title: Applicability of the Zwolle risk score for safe early discharge after primary percutaneous coronary intervention in ST-segment elevation myocardial infarction.
abstract: OBJECTIVE
  The optimal length of stay for patients with uncomplicated ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PPCI) is still undetermined. The Zwolle risk score (ZRS) is a simple tool designed to identify patients who can be safely discharged within 72 hours. The purpose of this study was to assess the applicability and performance of the ZRS in our population.
  
  
  METHODS
  We studied 276 consecutive patients (mean age 62 ± 14 years, 75% male, 20% Killip class >1) admitted over a two-year period for STEMI and treated with PPCI. ZRS, length of stay, 30-day mortality and readmission were obtained for all patients. Low risk was defined as ZRS ≤ 3.
  
  
  RESULTS
  The median ZRS was 3 (interquartile range [IQR] 1-4), with 171 patients (62%) being classified as low risk. Thirty-day mortality was 4.7% (13 patients). Compared to other patients, low-risk patients had shorter length of stay (median 5.0 [IQR 4-7] vs. 7.0 [5-13] days, p<0.001), and lower 30-day mortality (0 vs. 12.4%, p<0.001), yielding a negative predictive value of 100% (95% CI 97.0-100%) for the proposed cutoff. The ZRS showed excellent discriminative power (C-statistic: 0.937, 95% CI 0.906-0.968, p<0.001), and good calibration against the original cohort.
  
  
  CONCLUSIONS
  The ZRS appears to perform well in identifying low-risk STEMI patients who could be safely discharged within 72 hours of admission. Using the ZRS in our population could result in a more rational use of in-patient resources.
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal. Electronic address: atralhao@gmail.com.
authors: António
authors: A
authors: Tralhão
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: António Miguel
authors: AM
authors: Ferreira
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Sérgio
authors: S
authors: Madeira
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Miguel
authors: M
authors: Borges Santos
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Mariana
authors: M
authors: Castro
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Ingrid
authors: I
authors: Rosário
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Marisa
authors: M
authors: Trabulo
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Carlos
authors: C
authors: Aguiar
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Jorge
authors: J
authors: Ferreira
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Manuel Sousa
authors: MS
authors: Almeida
authors: Hospital de Santa Cruz, Western Lisbon Hospital Centre, Department of Cardiology, Carnaxide, Portugal.
authors: Miguel
authors: M
authors: Mendes
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D061214:Patient Safety; D062645:Percutaneous Coronary Intervention; D012189:Retrospective Studies; D018570:Risk Assessment; D000072657:ST Elevation Myocardial Infarction / Q000601:surgery*
keywords: Alta precoce; Early discharge; Enfarte agudo do miocárdio com supradesnivelamento de ST; Intervenção coronária percutânea primária; Primary percutaneous coronary intervention; ST-segment elevation myocardial infarction; Score de Zwolle; Zwolle risk score