Jonas Lehmacher

Dr. Jonas Lehmacher


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

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9 September 2019 in Biomolecules
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NSNils Arne Sörensen
Nils Arne Sörensen
SLSebastian Ludwig
Sebastian Ludwig
NMNataliya Makarova
Nataliya Makarova
JNJohannes Tobias Neumann
Johannes Tobias Neumann
JLJonas Lehmacher
Jonas Lehmacher
NSNiklas Schofer
Niklas Schofer
High-sensitivity troponin has proven to be a promising biomarker for the prediction of future adverse cardiovascular events. We aimed to assess the prognostic value of high-sensitivity troponin I (hs-TnI) on admission in patients with suspected acute myocardial infarction (AMI) analyzed by a novel (Singulex Clarity cTnI) and established hs-TnI assay (ARCHITECT STAT hs-TnI, Abbott). Hs-TnI was measured in a total of 2332 patients from two prospective cohort studies presenting to the emergency department with suspected AMI. The prognostic impact for overall and cardiovascular mortality of both hs-TnI assays was assessed in the total patient cohort as well as in the subgroups of patients with AMI (n = 518) and without AMI (non-AMI) (n = 1814). Patients presenting with highest hs-TnI levels showed higher overall and cardiovascular mortality rates compared to those with lower troponin levels, irrespective of the assay used. Both hs-TnI assays indicated association with overall mortality according to adjusted hazard ratio (HR) among the entire study population (HR for Singulex assay: 1.16 (95% CI 1.08–1.24) and HR for Abbott assay: 1.17 (95% CI 1.09–1.25)). This finding was particularly pronounced in non-AMI patients, whereas no association between hs-TnI and overall mortality was found in AMI patients for either assay. In non-AMI patients, both assays equally improved risk prediction for cardiovascular mortality beyond conventional cardiovascular risk factors. Hs-TnI is independently predictive for adverse outcomes in patients with suspected AMI, especially in the subset of patients without confirmed AMI. There was no difference between the established and the novel assay in the prediction of mortality.

Verified
Journal Article
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JLJonas Lehmacher
Jonas Lehmacher
JNJohannes Tobias Neumann
Johannes Tobias Neumann
NSNils Arne Sörensen
Nils Arne Sörensen
AGAlina Goßling
Alina Goßling
PHPaul Haller
Paul Haller
DWDirk Westermann
Dirk Westermann
The electrocardiogram (ECG) is an important diagnostic tool for patients with suspected acute myocardial infarction (AMI). Current guidelines recommend serial ECGs in case of persisting symptoms. We aimed to analyze the predictive value of ischemic ECG-signs in patients with suspected AMI. Patients presenting to the emergency department with suspected AMI were included. All patients with ST-elevation AMI were excluded from analyses. Patients received 12-lead-ECG and high-sensitive Troponin T (hs-TnT)-measurement at admission and after 3 h. Four groups were defined: no ischemic signs in either ECG; new ischemic signs in the second ECG; resolved ischemic signs in the second ECG; and persistent ischemic signs in both ECGs. Patients were followed for 2 years to assess the composite endpoint of all-cause-mortality, AMI, and coronary revascularization. Using a 30-day landmark analysis, a Cox regression with ischemic signs as the variable of interest, adjusted by cardiovascular risk factors, was calculated. Of 1675 patients, 1321 showed no ischemic signs, in 25 new-, in 92 resolved- and in 237 patients, persistent ischemic signs were documented. Patients with persistent ischemic signs had significantly worse outcomes, compared to those without. Compared to no ischemic signs, adjusted hazard ratios for the combined endpoint were 0.81 (95% CI 0.20, 3.31; p-value = 0.77) for new-, 0.59 (95% CI 0.26, 1.34; p-value = 0.21) for resolved-, and 1.47 (95% CI 1.102, 2.13; p-value = 0.041) for persistent ischemic signs. In patients with suspected AMI, persistent ischemic ECG-signs are predictive of a higher rate of all-cause-mortality, AMI, and revascularization.

