Impact of pacing mode and different echocardiographic parameters on cardiac output (PADIAC).

Introduction: The extent of the hemodynamic benefit from AV-synchronous pacing in patients with sinus rhythm and AV block is not completely understood. Thus, we systematically investigated the association of an array of echocardiographic and epidemiological parameters with the change in cardiac output depending on the stimulation mode (AV-synchronous or AV-asynchronous pacing). Methods: Patients in sinus rhythm after previous dual chamber pacemaker implantation underwent a thorough basic echocardiographic assessment of diastolic and systolic left ventricular function, and atrial function (26 echo parameters, including novel speckle tracking strain measurements). Then, stroke volume was measured with AV-synchronous (DDD) and AV-asynchronous (VVI) pacing. Each patient represented their own control, and the sequence of stroke volume measurements was randomized. Results: In this prospective single-center study (NCT04068233, registration August 22nd 2019), we recruited 40 individuals. The stroke volume was higher in all patients when applying AV-synchronous DDD pacing [median increase 12.8 ml (16.9%), P < 0.001]. No echo parameter under investigation was associated with the extent of stroke volume increase in a linear regression model. Of all epidemiological variables, a history of acute myocardial infarction (AMI) was associated with an attenuated stroke volume gain in a univariate and a multivariate regression model that adjusted for confounders. A- and S-wave velocities were reduced in the AMI group. Discussion: In our cohort of patients, each subject benefited from AV-synchronous DDD pacing. No single echo parameter could predict the amount of stroke volume increase. The beneficial effect of AV-synchronous pacing on stroke volume was attenuated after prior acute myocardial infarction.ClinicalTrials.gov identifier (NCT number): NCT04068233.

Diagnostic Accuracy of Bone Scintigraphy for the Histopathological Diagnosis of Cardiac Transthyretin Amyloidosis-A Retrospective Austrian Multicenter Study.

We aimed to ascertain the real-world diagnostic accuracy of bone scintigraphy in combination with free light chain (FLC) assessment for transthyretin (ATTR) cardiac amyloidosis (CA) using the histopathological diagnosis derived from endomyocardial biopsy (EMB) as a reference standard. We retrospectively analyzed 102 patients (22% women) with suspected CA from seven Austrian amyloidosis referral centers. The inclusion criteria comprised the available results of bone scintigraphy, FLC assessment, and EMB with histopathological analysis. ATTR and AL were diagnosed in 60 and 21 patients (59%, 21%), respectively, and concomitant AL and ATTR was identified in one patient. The specificity and positive predictive value (PPV) of Perugini score ≥ 2 for ATTR CA were 95% and 96%. AL was diagnosed in three out of 31 patients (10%) who had evidence of monoclonal proteins and a Perugini score ≥ 2. When excluding all patients with detectable monoclonal proteins (n = 62) from analyses, the PPV of Perugini score ≥ 2 for ATTR CA was 100% and the NPV of Perugini score < 2 for ATTR CA was 79%. Conclusively, ATTR CA can be diagnosed non-invasively in the case of a Perugini score ≥ 2 and an unremarkable FLC assessment. However, tissue biopsy is mandatory in suspected CA in any other constellation of non-invasive diagnostic work-up.

Myocarditis following mRNA COVID-19 vaccination: call for endomyocardial biopsy.

Acute myocarditis following mRNA COVID-19 vaccination was reported by the European Medicine Agency safety committee as a rare adverse event. We present a case series of three young male patients with suspected acute myocarditis following BNT162b2 mRNA COVID-19 vaccination including results of endomyocardial biopsies (EMB). Additionally, we analysed EMB of another 21 patients with clinically suspected acute myocarditis following vaccination to determine the pathohistological pattern. Overall, EMB revealed acute lymphocytic myocarditis in 5 (20.8%), chronic lymphocytic myocarditis in 6 (25%), cardiac sarcoidosis in 1 (4.2%), healed myocarditis in 6 (25%), and other diagnoses with cardiac damage of unclear aetiology in 6 (25%) cases. Our findings support the necessity of EMB in patients with suspected acute myocarditis following mRNA COVID-19 vaccination presenting with reduced EF to establish a correct and definite diagnosis. Concerns of these rare severe adverse events after COVID-19 immunization should not undermine its value for the global community.

Predictors of true-severe classical low-flow low-gradient aortic stenosis at resting echocardiography.

