Purpose: Mild therapeutic hypothermia is a neuroprotective procedure after cardiac arrest. Therefore, it is increasingly used. Likewise, there is a growing demand for coronary angiography and percutaneous coronary interventions under hypothermia. Case studies suggested that hypothermia may be associated with coronary vasospasm, heart rhythm events and platelet dysfunction. In this study, it was evaluated whether vasospasm, arrhythmia or bleeding occur to a relevant degree during cardiac catheterization under concomitant hypothermia.
Methods: In this prospective, single-center, open-label, non-interventional study, 29 patients after resuscitation for cardiac arrest were treated with mild hypothermia and underwent cardiac catheterization (coronary angiography n = 11, coronary angiography plus percutaneous intervention n = 18). The incidence of vasospasm, cardiac arrhythmia and relevant bleeding at the puncture site were evaluated.
Results: Mean temperature at cardiac catheterization was 33.9 ± 0.76°C. The mean heart rate was 82 ± 26 bpm at hospital admission and 67 ± 17 bpm under hypothermia (p < 0.05). There was no patient with relevant bradycardia beyond the expected hypothermia-induced rate reduction during the procedure. There were no unexpected ventricular tachycardias or episodes of ventricular fibrillation which might have been attributed to hypothermia. Twenty-nine of 29 patients (100%) were free from coronary vasospasm. There was no patient with a relevant bleeding at the puncture site. Potassium levels were low in 52% of the patients, even after resuscitation, which was partially attributed to hypothermia.
Conclusion: Coronary angiography and percutaneous coronary interventions under mild therapeutic hypothermia were safe in this small cohort and were performed without hypothermia-induced vasospasm, relevant rhythm events or bleeding complications. This result has to be confirmed in a large series of patients.