Early discharge after primary percutaneous coronary intervention: the added value of N-terminal pro-brain natriuretic peptide to the zwolle risk score

Background-the zwolle risk score (zrs) identifies st-elevation myocardial infarction (stemi) patients treated with primary percutaneous coronary intervention (ppci) eligible for early discharge. we aimed to investigate whether baseline n-terminal pro- brain natriuretic peptide (nt-probnp) is also able to identify these patients and could improve future risk strategies. methods and results-ppci patients included in the ongoing tirofiban in myocardial infarction evaluation (on-time) ii study were candidates (n=861). we analyzed whether zrs and baseline nt-probnp predicted 30-day mortality and assessed the occurrence of major adverse cardiac events (maces) and major bleeding. receiver operating characteristic curve analysis was used to assess discriminative accuracy for zrs,nt-pro-bnp,and their combination. after multiple imputation,845 patients were included. both zrs >3 (hazard ratio [hr]=9.42; p < 0.001) and log nt-pro-bnp (hr=2.61; p < 0.001) values were associated with 30-day mortality. on multivariate analysis,both the zrs (hr=1.41; 95% confidence interval [ci]=1.27 to 1.56; p < 0.001) and log nt-probnp (hr=2.09; 95% ci=1.59 to 2.74; p < 0.001) independently predicted death at 30 days. the area under the curve for 30-day mortality for combined zrs/nt-probnp was 0.94 (95% ci=0.90 to 0.99),with optimal predictive values of a zrs ≥2 and a nt-probnp value of ≥200 pg/ml. using these cut-off values,64% of the study population could be identified as very low risk with zero mortality at 30 days follow-up and low occurrence of maces and major bleeding between 48 hours and 10 days (1.3% and 0.6%,respectively). conclusion-baseline nt-probnp identifies a large group of low-risk patients who may be eligible for early (48-to 72-hour) discharge,whereas optimal predictive accuracy is reached by the combination of both baseline nt-probnp and zrs. © 2014 the authors.