27 October 2023 in European Heart Journal: Acute Cardiovascular Care
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Journal Article
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JLJonas Lehmacher
Jonas Lehmacher
NSNils Arne Sörensen
Nils Arne Sörensen
RTRaphael Twerenbold
Raphael Twerenbold
AGAlina Goßling
Alina Goßling
PHPaul Michael Haller
Paul Michael Haller
JNJohannes Tobias Neumann
Johannes Tobias Neumann
High-sensitivity cardiac troponin (hs-cTn) assays are used for detection of myocardial infarction (MI). 99th percentiles show wide inter-assay variation. Use of sex-specific cutoffs is recommended as definitory cutoff for MI. We compared diagnostic performance and prognostic value of sex-specific 99th percentiles of four hs-cTn assays in patients with suspected MI. Concentrations of four hs-cTn assays were measured at presentation and after 3 hours in patients with suspected MI. Final diagnoses were adjudicated according to 4th UDMI. Unisex and sex-specific 99th percentiles were evaluated as diagnostic cutoffs following the ESC 0/3h algorithm. These cutoffs were used in Cox-regression analyses to investigate the association with a composite endpoint of MI, revascularization, cardiac rehospitalization and death. Non-ST-elevation MI was diagnosed in 368 of 2,718 patients. Applying the unisex 99th percentile, Elecsys hs-cTnT provided highest negative predictive value (NPV) of 99.7 and a positive predictive value (PPV) of 75.9. The analyzed hs-cTnI assays showed slightly lower NPVs and comparable PPVs (Architect [NPV 98.0, PPV 71.4]; Atellica [NPV 97.7, PPV of 76.1]; Pathfast [NPV 97.7, PPV of 66.6]). Application of sex-specific 99th percentiles did not significantly affect diagnostic performance. Concentrations above 99th percentile were independent predictors for impaired long-term outcome (hazard ratios 1.2 - 1.5, p<0.001). We describe a good diagnostic accuracy of four hs-cTn assay using the assay-specific 99th percentile for detection of MI. Application of sex-specific 99th percentiles did neither affect diagnostic performance nor prognostic value significantly. Finally, values above the 99th percentile were associated with poor long-term outcome.

20 March 2023 in Clinical Chemistry
Verified
Journal Article
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JLJonas Lehmacher
Jonas Lehmacher
BTBetül Toprak
Betül Toprak
NSNils Arne Sörensen
Nils Arne Sörensen
RKRamona Bei der Kellen
Ramona Bei der Kellen
AGAlina Goßling
Alina Goßling
JNJohannes Tobias Neumann
Johannes Tobias Neumann
Background: Current guidelines recommend 0/1 h algorithms using high-sensitivity cardiac troponin (hs-cTn) for fast diagnosis of myocardial infarction (MI). Yet, for some assays, existing data is limited. We aimed to evaluate the diagnostic performance and the prognostic value of a rapid 0/1 h algorithm for the Access hs-cTnI assay. Methods: In consecutive patients presenting with suspected MI, we measured concentrations of Access hs-cTnI at presentation and after 1 hour. Final diagnosis was adjudicated independently by 2 cardiologists. Parameters for diagnostic performance were calculated, applying the recently derived European Society of Cardiology (ESC) 0/1 h algorithm for Access hs-cTnI. Additionally, we assessed the prognostic utility of Access hs-cTnI for the composite end point of all-cause mortality and incident MI at 3 years. Results: In 1879 patients, 257 non-ST-elevation MIs occurred. Application of the 0/1 h algorithm classified 44.5% as rule-out, 20.3% as rule-in, and triaged 35.1% to the observe group. High rule-out safety was confirmed with a sensitivity of 97.7% (95% CI, 95.0%–99.1%) and a negative predictive value of 99.3% (95% CI, 98.4%–99.7%). Rule-in capacity was moderate with a specificity of 88.0% (95% CI, 86.3%–89.6%) and a positive predictive value of 50.8% (95% CI, 45.7%–55.9%). After exclusion of patients with ST-elevation MI the results showed strong prognostic value, even after adjustment for cardiovascular risk factors and comorbidities, with adjusted hazard ratios of 2.51 (95% CI, 1.56–4.04) in the observe and 3.55 (95% CI, 2.18–5.79) in the rule-in group for the composite end point of all-cause mortality and incident MI at 3 years, compared to ruled-out patients. Conclusion: The ESC 0/1 h algorithm for Access hs-cTnI allows safe and efficient triage of patients with suspected MI and has strong prognostic utility up to 3 years after the initial evaluation.

