Invasive management of acute coronary syndrome: Interaction with competing risks

Anthony Ming-Yu Chuang; David G Hancock; Amera Halabi; Matthew Horsfall; Julian Vaile; Carmine De Pasquale; Ajay Sinhal; Dylan Jones; Richard Brogan; Derek P Chew

doi:10.1016/j.ijcard.2018.07.078

Invasive management of acute coronary syndrome: Interaction with competing risks

Int J Cardiol. 2018 Oct 15:269:13-18. doi: 10.1016/j.ijcard.2018.07.078. Epub 2018 Jul 19.

Affiliations

¹ School of Medicine, Flinders University of South Australia, Adelaide, Australia; Department of Cardiovascular Medicine, Southern Adelaide Local Health Network, Adelaide, Australia. Electronic address: anthony.chuang@sa.gov.au.
² School of Medicine, Flinders University of South Australia, Adelaide, Australia; Department of Cardiovascular Medicine, Southern Adelaide Local Health Network, Adelaide, Australia.
³ Department of Cardiovascular Medicine, Southern Adelaide Local Health Network, Adelaide, Australia.

PMID: 30037631
DOI: 10.1016/j.ijcard.2018.07.078

Abstract

Background: The aim of this study was to characterise the interaction between ACS- and non-ACS-risk on the benefits of invasive management in patients presenting with acute coronary syndrome (ACS).

Methods: Consecutive patients admitted to a tertiary hospital's Cardiac Care Unit in the months of July-December, 2003-2011 with troponin elevation (>30 ng/L) were included. "ACS-specific-risk" was estimated using the GRACE score and "non-ACS-risk" was estimated using the Charlson-Comorbidity-Index (CCI). Inverse-probability-of-treatment weighting was used to adjust for baseline differences between patients who did or did not receive invasive management. A multivariable flexible parametric model was used to characterise the time-varying hazard.

Results: In total, 3057 patients were included with a median follow-up of 9.0 years. Based on CCI, 1783 patients were classified as 'low-non-ACS risk' (CCI ≤ 1; invasive management 81%; 12-month mortality 5%), 820 as 'medium-non-ACS risk' (CCI 2-3; invasive management 68%; 12-month mortality 13%), and 468 as 'high-non-ACS risk' (CCI ≥ 4; invasive management 47%; 12-month mortality 29%). After adjustment, invasive management was associated with a significant reduction in one-year overall-mortality in the 'low-risk' and 'medium-risk' groups (HR = 0.38, 95%CI:0.26-0.56; HR = 0.46, 95%CI:0.32-0.67); but not in the 'high-risk' group (HR = 1.02, 95%CI:0.67-1.56). The absolute benefit of invasive management was greatest with higher baseline ACS-risk, with a non-linear interaction between ACS- and non-ACS-risk.

Conclusions: There is a complex interaction between ACS- and non-ACS-risk on the benefit of invasive management. These results highlight the need to develop robust methods to objectively quantify risk attributable to non-ACS comorbidities in order to make informed decisions regarding the use of invasive management in individuals with numerous comorbidities.

Keywords: Acute coronary syndromes; Flexible parametric; Percutaneous coronary intervention; Propensity score.

MeSH terms

Acute Coronary Syndrome / diagnosis
Acute Coronary Syndrome / mortality*
Acute Coronary Syndrome / surgery*
Aged
Aged, 80 and over
Disease Management*
Female
Follow-Up Studies
Humans
Male
Middle Aged
Mortality / trends
Percutaneous Coronary Intervention / methods
Percutaneous Coronary Intervention / trends
Prospective Studies
Registries
Risk Factors