Matthias Hammerer

Dr. Matthias Hammerer


Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

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

Representative Publications

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21 April 2025 in Journal of Clinical Medicine
Verified
Journal Article
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PKPhilipp Krombholz-Reindl
Philipp Krombholz-Reindl
AVAndreas Vötsch
Andreas Vötsch
KLKlaus Linni
Klaus Linni
RSRainald Seitelberger
Rainald Seitelberger
RGRoman Gottardi
Roman Gottardi
AWAndreas Winkler
Andreas Winkler
Objectives: Risk stratification in coronary artery bypass grafting (CABG) remains challenging despite existing models. The Endothelial Activation and Stress Index (EASIX), originally developed for hematological conditions, has shown promise in various medical fields as a predictor of adverse outcomes. EASIX, calculated from lactate dehydrogenase, creatinine, and platelet count, reflects endothelial dysfunction and systemic inflammation. This study investigates EASIX’s potential in predicting mortality and morbidity in patients undergoing CABG. Methods: A total of 475 patients undergoing isolated CABG between January 2017 and June 2020 were retrospectively analyzed. EASIX scores were calculated from pre-operative blood samples. Patients were stratified based on an EASIX cut-off value of 1.16. Results: Patients with EASIX ≥ 1.16 were older and had more comorbidities. They experienced higher 30-day mortality (5.0% vs. 0.8%, p = 0.004), increased wound infections (6.7% vs. 2.5%, p = 0.035), and more frequent prolonged ventilation (9.2% vs. 4.2%, p = 0.040). The long-term survival analysis showed significant differences at 3 years (p = 0.030) and 5 years (p < 0.001). EASIX demonstrated moderate discriminatory power for long-term survival (AUROC 0.669, 95% CI: 0.598–0.740, p < 0.001). Importantly, the multivariable analysis revealed EASIX as an independent risk factor for long-term mortality, even after adjusting for traditional risk factors and comorbidities (HR: 2.65, 95% CI: 1.59–4.42, p < 0.001). Conclusions: EASIX ≥ 1.16 was associated with postoperative morbidity and poorer long-term survival in patients undergoing CABG. This easily calculable score could enhance risk stratification and guide personalized postoperative management.

4 September 2022 in Journal of Personalized Medicine
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Journal Article
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SHStefan Hecht
Stefan Hecht
EBElke Boxhammer
Elke Boxhammer
RKReinhard Kaufmann
Reinhard Kaufmann
BSBernhard Scharinger
Bernhard Scharinger
CRChristian Reiter
Christian Reiter
Michael LichtenauerMichael Lichtenauer
Michael Lichtenauer
Background: Patients with severe aortic valve stenosis (AS) often present with heart failure and sarcopenia. Sarcopenia, described as progressive degradation of skeletal muscle mass, has frequently been implicated as a cause of increased mortality, prolonged hospitalization and generalized poor outcome after transcatheter aortic valve replacement (TAVR). At present, sarcopenia is defined by the European Working Group on Sarcopenia in Older People (EWGSOP) based on clinical examination criteria and radiological imaging. The aim of the present study was to compare patients with Computed Tomography (CT)-diagnosed sarcopenia with regard to the expression of cardiovascular biomarkers in order to obtain additional, laboratory-chemical information. Methods: A total of 179 patients with severe AS were included in this retrospective study. Sarcopenia was determined via CT by measurement of the psoas muscle area (PMA), which was indexed to body surface area (PMAi). According to previous studies, the lowest tertile was defined as sarcopenic. Patients with (59/179) and without sarcopenia (120/179) in the overall cohort were compared by gender-specific cut-offs with regard to the expression of cardiovascular biomarkers such as brain natriuretic peptide (BNP), soluble suppression of tumorigenicity-2 (sST2), growth/differentiation of factor-15 (GDF-15), heart-type fatty-acid binding protein (H-FABP), insulin like growth factor binding protein 2 (IGF-BP2) and soluble urokinase-type plasminogen activator receptor (suPAR). Additionally, binary logistic regression analyses were calculated to detect possible predictors of the presence of sarcopenia. Results: No statistical differences regarding one-year survival could be detected between sarcopenic and non-sarcopenic patients in survival curves (log rank test p = 0.179). In the entire cohort, only BNP and hemoglobin (HB) showed a statistically significant difference, with only HB emerging as a relevant predictor for the presence of sarcopenia after binary logistic regression analysis (p = 0.015). No relevant difference in biomarker expression could be found in the male cohort. Regarding the female cohort, statistically significant differences were found in BNP, HB and hematocrit (HK). In binary logistic regression, however, none of the investigated criteria could be related to sarcopenia. Conclusion: Regardless of gender, patients with imaging-based muscle degradation did not demonstrate significantly different cardiovascular biomarker expression compared to those without it.