BACKGROUND: Classical low-flow, low-gradient (LF/LG) aortic stenosis (AS) is subclassified into a true-severe (TS) and a pseudo-severe (PS) subform using low-dose dobutamine stress echocardiography (DSE). In clinical practice a resting peak jet velocity (Vmax) >3.5 m/s or a mean transvalvular gradient (MPG) >35 mmHg suggests the presence of TS classical LF/LG AS, but there is no data to support this. The aim of this study was therefore to investigate whether a resting Vmax >3.5 m/s or MPG >35 mmHg reliably predicted diagnosis of TS classical LF/LG AS. METHODS: One hundred (100) consecutive patients with classical LF/LG AS were prospectively recruited. All patients underwent DSE for subcategorization. The impact of Vmax and MPG for the presence of the TS subform were analyzed. RESULTS: TS classical LF/LG AS was diagnosed in 72 patients. Resting Vmax and resting MPG predicted true-severity with an ROC-AUC of 0.737 (95%CI: 0.635-0.838; p < 0.001) and 0.725 (95%CI: 0.615-0.834; p < 0.001), respectively. The optimal positive predictive values (PPV) for the diagnosis of TS classical LF/LG AS were obtained with a resting Vmax >3.5 m/s or resting MPG >35 mmHg. In a multivariate logistic regression analysis, Vmax >3.5 m/s was independently associated with a 5.33-fold odds-ratio of TS classical LF/LG AS (OR 5.33; 95%CI: 1.34-21.18, p = 0.018). CONCLUSIONS: TS classical LF/LG AS can be reliably predicted by a resting Vmax >3.5 m/s or a resting MPG >35 mmHg. Further imaging for subclassification is not needed in this situation.

High-molecular-weight von Willebrand Factor multimer ratio differentiates true-severe from pseudo-severe classical low-flow, low-gradient aortic stenosis.

AIMS: Upon high wall shear stress, high-molecular-weight (HMW) von Willebrand Factor (VWF) multimers are degraded, thus, HMW VWF multimer deficiency mirrors haemodynamics at the site of aortic stenosis (AS). The aim of the present study was to analyse the role of HMW VWF multimer ratio for subcategorization of classical low-flow, low-gradient (LF/LG) AS. METHODS AND RESULTS: Eighty-three patients with classical LF/LG AS were prospectively recruited and HMW VWF multimer pattern was analysed using a densitometric quantification of western blot bands. Patients were subclassified into true-severe (TS) and pseudo-severe (PS) classical LF/LG AS based on dobutamine stress echocardiography (DSE). Positive and negative predictive values (PPV/NPV) of HMW VWF multimer ratio for diagnosis of the TS subtype were calculated. HMW VWF multimer ratio in TS classical LF/LG AS was significantly decreased compared to PS classical LF/LG AS (0.86 ± 0.27 vs. 1.06 ± 0.09, P < 0.001). HMW VWF multimer deficiency occurred exclusively in the TS subtype with an optimal PPV of 1.000 and NPV of 0.379. HMW VWF multimer ratio showed a strong correlation with mean transvalvular pressure gradients during DSE (r = -0.616; P < 0.001). HMW VWF multimer ratio measured at baseline was higher compared to levels measured after DSE (0.87 ± 0.27 vs. 0.84 ± 0.31; P = 0.031) indicating DSE-induced increased proteolysis. CONCLUSION: HMW VWF multimer ratio represents a valuable biomarker for classical LF/LG AS subclassification and mirrors haemodynamics during DSE. HMW VWF multimer ratio identifies the TS subtype without the use of other imaging techniques.

Evaluation of the Manchester triage system for patients with acute coronary syndrome.

BACKGROUND: An early diagnosis of acute coronary syndrome (ACS) is crucial for treatment and prognosis. The aim of this study was to evaluate the Manchester triage system (MTS) for patients with ACS, e.g. ST-segment elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (N-STEMI) and unstable angina pectoris (UAP). METHODS: Retrospective analysis of patients diagnosed with ACS (STEMI, N­STEMI and UAP) who were triaged in the emergency department (ED) with the MTS. RESULTS: In this study 282 patients with ACS (STEMI: 34.0%, N­STEMI: 61.7%, UAP: 4.3%) were triaged as MTS level 1 (immediate assessment): 0.4%, MTS level 2 (very urgent): 51.4%, MTS level 3 (urgent): 41.5%, MTS level 4 (standard): 6.7%, MTS level 5 (non-urgent): 0%. We observed significantly lower mean MTS levels in males (male: 2.48 ± 0.59, female: 2.68 ± 0.68, p = 0.02) and in patients younger than 80 years (age <80 years: 2.50 ± 0.61, age ≥80 years: 2.70 ± 0.67, p = 0.03). We did not find a significant difference of mean MTS levels in different types of ACS (STEMI: 2.46 ± 0.6, N­STEMI: 2.59 ± 0.64, STEMI vs N­STEMI: p = 0.11, UAP: 2.67 ± 0.65, STEMI vs UAP: p = 0.26) and with respect to diabetes (diabetic: 2.47 ± 0.57, non-diabetic: 2.58 ± 0.65, p = 0.13). The in-hospital mortality was 2.5% (MTS level 2: n = 3, MTS level 3: n = 3, MTS level 4: n = 1). CONCLUSION: The majority of patients with ACS were classified as MTS levels 2 and 3. There was no significant difference of mean MTS levels in patients with STEMI, NSTEMI and UAP. In order to assure an early diagnosis of STEMI, an electrocardiogram (ECG) should be carried out immediately or at least within 10 min after first medical contact in the ED in all patients suspected for ACS, irrespective of the assigned MTS level.

