Introduction: Cardiogenic shock remains a life-threatening condition with a historically high mortality rate (~50%). Implementation of cardiogenic shock protocols emphasizing early diagnosis, hemodynamic profiling, and timely initiation of mechanical circulatory support (MCS) has demonstrated improved outcomes. We present a rare case of metformin toxicity resulting in biventricular failure managed successfully with dual Impella support (BiPella).
Description: A 71-year-old female with no prior cardiac history presented with acute kidney injury, profound metabolic acidosis (pH < 6.8), and lactic acid of 16 mmol/L. Her outpatient labs suggested AKI from volume depletion due to diarrhea while on metformin/sitagliptin. She was intubated and started on continuous renal replacement therapy (CRRT). Midway through CRRT, she developed bradycardia followed by PEA arrest. Return of spontaneous circulation was achieved after 6 minutes.
Post-arrest echocardiogram showed newly reduced LVEF (35–40%) and severe RV dysfunction. Hemodynamic evaluation revealed low cardiac output (CO 1.89), low cardiac index (0.9), elevated filling pressures, and a cardiac power output (CPO) of 0.4, consistent with biventricular cardiogenic shock. Due to her post-arrest status and poor transplant candidacy, she was not considered for VA ECMO. The multidisciplinary shock team initiated BiPella support with Impella RP and Impella CP.
Over the next 8 days, MCS was gradually weaned as clinical and echocardiographic parameters improved. She had complete recovery of biventricular function, resolution of lactic acidosis, normalization of hemodynamics, and was ultimately extubated and discharged to rehab.
Discussion: Cardiogenic shock due to metformin toxicity is rare but potentially reversible. Early application of a structured shock protocol and appropriate MCS selection can be lifesaving. In patients ineligible for ECMO but with reversible pathology, BiPella may offer a viable alternative to achieve cardiac recovery.
