Visit-to-Visit Heart Rate Variability in the Prediction of Clinical Outcomes of Patients with Atrial Fibrillation

BACKGROUND

 Visit-to-visit heart rate variability (VVV-HR) has been associated with adverse cardiovascular outcomes. We aimed to determine the predictive value of VVV-HR for adverse clinical outcomes in patients with nonvalvular atrial fibrillation (AF).

METHODS

 We used data from a prospective multicenter AF registry of 27 hospitals in Thailand during 2014 to 2017. After the baseline visit, patients were followed up every 6 months until 3 years. VVV-HR was calculated from the standard deviation of heart rate data from baseline visit and every follow-up visit. VVV-HR was categorized into four groups according to the quartiles. Clinical outcomes were all-cause death, ischemic stroke/systemic embolism (SE), and heart failure. Cox proportional hazard models were used for multivariable analysis.

RESULTS

 There were a total of 3,174 patients (mean age: 67.7 years; 41.8% female). The incidence rates of all-cause death, ischemic stroke/SE, and heart failure were 3.10 (2.74-3.49), 1.42 (1.18-1.69), and 2.09 (1.80-2.42) per 100 person-years respectively. The average heart rate was 77.8 ± 11.0 bpm and the average of standard deviation of heart rate was 11.0 ± 5.9 bpm. VVV-HR Q4 was an independent predictor of all-cause death, ischemic stroke/SE, and heart failure with adjusted hazard ratios of 1.45 (95% confidence interval: 1.07-1.98), 2.02 (1.24-3.29), and 2.63 (1.75-3.96), respectively. VVV-HR still remained a significant predictor of clinical outcomes when analyzed based on coefficient of variation and variability independent of mean.

CONCLUSION

 VVV-HR is an independent predictor for adverse clinical outcomes in patients with AF. A J-curve appearance was demonstrated for the effect of VVV-HR on all-cause death.

Predicting the Absolute Risk of Ischemic Stroke in Asian Patients with Atrial Fibrillation: Comparing the COOL-AF Risk Score with CARS/mCARS Models for Absolute Risk and the CHA2DS2-VASc Score

BACKGROUND

The aims of this study were (1) to validate the CARS and mCARS methods in an Asian population with atrial fibrillation (AF) and (2) to compare the CARS and mCARS models for absolute risk using the COOL-AF method and CHA₂DS₂VASc scores for the prediction of ischemic stroke or systemic embolism (SSE).

METHODS

We analyzed the results from a prospective nationwide multicenter AF registry. Follow-up data were collected for 3 years. The main outcomes were SSE. Predictive models of the 3-year SSE of the COOL-AF model, the CHA₂DS₂VASc score, the CARS for the no-OAC group, and the mCARS for the OAC group were developed and evaluated by C-statistics, and calibration plots were created for the whole group, as well as for oral anticoagulant (OAC) users and no-OAC patients.

RESULTS

We studied 3405 patients (mean age: 67.8 years; 58.2% male, 75.4% OAC). The incidence rates of SSE were 1.51 (1.26-1.78), 1.93 (1.39-2.60), and 1.37 (1.10-1.68) for all patients, no-OAC patients, and OAC patients, respectively. For the whole population, the COOL-AF score had a C-statistic of 0.697 (0.682-0.713), which was superior to the CHA₂DS₂-VASc [0.655 (0.639-0.671)]. For the no-OAC group, the CARS predicted SSE with a C-statistic of 0.685 (0.652-0.716), which was similar to the CHA₂DS₂-VASc [0.684 (0.651-0.7150] and COOL-AF models [0.692 (0.659-0.723)]. For the OAC group, the mCARS had a C-statistic of 0.687 (0.669-0.705) that was similar to the COOL-AF [0.704 (0.686-0.721)] and better than the CHA₂DS₂-VASc score [0.655 (0.637-0.674)].

