Is Hypothermia After Cardiac Arrest Effective in Both Shockable and Nonshockable Patients?: Insights From a Large Registry

• Published in: Circulation (New York, N.Y.) Vol. 123; no. 8; pp. 877 - 886
• Main Authors: DUMAS, Florence, GRIMALDI, David, EMPANA, Jean-Philippe, CARIOU, Alain, ZUBER, Benjamin, FICHET, Jérôme, CHARPENTIER, Julien, PENE, Frederic, VIVIEN, Benoit, VARENNE, Olivier, CARLI, Pierre, JOUVEN, Xavier
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01.03.2011
• Subjects: Aged; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cohort Studies; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Electric Stimulation Therapy - methods; Female; Heart; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Humans; Hypothermia, Induced - methods; Logistic Models; Male; Medical sciences; Middle Aged; Out-of-Hospital Cardiac Arrest - physiopathology; Out-of-Hospital Cardiac Arrest - therapy; Prognosis; Prospective Studies; Registries; Resuscitation - methods; Retrospective Studies; Tachycardia, Ventricular - physiopathology; Tachycardia, Ventricular - therapy; Treatment Outcome; Ventricular Fibrillation - physiopathology; Ventricular Fibrillation - therapy; Human; Cardiocirculatory arrest; Prognosis; Cardiovascular disease; outcome assessment; cardiac arrest; Resuscitation; Hypothermia
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.110.987347

Although the level of evidence of improvement is significant in cardiac arrest patients resuscitated from a shockable rhythm (ventricular fibrillation or pulseless ventricular tachycardia [VF/Vt]), the use of therapeutic mild hypothermia (TMH) is more controversial in nonshockable patients (pulseless electric activity or asystole [PEA/asystole]). We therefore assessed the prognostic value of hypothermia for neurological outcome at hospital discharge according to first-recorded cardiac rhythm in a large cohort. Between January 2000 and December 2009, data from 1145 consecutive out-of-hospital cardiac arrest patients in whom a successful resuscitation had been achieved were prospectively collected. The association of TMH with a good neurological outcome at hospital discharge (cerebral performance categories level 1 or 2) was quantified by logistic regression analysis. TMH was induced in 457/708 patients (65%) in VF/Vt and in 261/437 patients (60%) in PEA/asystole. Overall, 342/1145 patients (30%) reached a favorable outcome (cerebral performance categories level 1 or 2) at hospital discharge, respectively 274/708 (39%) in VF/Vt and 68/437 (16%) in PEA/asystole (P<0.001). After adjustment, in VF/Vt patients, TMH was associated with increased odds of good neurological outcome (adjusted odds ratio, 1.90; 95% confidence interval, 1.18 to 3.06) whereas in PEA/asystole patients, TMH was not significantly associated with good neurological outcome (adjusted odds ratio, 0.71; 95% confidence interval, 0.37 to 1.36). In this large cohort of cardiac arrest patients, hypothermia was independently associated with an improved outcome at hospital discharge in patients presenting with VF/Vt. By contrast, TMH was not associated with good outcome in nonshockable patients. Further investigations are needed to clarify this lack of efficiency in PEA/asystole.