Chest
Volume 141, Issue 6, June 2012, Pages 1431-1440
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Original Research
Cardiovascular Disease
Role of the CHADS2 Score in Acute Coronary Syndromes: Risk of Subsequent Death or Stroke in Patients With and Without Atrial Fibrillation

https://doi.org/10.1378/chest.11-0435Get rights and content

Background

Atrial fibrillation (AF) is common in patients with acute coronary syndromes (ACS). We aimed to describe the value of the CHADS2 (congestive heart failure, hypertension, age ≥ 75 years, diabetes, prior stroke or transient ischemic attack) score as a risk assessment tool for mortality and stroke in patients with ACS, irrespective of the presence or absence of AF.

Methods

Consecutive patients with ACS admitted to the coronary care unit were prospectively included in a risk stratification study. We calculated the CHADS2 scores from the data collected at admission, and all patients were followed until January 1, 2007, or death.

Results

Of 2,335 patients with ACS in this study, 442 (age 71 ± 8 years, 142 women) had AF. Their mean CHADS2 score was 1.6 ± 1.4 vs 1.0 ± 1.1 in patients without AF (P < .0001). The all-cause mortality at 10 years was strongly associated with the CHADS2 score in patients with AF (hazard ratio [HR] and 95% CI per unit increase in the six-grade CHADS2 score, 1.21 [1.07-1.36]; P = .002), but the same association was also present in patients without AF (HR 1.38 [1.28-1.48], P < .0001), after adjustment for potential confounders. The more complicated GRACE (Global Registry of Acute Coronary Events) risk score provided a better prediction for short- and long-term mortality than the simpler CHADS2 score (P < .0001). Hospitalization for stroke was significantly associated with the CHADS2 score in patients without AF (but not in those with AF) after adjustment (HR 1.46 [1.27-1.68], P < .0001).

Conclusions

In patients with ACS, AF is associated with poor prognosis. The CHADS2 score developed for AF has even greater prognostic value in patients who do not have AF, and it may help to identify patients with high risk for subsequent stroke or death and a need for optimization of risk-reducing treatment.

Section snippets

Materials and Methods

Consecutive patients with ACS were enrolled between September 15, 1995, and March 15, 2001, in a study assessing subsequent prognosis.13 The diagnosis of ACS was based on chest pain, other symptoms suggestive of myocardial ischemia, ECG changes, biochemical markers of myocardial necrosis, or previously recognized coronary artery disease. Patients aged > 80 years with a life expectancy < 1 year because of conditions other than coronary heart disease were not included. The study was approved by

Results

In this study, 2,335 patients (age 66 ± 10 years, 717 women) had confirmed ACS. Among them, 859 (37%) had ST segment elevation AMI (STEMI), 792 (34%) had non-ST segment elevation AMI (NSTEMI), and 684 (29%) had unstable angina. In total, 442 patients (age 71 ± 8 years, 142 women) had a type of AF, and 37% of these patients had STEMI, 41% had NSTEMI, and 21% had unstable angina. Among the 1,893 patients (age 64 ± 10 years, 575 women) without AF, 37% had STEMI, 32% had NSTEMI, and 31% had

Discussion

The CHADS2 score on admission was useful in predicting subsequent death and stroke in patients with ACS with and without AF, and scores > 2 were more predictive in patients without than with AF. The CHADS2 score, both unadjusted and when adjusted for potential confounders, correlated significantly with all-cause mortality. The score was also significantly associated with the rate of hospitalization for stroke. This association was strong in patients without AF, both unadjusted and after

Limitations

We cannot exclude the possibility that a study in a similar patient population at another site or at multiple sites might have other risk profiles and subsequent prognoses depending on differences in the care of ACS. Inclusion in the study took place between 1995 and 2001, and treatment strategies, especially for patients with STEMI, are different today, in our center and elsewhere. In patients with AF, the time course of events should be interpreted with caution because of the size of the

Conclusions

The CHADS2 score provided important information about risk and prognosis in patients with ACS, and AF was an important risk factor. In patients with an ACS, the CHADS2 score would identify patients with a higher risk of subsequent stroke and death, and an optimization of the therapy could result in a reduced risk of subsequent events.

Acknowledgments

Author contributions: Dr Poçi: contributed to the study concept and design, analysis and interpretation of data, drafting of the manuscript, critical revision of the manuscript for important intellectual content, and final approval.

Dr Hartford: contributed to the study concept and design, acquisition of data, analysis and interpretation of data, drafting of the manuscript, critical revision of the manuscript for important intellectual content, and final approval.

Mr Karlsson: contributed to the

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Parts of this article have been presented at different scientific meetings during 2010: (Heart Rhythm 2010, Denver, Colorado, May 14, 2010, poster; Cardisotim 2010, Nice, France, June 18, 2010, oral presentation; and ESC Congress 2010, Stockholm, Sweden, August 29, 2010, poster).

Funding/Support: This study was supported by the Swedish Research Council (14231), the Swedish Heart and Lung Foundation, the Vardal Foundation, Gothenburg University, and the Göteborg Medical Society.

Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.

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