28 October 2011 in Wiener klinische Wochenschrift
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Journal Article
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MHMatthias Hammerer
Matthias Hammerer
JSJochen Schuler
Jochen Schuler
JAJohann Altenberger
Johann Altenberger
JKJohannes Kraus
Johannes Kraus
EPErika Prinz
Erika Prinz
MHMatthias Heigert
Matthias Heigert

1 March 2020 in The Journal of Cardiovascular Surgery
Verified
Journal Article
Closed access
Moritz MirnaMoritz Mirna
Moritz Mirna
BWBernhard Wernly
Bernhard Wernly
SESarah Eder
Sarah Eder
Michael LichtenauerMichael Lichtenauer
Michael Lichtenauer
EPErika Prinz
Erika Prinz
MHMatthias Hammerer
Matthias Hammerer
BACKGROUND: Aortic valve stenosis is the most common valvulopathy in developed countries. Transcatheter aortic valve implantation (TAVI) is a therapeutic alternative in symptomatic patients at high or prohibitive perioperative risk. Predilatation by balloon aortic valvuloplasty (BAV) under rapid ventricular pacing (RVP) has been a routine part of TAVI. However, both RVP and BAV carry substantial risks and an increasing number of interventional centers are performing TAVI without predilatation (direct TAVI). A transient decrease of left ventricular function and elevated markers of myocardial injury after TAVI with predilatation were observed in previous studies. In this study, we investigated whether direct TAVI was associated with a similar increase in cardiac biomarkers and decrease in ejection fraction in a cohort of our patients. METHODS: Consecutive patients undergoing TAVI without predilatation using a self-expanding system at a single center between April 2013 and December 2015 were followed up for one year and were retrospectively analyzed regarding mortality, safety and efficacy endpoints as well as common laboratory and echocardiographic parameters. RESULTS: A total of 164 patients (83 +/- 6 years; 56% female) were included in the analysis. According to the Valve Academic Research Consortium 2 (VARC-2) criteria the technical success rate was 96.3% and 89.1% of patients remained free of a combined safety endpoint at 30 days. Mortality rates at 30 days and 1 year were 3.0% (N.=5) and 10.4% (N.=17), respectively. TAVI without predilatation was highly effective in lowering aortic valve peak velocity from 4.4 +/- 0.6 m/s before to 1.7 +/- 0.5 m/s (P<0.01), and mean pressure gradient across the valve from 48.7 +/- 15.1 mmHg to 83 +/- 4.5 mmHg (<0.05). Left ventricular function remained unaltered after the intervention (51 +/- 10% prior to TAVI and 51 +/- 9% post TAVI), whereas high sensitive troponin T (hs-TnT), a well-established marker for myocardial injury, increased significantly from 26 ng/L (interquartile range-18.00-44.00) to 119 ng/L (interquartile range-73.25-166.00, P15 times the upper limit of normal was associated with mortality both one month and one year after TAVI. CONCLUSIONS: TAVI without predilatation is feasible, safe and effective for aortic valve replacement in symptomatic patients with severe aortic stenosis who are at high perioperative risk. In contrast to a cohort of patients who underwent TAVI with predilatation previously published by another center, our patients did not suffer from transient impairment of left ventricular function. As a marker of myocardial injury, hs-TnT showed a less pronounced increase than reported previously. This might be a marker for a prognostic benefit as hs-TnT has been shown to be a strong predictor of outcome in patients undergoing TAVI. We conclude that direct TAVI is a less invasive option involving less myocardial stress.