CONCLUSIONS

The calculation of the individual absolute risks using the CARS and mCARS models can predict SSE in an Asian population. Small differences were evident between the COOL-AF and CHA₂DS₂-VASc scores.

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.

Soluble ST2 in the prediction of heart failure and death in patients with atrial fibrillation

Background

Biomarkers may be a useful marker for predicting heart failure (HF) or death in patients with atrial fibrillation (AF).

Hypothesis

Soluble ST2 (sST2) may be a good biomarker for the prediction of HF or death in patients with AF.

Methods

This is a prospective study of patients with nonvalvular AF. Clinical outcomes were HF or death. Clinical and laboratory data were compared between those with and without clinical outcomes. Univariate and multivariate analysis was performed to determine whether sST2 is an independent predictor for heart failure or death in patients with nonvalvular AF.

Results

A total of 185 patients (mean age: 68.9 ± 11.0 years) were included, 116 (62.7%) were male. The average sST2 and N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) levels were 31.3 ± 19.7 ng/ml and 2399.5 ± 6853.0 pg/ml, respectively. Best receiver operating characteristic (ROC) cut off of sST2 for predicting HF or death was 30.14 ng/ml. Seventy‐three (39.5%) patients had an sST2 level ≥30.14 ng/ml, and 112 (60.5%) had an sST2 level <30.14 ng/dl. The average follow‐up was 33.1 ± 6.6 months. Twenty‐nine (15.7%) patients died, and 33 (17.8%) developed HF during follow‐up. Multivariate analysis revealed that high sST2 to be an independent risk factor for death or HF with a HR and 95% CI of 2.60 (1.41–4.78). The predictive value of sST2 is better than NT‐proBNP, and it remained significant in AF patients irrespective of history of HF, and NT‐proBNP levels.

Conclusions

sST2 is an independent predictor of death or HF in patients with AF irrespective of history of HF or NT‐proBNP levels.

Efficacy of R2CHA2DS2-VA score for predicting thromboembolism in Thai patients with non-valvular atrial fibrillation

Background

There is no data specific to the addition of renal dysfunction and age 50–64 years as risk parameters to the CHA₂DS₂-VA score, which is known as the R₂CHA₂DS₂-VA score, among NVAF patients. Accordingly, the aim of this study was to validate the R₂CHA₂DS₂-VA score for predicting thromboembolism in Thai NVAF patients.

Methods

Thai NVAF patients were prospectively enrolled in a nationwide multicenter registry from 27 hospitals during 2014–2020. Each component of the CHA₂DS₂-VA and R₂CHA₂DS₂-VA scores was scored and recorded. The main outcomes were thromboembolism, including ischemic stroke, transient ischemic attack (TIA), and/or systemic embolism. The annual incidence rate of thromboembolism among patients in each R₂CHA₂DS₂-VA and CHA₂DS₂-VA risk score category is shown as hazard ratio (HR) and 95% confidence interval (95% CI). The performance of the R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores was demonstrated using c-statistics. Net reclassification index was calculated. Calibration plat was used to assess agreement between observed probabilities and predicted probabilities of both scoring system.

Results

A total of 3402 patients were enrolled during 2014–2020. The average age of patients was 67.38 ± 11.27 years. Of those, 46.9% had renal disease, 30.7% had a history of heart failure, and 17.1% had previous stroke or TIA. The average R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores were 3.92 ± 1.92 and 2.98 ± 1.43, respectively. Annual thromboembolic risk increased with incremental increase in R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores. Oral anticoagulants had benefit in stroke prevention in NVAF patients with an R₂CHA₂DS₂-VA score of 2 or more (adjusted HR: 0.630, 95% CI 0.413–0.962, p = 0.032). The c-statistics were 0.630 (95% CI 0.61–0.65) and 0.627 (95% CI 0.61–0.64), for R₂CHA₂DS₂-VA and CHA2DS2-VA scores respectively. NRI was 2.2%. The slope and R2 of the calibration plot were 0.73 and 0.905 for R₂CHA₂DS₂-VA and 0.70 and 0.846 for CHA₂DS₂-VA score respectively.

