Benjamin Kummer, MD
Percutaneous coronary intervention (PCI) is infrequently complicated by stroke, which tends to occur more frequently after emergent PCI, and is highly morbid when it occurs. However, the relationship between PCI setting (emergent vs. elective) or stroke subtype (ischemic vs. hemorrhagic) and stroke risk factors, as well as post-PCI stroke outcomes, remains unclear. Myint et al. sought to address these gaps in knowledge by studying approximately 560,000 PCI patients from the British Cardiovascular Intervention Society database, using in-hospital major adverse cardiovascular events (MACE) and 30-day mortality as outcomes.
The rate of any post-PCI stroke was low (0.13%), 80% of strokes were ischemic, and any post-PCI stroke was associated with increased odds of poor outcome irrespective of setting (ORs, no stroke as reference: elective MACE 21.05, p<0.001, emergent MACE 6.25, p<0.001, elective mortality 37.90, p<0.001, emergent mortality 5.00, p<0.001). ORs were higher in the elective vs. emergent setting. The odds of mortality after hemorrhagic stroke (ORs: elective 175.24, p<0.001, emergent 21.50, p<0.001) were higher than after ischemic stroke irrespective of setting (ORs: elective 17.61, p<0.001, emergent 3.11, p<0.001), consistent with the high mortality associated with ICH.
Generally, setting did not significantly affect the odds of poor outcome—except for ischemic stroke after emergent PCI, which had lower odds of in-hospital MACE than after ischemic stroke in the elective setting (OR 0.44, 95%CI 0.22-0.86). The authors attributed this to higher usage of “advanced” anti-platelet medications / GP IIb/IIIa inhibitors in emergent PCI settings.
Stroke risk factors differed by PCI setting. Female sex and cardiovascular comorbidities such as CABG, cardiogenic shock, ventilator/circulatory support and STEMI were associated with increased odds of stroke in the emergent setting, whereas female sex and the use of GP IIb/IIIa inhibitors were the main risk factors for the elective setting. There were also differences in risk factors according to stroke subtype; thrombectomy was associated with ischemic stroke, whereas thrombolysis was associated with hemorrhagic stroke. The main limitations were unclear ascertainment of stroke, absent functional status data and post-stroke management, plus the impossibility of gauging the timing of stroke in relation to PCI.
Overall, the study confirms the rarity and known high morbidity and mortality of post-PCI stroke once it occurs, and also shows that risk factors vary between stroke subtypes and settings. However, PCI setting does not seem to have major impact on the likelihood of poor outcome after post-PCI stroke.