[Temporary circulatory assistance by Impella™ in interventional cardiology: Observational study and medico-economic assessment after four years of use]. / Assistance circulatoire temporaire par Impella™ en cardiologie interventionnelle : étude observationnelle et bilan médicoéconomique après quatre ans d'utilisation.

OBJECTIVES: During life-threatening emergencies or risky cardiologic interventions, pharmacology can be limited and the use of appropriate medical devices is then necessary. The Impella™ catheter, CP and 2.5, has been referenced for the exclusive use of the interventional cardiology technical platform at Hôpital Nord (AP-HM) in the absence of rapid access to the Extracorporeal Circulation unit. It is a temporary mechanical circulatory support device mainly indicated in refractory cardiogenic shock and coronary angioplasty at high risk of hemodynamic instability. The objective of this study, observational and retrospective, is to carry out a clinical and economic assessment linked to the use of this device over a period of four years (2017-2020). METHODS: The criteria relating to the 71 patients (51 Impella™ CP and 20 Impella™ 2.5) and their clinical evolution as well as the costs and valuation of the stays were determined. RESULTS: In particular, the Impella™ CP enabled myocardial recovery in 18 out of 51 patients and it was an intermediary in the context of heavier care for 11 patients. The balance between expenditure and valuation shows a deficit of -819,937 euros over the study period, with however a probable margin for improvement. CONCLUSIONS: The Impella™ is of clinical interest under very specific conditions. Its high cost and the absence of inclusion on the list of reimbursements in addition to Homogeneous Groups of Stays represent a significant financial burden for health care establishments. Thus, optimizing the rating of future stays is a necessity.

Economic evaluation of fractional flow reserve-guided versus angiography-guided multivessel revascularisation in ST-segment elevation myocardial infarction patients in the FLOWER-MI randomised trial.

BACKGROUND: In patients with ST-segment elevation myocardial infarction (STEMI) who have multivessel disease, the FLOWER-MI trial found no significant clinical benefit to fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) compared to angiography-guided PCI. AIMS: Our aim was to estimate the cost-effectiveness and cost-utility of FFR-guided PCI, the secondary endpoint of the FLOWER-MI trial. METHODS: Costs, major adverse cardiovascular events (composite of all-cause death, non-fatal myocardial infarction [MI], and unplanned hospitalisation leading to urgent revascularisation), and quality-adjusted life years were calculated in both groups. The incremental cost-effectiveness and cost-utility ratios were estimated. Uncertainty was explored by probabilistic bootstrapping. The analysis was conducted from the perspective of the health care provider with a time horizon of one year. RESULTS: At one year, the average cost per patient was 7,560€ (±2,218) in the FFR-guided group and 7,089€ (±1,991) in the angiography-guided group (p-value<0.01). The point estimates for the incremental cost-effectiveness and cost-utility ratios found that the angiography-guided strategy was cost saving and improved outcomes, with a probabilistic sensitivity analysis confirming dominance. CONCLUSIONS: The FFR-guided strategy at one year is unlikely to be cost effective compared to the angiography-guided strategy on both clinical and quality of life outcomes.

Pump flow setting and assessment of unloading in clinical practice.

The rationale for mechanical circulatory support (MCS) in cardiogenic shock is to restore cardiac output in selected patients when critically low or in case of refractory cardiac arrest. Furthermore, an MCS device that moves blood from either the left atrium or the left ventricle to the systemic circulation will potentially unload the ventricle. These devices are used alone or in combination with venoarterial extracorporeal membrane oxygenation (VA-ECMO). If a left-sided Impella device is used, it should be run at the highest possible performance level during treatment while avoiding suction events. When combined with VA-ECMO, the Impella device should be run at a lower performance level, ensuring sufficient left ventricular emptying but avoiding suction. Continuous monitoring is pivotal and patients managed outside the catheterization laboratory should be monitored with an arterial line, a central venous catheter, frequent use of pulmonary artery catheters and regular imaging by transthoracic echocardiogram.

Doppler echocardiography for assessment of systemic vascular resistances in cardiogenic shock patients.

