities (n = 14, 2%), pulmonary nodules or masses (n = 9, 1%), and PEs (n = 8, 1%). Incidental findings led to a change of management in 17/55 (31%) patients of whom 13/55 (24%) had additional follow-up and 9/55 (16%) received treatment (anticoagulation n = 8, chemotherapy n = 1). Discussion & Conclusion Non-cardiac incidental findings were observed on cardiac CT in 8% of patients with a suspected stroke. These findings changed management in 31% of these patients.

Abstract Background Coronary computed tomography angiography (CCTA) is a non-invasive diagnostic modality for assessing coronary artery disease (CAD), with a growing global trend favouring a "CT-first" approach. However, this strategy strains healthcare systems as demand for CCTA increases. Pre-test probability (PTP) models for obstructive CAD are used to optimize the usage of CCTA. However, these models perform inconsistently across different subpopulations and offer limited discriminatory accuracy, with low positive predictive values (PPV). This study aims to enhance the PTP models with explainable artificial intelligence (XAI) on electrocardiogram (ECG) data. Methods Patients who underwent CCTA for suspected CAD with both CAD-Reporting and Data System (CAD-RADS) classification and Coronary Artery Calcium Score (CACS) were included. Obstructive CAD was defined as CAD-RADS 3 or above. Missing values were imputed. The Risk Factor Weighted Clinical Likelihood (RF-CL) model, based on clinical variables (age, sex, symptom type, smoking, hypertension, dyslipidaemia, diabetes, and family history) was computed. Two gradient descent decision tree models, "AI-ECG" and "AI-CAC," were developed for the pilot study. AI-ECG used clinical risk factors and ECG classification as abnormal, borderline or normal, while AI-CAC further incorporated CACS. We used a cutoff value of 15%, reflecting current guidelines. Comparative analysis was performed using area under the curve (AUC) analysis, the DeLong test for statistical comparison, and feature importance using SHAP values. We intend to develop and present a model based on ECG signal data during the conference. Pilot results We identified 6 178 patients who underwent CCTA between 2022 and 2024 at the Cardiology Centers Netherlands (CCN), of which 2 083 were included (mean age 57.4 ± 10.2 years; 48.1% male). Obstructive CAD was found in 413 (19.8%) patients. The RF-CL model was outperformed by both AI-ECG (AUC: 0.69 vs. 0.80, p&lt;0.001) and AI-CACS (AUC: 0.69 vs. 0.90, p&lt;0.001). Sensitivity increased in both AI models, from 0.46 to 0.87 for AI-ECG and to 0.83 for AI-CACS, while PPV improved only in the AI-CACS model (from 0.37 to 0.61). Key predictive features were CACS, age, sex, ECG classification, and family history. Conclusion and Discussion Our pilot study shows that integrating XAI with clinical risk factors and ECG classification enhances PTP estimation for obstructive CAD. Implementing this model can better stratify patients at risk of obstructive CAD, support more focused CCTA use and reduce unnecessary testing. Nonetheless, further external validation is needed to assess model performance in real-world, prospective clinical settings. Additionally, models based on raw ECG signals have the potential to extract more detailed information.Reciever Operating Characteristic CurvesFeature Importance

Increased epicardial adipose tissue attenuation on CT images was associated with the presence and recurrence of atrial fibrillation in studies using consistent or corrected tube voltage settings, suggesting its potential as a prognostic marker.

BACKGROUND: Left atrial (LA) diverticula are focal outpouchings of the LA wall and may increase ischemic stroke risk. We studied recurrent ischemic stroke in patients with acute ischemic stroke and LA diverticula detected on cardiac computed tomography. METHODS: We used data from a prospective cohort study of patients with acute ischemic stroke undergoing cardiac computed tomography acquired during the acute stroke imaging protocol. Cardiac radiologists systematically assessed the presence and characteristics of LA diverticula, defined as LA wall outpouchings with a length/ostium width ratio >0.5 and length ≥3 mm. We compared recurrent ischemic stroke and functional outcome (modified Rankin Scale) after 2 years between patients with and without LA diverticula, adjusting for age, history of atrial fibrillation and ischemic stroke, and anticoagulation use. RESULTS: Of 447 included patients (median age 72 [interquartile range (IQR), 62–81], 59% male), 126 (28%) had LA diverticula: median length 6 mm (IQR, 4–8), width 5 mm (IQR, 4–7), and volume 113 mm 3 (IQR, 52–254). There was no statistically significant difference in age (median 70 [IQR, 58–79] versus 73 [IQR, 63–81]; P =0.06), sex (64% versus 57% male; P =0.28), history of ischemic stroke (21% versus 17%; P =0.48), atrial fibrillation (11% versus 19%; P =0.09), or baseline National Institutes of Health Stroke Scale score (median 5 [IQR, 2–14] versus 5 [IQR, 3–14]; P =0.54) between patients with and without LA diverticula, respectively. Recurrent ischemic stroke was more common in patients with LA diverticula (18/124 [15%] versus 24/314 [8%], adjusted hazard ratio, 2.01 [95% CI, 1.08–3.77]), and recurrence risk increased with diverticulum volume (adjusted hazard ratio, 1.02 [95% CI, 1.01–1.03] per 10 mm 3 ). Functional outcome was better in patients with diverticula (median modified Rankin Scale score of 2 [IQR, 1–3] versus 3 [IQR, 1–6], adjusted common odds ratio, 0.62, [95% CI, 0.42–0.92]). CONCLUSIONS: LA diverticula are a common finding on cardiac computed tomography in patients with acute ischemic stroke, and the risk of recurrent ischemic stroke was increased in these patients, particularly in those with larger diverticula. Atrial diverticula may be a risk factor for recurrent ischemic stroke. REGISTRATION: URL: https://www.onderzoekmetmensen.nl/nl/trial/50352 ; Unique identifier: NL6413901818.

