Reversible myocardial dysfunction in survivors of out-of-hospital cardiac arrest

Objectives The aim of the study was to assess the hemodynamic status of survivors of out-of-hospital cardiac arrest (OHCA). Background The global prognosis after successfully resuscitated patients with OHCA remains poor. Clinical studies describing the hemodynamic status of survivors of OHCA and its impact on prognosis are lacking. Methods Among 165 consecutive patients admitted after successful resuscitation from OHCA, 73 required invasive monitoring because of hemodynamic instability, defined as hypotension requiring vasoactive drugs, during the first 72 h. Clinical features and data from invasive monitoring were analyzed. Results Hemodynamic instability occurred at a median time of 6.8 h (range 4.3 to 7.3) after OHCA. The initial cardiac index (CI) and filling pressures were low. Then, the CI rapidly increased 24 h after the onset of OHCA, independent of filling pressures and inotropic agents (2.05 [1.43 to 2.90] 8 h vs. 3.19 l/min per m2 [2.67 to 4.20] 24 h after OHCA; p < 0.001). Despite a significant improvement in CI at 24 h, a superimposed vasodilation delayed the discontinuation of vasoactive drugs. No improvement in CI at 24 h was noted in 14 patients who subsequently died of multiorgan failure. Hemodynamic status was not predictive of the neurologic outcome. Conclusions In survivors of OHCA, hemodynamic instability requiring administration of vasoactive drugs is frequent and appears several hours after hospital admission. It is characterized by a low CI that is reversible in most cases within 24 h, suggesting post-resuscitation myocardial dysfunction. Early death by multiorgan failure is associated with a persistent low CI at 24 h.