Not All Types of Atrial Fibrillation Carry the Same Stroke Risk, but Most Benefit From Oral Anticoagulation

Associations of Atrial Fibrillation Patterns With Mortality and Cardiovascular Events: Implications of the MISOAC-AF Trial

AIM

This retrospective cohort study aimed to evaluate the prognostic implications of the distinct atrial fibrillation (AF) temporal patterns: first diagnosed, paroxysmal, and persistent or permanent AF.

METHODS

In this post hoc analysis of the MISOAC-AF trial (NCT02941978), a total of 1052 patients with AF (median age 76 years), discharged from the cardiology ward between 2015 and 2018, were analyzed. Kaplan-Meier and Cox-regression analyses were performed to compare the primary outcome of all-cause mortality, the secondary outcomes of stroke, major bleeding and the composite outcome of cardiovascular (CV) mortality or hospitalization among AF patterns.

RESULTS

Of patients, 121 (11.2%) had first diagnosed, 356 (33%) paroxysmal, and 575 (53.2%) persistent or permanent AF. During a median follow-up of 31 months (interquartile range 10 to 52 months), 37.3% of patients died. Compared with paroxysmal AF, patients with persistent or permanent AF had higher mortality rates (adjusted hazard ratio (aHR), 1.37; 95% confidence interval [CI], 1.08-1.74, P = .009), but similar CV mortality or hospitalization rates (aHR, 1.09; 95% CI, 0.91-1.31, P = .35). Compared with first diagnosed AF, patients with persistent or permanent AF had similar mortality (aHR, 1.26; 95% CI, 0.87-1.82, P = .24), but higher CV mortality or hospitalization rates (aHR, 1.35; 95% CI, 1.01-1.8, P = .04). Stroke and major bleeding events did not differ across AF patterns (all P > .05).

CONCLUSIONS

In conclusion, in recently hospitalized patients with comorbid AF, the presence of persistent or permanent AF was associated with a higher incidence of mortality and morbidity compared with paroxysmal and first diagnosed AF.

The association between patterns of atrial fibrillation, anticoagulation, and cardiovascular events

AIMS

Guidelines do not recommend to take pattern of atrial fibrillation (AF) into account for the indication of anticoagulation (AC). We assessed AF pattern and the risk of cardiovascular events during 2-years of follow-up.

METHODS AND RESULTS

We categorized AF as paroxysmal, persistent, or permanent in 29 181 patients enrolled (2010-15) in the Global Anticoagulant Registry In the FIELD of AF (GARFIELD-AF). We used multivariable Cox regression to assess the risks of stroke/systemic embolism (SE) and death across patterns of AF, and whether this changed with AC on outcomes. Atrial fibrillation pattern was paroxysmal in 14 344 (49.2%), persistent in 8064 (27.6%), and permanent 6773 (23.2%) patients. Median CHA2DS2-VASc, GARFIELD-AF, and HAS-BLED scores assessing the risk of stroke/SE and/or bleeding were similar across AF patterns, but the risk of death, as assessed by the GARFIELD-AF risk calculator, was higher in non-paroxysmal than in paroxysmal AF patterns. During 2-year follow-up, after adjustment, non-paroxysmal AF patterns were associated with significantly higher rates of all-cause death, stroke/SE, and new/worsening congestive heart failure (CHF) than paroxysmal AF in non-anticoagulated patients only. In anticoagulated patients, a significantly higher risk of death but not of stroke/SE and new/worsening CHF persisted in non-paroxysmal compared with paroxysmal AF patterns.

CONCLUSION

In non-anticoagulated patients, non-paroxysmal AF patterns were associated with higher risks of stroke/SE, new/worsening HF and death than paroxysmal AF. In anticoagulated patients, the risk of stroke/SE and new/worsening HF was similar across all AF patterns. Thus AF pattern is no longer prognostic for stroke/SE when patients are treated with anticoagulants.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362.

Utility of the CHA2DS2-VASc score for predicting ischaemic stroke in patients with or without atrial fibrillation: a systematic review and meta-analysis

AIMS

Anticoagulants are the mainstay treatment for stroke prevention in patients with non-valvular atrial fibrillation (NVAF), and the CHA2DS2-VASc score is widely used to guide anticoagulation therapy in this cohort. However, utility of CHA2DS2-VASc in NVAF patients is debated, primarily because it is a vascular scoring system, which does not incorporate atrial fibrillation related parameters. Therefore, we conducted a meta-analysis to estimate the discrimination ability of CHA2DS2-VASc in predicting ischaemic stroke overall, and in subgroups of patients with or without NVAF.

METHODS AND RESULTS

PubMed and Embase databases were searched till June 2020 for published articles that assessed the discrimination ability of CHA2DS2-VASc, as measured by C-statistics, during mid-term (2-5 years) and long-term (>5 years) follow-up. Summary estimates were reported as random effects C-statistics with 95% confidence intervals (CIs). Seventeen articles were included in the analysis. Nine studies (n = 453 747 patients) reported the discrimination ability of CHA2DS2-VASc in NVAF patients, and 10 studies (n = 138 262 patients) in patients without NVAF. During mid-term follow-up, CHA2DS2-VASc predicted stroke with modest discrimination in the overall cohort [0.67 (0.65-0.69)], with similar discrimination ability in patients with NVAF [0.65 (0.63-0.68)] and in those without NVAF [0.69 (0.68-0.71)] (P-interaction = 0.08). Similarly, at long-term follow-up, CHA2DS2-VASc had modest discrimination [0.66 (0.63-0.69)], which was consistent among patients with NVAF [0.63 (0.54-0.71)] and those without NVAF [0.67 (0.64-0.70)] (P-interaction = 0.39).

CONCLUSION

This meta-analysis suggests that the discrimination power of the CHA2DS2-VASc score in predicting ischaemic stroke is modest, and is similar in the presence or absence of NVAF. More accurate stroke prediction models are thus needed for the NVAF population.

Rates and Anticoagulation Treatment of Known Atrial Fibrillation in Patients with Acute Ischemic Stroke: A Real-World Study

INTRODUCTION

Known atrial fibrillation (AF) rate and appropriate prescription of oral anticoagulants (OACs) in acute ischemic stroke (AIS) patients with AF in China are not as well known as in Western countries.

METHODS

Known AF and unknown AF, rate and adequacy of OACs use of AIS patients with AF attending five hospitals from April 2018 to August 2019 in the northwest region of China were investigated.

RESULTS

A total of 344 patients were enrolled. Of these, 237 (AF-known group; 237/344, 68.9%) and 107 patients (AF-unknown group; 107/344, 31.1%) were diagnosed with AF before and after AIS during this hospitalization, respectively. In the AF-known group with echocardiography results (178 patients, including 103 female and 75 male patients), 154 of overall, 88 of female and 66 of male patients, respectively, were indicated to be taking OACs. However, the actual OACs proportion was much lower [overall (30.5%, 47/154); female (31.8%, 28/88) and male (28.8%, 19/66) patients] than indicated. Only one female patient met the guideline-based criteria for OACs. As for patients diagnosed with massive cerebral infraction (MCI; 43.0%, 148/344), the known AF rate was 65.5% (97/148). Among the MCI patients in the AF-known group with echocardiography results (61 patients), 50 patients had an OACs indication. However, only 22.0% (11/50) of these patients took OACs, and none met the guideline-based criteria for OACs.

CONCLUSIONS

This study revealed a low known AF rate, low OACs use rate and low rate of meeting the guideline-based criteria for OACs in AIS patients with AF in the northwest region of China. These findings indicated the importance of AF as a public health problem in China.