Age-Related Clinical Outcomes of Patients with Non-Valvular Atrial Fibrillation: Insights from the COOL-AF Registry

Clinical outcomes and anticoagulation therapy in elderly non-valvular atrial fibrillation and heart failure patients

AIMS

Atrial fibrillation (AF) and heart failure (HF) often coexist. Older age is strongly associated with stroke, HF, and mortality. The association between coexistence of HF and a risk of clinical outcomes and the effectiveness of anticoagulation therapy including direct oral anticoagulants (DOACs) in elderly patients with AF and HF have not been investigated. We aimed to evaluate 2 years of outcomes and to elucidate the efficacy of DOACs or warfarin in elderly AF patients in the All Nippon AF In the Elderly (ANAFIE) Registry with and without a history of HF.

METHODS AND RESULTS

The ANAFIE Registry is a multicentre, prospective observational study following elderly non-valvular AF patients aged ≥75 years for 2 years. Hazard ratios (HRs) were calculated based on the presence or absence of an HF diagnosis and DOAC or warfarin use at enrolment. Among 32 275 eligible patients, 12 116 (37.5%) had been diagnosed with HF. Patients with HF had significantly higher rates of HF hospitalization or cardiovascular death (HR 1.94, P < 0.001), cardiovascular events (HR 1.59, P < 0.001), cardiovascular death (HR 1.49, P < 0.001), all-cause death (HR 1.32, P < 0.001), and net clinical outcome including stroke/systemic embolism, major bleeding, and all-cause death (HR 1.23, P < 0.001), compared with those without HF; however, HRs for stroke/systemic embolism (HR 0.96, P = 0.56) and major bleeding (HR 1.14, P = 0.13) were similar. DOAC use was associated with a low risk of stroke/systemic embolism (HR 0.86, P = 0.19 in HF; HR 0.79, P = 0.016 in non-HF; P for interaction = 0.56), major bleeding (HR 0.71, P = 0.008 in HF; HR 0.75, P = 0.016 in non-HF; P for interaction = 0.74), HF hospitalization or cardiovascular death (HR 0.81, P < 0.001 in HF; HR 0.78, P < 0.001 in non-HF; P for interaction = 0.26), cardiovascular events (HR 0.83, P < 0.001 in HF; HR 0.82, P = 0.001 in non-HF; P for interaction = 0.65), cardiovascular death (HR 0.84, P = 0.12 in HF; HR 0.75, P = 0.035 in non-HF; P for interaction = 0.18), all-cause death (HR 0.89, P = 0.082 in HF; HR 0.80, P = 0.001 in non-HF; P for interaction = 0.091), and net clinical outcome (HR 0.88, P = 0.019 in HF; HR 0.81, P < 0.001 in non-HF; P for interaction = 0.21) compared with warfarin, irrespective of the presence or absence of HF. Analysis using the propensity score matching method showed similar associations.

CONCLUSIONS

Non-valvular AF patients aged ≥75 years with a history of HF had higher risks of cardiovascular events and mortality. DOACs were favourable to warfarin regardless of the coexistence of HF. These results might encourage the use of DOACs in elderly patients with non-valvular AF with or without HF.

Time in target range of systolic blood pressure and clinical outcomes in atrial fibrillation patients: results of the COOL-AF registry

We aimed to investigate the relationship between time in target range of systolic blood pressure (SBP-TTr) and clinical outcomes in patients with atrial fibrillation (AF). We analyzed the results from multicenter AF registry in Thailand. Blood pressure was recorded at baseline and at every 6 monthly follow-up visit. SBP-TTr were calculated using the Rosendaal method, based on a target SBP 120-140 mmHg. The outcomes were death, ischemic stroke/systemic embolism (SSE), major bleeding, and heart failure. A total of 3355 patients were studied (mean age 67.8 years; 41.9% female). Average follow-up time was 32.1 ± 8.3 months. SBP-TTr was classified into 3 groups according to the tertiles. The incidence rates of all-cause death, SSE, major bleeding, and heart failure were 3.90 (3.51-4.34), 1.52 (1.27-1.80), 2.2 (1.90-2.53), and 2.83 (2.49-3.21) per 100 person-years, respectively. Patients in the 3rd tertile of SBP-TTr had lower rates of death, major bleeding and heart failure with adjusted hazard ratios 0.62 (0.48-0.80), p < 0.001, 0.64 (0.44-0.92), p = 0.016, and 0.61 (0.44-0.84), p = 0.003, respectively, compared to 1st SBP-TTr tertile. In conclusion, high SBP-TTr was associated with better clinical outcomes compared to other groups with lower SBP-TTr. This underscores the importance of good blood pressure control in AF patients.

Non‑persistence to Oral Anticoagulation Therapy in Elderly Patients with Non‑valvular Atrial Fibrillation

PURPOSE

To investigate the reasons for elderly atrial fibrillation (AF) patients not continuing their oral anticoagulation (OAC) treatment and the factors that influence this behavior.

METHODS

Elderly AF patients (aged≥75 years) hospitalized from December 2019 to May 2022 were consecutively enrolled. Clinical, demographic, and concomitant medication data were collected. The endpoint was defined as OAC discontinuation for more than 30 days or a switch to an alternative therapy. Predictors of OAC non-persistence were investigated using a multivariable Cox regression model.

