Balancing blood pressure and catecholamine support is critical in cardiogenic shock patients

Background: Hypotension in cardiogenic shock (CS) patients is treated with catecholamines. These drugs increase mean arterial pressure (MAP) and contribute to maintaining organ perfusion but cause damage to the heart and increase vascular resistance. Therefore, catecholamines are typically titrated aiming for a relatively low MAP.

Aim: To identify the optimal target MAP and catecholamine dose in patients with cardiogenic shock. Methods: CS patients without acute myocardial infarction were retrospectively enrolled (16 centres, 5 European countries, 2016-2021, NCT03313687). Catecholamine therapy was quantified by calculating an inotropic score at baseline ((dobutamine + epinephrine + norepinephrine dose [μg/kg per min]) × 100). The association of score and ICU discharge was tested by fitting an adjusted mixed effects logistic regression model; 30-day mortality (censored at hospital discharge) by a Cox regression model; both adjusted for age, sex, pH, lactate and resuscitation and stratified by centre. The mixed effects logistic regression model of the correlation between baseline characteristics and score incorporated age, sex, resuscitation and SCAI stage.  Significance was denoted as two-sided p<0.05. Results: In 780 analysed patients with a median inotropic score of 26 ug/kg/min, median age was 63 years (IQR 52, 72), the majority (569, 72.9%) were men. A history of ischaemic cardiomyopathy was present in 193 patients (40%), atrial fibrillation in 337 (43.6%). Tachyarrhythmia was the leading CS trigger (217, 32.5%). Every third patient was resuscitated prior to enrollment (265, 34.1%). MAP was 60 mmHg (53, 69), pH 7.3 (7.2, 7.4) and lactate 5.2 mmol/l (2.7, 8.9). Most patients were at SCAI stage C (269, 42.2%) (Table 1). Overall, 148 (19%) were treated with an Impella, 138 (17.7%) with a VA-ECMO and 82 (10.5%) with both. 379 patients (48.6%) were discharged from intensive care unit (ICU), 377 (48.3%) experienced 30-day survival. A higher logarithmised inotropic score was associated with decreased odds of ICU discharge (OR 0.77, 95% confidence interval 0.69-0.86, p<0.001) and increased 30-day mortality (HR 1.26, 1.15-1.37, p<0.001). Prior resuscitation (Beta 0.26, 0.03-0.5, p=0.027) and CS severity (SCAI E vs. C: Beta 1, 0.7-1.3, p<0.001) were associated with a higher score. The optimal ratio of score/MAP is presented in Figure 1. A higher ratio correlated with increased 30-day mortality (Figure 2).

Conclusion: Catecholamine support was higher in patients with prior resuscitation and more severe CS. It associates with worse ICU discharge rates and 30-day mortality. Therefore, it seems necessary to find a balance between sufficient MAP and catecholamine doses to avoid side effects. The potential of mechanical circulatory support to increase MAP and decrease catecholamine dose over time will be assessed in further analyses.