Samuel Lee

Dr. Samuel Lee


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 December 2022 in Antioxidants
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HGHenning Guthoff
Henning Guthoff
AHAlexander Hof
Alexander Hof
AKAnna Klinke
Anna Klinke
MMMartina Maaß
Martina Maaß
JKJürgen Konradi
Jürgen Konradi
MMMartin Mollenhauer
Martin Mollenhauer
Myocardial infarction (MI) is a leading cause of morbidity and mortality worldwide. Improved survival has led to an increasing incidence of ischemic cardiomyopathy, making it a major reason for hospitalization in the western world. The inflammatory response in the ischemic myocardium determines the extent of structural remodeling and functional deterioration, with neutrophils (PMN) being a key modulator of the propagation and resolution of inflammation. The heme enzyme myeloperoxidase (MPO) is abundantly expressed in PMN and is an important mediator of their inflammatory capacities. Here, we examine the effects of PMN reduction, MPO deficiency and MPO inhibition in two murine models of MI. Reduction in PMN count resulted in less scar formation and improved cardiac function. Similar results were obtained in genetically MPO deficient mice, suggesting that MPO is a critical factor in PMN-mediated cardiac remodeling. To test our findings in a therapeutic approach, we orally administered the MPO inhibitor AZM198 in the context of MI and could demonstrate improved cardiac function and reduced structural remodeling. Therefore, MPO appears to be a favorable pharmacological target for the prevention of long-term morbidity after MI.

18 January 2023 in Frontiers in Cardiovascular Medicine
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MMMax M. Meertens
Max M. Meertens
TTTobias Tichelbäcker
Tobias Tichelbäcker
SMSascha Macherey-Meyer
Sascha Macherey-Meyer
SHSebastian Heyne
Sebastian Heyne
SBSimon Braumann
Simon Braumann
SLSamuel Lee
Samuel Lee
Background: Incidence and mortality of cardiogenic shock (CS) in patients with acute myocardial infarction (AMI) remain high despite substantial therapy improvements in acute percutaneous coronary intervention over the last decades. Unloading the left ventricle in patients with Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) can be performed by using an intra-aortic balloon pumps’ (IABP) afterload reduction, which might be especially beneficial in AMI patients with CS.Objective: The objective of this meta-analysis was to assess the effect of VA-ECMO + IABP vs. VA-ECMO treatment on the mortality of patients with CS due to AMI.Methods: A systematic literature search was performed using EMBASE, COCHRANE, and MEDLINE databases. Studies comparing the effect of VA-ECMO + IABP vs. VA-ECMO on mortality of patients with AMI were included. Meta-analyses were performed to analyze the effect of the chosen treatment on 30-day/in-hospital mortality.Results: Twelve studies were identified by the literature search, including a total of 5,063 patients, 81.5% were male and the mean age was 65.9 years. One thousand one hundred and thirty-six patients received treatment with VA-ECMO in combination with IABP and 2,964 patients received VA-ECMO treatment only. The performed meta-analysis showed decreased mortality at 30-days/in-hospital after VA-ECMO + IABP compared to VA-ECMO only for patients with cardiogenic shock after AMI (OR 0.36, 95% CI 0.30–0.44, P≤0.001). Combination of VA-ECMO + IABP was associated with higher rates of weaning success (OR 0.29, 95% CI 0.16–0.53, P < 0.001) without an increase of vascular access complications (OR 0.85, 95% CI 0.35–2.08, P = 0.72).Conclusion: In this meta-analysis, combination therapy of VA-ECMO + IABP was superior to VA-ECMO only therapy in patients with CS due to AMI. In the absence of randomized data, these results are hypothesis generating only.