RESULTS

This study included 560 participants (51.1% men, mean age 80.9±0.2 years). During a median follow-up of 20 months, medication persistence was observed in 322 patients (57.5%). Non-persistence was found to be significantly higher with warfarin than with NOAC (48.8% vs 33.6%, p = 0.006). In the multivariate analysis, OAC non-persistence was independently predicted by a history of permanent pacemaker implantation, the use of antiplatelet drugs, employee Medicare, living with children, college degree or above, and persistent AF (HR = 1.580, 1.586, 0.604, 0.668, 0.028, 0.769, p < 0.05, respectively). Treatment discontinuation within 3 months of discharge was observed in a large number of patients (81.8%). Medication discontinuation due to bleeding was more frequently observed in patients who continued for longer than 3 months (p < 0.001), while discontinuation due to patient preference was more frequent in those with shorter durations (≤3 months) (p = 0.049). Patient preference was the second leading cause of non-persistence in patients, regardless of whether they were taking warfarin or NOAC.

CONCLUSION

OAC non-persistence remains high among elderly AF patients during long-term follow-up, with a significant proportion discontinuing shortly after discharge. This pattern of non-persistence is heavily influenced by demographic factors and patient preference. Further interventions should be developed based on the reasons and risk factors to improve persistence and initiated early in the treatment process.

The importance of assessing the safe and effective use of oral anticoagulants in older adults

See the Reply by Semla and Steinman in this issue.

Three-year outcomes of patients with non-valvular atrial fibrillation: the COOL-AF registry

BACKGROUND

Clinical outcomes of patients with non-valvular atrial fibrillation (AF) in Asian populations may be different from non-Asians. In this study, we aimed to determine the incidence of ischemic stroke/systemic embolism (SSE), major bleeding, and death, and the predictors for clinical outcomes in a contemporary Asian cohort of newly diagnosed AF patients.

METHODS

This is a prospective multicenter nationwide registry of patients with AF from 27 hospitals in Thailand. Baseline data and follow-up data were collected every 6 months until 3 years. Data collections included demographic, medical history, laboratory, and medication details. Clinical outcomes were SSE, major bleeding, and all-cause mortality. Incidence rates for each clinical outcome were calculated and presented as rate per 100 person-years. Univariate and multivariate analysis was performed to determine the independent predictors for clinical outcomes.

RESULTS

There was a total of 3405 patients: mean age was 67.8 ± 11.3 years, 1981 (58.2%) were male. During 30.8 ± 9.7 months follow-up, there was a total of 132 SSE (3.9%), 191 major bleeding (5.6%), and 357 all-cause deaths (10.5%). The incidence rates of SSE, major bleeding, and death were 1.56 (1.30-1.84), 2.26 (1.96-2.61), and 4.17 (3.33-4.25), per 100 person-years respectively. Independent predictors for clinical outcomes were age, type of AF, and the presence of comorbid conditions.

CONCLUSION

The incidence rate of SSE, major bleeding, and death remains high reflecting the unmet needs in AF management.

Predicting Heart Failure in Patients with Atrial Fibrillation: A Report from the Prospective COOL-AF Registry

BACKGROUND

This study aimed to determine risk factors and incidence rate and develop a predictive risk model for heart failure for Asian patients with atrial fibrillation (AF).

METHODS

This is a prospective multicenter registry of patients with non-valvular AF in Thailand conducted between 2014 and 2017. The primary outcome was the occurrence of an HF event. A predictive model was developed using a multivariable Cox-proportional model. The predictive model was assessed using C-index, D-statistics, Calibration plot, Brier test, and survival analysis.

RESULTS

There were a total of 3402 patients (average age 67.4 years, 58.2% male) with mean follow-up duration of 25.7 ± 10.6 months. Heart failure occurred in 218 patients during follow-up, representing an incidence rate of 3.03 (2.64-3.46) per 100 person-years. There were ten HF clinical factors in the model. The predictive model developed from these factors had a C-index and D-statistic of 0.756 (95% CI: 0.737-0.775) and 1.503 (95% CI: 1.372-1.634), respectively. The calibration plots showed a good agreement between the predicted and observed model with the calibration slope of 0.838. The internal validation was confirmed using the bootstrap method. The Brier score indicated that the model had a good prediction for HF.

CONCLUSIONS

We provide a validated clinical HF predictive model for patients with AF, with good prediction and discrimination values.

Improving risk prediction for death, stroke and bleeding in Asian patients with atrial fibrillation

BACKGROUND

The objectives of this study were to compare the GARFIELD Refitted model and CHA₂ DS₂ -VASc/HAS-BLED risk scores with the new model from the COOL-AF registry for all-cause death, ischaemic stroke/systemic embolism (SSE) and major bleeding in Asian patients with atrial fibrillation (AF).

METHODS

Patients with non-valvular AF in the nationwide COOL-AF registry were studied. Patients were enrolled from 27 hospitals in Thailand during 2014-2017. Main outcomes were all-cause mortality, SSE and major bleeding. Predictive models of the three outcomes were developed from the variables in the multivariable Cox-proportional Hazard model. Predictive values of the models were evaluated by C-statistics, calibration plots and decision curve analysis (DCA). The new COOL-AF models were compared with the GARFIELD Refitted models and CHA₂ DS₂ -VASc model for all-cause mortality, SSE/HAS-BLED model for major bleeding.

RESULTS

A total of 3405 patients were enrolled. The C-statistics for the COOL-AF models were 0.727 (0.712-0.742), 0.708 (0.693-0.724) and 0.706 (0.690-0.721) for all-cause mortality, SSE and major bleeding, respectively. Calibration plots showed good agreement between predicted probability the observed outcomes for the COOL-AF models with a calibration slope of 0.94-0.99. The predictive ability remains preserved after the internal validation with bootstraps and optimism (bias) correction. The COOL-AF predictive models tended to be superior to the GARFIELD Refitted, CHA₂ DS₂ -VASc and HAS-BLED models.

CONCLUSION

The COOL-AF predictive models for all-cause mortality, SSE and major bleeding in Asian patients with AF had a good predictive ability. The COOL-AF model for all-cause mortality was superior to the GARFIELD Refitted and CHA₂ DS₂ -VASc model.