Background: Renal impairment may be associated with reduced efficacy of thrombolysis, increased hemorrhagic complications and risk of contrast-induced nephropathy associated with catheter angiogram used in thrombectomies. It is unclear if creatinine interacts with IV-tpa and thrombectomy in predicting post stroke outcomes.
Methods: This is a retrospective analysis of consecutive patients admitted with acute ischemic stroke to a single tertiary care center between October 2012 and July 2015. Logistic regression analysis was used to evaluate whether there was a differential impact of the association of IV-tpa and/or thrombectomy with discharge disposition (discharge home vs. other) and 3 months functional outcome (modified Rankin Score mRS<3 vs. mRS≥3) based on the admission creatinine (Cr) level (<1.5 and ≥1.5) after adjusting for sex, age, race, NIHSS on admission, history of atrial fibrillation and history of stroke/TIA.
Results: A total of 570 subjects were included (48.6% male, 69.4% white, mean age 67years, mean NIHSS 7.1, mean Cr. 1.17 , 13.1% with Cr≥1.5). A total of 18.4% (N=105) received IV-tpa and an additional 6.5%(N=37) received thrombectomy in addition to IV-tpa. About 57% were discharged home and 46% had mRS<3 at 3 months. The mean NIHSS on admission was not significantly different based on creatinine level (7.0 vs.8.1, p=0.271 in subjects with Cr<1.5 and Cr≥1.5 respectively). After adjusting for other relevant variables, the interaction of creatinine with IV-tpa with/without thombectomy was significant in predicting both discharge home (p= 0.0009) and 3 months mRS (p=0.0063). In those with creatinine <1.5, IV-tpa with/without thrombectomy was associated with increased odds of being discharged home (OR=2.81, 95%CI 1.55-5.08), p=0.0006) and a good functional outcome (mRS<3 at 3 months) (OR= 2.91, 1.66-5.10), P=0.0002. In contrast, in those with Cr ≥1.5, IV tpa with/without thrombolysis was associated with lower odds of being discharged home (OR= 0.11; 95% CI 0.01-0.74), p=0.023 and lower odds of having a favorable 3 months functional outcome (mRS<3) (OR= 0.06; 95% CI 0.006-0.80), p=0.033.
Conclusions: Creatinine on admission modified the effect of IV-tpa and thrombectomy. Reasons for this interaction warrant further investigation.