Background: In the management of non-ST-elevation acute coronary syndrome (NSTACS)
a gap between guideline-recommended care and actual practice has been reported. A systematic
overview of the actual extent of this gap, its potential impact on patient-outcomes, and influential
factors is lacking.
Objective: To examine the extent of guideline adherence, to study associations with the occurrence
of adverse cardiac events, and to identify factors associated with guideline adherence.
Method: Systematic literature review, for which PUBMED, EMBASE, CINAHL, and the Cochrane
library were searched until March 2016. Further, a manual search was performed using reference
lists of included studies. Two reviewers independently performed quality-assessment and data extraction
of the eligible studies.
Results: Adherence rates varied widely within and between 45 eligible studies, ranging from less
than 5.0 % to more than 95.0 % for recommendations on acute and discharge pharmacological treatment,
34.3 % - 93.0 % for risk stratification, and 16.0 % - 95.8 % for performing coronary angiography.
Seven studies indicated that higher adherence rates were associated with lower mortality. Several
patient-related (e.g. age, gender, co-morbidities) and organization-related (e.g. teaching hospital)
factors influencing adherence were identified.
Conclusion: This review showed wide variation in guideline adherence, with a substantial proportion
of NST-ACS patients possibly not receiving guideline-recommended care. Consequently, lower adherence
might be associated with a higher risk for poor prognosis. Future research should further
investigate the complex nature of guideline adherence in NST-ACS, its impact on clinical care, and
factors influencing adherence. This knowledge is essential to optimize clinical management of NSTACS
patients and could guide future quality improvement initiatives.