Clinical usefulness of the SAMe-TT2R2 score: A systematic review and simulation meta-analysis

Modified application of SAMe-TT2R2 scoring system in Asian patients with atrial fibrillation for the selection of oral anticoagulants

BACKGROUND/AIMS

The SAMe-TT2R2 score is used for assessing anticoagulation control (AC) quality with warfarin. However, it is hard to apply SAMe-TT2R2 score in Asian patients with atrial fibrillation (AF), because it has not been proven in those populations. This study aimed to validate the SAMe-TT2R2 score in Asian patients with AF and suggest a modified SAMe- TT2R2 score for this population.

METHODS

We analyzed 710 Korean patients with AF who were using warfarin. The AC quality was assessed as the mean time in therapeutic range (TTR). Each component of SAMe-TT2R2 score was evaluated for the relationship with AC. Further clinical factors that predict AC were analyzed. Identified factors were re-assorted and constructed as SA2Me-TTR scoring system.

RESULTS

Of the components of the SAMe-TT2R2 score, female, age, and rhythm control were associated with AC. Heart failure and renal insufficiency were newly identified factors associated with AC. The modified SA2Me-TTR score was reconstructed with the relevant risk factors (S, female gender, 1 point; A, age < 60 yr, 2 points; Me, medical history of heart failure, 1 point; T, treatment for rhythm control, 1 point; T, history of stroke or transient ischemic attack, 1 point; R, renal insufficiency, 1 point). The modified SA2Me-TTR score demonstrated an excellent relationship with the grading of AC. The modified SA2Me-TTR score ≤ 1 identified patients with good AC (hazard ratio 2.46, 95% CI 1.75-3.47).

CONCLUSION

The modified SA2Me-TTR score was useful for guiding oral anticoagulants selection in Asian patients with AF.

SAMe-TT2R2 Score to Predict Time in Therapeutic Range of Vitamin K Antagonists in Asian and Non-Asian patients: A Systematic Review and Meta-analysis

BACKGROUND

Sex, age, medical history, treatment, tobacco use, and race (SAMe-TT2R2) score helps detect patients at risk of suboptimal anticoagulation control. A score above two suggests poor control; however, non-Caucasian status being assigned two points might hinder the recognition of poor control in patients of other races.

OBJECTIVE

To evaluate the SAMe-TT2R2 score's ability to predict poor anticoagulation control [defined as time in therapeutic range (TTR) < 60-70%] in Asian and non-Asian populations on vitamin K antagonists (VKAs).

METHODS

We searched PubMed, Cochrane Library, Scopus, SpringerLink, and Web of Science using the keyword "SAMe-TT2R2." Articles published before April 2022 were screened. We gathered mean TTR and diagnostic accuracy data for different SAMe-TT2R2 thresholds and conducted meta-analyses using random-effects models.

RESULTS

A total of 30 studies were included (N = 36,690). The overall mean TTR differences were - 4.88 and - 6.41 for the cutoffs of ≥ 3 and ≥ 4, respectively. For non-Asian patients, the mean TTR differences were - 3.86, - 5.12, and - 8.09 for the cutoffs ≥ 2, ≥ 3, and ≥ 4, respectively. For Asian patients, the mean TTR differences were - 3.99 and - 4.07 for the cut-offs ≥ 3 and ≥ 4, respectively. The highest positive likelihood ratio (LR+) for the Asian subgroup was 1.17 [95% confidence interval (CI): 1.06-1.28; I2 = 0%, p heterogeneity = 0.500] at cutoff ≥ 4 and for the non-Asian subgroup, at cut-off ≥ 3, the LR+ was 1.24 (95% CI 1.14-1.34; I2 = 0% p heterogeneity = 0.455). The lowest LR- was found at a lower cutoff for both races (at cutoff ≥ 3 and ≥ 2 for Asian and non-Asian subgroups, respectively). The pooled results of other accuracy parameters were modest at all cutoffs, except for the sensitivity at cutoff ≥ 3 in the Asian subgroup (83.05%).

CONCLUSION

Our study results suggest that a higher SAMe-TT2R2 score resulted in a greater reduction of TTR among Asian and all races. The accuracy parameters showed the highest sensitivity for poor TTR at the SAMe-TT2R2 cutoff of ≥ 3 for Asian patients. However, the ability to identify patients likely to have poor TTR was limited. Further research is needed to enhance the risk assessment for poor anticoagulation control with VKAs.

REGISTRATION

The protocol of this systematic review was registered in the International Prospective Register of Scientific Reviews: PROSPERO, registration number CRD42021291865.

