Therapeutic limitation in cardiogenic shock: lessons learnt from the Altshock-2 registry
Authors: Ditali V , Colombo C , Villanova L , Garatti L , Montalto C , Frea S , Bertaina M , Briani M , Sorini Dini C , Sionis A , Tavazzi G , Oliva F , Pappalardo F , Morici N , Sacco A 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Mortality from cardiogenic shock (CS) shows great disparities (1). This evidence reflects variations in access to care and medical practice, related to the lack of clear guidelines for appropriate patient selection for mechanical circulatory support (MCS) application. In this regard, the results of most trials or meta-analyses were neutral on survival, and the costs in terms of patient morbidity/mortality are high and unproven (2). Accordingly, a judicious use of MCS is crucial for an adequate resource allocation and to avoid futility.

Purpose
To characterize trends in use of support devices and compare outcomes between CS patients included in a contemporary national Cardiac Intensive Care Units (CICUs) registry, treated or not with MCS.

Methods
324 sequential patients admitted with CS at a CICUs network between March 2020 and August 2022 were identified. We categorized patients according to treatment with MCS (n=204; 63%) and medical therapy (n=120; 37%). We investigated differences in clinical, laboratory, hemodynamics, echocardiographic and prognostic scores on admission, at 24-hours and at discharge. In-hospital outcome and mid-term survival were described for each treatment cohort. Comparison of continuous variables was performed using Student’s t-test. For categorical variables, the χ2 statistic was used.

Results
CS was a complication of acute myocardial infarction in 141 patients (44%) and of acute on chronic heart failure in 124 patients (38%); 58 patients (18%) presented with other diagnosis. In MCS cohort, we reported more advanced Society for Cardiovascular Angiography and Interventions (SCAI) shock stages and MCS implantation was more prevalent within 24-hours in SCAI C (48,6% on admission; 51,2% at 24-hours). In-hospital mortality did not differ between the two groups (38% in MCS and 37% in medically treated patients, p=0,874). Chronic kidney disease (OR 2.1, 95%CI 1.2-3.5, p=0,009), elevated lactates and SCAI stage at 24-hours (OR and 95%CI were, respectively, 3.45, 1.99-5.97 and 3.67, 2.46-5.47, p&lt;0,001) emerged as major independent predictors of in-hospital mortality in MCS subgroup. A significant protective association persisted for those monitored with pulmonary artery catheter (OR 0.61, 95%CI 0.51-0.92, p=0.001). Among the 196 patients evaluated at mid-term follow up MCS treatment had not markedly improved cumulative survival compared to medical treatment (51,9% in MCS subgroup versus 55,6% in medical therapy, p=0,806). Palliative care team was rarely engaged (14% in MCS cohort vs 27% in medical therapy, p=0,83).

Conclusions
In this nation-wide study, mortality in MCS patients was high and no statistically significant difference on in-hospital and mid-term survival emerged between patients receiving MCS compared to medical therapy. Hence, a prompt and constant risk-stratification is mandatory to exclude patients too sick to derive any benefits from invasive therapies, avoiding futility.