Training-related modulations of the autonomic nervous system in endurance athletes: is female gender cardioprotective?

The risk of sudden death is increased in athletes with a male predominance. Regular physical activity increases vagal tone, and may protect against exercise-induced ventricular arrhythmias. We investigated training-related modulations of the autonomic nervous system in female and male endurance athletes. Runners of a 10-mile race were invited. Of 873 applicants, 68 female and 70 male athletes were randomly selected and stratified according to their average weekly training hours in a low (≤4h) and high (>4h) volume training group. Analysis of heart rate variability was performed over 24h. Spectral components (high frequency [HF] and low frequency [LF] power in normalized units) were analyzed for hourly 5min segments and averaged for day- and nighttime. One hundred and fourteen athletes (50% female, mean age 42±7years) were included. No significant gender difference was observed for training volume and 10-mile race time. Over the 24-h period, female athletes exhibited a higher HF and lower LF power for each hourly time-point. Female gender and endurance training hours were independent predictors of a higher HF and lower LF power. In female athletes, higher training hours were associated with a higher HF and lower LF power during nighttime. In male athletes, the same was true during daytime. In conclusion, female and male athletes showed a different circadian pattern of the training-related increase in markers of vagal tone. For a comparable amount of training volume, female athletes maintained their higher markers of vagal tone, possibly indicating a superior protection against exercise-induced ventricular arrhythmia

Is It Safe to Irradiate the Newest Generation of Ventricular Assist Devices? A Case Report and Systematic Literature Review.

An increasing number of mechanical assist devices, especially Left Ventricular Assist Devices (VAD), are being implanted for prolonged periods and as destination therapy. Some VAD patients require radiotherapy due to concomitant oncologic morbidities, including thoracic malignancies. This raises the potential of VAD malfunction via radiation-induced damage. So far, only case reports and small case series on radiotherapy have been published; most of them on HeartMate IITM (HMII, Abbott, North Chicago, IL, USA). Significantly, the effects of irradiation on the HeartMate 3TM (HM3, Abbott, North Chicago, IL, USA) remain undefined, despite the presence of controller components engineered within the pump itself. We report the first case of a patient with a HM3 who successfully underwent stereotactic hypo-fractionated radiotherapy due to an early stage non-small-cell lung cancer. The patient did not suffer from any complications; including toxicity or VAD malfunction. Based on this case report and on published literature, we think that performing radiotherapy after VAD implantation with the aid of a multidisciplinary team could be performed, but more in-vitro and cases series are needed to reinforce this statement

Diagnostic performance of cardiac magnetic resonance segmental myocardial strain for detecting microvascular obstruction and late gadolinium enhancement in patients presenting after a ST-elevation myocardial infarction.

Background Microvascular obstruction (MVO) and Late Gadolinium Enhancement (LGE) assessed in cardiac magnetic resonance (CMR) are associated with adverse outcome in patients with ST-elevation myocardial infarction (STEMI). Our aim was to analyze the diagnostic performance of segmental strain for the detection of MVO and LGE. Methods Patients with anterior STEMI, who underwent additional CMR were enrolled in this sub-study of the CARE-AMI trial. Using CMR feature tracking (FT) segmental circumferential peak strain (SCS) was measured and the diagnostic performance of SCS to discriminate MVO and LGE was assessed in a derivation and validation cohort. Results Forty-eight STEMI patients (62 ± 12 years old), 39 (81%) males, who underwent CMR (i.e., mean 3.0 ± 1.5 days) after primary percutaneous coronary intervention (PCI) were included. All patients presented with LGE and in 40 (83%) patients, MVO was additionally present. Segments in all patients were visually classified and 146 (19%) segments showed MVO (i.e., LGE+/MVO+), 308 (40%) segments showed LGE and no MVO (i.e., LGE+/MVO-), and 314 (41%) segments showed no LGE (i.e., LGE-). Diagnostic performance of SCS for detecting MVO segments (i.e., LGE+/MVO+ vs. LGE+/MVO-, and LGE-) showed an AUC = 0.764 and SCS cut-off value was -11.2%, resulting in a sensitivity of 78% and a specificity of 67% with a positive predictive value (PPV) of 30% and a negative predictive value (NPV) of 94% when tested in the validation group. For LGE segments (i.e., LGE+/MVO+ and LGE+/MVO- vs. LGE-) AUC = 0.848 and SCS with a cut-off value of -13.8% yielded to a sensitivity of 76%, specificity of 74%, PPV of 81%, and NPV of 70%. Conclusion Segmental strain in STEMI patients was associated with good diagnostic performance for detection of MVO+ segments and very good diagnostic performance of LGE+ segments. Segmental strain may be useful as a potential contrast-free surrogate marker to improve early risk stratification in patients after primary PCI

