Evaluation of the Marburg Heart Score and INTERCHEST score compared to current telephone triage for chest pain in out-of-hours primary care.

INTRODUCTION: Chest pain is a common and challenging symptom for telephone triage in urgent primary care. Existing chest-pain-specific risk scores originally developed for diagnostic purposes may outperform current telephone triage protocols.

METHODS: This study involved a retrospective, observational cohort of consecutive patients evaluated for chest pain at a large-scale out-of-hours primary care facility in the Netherlands. We evaluated the performance of the Marburg Heart Score (MHS) and INTERCHEST score as stand-alone triage tools and compared them with the current decision support tool, the Netherlands Triage Standard (NTS). The outcomes of interest were: C‑statistics, calibration and diagnostic accuracy for optimised thresholds with major events as the reference standard. Major events are a composite of all-cause mortality and both cardiovascular and non-cardiovascular urgent underlying conditions occurring within 6 weeks of initial contact.

RESULTS: We included 1433 patients, 57.6% women, with a median age of 55.0 years. Major events occurred in 16.4% (n = 235), of which acute coronary syndrome accounted for 6.8% (n = 98). For predicting major events, C‑statistics for the MHS and INTERCHEST score were 0.74 (95% confidence interval: 0.70-0.77) and 0.76 (0.73-0.80), respectively. In comparison, the NTS had a C-statistic of 0.66 (0.62-0.69). All had appropriate calibration. Both scores (at threshold ≥ 2) reduced the number of referrals (with lower false-positive rates) and maintained equal safety compared with the NTS.

CONCLUSION: Diagnostic risk stratification scores for chest pain may also improve telephone triage for major events in out-of-hours primary care, by reducing the number of unnecessary referrals without compromising triage safety. Further validation is warranted.