SAMe-TT2R2 to Predict Clinical Outcomes and Time in Therapeutic Range in Patients on Vitamin K Antagonists: A Systematic Review and Meta-Analysis

BACKGROUND

The SAMe-TT2R2 score identifies patients on vitamin K antagonists (VKAs) who are more likely to have poor time in therapeutic range (TTR); however, the association between SAMe-TT2R2 and clinical outcomes remains controversial.

OBJECTIVES

The objective is to assess the association of SAMe-TT2R2 score with clinical outcomes and poor TTR in patients on VKAs.

METHODS

We searched using the term "SAMe-TT2R2." Original articles reporting clinical outcomes and SAMe-TT2R2 scores before October 2021 were included. Odds ratios (ORs) of clinical outcomes, diagnostic accuracy parameters of poor TTR (<60%-70%), and mean TTR were extracted. Meta-analysis was performed using random-effects models.

RESULTS

Ten studies were included (N = 22 894); 4 showed pooled changes in TTR of -3.61% (95% CI:-4.88% to -2.35%) and -3.98% (95% CI: -6.08% to -1.87%) at SAMe-TT2R2 scores ≥2 and ≥3, respectively, compared with lower scores. The diagnostic accuracy parameters for poor TTR were too heterogeneous to conclude. SAMe-TT2R2 ≥3 significantly correlated with all adverse events (OR = 1.43 [95% CI: 1.29-1.54; P < 0.001]), composite thromboembolism (OR = 1.53 [95% CI: 1.19-1.97; P = 0.001]), and composite bleeding (OR = 1.33 [95% CI: 1.12-1.59; P = 0.001] regardless of the indication, while an SAMe-TT2R2 ≥2 significantly correlated with mortality (OR = 1.32 [95% CI: 1.02-1.70; P = 0.033]). We found no relationship between an SAMe-TT2R2 ≥3 and mortality or between a score ≥2 and clinical outcomes.

CONCLUSIONS AND RELEVANCE

Patients on VKAs with SAMe-TT2R2 ≥3 experienced more adverse events, bleeding, and thromboembolism compared with patients who had an SAMe-TT2R2 <3. However, the score had limited and inconclusive predictability for poor TTR in the study.

The SAMe-TT2R2 score as an indicator of warfarin control for patients with deep vein thrombosis in Queensland, Australia

Oral anticoagulation options for patients with venous thromboembolism (VTE) include vitamin K antagonists like warfarin. Good warfarin control is linked to outcomes of therapy, and the SAMe-TT₂R₂ model has been reported to predict control in atrial fibrillation patients with scores ≥ 2 linked to poor control. There has been limited and conflicting data in VTE populations, therefore this study aimed at determining the predictive ability of this model in Australian patients with deep vein thrombosis. Retrospective data of patients receiving warfarin care at a private pathology clinic in Queensland was collected. The time in therapeutic range (TTR) and SAMe-TT₂R₂ score was calculated for individual patients. Mean TTR and patients with TTR ≥ 65% were used for analysis and comparison across patients categorised as a score of 0-1 and ≥ 2. Of the 533 patients, the majority had a SAMe-TT₂R₂ score of 0-1. No significant difference was found in mean TTR between patients with a score of 0-1 and ≥ 2 but there was a significantly higher percentage of patients with a TTR ≥ 65% between groups (93.8% vs. 69.2%, p < 0.0001, respectively). The SAMe-TT₂R₂ score may assist in identifying patients with VTE likely to achieve good control (TTR ≥ 65%), but further investigation is required to determine the most suitable model for predicting warfarin control in this population.

Factors predicting poor anticoagulant control on warfarin in a Thai population with non-valvular atrial fibrillation (NVAF): the ACAChE score

Background

In many low- to middle-income countries in Asia, patients with NVAF usually received warfarin for thromboembolic prevention due to cost-effectiveness. The SAMe-TT2R2 score has been proposed to predict TTR in NVAF patients. However, the SAMe-TT2R2 score has not been much validated in Asian population. Interestingly, it may overestimate patients who had TTR < 65% due to regarding being Asians as a risk factor.

Objectives

To determine the factors predicting poor anticoagulant control on warfarin, create new scoring system, and compare with the SAMe-TT2R2 score in a Thai population with NVAF.

Methods

This is a retrospective study in a tertiary care hospital. We enrolled NVAF patients who received warfarin from January 2014 to December 2018. TTR was calculated based on Rosendaal method. Multiple logistic regression and AUC-ROC curve were used for analysis.