1 March 2023 in Open Heart
Verified
Journal Article
Open access
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JLJonas Lehmacher
Jonas Lehmacher
JNJohannes T Neumann
Johannes T Neumann
NSNils Arne Sörensen
Nils Arne Sörensen
AGAlina Goßling
Alina Goßling
SSSamuel Emil Schmidt
Samuel Emil Schmidt
PCPeter M Clemmensen
Peter M Clemmensen
Background As only a small proportion of patients with chest pain suffers from myocardial infarction (MI), safe rule-out of MI is of immense importance. Recently an ultrasensitive microphone performing diastolic heart sound analysis (CADScorSystem) for rule-out of coronary artery disease (CAD) has emerged. In this explorational study, we aimed to evaluate the feasibility of the CADScorSystem for diagnosis of MI in the setting of a large emergency department. Methods Patients presenting to the emergency department with suspected MI were included. Acoustic heart sound analysis was performed in all patients and automated CAD-score values were calculated via a device-embedded algorithm, which also requires inclusion of three clinical variables: age, sex and presence of hypertension. Patients additionally received serial high-sensitive troponin T measurement measurements to assess the final diagnosis according to third Universal Definition of Myocardial Infarction applying the European Society of Cardiology 0 hour/3 hours algorithm. Diagnostic parameters for MI, considering different CAD-score cut-offs, were computed. Results Of 167 patients, CAD-scores were available in 61.1%. A total of eight patients were diagnosed with MI. At a cut-off value of <20, CAD-score had a negative predictive value (NPV) of 90.7 (78.4–96.3). The corresponding positive predictive value (PPV) was 6.8 (2.7–16.2). For the adjusted CAD-score (age, sex, hypertension), at a cut-off value of <20, NPV was 90.0 (59.6–99.5) with a PPV of 10.8 (5.3–20.6). Conclusion In this explorative analysis, a transcutaneous ultrasensitive microphone for heart sound analysis resulted in a high NPV analogous to the findings in rule-out of stable CAD in elective patients yet inferior to serial high-sensitivity cardiac troponin measurements and does not seem feasible for application in an emergency setting for rule-out of MI. Trial registration number NCT02355457.

1 October 2022 in European Heart Journal
Verified
Journal Article
Open access
PDF file
JLJonas Lehmacher
Jonas Lehmacher
BTBetül Toprak
Betül Toprak
AGA Gossling
A Gossling
LILicia Iacoviello
Licia Iacoviello
BTBarbara Thorand
Barbara Thorand
RTRaphael Twerenbold
Raphael Twerenbold
Background: Accurate risk prediction for future cardiovascular disease (CVD) is crucial for timely initiation of preventive measures in high-risk individuals. Most risk scores, such as the recently updated SCORE2 risk-prediction model supported by the European Society of Cardiology, consider only traditional cardiovascular risk factors. Whether the addition of circulating biomarkers to the existing SCORE2 model may improve risk prediction is unclear. Purpose: We aimed to evaluate the incremental utility of four widely available circulating biomarkers to improve the prediction of 10-year CVD-risk beyond SCORE2. Methods: Data from ten prospective population-based cohorts from seven countries across Europe were collected if information on SCORE2-variables and at least one of the following four investigational biomarkers was available: high-sensitivity cardiac troponin I (hs-cTnI), NT-pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hs-CRP) and creatinine-based estimated glomerular filtration rate (eGFR). Primary outcome was incidence of CVD at 10 years, defined as the composite of cardiovascular mortality, non-fatal myocardial infarction and non-fatal stroke. We used Fine and Gray models adjusted for competing-risk and SCORE2-variables as well as penalized cubic splines to assess and visualize the association of individual biomarkers with incident CVD. In a multimarker approach, we performed backward selection to identify biomarkers providing independent predictive value beyond SCORE2-components. C-indices and category-free net reclassification index (cfNRI) were used to compare the performance of the original SCORE2 model to the biomarker-extended model. Results: In 78'507 individuals, median age was 50 years and 50.3% were females. NT-proBNP, hs-CRP and hs-cTnI but not eGFR showed strong associations with 10-year CVD-risk when adjusted for SCORE2 and provided incremental predictive value when individually added to SCORE2 (Figure 1). In a multimarker approach, all three biomarkers remained independently associated with CVD beyond SCORE2 with strongest association of NT-proBNP, followed by hs-CRP and hs-cTnI (Table 1). The simultaneous addition of these three biomarkers to the SCORE2 model significantly increased discrimination (C-index; 0.782 [95% CI, 0.757, 0.806] versus 0.793 [95% CI, 0.768, 0.817], Delta 0.011 [95% CI, 0.005, 0.016]) and risk reclassification, driven by an improvement in non-events (cfNRIoverall 0.17 [95% CI, 0.12, 0.22], cfNRIevents 0.06 [95% CI, 0.02, 0.11], cfNRInon-events 0.11 [95% CI, 0.10, 0.11]). Conclusion: NT-proBNP, hs-CRP and hs-cTnI but not eGFR provide incremental predictive value when added to the SCORE2 risk-prediction model and may help to further improve personalized CVD-risk prediction. Funding Acknowledgement: Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Community's Seventh Framework Programme (FP7/2007-2013)