OBJECTIVE: Impaired vascular tone plays an important role in cardiogenic shock. Doppler echocardiography provides a non-invasive estimation of systemic vascular resistance. The aim of the present study was to compare Doppler echocardiography with the transpulmonary thermodilution method for the assessment of systemic vascular resistance in patients with cardiogenic shock. METHODS: This prospective monocentric comparison study was conducted in a single cardiology intensive care unit (Hopital Nord, Marseille, France). We assessed the systemic vascular resistance index by both echocardiography and transpulmonary thermodilution in 28 patients admitted for cardiogenic shock, on admission and after the introduction of an inotrope or vasopressor treatment. RESULTS: A total of 35 paired echocardiographic and transpulmonary thermodilution estimations of the systemic vascular resistance index were compared. Echocardiography values ranged from 1309 to 3526 dynes.s.m2/cm5 and transpulmonary thermodilution values ranged from 1320 to 3901 dynes.s.m2/cm5. A statistically significant correlation was found between echocardiography and transpulmonary thermodilution (r=0.86, 95% confidence interval (CI) 0.74, 0.93; P<0.0001). The intraclass correlation coefficient was 0.84 (95% CI 0.72, 0.92). The mean bias was -111.95 dynes.s.m2/cm5 (95% CI -230.06, 6.16). Limits of agreement were -785.86, 561.96. CONCLUSIONS: Doppler echocardiography constitutes an accurate non-invasive alternative to transpulmonary thermodilution to provide an estimation of systemic vascular resistance in patients with cardiogenic shock.

Poor agreement between light transmission aggregometry, Verify Now P2Y12 and vasodilatator-stimulated phosphoprotein for clopidogrel low-response assessment: a potential explanation of negative results of recent randomized trials.

Clopidogrel low response as assessed by several different biological tests correlates with poor prognosis after percutaneous coronary intervention (PCI). However, recent randomized clinical trials (RCT) testing the strategy of individual antiplatelet therapy tailoring based on one sole test have all shown negative results. Poor correlation between the different tests may explain the difficulties of patient selection and identification of "true poor responders" to clopidogrel. In this prospective study, clopidogrel response was assessed in 100 consecutive patients between 18 and 24 hours after a 600 mg clopidogrel loading dose using three different tests: light transmission aggregometry with 10 µmol ADP (LTA, results expressed as platelet aggregation percentage: PAP), Verify Now P2Y12 (VN, results expressed as P2Y12 reaction unit: PRU) and vasodilatator-stimulated phosphoprotein (VASP, results expressed as platelet reactivity index: PRI). Patients under chronic clopidogrel therapy were excluded. The mean PAP, PRU and PRI values were 38.6%, 176.1 PRU and 52.4%, respectively. When clopidogrel response was analyzed as continuous variable, there was a good correlation between the different tests: LTA/VN (R(2 )= 0.642, p < 0.001), LTA/VASP (R(2 )= 0.409, p < 0.001) and VN/VASP (R(2 )= 0.616, p < 0.001). However, when clopidogrel response was analyzed as pre-specified cut-off points to define patients as "poor or good responders" (according to the literature: 50% PAP for LTA, 235 PRU for VN and 50% PRI for VASP), only 47% of the patients were defined as "good" or "poor responders" by the three tests. Altogether, 33% of the patients were defined as "poor responders" by only one test, 20% by two tests and only 16% by the three tests. The correlation between the different tests is good when clopidogrel response is analyzed as continuous variable. Each individual is however rarely (less than 50%) defined as "poor or good responder" by all the three tests when pre-specified cut-off values are used. A sole test might not be sufficient to manage antiplatelet therapy in an individual patient and these results may explain the results of recent RCT showing the lack of benefit of systematic antiplatelet therapy monitoring strategy.

Genotypic and phenotypic assessment of platelet function and response to P2Y12 antagonists.

The P2Y12-ADP receptor antagonists are the cornerstone of oral antiplatelet therapy in the secondary prevention of coronary artery disease, especially after acute coronary syndrome or percutaneous coronary intervention. Currently, the therapeutic agents available to block the receptor include clopidogrel and prasugrel; ticagrelor is not available everywhere. Clopidogrel was the gold standard, but recently it has been challenged by prasugrel and ticagrelor. One pitfall of clopidogrel is that in some patients it cannot induce optimal platelet reactivity inhibition in connection with several factors, including some genetic polymorphisms of enzymes participating in its bioabsorption or metabolism. This variability of response can be evaluated by platelet reactivity monitoring. This comprehensive review provides the available data regarding the genotypic and phenotypic interaction with the response to P2Y12-ADP receptor antagonists and discusses the concept of personalized antiplatelet therapy based on a genotypic or phenotypic profile.