Antiplatelet Therapy in Acute Myocardial Infarction and Cardiogenic Shock: Insights From the National Cardiogenic Shock Initiative.

BACKGROUND: Patients presenting with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) are at high risk for impaired antiplatelet activity secondary to malabsorption, systemic hypoperfusion, hypothermia, need for mechanical ventilation, and high use of analgesics. The use of antiplatelet therapy in these high-risk patients is not well studied. METHODS: Using the National Cardiogenic Shock Initiative database, we analyzed patients who presented with AMI-CS at 60 hospitals from March 2018 to December 2020. All patients were treated using a standard shock protocol. Herein, the patterns of antiplatelet use are described. RESULTS: A total of 204 patients were included in the analysis, of which 174 (85.3%) presented with ST-segment elevation myocardial infarction (STEMI). The majority (84.3%) received antiplatelet therapy before percutaneous coronary intervention (PCI); of those who received antiplatelets, 77.9% received aspirin, 55.2% received an oral P2Y12 inhibitor, and 19.2% received intravenous (IV) antiplatelet therapy. Ticagrelor was the most common P2Y12 inhibitor administered (41.9%), followed by clopidogrel (12.2%) and prasugrel (1.2%). Only 18.6% of oral antiplatelet agents were crushed. Baseline characteristics of patients who received IV vs non-IV antiplatelet agents were similar. Thrombolysis in Myocardial Infarction (TIMI) 0 flow was present in 69.6% of patients before PCI and aspiration thrombectomy was performed in 24.5% of patients. The presence of STEMI, cardiac arrest, cardiopulmonary resuscitation, hypothermia, vasopressor use, elevated lactate levels, or number of vessels treated did not influence the use of IV antiplatelet agents. CONCLUSIONS: The use of crushed and IV antiplatelet agents in AMI-CS is low. Further studies are needed in this high-risk population to assess whether more potent antiplatelet inhibition will improve outcomes.

A Rare Case of Takotsubo Syndrome and Acute Coronary Syndrome of the Right Coronary Artery.

Takotsubo syndrome (TTS) is an increasingly recognized heart disease that was initially regarded as a benign condition, but since has proven to cause irreversible myocardial damage, resembling that of acute coronary syndrome (ACS). The etiology of TTS is still uncertain but may be associated with catecholamine elevations during times of emotional or physical stress. Catecholamines are also understood to have prothrombotic properties, which could lead to ACS. With these similarities, differentiating these two pathologies can be difficult, especially when TTS and ACS occur simultaneously.

Impact of ethanol on the natural attenuation of MTBE in a normally sulfate-reducing aquifer.

Side-by-side experiments were conducted in an aquifer contaminated with methyl-tert-butyl ether (MTBE) at a former fuel station to evaluate the effect of ethanol release on the fate of pre-existing MTBE contamination. On one side, for approximately 9 months we injected groundwater amended with 1-3 mg/L benzene, toluene, and o-xylene (BToX). On the other side, we injected the same, adding approximately 500 mg/L ethanol. The fates of BToX in both sides ("lanes") were addressed in a prior publication. No MTBE transformation was observed in the "No Ethanol Lane." In the "With Ethanol Lane", MTBE was transformed to tert-butyl alcohol (TBA) underthe methanogenic and/or acetogenic conditions induced by the in situ biodegradation of the ethanol downgradient of the injection wells. The lag time before onset of this transformation was less than 2 months and the pseudo-first-order reaction rate estimated after 7-8 months was 0.046 d(-1). Our results imply that rapid subsurface transformation of MTBE to TBA may be expected in situations where strongly anaerobic conditions are sustained and fluxes of requisite nutrients and electron donors allow development of an active acetogenic/methanogenic zone beyond the reach of inhibitory effects such as those caused by high concentrations of ethanol.

Impact of ethanol on the natural attenuation of benzene, toluene, and o-xylene in a normally sulfate-reducing aquifer.

