During refractory cardiogenic shock (rCS), macro- and microcirculation were successfully maintained with the assistance of venoarterial extracorporeal membrane oxygenation (VA ECMO). For a study, researchers sought to examine the effect of increasing VA ECMO flow or dobutamine dose on microcirculation in stabilized VA ECMO–treated patients with rCS. In this prospective interventional trial, investigators enrolled consecutive intubated patients with ECMO-supported rCS and stable hemodynamics who could tolerate stepwise incremental dobutamine dosages (from 5 to 20 gamma/kg/min) or ECMO flows (progressive increase by 25% over baseline ECMO flow). The baseline was determined as the minimum VA ECMO flow, and dobutamine 5 μg/kg/min (DOBU5) required to maintain a mean arterial pressure (MAP) more than or equal to 65 mmHg. After 30 minutes at each level, macro and micro circulations were assessed. There were 14 patients included. Macro- and micro circulations were evaluated 2 [2–5] days after the initiation of ECMO. Dose increases of dobutamine did not affect microcirculation parameters. ECMO-flow increments decreased only the De Backer score (P=0.08), whereas other microcirculation parameters were unaffected. These results did not differ between patients successfully weaned off ECMO (n=6) and those who were not. When macrocirculation was already recovered in patients with rCS supported by ECMO, increasing dobutamine (above 5 μg/kg/min) or ECMO flow did not improve microcirculation.