Analysis of a Cardiac-Necrosis-Biomarker Release in Patients with Acute Myocardial Infarction via Nonlinear Mixed-Effects Models

The release of the cardiac troponin T (cTnT) in patients with acute myocardial infarc tion (AMI) has been analyzed through a methodology based on nonlinear mixed-effects (NME) models. The aim of this work concerns the investigation of any possible relationship between clin ical covariates and the dynamics of the release of cTnT to derive more detailed and useful clinical information for the correct treatment of these patients. An ad-hoc mechanistic model describing the biomarker release process after AMI has been devised, assessed, and exploited to evaluate the im pact of the available clinical covariates on the cTnT release dynamic. The following approach was tested on a preliminary dataset composed of a small number of potential clinical covariates: em ploying an unsupervised approach, and despite the limited sample size, dyslipidemia, a known risk factor for cardiovascular disease, was found to be a statistically significant covariate. By increasing the number of covariates considered in the model, and patient cohort, we envisage that this approach may provide an effective means to automatically classify AMI patients and to investigate the role of interactions between clinical covariates and cTnT relea

Contrasting styles of (U)HP rock exhumation along the Cenozoic Adria-Europe plate boundary (Western Alps, Calabria, Corsica)

Since the first discovery of ultrahigh pressure (UHP) rocks 30 years ago in the Western Alps, the mechanisms for exhumation of (U)HP terranes worldwide are still debated. In the western Mediterranean, the presently accepted model of synconvergent exhumation (e.g., the channel-flow model) is in conflict with parts of the geologic record. We synthesize regional geologic data and present alternative exhumation mechanisms that consider the role of divergence within subduction zones. These mechanisms, i.e., (i) the motion of the upper plate away from the trench and (ii) the rollback of the lower plate, are discussed in detail with particular reference to the Cenozoic Adria-Europe plate boundary, and along three different transects (Western Alps, Calabria-Sardinia, and Corsica-Northern Apennines). In the Western Alps, (U)HP rocks were exhumed from the greatest depth at the rear of the accretionary wedge during motion of the upper plate away from the trench. Exhumation was extremely fast, and associated with very low geothermal gradients. In Calabria, HP rocks were exhumed from shallower depths and at lower rates during rollback of the Adriatic plate, with repeated exhumation pulses progressively younging toward the foreland. Both mechanisms were active to create boundary divergence along the Corsica-Northern Apennines transect, where European southeastward subduction was progressively replaced along strike by Adriatic northwestward subduction. The tectonic scenario depicted for the Western Alps trench during Eocene exhumation of (U)HP rocks correlates well with present-day eastern Papua New Guinea, which is presented as a modern analog of the Paleogene Adria-Europe plate boundary

Takotsubo Syndrome after Pacemaker Implantation: A Systematic Review

Background: Takotsubo syndrome (TTS) is an acute cardiac condition characterized by a temporary wall motion abnormality of the left ventricle that mimics an acute coronary syndrome (ACS). TTS usually occurs following emotional or physical triggering event. More recently, sporadic cases of TTS arising after pacemaker implantation were reported. Methods: We performed a systematic review of the available literature to provide a comprehensive overview of the current knowledge about pacemaker implantation-induced TTS. Results: The articles selected included case reports and one registry on 28 patients. Most cases occurred in women (75%), encompassing a broad age range. The mean age of the cases described was 74 years. Full recovery of cardiac function was reported in most cases (92.3%), with largely varying recovery times, on average 7 weeks. The most common comorbidity was arterial hypertension and the average ejection fraction at admission was approximately 62%. Clinical severity ranges from asymptomatic cases to severe clinical heart failure syndrome. Altogether the case fatality rate was 3.6%. Conclusions: For rare it might be, awareness about the potential to develop TTS after pacemaker implantation should prompt careful clinical monitoring, with daily electrocardiogram (ECG) monitoring and at least one echocardiographic examination prior to patients’ discharge to allow early diagnosis and minimize the clinical risk

A combined simulation and machine learning approach to classify severity of infarction patients

Knowledge-driven and data-driven strategies have been widely used to address many bioengineering and clinical open questions. However, little attention has been paid to the potential advantages the integration of such strategies could open up. To this aim, in this paper, we describe a sequential simulation and machine learning (ML) framework. Firstly, an ad-hoc mathematical model, based on differential equations, was used to simulate – starting from real data – cardiac troponin concentration curves of 27 patients (with Acute Myocardial Infarction and ST-segment elevation) in a 200h time frame; later, the curves were analyzed to extract 4 time-domain features which, fed to 3 tree-based ML algorithms, allowed to successfully classify – ML scores > 75% for Gradient Boosted Tree – patients in two risk classes according to Thrombolysis in Myocardial Infarction risk index. These promising results could stimulate researchers to consider combined knowledge-driven and data-driven strategies to address other cardiovascular and/or clinical research questions

Analysis of a Cardiac-Necrosis-Biomarker Release in Patients with Acute Myocardial Infarction via Nonlinear Mixed-Effects Models

The release of the cardiac troponin T (cTnT) in patients with acute myocardial infarction (AMI) has been analyzed through a methodology based on nonlinear mixed-effects (NME) models. The aim of this work concerns the investigation of any possible relationship between clinical covariates and the dynamics of the release of cTnT to derive more detailed and useful clinical information for the correct treatment of these patients. An ad-hoc mechanistic model describing the biomarker release process after AMI has been devised, assessed, and exploited to evaluate the impact of the available clinical covariates on the cTnT release dynamic. The following approach was tested on a preliminary dataset composed of a small number of potential clinical covariates: employing an unsupervised approach, and despite the limited sample size, dyslipidemia, a known risk factor for cardiovascular disease, was found to be a statistically significant covariate. By increasing the number of covariates considered in the model, and patient cohort, we envisage that this approach may provide an effective means to automatically classify AMI patients and to investigate the role of interactions between clinical covariates and cTnT release