Association between speckle tracking echocardiography and pressure-volume loops during cardiogenic shock development.

BACKGROUND: The relationship between speckle tracking assessed global longitudinal strain (GLS) and Doppler-based echocardiography with basic physiological markers of cardiac function derived from pressure-volume loops is poorly elucidated. OBJECTIVE: We aimed to describe the association between LS and Doppler-based echocardiography and direct measurements of central haemodynamic parameters from conductance catheter-based pressure-volume loops in an animal model with increasing left ventricular (LV) dysfunction. METHODS: 12 Danish landrace female pigs (75-80 kg) were used. All instrumentations were performed percutaneously, including the conductance catheter in the LV. Progressive LV dysfunction was induced by embolisation through the left main coronary artery with microspheres every 3 min until a >50% reduction in cardiac output (CO) or mixed venous saturation (SvO2), compared with baseline, or SvO2 <30%. Echocardiography was performed at baseline and 90 s after each injection. RESULTS: With progressive LV dysfunction, mean CO decreased from 5.6±0.9 L/min to 2.1±0.9 L/min, and mean SvO2 deteriorated from 61.1±7.9% to 35.3±6.1%. Mean LS and LV outflow tract velocity time integral (LVOT VTI) declined from -13.8±3.0% to -6.1±2.0% and 16.9±2.6 cm to 7.8±1.8 cm, respectively. LS and LVOT VTI showed the strongest correlation to stroke work in unadjusted linear regression (r2=0.53 and r2=0.49, respectively). LS correlated significantly with stroke volume, end-systolic elastance, systolic blood pressure, ventriculo-arterial coupling and arterial elastance. CONCLUSION: In an animal model of acute progressive LV dysfunction, echocardiographic and conductance catheter-based measurements changed significantly. LS and LVOT VTI displayed the earliest and the largest alterations with increased myocardial damage and both correlated strongest with stroke work.

Haemodynamic implications of VA-ECMO vs. VA-ECMO plus Impella CP for cardiogenic shock in a large animal model.

AIMS: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) with profound left ventricular (LV) failure is associated with inadequate LV emptying. To unload the LV, VA-ECMO can be combined with Impella CP (ECMELLA). We hypothesized that ECMELLA improves cardiac energetics compared with VA-ECMO in a porcine model of cardiogenic shock (CS). METHODS AND RESULTS: Land-race pigs (weight 70 kg) were instrumented, including a LV conductance catheter and a carotid artery Doppler flow probe. CS was induced with embolization in the left main coronary artery. CS was defined as reduction of ≥50% in cardiac output or mixed oxygen saturation (SvO2) or a SvO2 < 30%. At CS VA-ECMO was initiated and embolization was continued until arterial pulse pressure was <10 mmHg. At this point, Impella CP was placed in the ECMELLA arm. Support was maintained for 4 h. CS was induced in 15 pigs (VA-ECMO n = 7, ECMELLA n = 8). At time of CS MAP was <45 mmHg in both groups, with no difference at 4 h (VA-ECMO 64 mmHg ± 11 vs. ECMELLA 55 mmHg ± 21, P = 0.08). Carotid blood flow and arterial lactate increased from CS and was similar in VA-ECMO and ECMELLA [239 mL/min ± 97 vs. 213 mL/min ± 133 (P = 0.6) and 5.2 ± 3.3 vs. 4.2 ± 2.9 mmol/ (P = 0.5)]. Pressure-volume area (PVA) was significantly higher with VA-ECMO compared with ECMELLA (9567 ± 1733 vs. 6921 ± 5036 mmHg × mL/min × 10-3, P = 0.014). Total diureses was found to be lower in VA-ECMO compared with ECMELLA [248 mL (179-930) vs. 506 mL (418-2190); P = 0.005]. CONCLUSIONS: In a porcine model of CS, we found lower PVA, with the ECMELLA configuration compared with VA-ECMO, indicating better cardiac energetics without compromising systemic perfusion.

Immediate inflammatory response to mechanical circulatory support in a porcine model of severe cardiogenic shock.

BACKGROUND: In selected cases of cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is combined with trans valvular micro axial flow pumps (ECMELLA). Observational studies indicate that ECMELLA may reduce mortality but exposing the patient to two advanced mechanical support devices may affect the early inflammatory response. We aimed to explore inflammatory biomarkers in a porcine cardiogenic shock model managed with V-A ECMO or ECMELLA. METHODS: Fourteen landrace pigs had acute myocardial infarction-induced cardiogenic shock with minimal arterial pulsatility by microsphere embolization and were afterwards managed 1:1 with either V-A ECMO or ECMELLA for 4 h. Serial blood samples were drawn hourly and analyzed for serum concentrations of interleukin 6 (IL-6), IL-8, tumor necrosis factor alpha, and serum amyloid A (SAA). RESULTS: An increase in IL-6, IL-8, and SAA levels was observed during the experiment for both groups. At 2-4 h of support, IL-6 levels were higher in ECMELLA compared to V-A ECMO animals (difference: 1416 pg/ml, 1278 pg/ml, and 1030 pg/ml). SAA levels were higher in ECMELLA animals after 3 and 4 h of support (difference: 401 ng/ml and 524 ng/ml) and a significant treatment-by-time effect of ECMELLA on SAA was identified (p = 0.04). No statistical significant between-group differences were observed in carotid artery blood flow, urine output, and lactate levels. CONCLUSIONS: Left ventricular unloading with Impella during V-A ECMO resulted in a more extensive inflammatory reaction despite similar end-organ perfusion.