Isolation and characterization of bacteriophages from the human skin microbiome that infect Staphylococcus epidermidis

Phage therapy might be a useful approach for the treatment of nosocomial infections; however, only few lytic phages suitable for this application are available for the opportunistic pathogen, Staphylococcus epidermidis. In the current study, we developed an efficient method to isolate bacteriophages present within the human skin microbiome, by using niche-specific S. epidermidis as the host for phage propagation. Staphylococcus epidermidis was identified on the forehead of 92% of human subjects tested. These isolates were then used to propagate phages present in the same skin sample. Plaques were observable on bacterial lawns in 46% of the cases where S. epidermidis was isolated. A total of eight phage genomes were genetically characterized, including the previously described phage 456. A total of six phage sequences were unique, and spanned each of the major staphylococcal phage families; Siphoviridae (n = 3), Podoviridae (n = 1) and Myoviridae (n = 2). One of the myoviruses (vB_SepM_BE06) was identified on the skin of three different humans. Comparative analysis identified novel genes including a putative N-acetylmuramoyl-L-alanine amidase gene. The host-range of each unique phage was characterized using a panel of diverse staphylococcal strains (n = 78). None of the newly isolated phages infected more than 52% of the S. epidermidis strains tested (n = 44), and non-S. epidermidis strains where rarely infected, highlighting the narrow host-range of the phages. One of the phages (vB_SepM_BE04) was capable of killing staphylococcal cells within biofilms formed on polyurethane catheters. Uncovering a richer diversity of available phages will likely improve our understanding of S. epidermidis-phage interactions, which will be important for future therapy

Training-related modulations of the autonomic nervous system in endurance athletes: is female gender cardioprotective?

The risk of sudden death is increased in athletes with a male predominance. Regular physical activity increases vagal tone, and may protect against exercise-induced ventricular arrhythmias. We investigated training-related modulations of the autonomic nervous system in female and male endurance athletes. Runners of a 10-mile race were invited. Of 873 applicants, 68 female and 70 male athletes were randomly selected and stratified according to their average weekly training hours in a low (≤4 h) and high (>4 h) volume training group. Analysis of heart rate variability was performed over 24 h. Spectral components (high frequency [HF] and low frequency [LF] power in normalized units) were analyzed for hourly 5 min segments and averaged for day- and nighttime. One hundred and fourteen athletes (50 % female, mean age 42 ± 7 years) were included. No significant gender difference was observed for training volume and 10-mile race time. Over the 24-h period, female athletes exhibited a higher HF and lower LF power for each hourly time-point. Female gender and endurance training hours were independent predictors of a higher HF and lower LF power. In female athletes, higher training hours were associated with a higher HF and lower LF power during nighttime. In male athletes, the same was true during daytime. In conclusion, female and male athletes showed a different circadian pattern of the training-related increase in markers of vagal tone. For a comparable amount of training volume, female athletes maintained their higher markers of vagal tone, possibly indicating a superior protection against exercise-induced ventricular arrhythmias

Computed tomography detection and quantification of left atrial appendage residual patency as collateral finding after percutaneous closure.

Background: Peridevice leaks after left atrial appendage closure (LAAC) may increase the risk of embolic stroke. This study appraises the value of a clinically indicated angio-computed tomography (CT) to assess the presence and size of LAA patency after percutaneous closure. Methods: We retrospectively analysed patients who underwent LAAC in our centre for a clinically indicated angio-CT to quantify Hounsfield units (HU) in LAA and in the left atrium (LA) and correlated them with the presence and size of LAA leaks at TEE. Results: CT scan was available in 56 patients of whom 40 also underwent TEE assessment. Any LAA leak at TEE was present in 9/40 (22.5%) patients of whom all had HU >100 in the LAA. However, HU measured in the LAA was >100 HU in 8 additional patients with no leak at TEE, leading to a sensitivity of 100% (9/9), specificity of 74.1% (23/31) and diagnostic accuracy of 80% (32/40). LAA HU or LAA/LA HU ratio did not discriminate LAA leak size at angio-CT. However, a coaptation gap >3 mm at angio-CT between device and LAA ostium was present in all cases with leak size >3 mm at TEE. Conclusions: HU > 100 in the LAA and a coaptation gap >3 mm between device and LAA ostium at angio-CT identified all LAA leaks and those >3 mm at TEE, respectively