Abstract Background Patients with atrial fibrillation (AF) are at increased risk of stroke, often arising from a thrombus in the left atrial appendage (LAA). In selected cases, left atrial appendage occlusion or closure is an alternative for stroke prevention with oral anticoagulation. To assess the risk of stroke and the benefit of LAA closure and to select the appropriate device, it is crucial to quantify the morphology and dynamics of the left atrial appendage (LAA). To date, much about LAA dynamics in this setting is unknown, and subsequently the risk of embolic stroke and inappropriate device positioning is insufficiently explored. Purpose We describe the morphological and dynamic differences of the left atrium (LA) and LAA in high risk AF patients compared to controls undergoing trans catheter aortic valve implantation (TAVI). Methods Our study population consists of 14 patients, seven with AF and seven without AF, undergoing TAVI, since dynamic computed tomography (CT) angiography scans are performed in the standard of care in these patients. The scans were acquired every 5% of the cardiac cycle (i.e., R-R interval on the ECG) (Figure 1a). The LA and LAA were semi-automatically segmented (Figure 1b) to determine the following parameters across the entire cardiac cycle: LA volume; LAA volume, depth, height, and length; and ostium area, eccentricity, and diameter. Results AF patients had a significantly larger LA volume (108 mL vs 68 mL, p=0.03), while the LA volume change throughout the cardiac cycle was similar in AF patients and controls. Both groups had an LA volume change of 35mL on average. Figure 1cd shows the LA and LAA volume curves of a patient with and without AF. The LAA ostium size and volume of AF patients exhibited larger dynamic variations than those from non-AF patients, while the ostium eccentricity in AF patients showed less variation and the ostium shape was rounder. Conclusions We found differences in morphologic and dynamic parameters of the LA and LAA between AF and non-AF patients. The morphology and dynamics of the LAA can increase the understanding of LAA thrombus formation. Moreover, it may have implications for the risk of embolic stroke and may assist in the selection of the optimal LAA closure device type and size.

ABSTRACT Background The relationship between height differences related to graft anatomy and physiological pressure indices in coronary bypass grafts has not been studied. We sought to study the impact of hydrostatic pressure on fractional flow reserve (FFR) in saphenous vein grafts (SVGs). Methods Included were 66 symptomatic patients (76 SVGs) with prior coronary artery bypass grafting who underwent coronary computed tomography angiography (CCTA) preceding invasive coronary angiography with FFR interrogation of ≥ 1 SVGs. The graft course and height excursion were reconstructed based on CCTA images. The impact of hydrostatic pressure on FFR (corrected FFR) was calculated by adding or subtracting 0.077 mmHg to the distal coronary pressure for every millimeter height difference in a supine position between the SVG ostium and the pressure wire tip position. Results The height difference (mm) between the SVG ostium and pressure wire tip position was largest for single SVGs to the circumflex artery (Cx; −55.1 ± 17.0), followed by sequential SVGs to the Cx (−51.8 ± 17.3) and the right coronary artery (RCA; −36.7 ± 21.6). The correlation between height difference and uncorrected FFR was −0.59 ( p < 0.001). Corrected FFR was lower as compared to uncorrected FFR in the overall cohort (0.86 ± 0.17 vs. 0.88 ± 0.18), in single SVGs to Cx (0.85 ± 0.17 vs. 0.90 ± 0.18), and in sequential SVGs to Cx (0.92 ± 0.14 vs. 0.96 ± 0.15) and RCA (0.82 ± 0.17 vs. 0.85 ± 0.21) ( p < 0.001 for all). Conclusions Hydrostatic pressure related to height differences along the course anatomy of SVGs can impact FFR measurements, with corrected FFR being significantly lower in SVGs to the Cx and sequential SVGs to the RCA.