Monocenter Investigation Micra® MRI study (MIMICRY): feasibility study of the magnetic resonance imaging compatibility of a leadless pacemaker system.

AIMS: As in vivo real-life data are still scarce, we conducted a study to assess the safety and feasibility of cardiac magnetic resonance imaging (MRI) in patients with a leadless pacemaker system. METHODS AND RESULTS: In this prospective non-randomized interventional trial, we enrolled 15 patients with an MRI conditional Micra® leadless pacemaker system to undergo either a 1.5 T or 3.0 T cardiac MRI scan. Clinical adverse events as well as device parameters such as pacing threshold, sensing, impedance, and battery life were assessed at baseline as well as 1 and 3 months after the scan. Device parameter changes between different time points were tested for statistical significance and compared with pre-set cut-off values. Fourteen patients underwent the cardiac MRI scan according to the protocol as well as the scheduled follow-up visits. One participant was excluded from analysis, as the MRI scan was not possible because of severe claustrophobia. Other clinical events did not occur during the scan and the follow-up period. Device parameters stayed stable and changes during the observational period were statistically not significant (changes vs. baseline: pacing threshold: 0.01 ± 0.05 V, P = 0.308, 0.01 ± 0.07 V, P = 0.419, sensing: -0.15 ± 1.11 mV, P = 0.658, -0.19 ± 1.17 mV, P = 0.800, impedance: -7.86 ± 30.7 Ohm, P = 0.447, -7.86 ± 25.77 Ohm, P = 0.183, at 1 and 3 months follow-up, respectively). Parameter changes were not statistically different between patients who underwent imaging at 1.5 T (n = 7) or 3.0 T (n = 7). CONCLUSION: In our set of patients with a Micra® leadless pacemaker, cardiac magnetic resonance imaging at either 1.5 T or 3.0 T proved feasible and safe with no relevant changes in device parameters within 3 months of follow-up.

Artefacts in 1.5 Tesla and 3 Tesla cardiovascular magnetic resonance imaging in patients with leadless cardiac pacemakers.

BACKGROUND: There are limited data on patients with leadless cardiac pacemakers (LCP) undergoing magnetic resonance imaging. The aim of this prospective, single-center, observational study was to evaluate artefacts on cardiovascular magnetic resonance (CMR) images in patients with LCP. METHODS: Fifteen patients with Micra™ LCP, implanted at least 6 weeks prior to CMR scan, were enrolled and underwent either 1.5 Tesla or 3 Tesla CMR imaging. Artefacts were categorized into grade 1 (excellent image quality), grade 2 (good), grade 3 (poor) and grade 4 (non-diagnostic) for each myocardial segment. One patient was excluded because of an incomplete CMR investigation due to claustrophobia. RESULTS: LCP caused an arc-shaped artefact (0.99 ± 0.16 cm2) at the right ventricular (RV) apex. Of 224 analyzed myocardial segments of the left ventricle (LV) 158 (70.5%) were affected by grade 1, 27 (12.1%) by grade 2, 17 (7.6%) by grade 3 and 22 (9.8%) by grade 4 artefacts. The artefact burden of grade 3 and 4 artefacts was significantly higher in the 3 Tesla group (3 Tesla vs 1.5 Tesla: 3.7 ± 1.6 vs 1.9 ± 1.4 myocardial segments per patient, p = 0.03). A high artefact burden was particularly observed in the mid anteroseptal, inferoseptal and apical septal myocardial segments of the LV and in the mid and apical segments of the RV. Quantification of LV function and assessment of valves were feasible in all patients. We did not observe any clinical or device-related adverse events. CONCLUSION: CMR imaging in patients with LCP is feasible with excellent to good image quality in the majority of LV segments. The artefact burden is comparable small allowing an accurate evaluation of LV function, cardiac structures and valves. However, artefacts in the mid anteroseptal, inferoseptal and apical septal myocardial segments of the LV due to the LCP may impair or even exclude diagnostic evaluation of these segments. Artefacts on CMR images may be reduced by the use of 1.5 Tesla CMR scanners.

