Risk Levels and Adverse Clinical Outcomes Among Patients With Nonvalvular Atrial Fibrillation Receiving Oral Anticoagulants

Abstract

IMPORTANCEThe CHA 2 DS 2 -VASc score (calculated as congestive heart failure, hypertension, age 75 years and older, diabetes, stroke or TIA, vascular disease, age 65 to 74 years, and sex category) is the standard for assessing risk of stroke and systemic embolism and includes age and thromboembolic history. To our knowledge, no studies have comprehensively evaluated safety and effectiveness outcomes among patients with nonvalvular atrial fibrillation receiving oral anticoagulants according to independent, categorical risk strata. OBJECTIVETo evaluate the incidence of key adverse outcomes among patients with nonvalvular atrial fibrillation receiving oral anticoagulants by CHA 2 DS 2 -VASc risk score range, thromboembolic event history, and age group. DESIGN, SETTING, AND PARTICIPANTSThis cohort study was a retrospective claims data analysis using combined data sets from 5 large health claims databases. Eligible participants were adult patients with nonvalvular atrial fibrillation who initiated oral anticoagulants. Data were analyzed between January 2012 and June 2019. EXPOSURE Initiation of oral anticoagulants. MAIN OUTCOMES AND MEASURESWe observed clinical outcomes (including stroke or systemic embolism, major bleeding, and a composite outcome) on treatment through study end, censoring for discontinuation of oral anticoagulants, death, and insurance disenrollment. The population was stratified by CHA 2 DS 2 -VASc risk score; history of stroke, systemic embolism, or transient ischemic attack; and age groups. We calculated time to event, incidence rates, and cumulative incidence for outcomes. RESULTSWe identified 1 141 097 patients with nonvalvular atrial fibrillation; the mean (SD) age was 75.0 (10.5) years, 608 127 patients (53.3%) were men, and over 1 million were placed in the 2 highest risk categories (high risk 1, 327 766 participants; high risk 2, 688 449 participants). Deyo-Charlson Comorbidity Index scores ranged progressively alongside CHA 2 DS 2 -VASc risk score strata (mean [SD] scores: low risk, 0.4 [1.0]; high risk 2, 4.1 [2.9]). The crude incidence of stroke and systemic embolism generally progressed alongside risk score strata (low risk, 0.25 events per 100 person-years [95% CI, 0.18-0.34 events]; high risk 2, 3.43 events per 100 person-years [95% CI, 3.06-4.20 events]); patients at the second-highest risk strata with thromboembolic event history had higher stroke incidence vs patients at the highest risk score strata without event history (2.06 events per 100 person-years [95% CI, 2.00-3.12 events] vs 1.18 events per 100 person-years [95% CI, 1.14-1.30 events]). Major bleeding and composite incidence also increased progressively alongside risk score strata (major bleeding: low risk, 0.68 events per 100 person-years [95% CI, 0.56-0.82 events]; high risk 2, 6.29 events per 100 person-years [95% CI, 6.21-6.62 events]; composite incidence: 1.22 (continued) Key Points Question What are the relative safety and effectiveness outcomes among patients with nonvalvular atrial fibrillation receiving anticoa...

Clinical Outcomes, Management, Healthcare Resource Utilization, and Cost According to the CHA2DS2-VASc Scores in Asian Patients with Nonvalvular Atrial Fibrillation

“…This result was consistent with a previous study based on five large health claims databases in the United States, where 89.0% of patients were estimated to have a high-risk of stroke. 12 Similar demographic characteristics, including an average age of over 70 years old and a higher proportion of males, were observed in comparable investigations. 14,23 This study revealed a higher incidence of adverse clinical outcomes compared to previous studies and an increasing trend with higher CHA 2 DS 2 -VASc scores.…”

“…The incidence of IS in Asian patients included in this study was notably higher across different CHA 2 DS 2 -VASc score categories compared to Western populations. 11,12 Additionally, the estimated incidence of IS in our study was higher than those reported in most prior studies involving Asian populations, highlighting a greater disease burden for the Chinese population. [13][14][15][16] We observed that the incidence of TIA and AE also increased with the CHA 2 DS 2 -VASc scores.…”

“…7,10 Previous studies have shown a higher incidence of adverse clinical outcomes among nonvalvular atrial fibrillation (NVAF) patients with higher levels of CHA 2 DS 2 -VASc risk scores. [11][12][13][14][15][16] However, these studies were primarily based on Western populations or relied on limited sample sizes or data from years past. Considering the differences in ethnicity and the evolving spectrum of diseases, the incidence of adverse outcomes among contemporary Asian NVAF patients with different CHA 2 DS 2 -VASc scores remains unclear.…”

Refining Atrial Fibrillation Stroke Risk Estimates—A Call for Thoughtful Implementation Planning

“…Lip and colleagues conducted a real-world observational analysis by combining 5 large US insurance claims data sets consisting of over 1.1 million patients with AF who received oral anticoagulation between January 2012 and June 2019. The most common stroke risk factor was hypertension (84.5%) followed by coronary artery disease (42.7%), diabetes (36.0%), and congestive heart failure (28.8%).…”

“…While the analysis by Lip and colleagues largely validates the guideline-supported CHA 2 DS 2 -VASc risk score approach, it raises question as to how the score is applied. For instance, a man with a CHA 2 DS 2 -VASc score of 2 due to hypertension and diabetes is estimated to have a stroke or systemic incidence rate of only 0.56 events per 100 person-years, which is markedly lower than the estimated rate of major bleeding (2.17 events per 100 person-years).…”