Coronary angioplasty and COVID-19: are heparin requirements and thrombotic complications increasing?

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Covid-19 infection is associated with coagulopathy and possible heparin resistance, raising concerns that routine heparin during percutaneous coronary intervention (PCI) is failing to achieve adequate anticoagulation. We examined heparin requirements and efficacy in patients treated by PCI before and after the first reported UK case of Covid-19 (January 31st 2020). METHODS: We retrospectively compared heparin dose, Activated Clotting Time (ACT) and coronary flow (TIMI grade) for PCI procedures at a London cardiac centre in the 3 months before the UK pandemic and the three months afterwards. Testing for COVID was not routinely performed. Pre-specified analyses in patients with STEMI, NSTEMI and Stable angina were undertaken. RESULTS: Of 1227 PCI procedures performed over the period of observation, 690 were pre-pandemic and 537 were afterwards. Overall median heparin dose per case was 11000units versus 11500units (p = 0.137) and maximum ACTs were 291s versus 305s, respectively (p = 0.135). Pre-PCI TIMI 3 flow was lower during the pandemic than before (60% v 65%, p = 0.005) but Post-PCI flow was similar (96% versus 96%, p = 0.839). There were no statistically significant differences in heparin dose or achieved ACT among patients with STEMI, NSTEMI or Stable presentations. CONCLUSION: In spite of the increasing evidence that COVID-19 infection causes thrombosis, it appears that standard heparin management during PCI is sufficient to achieve effective anticoagulation and avoid peri-procedural thrombotic complications.