RESUMO
BACKGROUND: Mild therapeutic hypothermia has been shown to reduce mortality and neurological morbidity in post cardiac arrest survivors. These beneficial effects had initially been reported in retrospective studies and subsequently more evidence has been gathered by two cornerstone randomized control trials. All these studies focused on the acute outcome and the clinical status at the time of hospital discharge. The main goal of this study was to describe the long term effects of therapeutic hypothermia in this population. PATIENTS AND METHODS: A prospective cohort with a historical control group was used in this study. All consecutive patients eligible for therapeutic hypothermia after cardiac arrest were enrolled. These patients were compared to an historical control group of patients who had met the same criteria of treatment with therapeutic hypothermia, but were not treated since it was not yet available. Patients' records and clinical assessment at 1 week, one, six and twelve months follow-up were collected. RESULTS: In the present study 54 consecutive patients were recruited prospectively, treated with mild hypothermia and 41 patients served as the historical control group for a similar period of time. The cooling group was significantly younger than the control group, 54 ± 16.3 versus 61.1 ± 14.5 years (p < 0.04). Peripheral arterial embolism complication was more common in the hypothermia group. 11.1% versus 0% (p < 0.035). No other clinically meaningful differences were found. In this respect, the beneficial trend towards reduced neurological outcome and mortality was observed in favor of the cooling group, which was statistically significant at six months follow-up (p < 0.044). Beyond 6 months the differences did not reach statistical significance. CONCLUSION: In the current phase of the study, a tendency in favor of mild cooling was observed in the short and medium term outcomes in patients resuscitated after out of hospital cardiac arrest due to fatal arrhythmia. The current results indicate that in spite of high survival rates after the acute stage in the cooling group, the long term mortality rate in this group is still high.