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HWHendrik Wienemann
Hendrik Wienemann
MLMarcel C. Langenbach
Marcel C. Langenbach
VMVictor Mauri
Victor Mauri
MBMaryam Banazadeh
Maryam Banazadeh
KKKonstantin Klein
Konstantin Klein
MAMatti Adam
Matti Adam
Background: Computed tomography derived Fractional Flow Reserve (CT-FFR) has been shown to decrease the referral rate for invasive coronary angiography (ICA). The purpose of the study was to evaluate the diagnostic performance of CT-FFR compared to hyperemia-free index Resting Full-cycle Ratio (RFR) in patients with relevant aortic stenosis (AS) and intermediate coronary stenosis. Methods: 41 patients with 46 coronary lesions underwent ICA with quantitative coronary angiography (QCA), pressure wire assessment and routine pre-transcatheter aortic valve replacement (TAVR) computed tomography (CT). CT-FFR analysis was performed using prototype on-site software. Results: RFR showed a significant correlation with CT-FFR (Pearson’s correlation, r = 0.632, p < 0.001). On a per-lesion basis, diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR were 82.6% (95% CI 68.6–92.2), 69.6% (95% CI 47.1–86.8), 95.7% (95% CI 78.1–99.9), 94.1% (95% CI 69.8–99.1), and 75.9% (95% CI 62.7–85.4), respectively. The optimal cutoff value of the CT-FFR for RFR ≤ 0.89 prediction was 0.815. The area under the receiver curve showed a larger area under the curve for CT-FFR (0.87; 95% CI 0.75–0.98) compared with CTA stenosis of ≥50% (0.54, 95% CI 0.38–0.71), CTA ≥ 70% (0.72, 95% CI 0.57–0.87) and QCA ≥ 50% (0.67, 95% CI 0.52–0.83). Conclusions: CT-FFR assessed by routine pre-TAVR CT is safe and feasible and shows a significant correlation with RFR in patients with AS. CT-FFR is superior to QCA ≥ 50%, CT ≥ 50% and CT ≥ 70% in assessing the hemodynamic relevance of intermediate coronary lesions. Thus, CT-FFR has the potential to guide revascularization in patients with AS.

Verified
Journal Article
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SMSascha Macherey-Meyer
Sascha Macherey-Meyer
KSKhalid Salem
Khalid Salem
SHSebastian Heyne
Sebastian Heyne
MMMax Maria Meertens
Max Maria Meertens
KFKarl Finke
Karl Finke
SLSamuel Lee
Samuel Lee
Background/Objectives: Chronic total occlusion (CTO) is a prevalent finding in patients with coronary artery disease and is associated with increased mortality. Prior reports on the efficacy of percutaneous coronary intervention (PCI) compared to optimal medical therapy (OMT) were controversial. Following the emergence of recently published new evidence, a meta-analysis is warranted. The current meta-analysis assessed the effects of PCI compared to OMT in the treatment of CTO. Methods: A structured literature search was performed. Randomized controlled trials (RCTs) and non-randomized controlled studies of interventions were eligible. The primary outcome was an accumulated composite of cardiac mortality, myocardial infarction and target vessel/lesion revascularization events. Results: Thirty-two studies reporting on 11260 patients were included. Of these, 5712 (50.7%) were assigned to the PCI and 5548 (49.3%) were allocated to the OMT group. The primary outcome occurred in 14.6% of the PCI and 20.1% of the OMT group (12 trials, OR 0.66, 95% CI 0.50 to 0.88, p = 0.005, I2 = 67%). Subgrouping demonstrated a consistent reduction in the primary outcome for the PCI group in RCTs (six trials, OR 0.58, 95% CI 0.33 to 0.99, p = 0.05). The primary outcome reduction was irrespective of the study design, and it was replicable in sensitivity and subgroup analyses. Advantages in other outcomes were rather related to statistical pooling effects and dominated by observational data. Conclusions: CTO-PCI was associated with improved patient-oriented primary outcome compared to OMT in a study-level meta-analysis. This composite outcome effect was mainly driven by target vessel treatment, but a significant reduction in mortality and myocardial infarction was observed, irrespectively. These findings have hypothesis-generating implications. Future RCTs with adequate statistical power are eagerly awaited.