Timing and Causes of Death in Acute Myocardial Infarction Complicated by Cardiogenic Shock (from the RETROSHOCK Cohort).

Acute myocardial infarction complicated by cardiogenic shock (AMICS) comprises a heterogeneous population with high mortality. Insight in timing and cause of death may improve understanding of the condition and aid individualization of treatment. This was assessed in a retrospective, multicenter observational cohort study based on 1,716 patients with AMICS treated during the period of 2010 to 2017, of whom 904 died before hospital discharge. Patients with AMICS were identified through national registries and review of individual patients charts. In 904 patients with AMICS who died before hospital discharge (median age 72 years [interquartile range (IQR) 63 to 79], 70% men), 342 (38%) had suffered out-of-hospital cardiac arrest. The most frequent cause of death was primary cardiac (54%), whereas 24% died of neurologic injury, and 20% of multiorgan failure (MOF). Time to death was 13 hours (IQR 5 to 43) for heart failure; 140 hours (IQR 95 to 209) in neurologic injury; and 137 hours (IQR 59 to 321) in MOF, p <0.001. The causes of death in patients presenting with out-of-hospital cardiac arrest (OHCA) were: neurologic injury in 57%, as opposed to 4% in patients not presenting with OHCA, p <0.001. In conclusion, in patients with AMICS, cause of death was mainly primary heart failure followed by neurologic injury and MOF. Median time from first medical contact to death was only 13 hours in patients dying from cardiac causes. The risk of dying of neurologic injury was low in patients without OHCA.

Data-driven point-of-care risk model in patients with acute myocardial infarction and cardiogenic shock.

BACKGROUND: Prognosis models based on stepwise regression methods show modest performance in patients with cardiogenic shock (CS). Automated variable selection allows data-driven risk evaluation by recognizing distinct patterns in data. We sought to evaluate an automated variable selection method (least absolute shrinkage and selection operator, LASSO) for predicting 30-day mortality in patients with acute myocardial infarction and CS (AMICS) receiving acute percutaneous coronary intervention (PCI) compared to two established scores. METHODS AND RESULTS: Consecutive patients with AMICS receiving acute PCI at one of two tertiary heart centres in Denmark 2010-2017. Patients were divided according to treatment with mechanical circulatory support (MCS); PCI-MCS cohort (n = 220) versus PCI cohort (n = 1180). The latter was divided into a development (2010-2014) and a temporal validation cohort (2015-2017). Cohort-specific LASSO models were based on data obtained before PCI. LASSO models outperformed IABP-SHOCK II and CardShock risk scores in discriminative ability for 30-day mortality in the PCI validation [receiver operating characteristics area under the curve (ROC AUC) 0.80 (95% CI 0.76-0.84) vs 0.73 (95% CI 0.69-0.77) and 0.70 (95% CI 0.65-0.75), respectively, P < 0.01 for both] and PCI-MCS development cohort [ROC AUC 0.77 (95% CI 0.70-0.83) vs 0.64 (95% CI 0.57-0.71) and 0.64 (95% CI 0.57-0.71), respectively, P < 0.01 for both]. Variable influence differed depending on MCS, with age being the most influential factor in the LASSO-PCI model, whereas haematocrit and estimated glomerular filtration rate were the highest-ranking factors in the LASSO-PCI-MCS model. CONCLUSION: Data-driven prognosis models outperformed established risk scores in patients with AMICS receiving acute PCI and exhibited good discriminative abilities. Observations indicate a potential use of machinelearning to facilitate individualized patient care and targeted interventions in the future.

The Vasoactive Mas Receptor in Essential Hypertension.

The renin-angiotensin-aldosterone system (RAAS) has been studied extensively, and with the inclusion of novel components, it has become evident that the system is much more complex than originally anticipated. According to current knowledge, there are two main axes of the RAAS, which counteract each other in terms of vascular control: The classical vasoconstrictive axis, renin/angiotensin-converting enzyme/angiotensin II/angiotensin II receptor type 1 (AT1R), and the opposing vasorelaxant axis, angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas receptor (MasR). An abnormal activity within the system constitutes a hallmark in hypertension, which is a global health problem that predisposes cardiovascular and renal morbidities. In particular, essential hypertension predominates in the hypertensive population of more than 1.3 billion humans worldwide, and yet, the pathophysiology behind this multifactorial condition needs clarification. While commonly applied pharmacological strategies target the classical axis of the RAAS, discovery of the vasoprotective effects of the opposing, vasorelaxant axis has presented encouraging experimental evidence for a new potential direction in RAAS-targeted therapy based on the G protein-coupled MasR. In addition, the endogenous MasR agonist angiotensin-(1-7), peptide analogues, and related molecules have become the subject of recent studies within this field. Nevertheless, the clinical potential of MasR remains unclear due to indications of physiological-biased activities of the RAAS and interacting signaling pathways.