Abstract
Background
CHA2DS2-VASc score has been used as a surrogate marker for predicting outcomes beyond thromboembolic risk in patients with atrial fibrillation (AF). Likewise, cardiac troponin I (cTnI) is a predictor of mortality in AF.
Purpose
This study aimed to investigate the association of cTnI and CHA2DS2-VASc score with long-term prognosis in patients admitted to the emergency department with AF.
Methods
A retrospective cohort study conducted between January 2012 and December 2013, enrolling patients admitted to the emergency department with AF and having documented cTnI measurements. CHA2DS2-VASc score was estimated. Primary endpoint was 5-year all-cause mortality, readmission for heart failure (HF), readmission for myocardial infarction (MI) and the composite end point of major adverse cardiac events defined as death, readmission for HF or readmission for MI (MACE).
Results
A total of 578 patients with AF were studied, of whom 252 patients had elevated levels of cTnI (43.6%) and 334 patients had CHA2DS2-VASc score >3 (57.8%). Patients with elevated cTnI tended to be oldercompared with those who did not have cTnI elevation and were more frequently comorbid and of higher ischemic risk, including hypertension, prior MI, prior HF, chronic renal failure and peripheral artery disease. The overall median CHA2DS2-VASc score was higher in those with cTnI elevation compared to those patients elevated cTnI levels (4.2 vs 3.3 points, p<0.001). Main diagnoses at hospital discharge were tachyarrhythmia 30.3%, followed by heart failure 17.7%, respiratory infections 9.5% and acute coronary syndrome 7.3%. At 5-year follow-up, all-cause death was significantly higher for patients with cTnI elevation compared with those who did not have cTnI elevation (56.4% vs. 27%; logrank test p<0.001). Specifically, for readmissions for HF and readmissions for MI there were no differences in between patients with or without cTnI elevation. In addition, MACE was reached in 165 patients (65.5%) with cTnI elevation, compare to 126 patients (38.7%) without cTnI elevation (p<0.001). On multivariable Cox regression analysis, cTnI elevation was an independent predictor of all-cause death (hazard ratio, 1.67, 95% confidence interval [CI]: 1.24–2.26, p=0.001) and of MACE (hazard ratio 1.47, 95% confidence interval 1.15–1.88; P=0.002), but it did not reach statistical significance for readmissions for MI and readmissions for HF. CHA2DS2-VASc score was a predictor on univariate Cox regression analysis for each endpoint, but it did not reach significance on multivariable Cox regression analysis for any endpoint.
Conclusions
cTnI is independently associated with long-term all-cause mortality in patients attending the emergency department with AF. cTnI compared to CHA2DS2-VASc score is thus a biomarker with predictive capacity for mortality in late follow-up, conferring utility in the risk stratification of patients with atrial fibrillation.
Persistent Cardiac Troponin I Elevation in Stabilized Patients After an Episode of Acute Coronary Syndrome Predicts Long-Term Mortality
