Elsevier

American Heart Journal

Volume 162, Issue 2, August 2011, Pages 347-355.e1
American Heart Journal

Clinical Investigation
Diabetes and Metabolism
Temporal changes in the management and outcome of Canadian diabetic patients hospitalized for non–ST-elevation acute coronary syndromes

https://doi.org/10.1016/j.ahj.2011.05.020Get rights and content

Background

There are limited data on the contemporary management and outcomes of non–ST-elevation acute coronary syndrome (NSTE-ACS) patients with diabetes in the “real world.” We sought to evaluate (1) the temporal changes in the medical and invasive management and (2) in-hospital outcome of NSTE-ACS patients with and without diabetes.

Methods

We included Canadian patients hospitalized for NSTE-ACS enrolled in 4 consecutive, prospective, multicenter registries: Canadian ACS-I (n = 3259; 1999-2001), ACS-II (n = 1,956; 2002-2003), Global Registry of Acute Coronary Events (GRACE/GRACE2 [n = 7,561; 2004-2007]) and Canadian Registry of Acute Coronary Events (n = 1,326; 2008). Participants were stratified by the presence or absence of preexisting diabetes on admission. Temporal changes in patient management and outcomes were evaluated across the 4 registries. Multivariable analyses were performed to determine the independent prognostic significance of diabetes.

Results

Of the 14,102 NSTE-ACS patients, 4,046 (28.7%) had previously diagnosed diabetes. Patients with diabetes were older; were more likely to have prior cardiac history including myocardial infarction, revascularization, and heart failure; and had worse Killip class and higher GRACE risk score (all P < .001). Over time, there were significant increases in the use of in-hospital coronary angiography and revascularization. However, diabetic patients were less likely to undergo coronary angiography (52.5% vs 57%, P < .001) or revascularization (28.4% vs 33.4%, P < .001). The underuse of invasive procedures in diabetic patients was seen in all registries and was persistent over time. Overall, compared with the group without diabetes, diabetic patients had higher unadjusted rates of in-hospital mortality (3.0% vs 1.6%, P < .001). In multivariable analysis adjusting for components of the GRACE risk score, diabetes remained an independent predictor of in-hospital death (adjusted odds ratio 1.66, 95% CI 1.30-2.11, P < .001).

Conclusions

Over the last decade, NSTE-ACS patients with diabetes continue to be treated more conservatively, despite evidence that they would derive similar or even greater benefits from aggressive treatment. This underutilization of evidence-based therapies among diabetic patients with NSTE-ACS in the “real world” may partly explain their worse outcome.

Section snippets

Registry design and study population

Our study population included Canadian patients with NSTE-ACS enrolled in 4 multicenter, prospective observational studies from consecutive time periods: the Canadian ACS-I registry (1999-2001), the Canadian ACS-II registry (2002-2003), Canadian Global Registry of Acute Coronary Events (GRACE; 2004-2007), and Canadian Registry of Acute Coronary Events (CANRACE; 2008). Details of these registries have been published previously.17, 18 To summarize, the Canadian ACS registries were national

Study population

A total of 14,205 patients from the 4 registries had a final diagnosis of NSTE-ACS. Data regarding prior diabetes status were missing in 103 (0.7%) patients who were excluded from our study. Thus, a total of 14,102 patients were included in our analysis; of these patients, 4,046 (28.7%) had previously diagnosed diabetes. The rate of diagnosed diabetes increased from 27.2% in the ACS-I registry to 29.9% in CANRACE (P for trend = 0.005). Baseline characteristics of patients with and without

Discussion

Several important findings are demonstrated in our study. First, in the contemporary era, across a broad spectrum of NSTE-ACS, patients with diabetes have a worse prognosis than those without diabetes. Second, despite the overall increase in the utilization of evidence-based therapies in the management of NSTE-ACS over time, treating physicians continue to manage patients with diabetes less aggressively than those without diabetes. This is discordant with current management guidelines that do

Acknowledgements

We thank Sue Francis, BA, for her assistance in the preparation of this manuscript. We are grateful to all the study investigators, coordinators, and patients who participated in the Canadian ACS-I, ACS-II, GRACE/GRACE,2 and CANRACE registries. Dr Andrew Yan is supported by a New Investigator Award from the Heart and Stroke Foundation of Canada.

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    • Cited by (0)

    h

    On behalf of the Canadian Acute Coronary Syndrome Registries I and II, and the Canadian Global Registry of Acute Coronary Events (GRACE/GRACE2) and Canadian Registry of Acute Coronary Events (CANRACE) Investigators. (See the online Appendix).

    i

    Drs Elbarouni and Ismaeil contributed equally to this work.

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