Impact of individual stroke risk on outcome after Amplatzer left atrial appendage closure in patients with atrial fibrillation

OBJECTIVES To investigate periprocedural and long-term outcome of left atrial appendage closure (LAAC) using Amplatzer occluders with respect to individual pre-procedural stroke risk. BACKGROUND LAAC is a proven strategy for prevention from stroke and bleeding in patients with nonvalvular atrial fibrillation not amenable to oral anticoagulation. Whether individual pre-procedural stroke risk may affect procedural and long-term clinical outcome after LAAC is unclear. METHODS Multicenter study of consecutive patients who underwent Amplatzer-LAAC. Using pre-procedural CHADS$_{2}$ score, outcomes were compared between a low (0-2 points) and a high stroke risk group (3-6 points). RESULTS Five hundred consecutive patients (73.9 ± 10.1 years) who underwent Amplatzer-LAAC. Two hundred and forty eight had preprocedural CHADS$_{2}$ score ≤ 2 points (low-risk group) and the remaining 252 patients had 3-6 points (high-risk group). Periprocedural complication rates (6.0% vs. 5.6%, p = .85), procedural success (LAAC without major periprocedural or device-related complications or major para-device leaks: 89.4% vs. 87.9%, p = .74), and 30-day-mortality (2.4% vs. 2.6%, p = .77) were comparable. After 1,346 patient-years (PY), the long-term composite efficacy endpoint (stroke, systemic embolism, cardiovascular, and unexplained death) was reached in 23/653 (3.5/100 PY) versus 52/693 (7.5/100 PY); HR = 2.13; 95%-CI, 1.28-3.65, p = .002) with stroke rates 67% and 68% lower than anticipated by preprocedural CHADS$_{2}$ score. Combined safety endpoint (major periprocedural complications and major, life-threatening or fatal bleedings) occurred in 22/653 (3.4/100 PY) versus 28/693 (4.0/100 PY); HR = 1.20; 95%-CI, 0.66-2.20, p = .52). CONCLUSIONS Compared with patients at low risk of stroke, LAAC with Amplatzer devices is associated with similar safety and efficacy in high-risk patients in our study

Dynamics of bacterial pathogens at the driveline exit site in patients with ventricular assist devices: a prospective, observational, single-centre cohort study.

BACKGROUND Driveline infections (DLIs) at the exit site are frequent in patients with left ventricular assist devices (LVADs). The dynamics from colonization to infection are yet to be investigated. We combined systematic swabbing at the driveline exit site and genomic analyses to study the dynamics of bacterial pathogens and get insights into DLIs pathogenesis. METHODS A prospective, observational, single-centre cohort study at the University Hospital of Bern, Switzerland was performed. Patients with LVAD were systematically swabbed at the driveline exit site between June 2019 and December 2021, irrespective of signs and symptoms of DLI. Bacterial isolates were identified and a subset was whole-genome sequenced. RESULTS Fifty-three patients were screened, of which 45 (84.9%) were included in the final population. Bacterial colonization at the driveline exit site without manifestation of DLI was frequent and observed in 17 patients (37.8%). Twenty-two patients (48.9%) developed at least one DLI episode over the study period. Incidence of DLIs reached 2.3 cases per 1,000 LVAD days. The majority of the organisms cultivated from exit sites were Staphylococcus species. Genome analysis revealed that bacteria persisted at the driveline exit site over time. In four patients, transition from colonization to clinical DLI was observed. CONCLUSION Our study is the first to address bacterial colonization in the LVAD-DLI setting. We observed that bacterial colonization at the driveline exit site was a frequent phenomenon, and in a few cases it preceded clinically relevant infections. We also provided acquisition of hospital-acquired multidrug-resistant bacteria and the transmission of pathogens between patients