29 September 2022 in Diagnostics
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Journal Article
Open access
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EBElke Boxhammer
Elke Boxhammer
BSBernhard Scharinger
Bernhard Scharinger
RKReinhard Kaufmann
Reinhard Kaufmann
HBHerwig Brandtner
Herwig Brandtner
LSLukas Schmidbauer
Lukas Schmidbauer
SHStefan Hecht
Stefan Hecht
Background: Computed tomography (CT) of the aorta and cardiac vessels, which is performed in patients with severe aortic valve stenosis (AS) before transcatheter aortic valve replacement (TAVR), offers the possibility of non-invasive detection of pulmonary hypertension (PH), for example, by determining the diameter of the main pulmonary artery (PA), the right pulmonary artery (RPA) or the left pulmonary artery (LPA). An improvement of the significance of these radiological parameters is often achieved by indexing to the body surface area (BSA). The aim of this study was to compare different echocardiographic systolic pulmonary artery pressure (sPAP) values with radiological data in order to define potential clinical cut-off values for the presence or absence of PH. Methods: A total of 138 patients with severe AS undergoing TAVR underwent pre-interventional transthoracic echocardiography with determination of sPAP values and performance of CT angiography (CTA) of the aorta and femoral arteries. Radiologically, the PA, RPA, LPA, and ascending aorta (AA) diameters were obtained. Vascular diameters were not only indexed to BSA but also ratios were created with AA diameter (for example PA/AA-ratio). From these CT-derived vascular parameters, AUROC curves were obtained regarding the prediction of different sPAP values (sPAP 40–45–50 mmHg) and finally correlation analyses were calculated. Results: The best AUROC and correlation analyses were generally obtained at an sPAP ≥ 40 mmHg. When considering diameters alone, the PA diameter was superior to the RPA and LPA. Indexing to BSA generally increased the diagnostic quality of the parameters, and finally, in a synopsis of all results, PA/BSA had the best AUC 0.741 (95% CI 0.646–0. 836; p < 0.001; YI 0.39; sensitivity 0.87; specificity 0.52) and Spearman’s correlation coefficient (r = 0.408; p < 0.001) at an sPAP of ≥40 mmHg. Conclusions: Features related to pulmonary hypertension are fast and easily measurable on pre-TAVR CT and offer great potential regarding non-invasive detection of pulmonary hypertension in patients with severe AS and can support the echocardiographic diagnosis. In this study, the diameter of the main pulmonary artery with the additionally determined ratios were superior to the values of the right and left pulmonary artery. Additional indexing to body surface area and thus further individualization of the parameters with respect to height and weight can further improve the diagnostic quality.

29 September 2024 in Biomedicines
Verified
Journal Article
Open access
PDF file
EBElke Boxhammer
Elke Boxhammer
MHMatthias Hammerer
Matthias Hammerer
CSChristiana Schernthaner
Christiana Schernthaner
EPErika Prinz
Erika Prinz
MBMathias Christoph Brandt
Mathias Christoph Brandt
Kristen Laura KoppKristen Laura Kopp
Kristen Laura Kopp
Background: Prediabetes is frequently underdiagnosed and undertreated, yet it poses significant cardiovascular risks. This study investigates the impact of prediabetes on short- and long-term survival outcomes in patients who experienced ST-elevation myocardial infarction (STEMI). Methods: In this retrospective, single-center cohort study, we evaluated 725 STEMI patients stratified into non-diabetic, prediabetic, and diabetic groups based on HbA1c levels at presentation. A Kaplan–Meier survival analysis was employed to compare long-term outcomes over a three-year follow-up period. Cardiovascular risk factors, including hypertension and dyslipidemia, were analyzed across the groups. The discriminatory power of HbA1c for predicting all-cause mortality was assessed using an Area Under the Receiver Operating Characteristic (AUROC) analysis. Results: Of the 725 patients, 407 (56.1%) were non-diabetic, 184 (25.4%) were prediabetic, and 134 (18.5%) were diabetic. Prediabetic patients exhibited significant additional cardiovascular risk factors, such as arterial hypertension (67.4%) and dyslipidemia (78.3%), with prevalence rates between those of non-diabetic and diabetic patients. The Kaplan–Meier analysis revealed that at a three-year follow-up, prediabetic patients faced a survival disadvantage, with a significant decrease in survival rates compared to non-diabetic patients (log-rank p = 0.016); their survival outcomes approached those of diabetic patients (p = 0.125). The AUROC analysis demonstrated that HbA1c was a significant predictor of short- and long-term mortality, with a cut-off value of 5.75% and an Area Under the Curve (AUC) of 0.580–0.617 (95% CI: 0.458–0.721), indicating a moderate ability to predict survival in patients with STEMI. Conclusions: Prediabetes significantly worsens survival outcomes following STEMI, nearly approaching the risk level of diabetes. Integrating rigorous cardiovascular risk management strategies for prediabetic individuals, including lifestyle interventions and potentially pharmacological treatments, could prevent the progression to diabetes and mitigate associated cardiovascular risks.