Side-by-side experiments were conducted in a sulfate-reducing aquifer at a former fuel station to evaluate the effect of ethanol on biodegradation of other gasoline constituents. On one side, for approximately 9 months we injected groundwater amended with 1-3 mg/L benzene, toluene, and o-xylene (BToX). On the other side, we injected the same, adding approximately 500 mg/L ethanol. Initially the BToX plumes on both sides ("lanes") extended approximately the same distance. Thereafter, the plumes in the "No Ethanol Lane" retracted significantly, which we hypothesize to be due to an initial acclimation period followed by improvement in efficiency of biodegradation under sulfate-reducing conditions. In the "With Ethanol Lane", the BToX plumes also retracted, but more slowly and not as far. The preferential biodegradation of ethanol depleted dissolved sulfate, leading to methanogenic/acetogenic conditions. We hypothesize that BToX in the ethanol-impacted lane were biodegraded in part within the methanogenic/acetogenic zone and, in part, within sulfate-reducing zones developing along the plume fringes due to mixing with sulfate-containing groundwater surrounding the plumes due to dispersion and/or shifts in flow direction. Overall, this research confirms that ethanol may reduce rates of biodegradation of aromatic fuel components in the subsurface, in both transient and near steady-state conditions.

Bispectral analysis as a tool to investigate dynamics of cardiorespiratory physiology.

INTRODUCTION: Recent studies show that cardiorespiratory variables are nonlinearly coupled. In the present study, we tested the feasibility of using bispectral analysis to estimate changes in nonlinear phase coupling. METHODS: We stimulated chemo- and baro-reflexes by switching inspired gas between air and air with 5% CO2 added during supine and 70 degrees head-up tilt. Bispectra were estimated using Fourier transform of the triple cumulant and were integrated between 0.04 and 0.3 Hz. Variables analyzed included cardiac RR intervals, systolic BP (SBP), tidal volume (VT), end tidal pressure of CO2 (PETCO2) and mean cerebral blood flow velocity (CBFM). Data were collected in 30 healthy adults who were then grouped according to whether they become presyncopal (PS) during tilt or remained normal with no signs or symptoms of presyncope (NPS). RESULTS: Six subjects (20%) developed presyncope. During tilt with room air breathing, phase coupling in RR, SBP, and between RR-SBP and RR-VT was lower in PS than in NPS, while phase coupling between CBFM-SBP was higher. In contrast, during tilt with 5% inhaled CO2, phase coupling between CBFM-PETCO2 was lower for PS than for NPS. DISCUSSION: Perturbations to baro- and chemo-reflexes led to changes in nonlinear phase coupling that were altered in presyncope. Although physiological interpretation of changes in phase coupling are less than clear at this time, our results show that such nonlinear indexes may provide a helpful perspective in understanding the complex phenomenon of orthostatically mediated syncope.

Transfer function analysis of gender-related differences in cerebral autoregulation.

Effects of gender in cardiovascular regulation are widely investigated, however differences in cerebral autoregulation (CA) between genders remains less explored. In the present study, we used spectral analysis to analyze differences in cerebral autoregulation between 10 men and 10 age-matched women. Subjects rested in a supine position (20 min) and then were passively tilted to a 70-degree head up tilt position (30 min). During the first 10 min of supine they breathed only room air (Supine Control) while during the second 10 min of supine they breathed room air or room air plus 5% CO2 in a Pseudo Random Binary Sequence (PRBS) (Supine PRBS). During the first 10 min of tilt, subjects breathed room air or room air plus 5% CO2 switched in a PRBS (Tilt PRBS). For the remaining 20 min of tilt, they breathed only room air (Tilt Control). Blood pressure (BP) and cerebral blood flow velocity (CBFV) were non-invasively recorded using Finapres and Transcranial Doppler. Coherence and transfer function between mean BP and mean CBFV were estimated. During Supine Control, women had higher coherence (p < 0.05) and transfer function gain (p < 0.01) within 0.03-0.10 Hz and 0.22-0.31 Hz than men. During tilt, coherence within 0.05-0.26 Hz were higher in men than in women (P < 0.02). Although the reasons for these gender-related differences in cerebral autoregulation remain unclear, our results suggest that in investigating cerebral autoregulation, gender may need to be considered as a factor.