Reversible impairment of coronary flow reserve in acute myocarditis.

OBJECTIVE: Acute myocarditis is accompanied by an impaired coronary microcirculation. These microcirculatory disturbances are not well defined, and data are derived from complex invasive measurements. Therefore, this study aimed to evaluate the inflammation-induced microcirculatory dysfunction including its reversibility and association with markers of inflammation severity (extent of LGE on CMR imaging and laboratory markers of myocardial necrosis) using the noninvasive technique of echocardiographic CFR measurement. METHODS: Patients (n = 14) with clinically suspected acute myocarditis in the absence of coronary artery disease were prospectively enrolled, and echocardiographic CFR was determined by measuring peak diastolic coronary blood flow velocity at rest (PDV1) and under adenosine-induced hyperemia (PDV2) at baseline and 3-month follow-up. RESULTS: Eight of 14 (57.1%) patients showed an impaired baseline CFR (PDV2/PDV1 < 2). These patients were characterized by higher levels of cardiac troponin T (0.55 ± 0.39 vs 0.18 ± 0.08; P = 0.008) and larger areas of LGE on CMR. At 3-month follow-up, CFR was normal in all patients. CONCLUSION: A reversibly impaired coronary microcirculation is a frequent finding in acute myocarditis and is associated with markers of inflammation severity. Echocardiographic CFR measurement represents a feasible and safe method for its assessment.

Economic assessment of traditional surgical intervention versus use of a new innovative radiofrequency based surgical system in device replacements.

INTRODUCTION: Intra-operative complications like mechanical damages to the leads, infections and hematomas during generator replacements of implantable pacemakers and defibrillators contribute to additional costs for hospitals. The aim of this study was to evaluate operation room use, costs and budget impact of generator replacements using either a traditional surgical intervention (TSI) with scissors, scalpel and electrocautery vs. a new radiofrequency energy based surgical system, called PEAK PlasmaBladeTM (PPB). MATERIALS AND METHODS: We conducted a retrospective analysis of a population including 508 patients with TSI and 254 patients with PPB who underwent generator replacement at the Kepler University Hospital in Linz or the St. Josef Hospital in Braunau, Austria. The economic analysis included costs of resources used for intra-operative complications (lead damages) and of procedure time for TSI vs. PPB. RESULTS: Proportion of males, mean age and type of generator replaced were similar between the two groups. Lead damages occurred significantly more frequent with TSI than with PPB (5.3% and 0.4%; p< 0.001) and the procedure time was significantly longer with TSI than with PPB (47.9±24.9 and 34.1±18.1 minutes; p<0.001). Shorter procedure time and a lower rate of lead damages with PPB resulted in per patient cost savings of €81. Based on estimated 2,700 patients annually undergoing generator replacement in Austria, the use of PPB may translate into cost savings of €219,600 and 621 saved operating facility hours. CONCLUSION: PPB has the potential to minimize the risk of lead damage with more efficient utilization of the operating room. Along with cost savings and improved quality of care, hospitals may use the saved operating room hours to increase the number of daily surgeries.

Subcutaneous Double "Purse String Suture"-A Safe Method for Femoral Vein Access Site Closure after Leadless Pacemaker Implantation.

BACKGROUND: Leadless cardiac pacemaker (LCP) requires large-caliber venous sheaths for device placement. Sheath sizes for these procedures vary from 18- to 23-French (F). The most common complications are hematomas, pseudoaneurysms, and arteriovenous fistulas. Complete and secure closure of the venous access is an important step at the end of such a procedure. METHODS: We performed a retrospective analysis of all patients who had undergone LCP implantation at our institution. Patients and procedural characteristics as well as groin complications at 30 days and 3 months were evaluated. After sheath removal venous access sites were closed performing a so-called "purse-string" suture (PSS). RESULTS: Seventy-seven patients received an LCP at our institution. In 27 (35%) of these patients a heparin bolus was given at the beginning of the procedure. Anticoagulation therapy with phenprocoumon was present in 32 (40%) of patients. In 76 (98.7%) patients, the LCP was implanted without complications. In one (1.3%) patient a perforation occurred during implantation, which required surgical intervention. Access site complications occurred in three (3.9%) patients, two (2.6%) groin hematomas, and one (1.3%) arteriovenous fistula. The hematomas disappeared completely after 3 weeks, and the fistula was not detectable by ultrasound anymore after 4 weeks. CONCLUSION: Use of subcutaneous absorbable double PSS closure after removal of large-caliber venous sheaths is a safe technique to achieve immediate postprocedural hemostasis. Especially for sheath sizes with an inner diameter of 23F, this technique creates a very secure and also cosmetically appealing closure.