Case Report First-in-Man Method Description: Left Ventricular Unloading With iVAC2L During Veno-Arterial Extracorporeal Membrane Oxygenation: From Veno-Arterial Extracorporeal Membrane Oxygenation to ECMELLA to EC-iVAC®.

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is increasingly used in bi-ventricular failure with cardiogenic shock to maintain systemic perfusion. Nonetheless, it tends to increase left ventricular (LV) afterload and myocardial oxygen demand. In order to mitigate these negative effects on the myocardium, an Impella CP® (3.5 L/min Cardiac Output) can be used in conjunction with V-A ECMO (ECMELLA approach). We implemented this strategy in a patient with severe acute myocarditis complicated by cardiogenic shock. Due to a hemolysis crisis, Impella CP® had to be substituted with PulseCath iVAC2L®, which applies pulsatile flow to unload the LV. A subsequent improvement in LV systolic function was noted, with increased LV ejection fraction (LVEF), LV end-diastolic diameter (LVEDD) reduction, and a reduction in plasma free hemoglobin. This case documents the efficacy of iVAC2L in replacing Impella CP as a LV vent during V-A ECMO, with less hemolysis.

Determination of cardiac output from pulse pressure contour during intra-aortic balloon pumping in patients with low ejection fraction.

Evaluation of a new Windkessel model based pulse contour method (WKflow) to calculate stroke volume in patients undergoing intra-aortic balloon pumping (IABP). Preload changes were induced by vena cava occlusions (VCO) in twelve patients undergoing cardiac surgery to vary stroke volume (SV), which was measured by left ventricular conductance volume method (SVlv) and WKflow (SVwf). Twelve VCO series were carried out during IABP assist at a 1:2 ratio and seven VCO series were performed with IABP switched off. Additionally, SVwf was evaluated during nine episodes of severe arrhythmia. VCO's produced marked changes in SV over 10-20 beats. 198 paired data sets of SVlv and SVwf were obtained. Bland-Altman analysis for the difference between SVlv and SVwf during IABP in 1:2 mode showed a bias (accuracy) of 1.04 ± 3.99 ml, precision 10.9% and limits of agreement (LOA) of - 6.94 to 9.02 ml. Without IABP bias was 0.48 ± 4.36 ml, precision 11.6% and LOA of - 8.24 to 9.20 ml. After one thermodilution calibration of SVwf per patient, during IABP the accuracy improved to 0.14 ± 3.07 ml, precision to 8.3% and LOA to - 6.00 to + 6.28 ml. Without IABP the accuracy improved to 0.01 ± 2.71 ml, precision to 7.5% and LOA to - 5.41 to + 5.43 ml. Changes in SVlv and SVwf were directionally concordant in response to VCO's and during severe arrhythmia. (R2 = 0.868). The SVwf and SVlv methods are interchangeable with respect to measuring absolute stroke volume as well as tracking changes in stroke volume. The precision of the non-calibrated WKflow method is about 10% which improved to 7.5% after one calibration per patient.

Primary intra-aortic balloon support versus inotropes for decompensated heart failure and low output: a randomised trial.

AIMS: The haemodynamic effects of primary implantation of an intra-aortic balloon pump (IABP) versus inotropes in decompensated heart failure and low output (DHF-LO), but without an acute coronary syndrome, have not been investigated. We therefore aimed to investigate the effect of primary IABP implantation as compared to inotropes on haemodynamics in DHF-LO with no acute ischaemia. METHODS AND RESULTS: Patients (n=32) with DHF-LO despite IV diuretics were randomised to primary 50 mL IABP or inotropes (INO: enoximone or dobutamine). The primary endpoint was the improvement of organ perfusion assessed by ∆ mixed-venous oxygen saturation (SvO2) at 3 hours; secondary endpoints included ∆ cardiac power output (CPO), NT-proBNP proportional change, cumulative fluid balance and ∆ dyspnoea severity score, all at 48 hours. Data are presented as median (IQR). Patients were 60 (48-69) years old and 72% were male. Baseline SvO2 was 44 (39-53)%. ∆SvO2 was higher in the IABP group (+17 [+9; +24] vs. +5 [+2; +9]%, p<0.05). IABP patients had a higher ∆CPO, a greater relative reduction in NT-proBNP, a more negative cumulative fluid balance, and a greater reduction in dyspnoea severity score. There were no IABP-related serious adverse events (SAEs). Thirty-day mortality was 23% (IABP) vs. 44% (INO). CONCLUSIONS: Primary circulatory support by IABP showed a significant increase in improved organ perfusion assessed by SvO2.