Verified
Journal Article
Open access
PDF file
SMSascha Macherey-Meyer
Sascha Macherey-Meyer
SHSebastian Heyne
Sebastian Heyne
MMMax M. Meertens
Max M. Meertens
SBSimon Braumann
Simon Braumann
SNStephan F. Niessen
Stephan F. Niessen
CAChristoph Adler
Christoph Adler
Background: Out-of-hospital cardiac arrest (OHCA) has a high prevalence of obstructive coronary artery disease and total coronary occlusion. Consequently, these patients are frequently loaded with antiplatelets and anticoagulants before hospital arrival. However, OHCA patients have multiple non-cardiac causes and high susceptibility for bleeding. In brief, there is a gap in the evidence for loading in OHCA patients. Objective: The current analysis stratified the outcome of patients with OHCA according to pre-clinical loading. Material and Methods: In a retrospective analysis of an all-comer OHCA registry, patients were stratified by loading with aspirin (ASA) and unfractionated heparin (UFH). Bleeding rate, survival to hospital discharge and favorable neurological outcomes were measured. Results: Overall, 272 patients were included, of whom 142 were loaded. Acute coronary syndrome was diagnosed in 103 patients. One-third of STEMIs were not loaded. Conversely, 54% with OHCA from non-ischemic causes were pretreated. Loading was associated with increased survival to hospital discharge (56.3 vs. 40.3%, p = 0.008) and a more favorable neurological outcome (80.7 vs. 62.6% p = 0.003). Prevalence of bleeding was comparable (26.8 vs. 31.5%, p = 0.740). Conclusions: Pre-clinical loading did not increase bleeding rates and was associated with favorable survival. Overtreatment of OHCA with non-ischemic origin, but also undertreatment of STEMI-OHCA were documented. Loading without definite diagnosis of sustained ischemia is debatable in the absence of reliable randomized controlled data.

29 November 2021 in Scientific Reports
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Journal Article
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SMS. Macherey
S. Macherey
MMM. M. Meertens
M. M. Meertens
CAC. Adler
C. Adler
SBS. Braumann
S. Braumann
SHS. Heyne
S. Heyne
SLSamuel Lee
Samuel Lee
The effect of respiratory infectious diseases on STEMI incidence, but also STEMI care is not well understood. The Influenza 2017/2018 epidemic and the COVID-19 pandemic were chosen as observational periods to investigate the effect of respiratory virus diseases on these outcomes in a metropolitan area with an established STEMI network. We analyzed data on incidence and care during the COVID-19 pandemic, Influenza 2017/2018 epidemic and corresponding seasonal control periods. Three comparisons were performed: (1) COVID-19 pandemic group versus pandemic control group, (2) COVID-19 pandemic group versus Influenza 2017/2018 epidemic group and (3) Influenza 2017/2018 epidemic group versus epidemic control group. We used Student’s t-test, Fisher’s exact test and Chi square test for statistical analysis. 1455 patients were eligible. The daily STEMI incidence was 1.49 during the COVID-19 pandemic, 1.40 for the pandemic season control period, 1.22 during the Influenza 2017/2018 epidemic and 1.28 during the epidemic season control group. Median symptom-to-contact time was 180 min during the COVID-19 pandemic. In the pandemic season control group it was 90 min (p = 0.183), and in the Influenza 2017/2018 cohort it was 90 min, too (p = 0.216). Interval in the epidemic control group was 79 min (p = 0.733). The COVID-19 group had a door-to-balloon time of 49 min, corresponding intervals were 39 min for the pandemic season group (p = 0.038), 37 min for the Influenza 2017/2018 group (p = 0.421), and 38 min for the epidemic season control group (p = 0.429). In-hospital mortality was 6.1% for the COVID-19 group, 5.9% for the Influenza 2017/2018 group (p = 1.0), 11% and 11.2% for the season control groups. The respiratory virus diseases neither resulted in an overall treatment delay, nor did they cause an increase in STEMI mortality or incidence. The registry analysis demonstrated a prolonged door-to-balloon time during the COVID-19 pandemic.