Therapeutic hypothermia in cardiovascular disease

Introduction: Historical trials demonstrated clinical benefit of therapeutic hypothermia (TH) in unconscious cardiac arrest survivors. However, recent research raised important unanswered questions about this concept. Cardiac arrest associated mortality and morbidity including psychological trauma for survivors and caregivers remain alarmingly high, warranting further research in this field. TH has also been shown to offer additional protection against reperfusion injury in experimental models of myocardial ischaemia. However, co-administration of TH in conscious patients undergoing treatment for acute myocardial infarction (AMI) is potentially challenging. Methodology: (i) Rhinochill®, a novel intranasal cooling device is compared to Blanketrol for TH induction in unconscious cardiac arrest survivors, investigating efficacy and clinical outcome at hospital discharge. (ii) The emotional burden of cardiac arrest in patients and their caregivers is documented and the impact of simple interventions on quality of life is assessed. (iii) The feasibility of co-administration of TH in conscious patients undergoing emergency treatment of AMI is investigated. Results: (i) Rhinochill® is found to be more efficient in TH induction when measured from the tympanic membrane. However, Rhinochill® did not offer any superior clinical benefit. (ii) Simple psychological interventions are shown to improve quality of life in cardiac arrest survivors. (iii) Co-administration of endovascular cooling is shown to be feasible in conscious patients undergoing AMI treatment with minimum disruption to patient care. Discussion: Delays in TH administration may offset any potential benefit that it can offer in neuroprotection and therefore, earlier targeted brain cooling with more efficient portable devices is worth investigating. Improving quality of life of cardiac arrest survivors has been shown to be cost effective and therefore, investing in resources to better identify and help those at risk is justified. Delivery of TH in conscious heart attack patients is feasible and safe but more efficient endovascular cooling devices are required and these will need to be assessed in larger trials to assess the effect on clinical outcomes.