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

Abstract

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 cardiac damage and increase vascular resistance. Thus, they are typically titrated aiming for a target MAP. Purpose(s): To identify the optimal trade-off between MAP and catecholamine dose in patients with heart failure-related CS (HF-CS). Method(s): HF-CS patients (i.e., without acute myocardial infarction) were retrospectively enrolled (16 centres, 5 European countries, 2016-2021). Catecholamine therapy was quantified by an inotropic score at baseline ((dobutamine + epinephrine + norepinephrine mug/kg/min]) x 100) and a summarised one (days 1, 3, 5 and 7; deceased patients were assigned their individual highest score for missing data points if death before day 7). The associations of both scores with intensive care unit (ICU) discharge (mixed effects logistic regression model) and 30-day mortality (censored at hospital discharge; Cox regression model) were tested. Association of mechanical circulatory support (MCS) with the summarised score was tested by a mixed effects linear regression model. All analyses were adjusted for age, sex, pH, lactate, resuscitation and centre. Spline charts were stratified by centre. Result(s): Of 704 included patients, median baseline inotropic score was 25 ug/kg/min, age 63 years, the majority (519, 74%) were men. Ischaemic cardiomyopathy was present in 174 patients (41%), atrial fibrillation in 311 (45%). Tachyarrhythmia was the leading CS trigger (199, 33%). Every third patient was resuscitated prior to enrollment (238, 34%). Median MAP was 60 mmHg, pH 7.3, lactate 5.2 mmol/l. Most patients were at SCAI stage C (252, 44%) (Table 1). In total, 375 patients (53%) were discharged from ICU, 369 (52%) survived 30 days. A higher logarithmised inotropic score at baseline was associated with decreased ICU discharge (OR 0.78, 95% confidence interval 0.69-0.88, p<0.001) and increased 30-day mortality (HR 1.27, 1.15-1.40, p<0.001), even after adjustment. The same but with greater magnitude was true for the summarised score: ICU discharge was less likely with higher logarithmised score (OR 0.46, 0.38-0.56, p<0.001), 30-day mortality more likely (HR 1.83, 1.60-2.09, p<0.001). For ICU discharge, a ratio score/MAP (both baseline) <0.403 correlated with better outcomes (optimum at 0.024, Figure 1). A ratio <0.426 associated with lower 30-day mortality (optimum at 0.360 but without detected ceiling effect, Figure 2). MCS correlated with an increased summarised score (Beta 0.69, 0.42-0.97, p<0.001). Conclusion(s): Catecholamine support in patients with HF-CS associates with lower ICU discharge rates and higher 30-day mortality. However, this study determined an optimal balance between sufficient MAP and catecholamine doses. Surprisingly, MCS was not associated with decreased but rather increased catecholamine support.