Performance of Early Capillary Refill Time Measurement on Outcomes in Cardiogenic Shock: An Observational, Prospective Multicentric Study

Rationale: Identification of cardiogenic shock severity is a critical step to adapt the management level upon admission. Peripheral tissue perfusion signs, simple and reliable markers of tissue hypoperfusion have never been extensively assessed during cardiogenic shock. Objectives: To assess the correlation of capillary refill time values with 90-day mortality in cardiogenic shock patients or the need for venoarterial extracorporeal membrane oxygenation (VA-ECMO) support. Also to assess the correlation between capillary refill time and hemodynamic parameters. Methods: All consecutive patients with cardiogenic shock admitted to the intensive care unit of two tertiary teaching hospitals were included in a prospective observational study. Macro-hemodynamic parameters (such as heart rate, blood pressure, left ventricular ejection fraction, and cardiac index) and peripheral tissue perfusion signs, such as capillary refill time on the index fingertip, mottling, and Pv-aCO2 (the difference between partial pressure of CO2 between venous and arterial blood) were recorded at inclusion (0 hour), 6 hours, 12 hours, 24 hours, and 48 hours. The composite primary endpoint was the association between 90-day mortality or the need for VA-ECMO support. Measurements and Main Results: A total of 61 patients were included; at inclusion, simplified acute physiology score II was 64 (52-77) points. The primary endpoint was met by 42% of patients. Capillary refill time values were significantly higher at all time points in nonsurvivors or patients needing VA-ECMO support. In univariate analysis, capillary refill time > 3 seconds at inclusion was associated with 90-day all-cause mortality or VA-ECMO support (hazard ratio, 12.38; 95% confidence interval, 2.91-52.71). Capillary refill time at inclusion was poorly associated with macrocirculatory parameters but significantly correlated with microcirculatory parameters. Further, capillary refill time added incremental value to Cardshock score, with an AUC combination at 0.93. Conclusions: In patients with cardiogenic shock admitted to the ICU, our preliminary data suggest that a prolonged capillary refill time >3 seconds was associated with an early prediction of 90-day mortality or the need for VA-ECMO support.