Development and validation of a prediction rule for patients suspected of acute coronary syndrome in primary care: a cross-sectional study

OBJECTIVE

To develop and validate a symptom-based prediction rule for early recognition of acute coronary syndrome (ACS) in patients with acute chest discomfort who call out-of-hours services for primary care (OHS-PC).

DESIGN

Cross-sectional study. A diagnostic prediction rule was developed with multivariable regression analyses. All models were validated with internal-external cross validation within seven OHS-PC locations. Both age and sex were analysed as statistical interaction terms, applying for age non-linear effects.

SETTING

Seven OHS-PC in the Netherlands.

PARTICIPANTS

2192 patients who called OHS-PC for acute chest discomfort (pain, pressure, tightness or discomfort) between 2014 and 2017. Backed up recordings of telephone triage conversations were analysed.

PRIMARY AND SECONDARY OUTCOMES MEASURES

Diagnosis of ACS retrieved from the patient's medical records in general practice, including hospital specialists discharge letters. Performance of the prediction rules was calculated with the c-statistic and the final model was chosen based on net benefit analyses.

RESULTS

Among the 2192 patients who called the OHS-PC with acute chest discomfort, 8.3% females and 15.3% males had an ACS. The final diagnostic model included seven predictors (sex, age, acute onset of chest pain lasting less than 12 hours, a pressing/heavy character of the pain, radiation of the pain, sweating and calling at night). It had an adjusted c-statistic of 0.77 (95% CI 0.74 to 0.79) with good calibration.

CONCLUSION

The final prediction model for ACS has good discrimination and calibration and shows promise for replacing the existing telephone triage rules for patients with acute chest discomfort in general practice and OHS-PC.

TRIAL REGISTRATION NUMBER

NTR7331.

Gender-stratified analyses of symptoms associated with acute coronary syndrome in telephone triage: a cross-sectional study

OBJECTIVES

To identify clinical variables that are associated with the diagnosis acute coronary syndrome (ACS) in women and men with chest discomfort who contact out-of-hours primary care (OHS-PC) by telephone, and to explore whether there are indications whether these variables differ among women and men.

DESIGN

Cross-sectional study in which we compared patient and call characteristics of triage call recordings between women with and without ACS, and men with and without ACS.

SETTING

Nine OHS-PC in the Netherlands.

PARTICIPANTS

993 women and 802 men who called OHS-PC for acute chest discomfort (pain, pressure, tightness or discomfort) between 2014 and 2016.

PRIMARY OUTCOME MEASURE

Diagnosis of ACS retrieved from the patient's medical record in general practice, including hospital specialists' discharge letters.

RESULTS

Among 1795 patients (mean age 58.8 (SD 19.5) years, 55.3% women), 15.0% of men and 8.6% of women had an ACS. In both sexes, retrosternal chest pain was associated with ACS (women with ACS vs without 62.3% vs 40.3%, p=0.002; men with ACS vs without 52.5% vs 39.7%, p=0.032; gender interaction, p=0.323), as was pressing/heavy/tightening pain (women 78.6% vs 61.5%, p=0.011; men 82.1% vs 57.4%, p=<0.001; gender interaction, p=0.368) and radiation to the arm (women 75.6% vs 45.9%, p<0.001; men 56.0% vs 34.8%, p<0.001; gender interaction, p=0.339). Results indicate that only in women were severe pain (65.4% vs 38.1%, p=0.006; gender interaction p=0.007) and radiation to jaw (50.0% vs 22.9%, p=0.007; gender interaction p=0.015) associated with ACS.Ambulances were dispatched equally in women (72.9%) and men with ACS (70.0%).

CONCLUSION

Our results indicate there were more similarities than differences in symptoms associated with the diagnosis ACS for women and men. Important exceptions were pain severity and radiation of pain in women. Whether these differences have an impact on predicting ACS needs to be further investigated with multivariable analyses.

TRIAL REGISTRATION NUMBER

NTR7331.