New-generation mechanical circulatory support during high-risk PCI: a cross-sectional analysis.

AIMS: The aim of the study was to establish the value of new-generation mechanical circulatory support (MCS) devices such as HeartMate PHP, Impella CP and PulseCath iVAC2. METHODS AND RESULTS: We retrospectively analysed all consecutive elective high-risk PCI procedures performed in the Erasmus Medical Center (2011-2018) in order to compare MCS protected and unprotected patients. The primary endpoint was a composite of procedure-related adverse events including death (<24 hours), cardiac arrest, need for vasopressors, rescue MCS, endotracheal intubation and limb ischaemia with need for surgery. Secondary endpoints included 30-day survival. A total of 198 elective high-risk PCI patients were included (69 [35%] MCS protected, 129 [65%] MCS unprotected). When compared with unprotected patients, MCS protected patients had a significantly worse left ventricular ejection fraction (LVEF) (25±10 vs 33±8%, p<0.01) and higher SYNTAX I score (33±11 vs 24±8, p<0.01). The primary endpoint occurred in 26 (20%) of the unprotected patients and in 6 (9%) of the MCS protected patients (OR 0.38, 95% CI: 0.15-0.97, p=0.04). Patients under 75 years of age, with a SYNTAX I score above 32 and with an LVEF below 30% showed most potential benefit from MCS. Survival during the first 24 hours after the procedure and at 30 days was significantly higher in MCS protected patients (100% vs 95%, p=0.04 at 24 hours, and 98% vs 87%, OR 10.32, 95% CI: 1.34-79.31, p=0.006 at 30 days). CONCLUSIONS: In a consecutive real-world cohort of high-risk PCI patients, protection with new-generation MCS resulted in better procedural outcomes despite worse EF and more complex coronary artery disease at baseline. Larger prospective studies are needed to confirm these findings.

Pressure-volume analysis in athyroid patients off and on thyroxine supplementation: a pilot study.

Thyroid hormone importantly affects the cardiovascular system. However, evaluation of stroke volume (SV) and its determinants is confounded by variations in volume status that occur along different thyroid states. This study applied the pressure-volume (PV) framework to obtain relatively load-independent estimates of cardiac function in hypothyroidism as compared to euthyroidism. Ten athyroid patients were assessed echocardiographically after 4 weeks in deep hypothyroid state, and again after supplementation with oral Levothyroxine (LT4) for 3 months. Thyroid hormone levels were assessed and noninvasive pressure-volume (PV) analysis based on dedicated repeated echocardiograms was performed. Changes were assessed using paired tests. Results are presented as medians and interquartile ranges. Hypothyroidism was associated with reduced stroke volume (SV: 67.6 ± 17 vs. 75.7 ± 20.6 mL, P = 0.024), preload (end-diastolic volume, EDV: 122.6 ± 32.5 vs. 135.7 ± 33.6 mL, P = 0.004), and contractility (end-systolic elastance, Ees : 1.7 ± 0.33 vs. 2.58 ± 1.33 mmHg/mL, P = 0.01). Afterload was constant (effective arterial elastance, Ea : 1.66 ± 0.32 vs. 1.79 ± 0.52 mmHg/mL, P = 0.43) and the total energy spent was lower (PVA∙HR: 86.7 ± 28 vs. 110.9 ± 32.1 J, P = 0.04). Hemodynamic manifestations of frank hypothyroidism in humans are characterized by reduced preload and contractility, and unchanged total afterload. LT4 therapy increased work efficiency and heart rate, but not the net energy expenditure. Noninvasive PV analysis may be useful to follow-up different thyroid states.