Conclusions

R₂CHA₂DS₂-VA score was found to be at least as good as CHA₂DS₂-VA score for predicting thromboembolism in Thai patients with NVAF. Similar to CHA₂DS₂-VA score, thromboembolism increased with incremental increase in R₂CHA₂DS₂-VA score.

Average Systolic Blood Pressure and Clinical Outcomes in Patients with Atrial Fibrillation: Prospective Data from COOL-AF Registry

Purpose

Hypertension is associated with incident atrial fibrillation (AF) and AF-related complications. We investigated the associations between average systolic blood pressure (SBP) and outcomes in a nationwide cohort of Asian patients with non-valvular atrial fibrillation (NVAF).

Patients and Methods

A multicenter nationwide registry of patients with NVAF in Thailand was conducted during 2014–2017. Clinical data, including blood pressure, were recorded at baseline and then every 6 months. Average SBP was calculated from the average of SBP from every visit. Cox regression models were used to calculate the rate of clinical outcomes of interest, ie ischemic stroke or transient ischemic attack (TIA), intracerebral hemorrhage (ICH), and all-cause death. Average SBP was categorized into three groups: <120, 120–140, and ≥140 mmHg.

Results

A total of 3402 patients were included, and the mean age was 67.4±11.3 years. The mean (±SD) baseline and average SBPs were 128.5±18.5 and 128.0±13.4 mmHg, respectively. The mean follow-up duration was 25.7±10.6 months. The median rate of ischemic stroke/TIA, ICH, and all-cause death was 1.43 (1.17–1.74), 0.70 (0.52–0.92), and 3.77 (3.33–4.24) per 100 person-years, respectively. The rate of ischemic stroke/TIA and ICH was lowest in patients with average SBP <120 mmHg, and highest among those with average SBP ≥140 mmHg. The death rates were consistent with a J-curve effect, being lowest in patients with an average SBP 120–140 mmHg. Sustained SBP control is more important than the SBP from a single visit.

Conclusion

Sustained control of SBP was significantly associated with a reduction in adverse clinical outcomes in patients with NVAF.

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

Purpose

We aimed to compare the rate of clinical outcomes among three age groups (<65, 65–74, and ≥75 years) of adult patients with non-valvular atrial fibrillation (NVAF).

Patients and Methods

We prospectively enrolled NVAF patients from 27 Thailand medical centers. The following were collected at baseline: demographic data, risk factors, comorbid conditions, laboratory data, and medications. The clinical outcomes were ischemic stroke (IS) or transient ischemic attack (TIA), major bleeding (MB), intracerebral hemorrhage (ICH), heart failure (HF), and death. All events were adjudicated. Patients were categorized according to age group into three groups; age <65, 65–74, and ≥75 years.

Results

Among the 3402 patients that were enrolled during 2014–2017, the mean age was 67.4±11.3 years, and 2073 (60.9%) were older. The average follow-up was 25.7±10.6 months. Oral anticoagulants were given in 75.4% of patients (91.1% of OAC was warfarin). The incidence rate of IS/TIA, MB, ICH, HF, and death was 1.43 (1.17–1.74), 2.11 (1.79–2.48), 0.70 (0.52–0.92), 3.03 (2.64–3.46), and 3.77 (3.33–4.24) per 100 person-years, respectively. The risk of IS/TIA, MB, ICH, HF, and death increased with age both before and after adjustment for potential confounders. Even though OAC reduced the risk of IS/TIA, it increased the risk of MB. Net clinical benefit (NCB) analysis favored oral anticoagulant (OAC) in the high-risk subset of older adults.

Conclusion

Older adult NVAF patients had a significantly increased risk of IS/TIA, MB, ICH, HF, and death compared to younger NVAF before and after adjustment for potential confounders. Strategies to reduce overall risk, including OAC use and choice and integrated care, should be implemented.