Monitoring a Mystery: The Unknown Right Ventricle during Left Ventricular Unloading with Impella in Patients with Cardiogenic Shock.

Background: Right ventricular (RV) dysfunction or failure occurs in more than 30% of patients in cardiogenic shock (CS). However, the importance of timely diagnosis of prognostically relevant impairment of RV function is often underestimated. Moreover, data regarding the impact of mechanical circulatory support like the Impella on RV function are rare. Here, we investigated the effects of the left ventricular (LV) Impella on RV function. Moreover, we aimed to identify the most optimal and the earliest applicable parameter for bedside monitoring of RV function by comparing the predictive abilities of three common RV function parameters: the pulmonary artery pulsatility index (PAPi), the ratio of right atrial pressure to pulmonary capillary wedge pressure (RA/PCWP), and the right ventricular stroke work index (RVSWI). Methods: The data of 50 patients with CS complicating myocardial infarction, supported with different flow levels of LV Impella, were retrospectively analyzed. Results: Enhancing Impella flow (1.5 to 2.5 L/min ± 0.4 L/min) did not lead to a significant variation in PAPi (p = 0.717), RA/PCWP (p = 0.601), or RVSWI (p = 0.608), indicating no additional burden for the RV. PAPi revealed the best ability to connect RV function with global hemodynamic parameters, i.e., cardiac index (CI; p < 0.001, 95% CI: 0.181-0.663), pulmonary capillary wedge pressure (PCWP; p = 0.005, 95% CI: -6.721--1.26), central venous pressure (CVP; p < 0.001, 95% CI: -7.89-5.575), and indicators of tissue perfusion (central venous oxygen saturation (SvO2); p = 0.008, 95% CI: 1.096-7.196). Conclusions: LV Impella does not impair RV function. Moreover, PAPi seems to be to the most effective and valid predictor for early bedside monitoring of RV function.

Discussion of hemodynamic optimization strategies and the canonical understanding of hemodynamics during biventricular mechanical support in cardiogenic shock: does the flow balance make the difference?

BACKGROUND: Mechanical circulatory support (MCS) devices may stabilize patients with severe cardiogenic shock (CS) following myocardial infarction (MI). However, the canonical understanding of hemodynamics related to the determination of the native cardiac output (CO) does not explain or support the understanding of combined left and right MCS. To ensure the most optimal therapy control, the current principles of hemodynamic measurements during biventricular support should be re-evaluated. METHODS: Here we report a protocol of hemodynamic optimization strategy during biventricular MCS (VA-ECMO and left ventricular Impella) in a case series of 10 consecutive patients with severe cardiogenic shock complicating myocardial infarction. During the protocol, the flow rates of both devices were switched in opposing directions (+ / - 0.7 l/min) for specified times. To address the limitations of existing hemodynamic measurement strategies during biventricular support, different measurement techniques (thermodilution, Fick principle, mixed venous oxygen saturation) were performed by pulmonary artery catheterization. Additionally, Doppler ultrasound was performed to determine the renal resistive index (RRI) as an indicator of renal perfusion. RESULTS: The comparison between condition 1 (ECMO flow > Impella flow) and condition 2 (Impella flow > VA-ECMO flow) revealed significant changes in hemodynamics. In detail, compared to condition 1, condition 2 results in a significant increase in cardiac output (3.86 ± 1.11 vs. 5.44 ± 1.13 l/min, p = 0.005) and cardiac index (2.04 ± 0.64 vs. 2.85 ± 0.69, p = 0.013), and mixed venous oxygen saturation (56.44 ± 6.97% vs. 62.02 ± 5.64% p = 0.049), whereas systemic vascular resistance decreased from 1618 ± 337 to 1086 ± 306 s*cm-5 (p = 0.002). Similarly, RRI decreased in condition 2 (0.662 ± 0.05 vs. 0.578 ± 0.06, p = 0.003). CONCLUSIONS: To monitor and optimize MCS in CS, PA catheterization for hemodynamic measurement is applicable. Higher Impella flow is superior to higher VA-ECMO flow resulting in a more profound increase in CO with subsequent improvement of organ perfusion.

Hemoadsorption as part of a multimodal therapy concept to treat Capnocytophaga sepsis with thrombocytopenia and multiple organ failure.

BACKGROUND: Capnocytophaga, a bacteria native to the oral flora of canines, in rare cases can lead to severe infections resulting in septic shock, respiratory tract infection, and multiple organ failure. In case of trauma following animal bites with rapidly progressing clinical courses, also adjunctive therapeutic measures such as extracorporeal blood purification therapies might be beneficial. CASE PRESENTATION: We report on a 68-year-old male who was hospitalized with fever, oliguria and repeated vomiting after suffering a minor bite by his dog. On admission, he was diagnosed with sepsis. In addition, his coagulation status was markedly deranged resulting in the administration of mass transfusions to stabilize his coagulative status. Following detection of Capnocytophaga canimorsus, anti-infective therapy was initiated. In the context of a progressive respiratory deterioration and an increasing vigilance disorder, he had to be intubated. Due to development of renal failure, dialysis was started in conjunction with CytoSorb hemoadsorption therapy to control the hyperinflammatory condition. All of the applied therapeutic measures led to a rapid clinical stabilization, a control of the hyperinflammatory situation, and an improvement in his neurological status. The therapy was well tolerated with no complications encountered. CONCLUSIONS: This case supports the clinical recognition of severe Capnocytophaga infection that can lead to critical conditions even in immunocompetent patients. Combined broad spectrum antibiotic therapy, mass transfusions, CRRT, and CytoSorb hemoadsorption therapy resulted in a control of the critical situation. However, further research is needed to fully elucidate the role of hemoadsorption in this rare but life-threatening setting.

Factor VII Activating Protease Expression in Human Platelets and Accumulation in Symptomatic Carotid Plaque.

Background Factor VII activating protease (FSAP) is of interest as a marker for vascular inflammation and plaque destabilization. The aim of this study was to analyze the expression profile of FSAP in endarterectomy specimens that were taken from patients with asymptomatic and symptomatic carotid atherosclerotic plaques and to compare them with circulating FSAP levels. Methods and Results Plasma FSAP concentration, activity, and mRNA expression were measured in endarterectomy specimens and in monocytes and platelets. Plaque and plasma FSAP levels were higher in symptomatic patients (n=10) than in asymptomatic patients (n=14). Stronger FSAP immunostaining was observed in advanced symptomatic lesions, in intraplaque hemorrhage-related structures, and in lipid-rich areas within the necrotic core. FSAP was also colocalized with monocytes and macrophages (CD11b/CD68-positive cells) and platelets (CD41-positive cells) of the plaques. Moreover, human platelets expressed FSAP in vitro, at both the mRNA and protein levels. Expression is stimulated by thrombin receptor-activating peptide and ADP and reduced by acetylsalicylic acid. Conclusions Plasma FSAP levels were significantly increased in patients with symptomatic carotid stenosis and thus may be involved in plaque development This plaque-associated FSAP may be produced by platelets or macrophages or may be taken up from the circulation. To establish FSAP's utility as a circulating or plaque biomarker in patients with symptomatic carotid atherosclerotic plaques, further studies are needed.