Results

A total of 864 patients were enrolled with mean age of 73.6 ± 11.58 years. The mean TTR was 48.1 ± 25.2%. Using multivariate regression analysis, the predictive factors for TTR < 65% were antiplatelet use (OR 4.49, p ≤ 0.001), LVEF < 40% (OR 1.92, p = 0.037), chronic kidney disease (GFR < 50 ml/min/1.73 m2) (OR 1.68, p = 0.013), history of CHF (OR 1.7, p = 0.047), and age ≥ 75 years (OR 1.4, p = 0.037). Based on the regression coefficients, we developed the new scoring system called ACAChE score [A, antiplatelet use (4 points); C, chronic kidney disease, GFR < 50 ml/min/1.73 m2 (2 points); A, age ≥ 75 years (1 point); Ch, history of CHF (2 points); E, LVEF < 40% (2 points)]. ROC curve showed discrimination performance of the ACAChE score and SAMe-TT2R2 score for prediction of TTR < 65% with the C-statistic of 0.62 (95%CI 0.57–0.65) and 0.54 (95%CI 0.50–0.58), respectively.

Conclusion

In Thai NVAF patients, the ACAChE score (antiplatelet use, chronic kidney disease (GFR < 50 ml/min/1.73 m2), age ≥ 75 years, history of congestive heart failure, and LVEF < 40%) has better prediction for TTR < 65% than SAMe-TT2R2 score. Thus, it expected to guide the selection of oral anticoagulation in Asian patients with NVAF.

Effect of SAMe-TT2R2 score and genetic polymorphism on the quality of anticoagulation control in Qatari patients treated with warfarin

There is no strong evidence on pharmacogenetics role on the quality of INR control after the initiation phase and on the maintenance of stable INR on the long term as measured by the time in therapeutic range (TTR). The benefit of a score such as SAMe-TT₂R₂ is that it can preemptively guide clinicians on whether to start the patient on warfarin or direct oral anticoagulant. To determine the association between genetic variants in CYP2C9, VKORC1, and CYP4F2 and TTR. To validate SAMe-TT₂R₂ score predictive ability on the quality of anticoagulation in Qatari patients. This is an observational nested case–control study that was conducted on a cohort of Qatari patients treated with warfarin with previously identified genotype for the CYP2C9, VKORC1, and CYP2F4. The sample size of this cohort was 148 patients. Mean TTR was 62.7 ± 21%. TTR was not significantly different among carriers of the CYP2C9*2 &*3, VKORC1(–1639G>A) or CYP4F2*3 compared to their non-carriers alleles. None of the factors in the SAMe-TT₂R₂ score had a significant effect on the TTR except for the female gender where TTR was significantly lower in females (n = 89) compared to males (n = 59) (59.6 ± 21% vs. 67.2 ± 20%, p = 0.03). Furthermore, patients with SAMe-TT₂R₂ score of zero had significantly better TTR compared to those with higher scores (76.5 ± 17% vs. 61.8 ± 21%, p = 0.04). Logistic regression analysis showed that high SAMe-TT₂R₂ score was the only statistically significant predicting factor of poor INR control (odds ratio (OR) 5.7, 95% confidence interval (CI) 1.1–28.3, p = 0.034). Genetic variants have no contribution to the quality of INR control. SAMe-TT₂R₂ score was predictive for the poor quality of anticoagulation in a cohort of Qatari patients.

A nurse-led atrial fibrillation clinic: Impact on anticoagulation therapy and clinical outcomes

BACKGROUND

Nurses play a central role in the management of atrial fibrillation (AF) patients. An unresolved question is whether a nurse-led clinic would improve clinical outcomes. Herein, we investigated the impact of a nurse-led clinic on anticoagulation therapy and clinical outcomes in a cohort of naïve AF patients.

METHODS

Prospective study including AF patients starting vitamin K antagonists (VKAs) into a nurse-led AF clinic. These patients were followed in this specific AF clinic. Additionally, AF patients already taking VKAs for 6 months followed according to the routine clinical practice were included as comparison group. The quality of anticoagulation was assessed at 6 months. Efficacy and safety endpoints were recorded during follow-up.

RESULTS

We included 223 patients (Nurse-led clinic: 107; Usual care: 116). The mean time in therapeutic range and the proportion of INRs within the therapeutic range were similar in both groups. During 2.06 (IQR 1.01-2.94) years of follow-up, 64 (28.7%) patients changed to direct-acting oral anticoagulants. The proportion of switchers was higher in the nurse-led clinic (37.4%) than in the usual care group (20.7%) (P = .006) and these patients spent less time to switch (2.0 [IQR 0.7-2.9] vs 6.0 [IQR 3.7-11.2] years; P < .001). Importantly, the annual rate of ischaemic stroke/TIA was significantly lower in the nurse-led clinic (0.47%/year vs 3.88%/year, P = .016), without differences in safety endpoints.

CONCLUSION

A nurse-led AF clinic may offer a "patient-centered" review and holistic follow-up, and it would be associated with a reduction of ischaemic stroke/TIA, without increasing bleeding complications. Further studies should confirm these results.

Evaluation of the SAMe-TT2R2 score to predict the quality of anticoagulation control in patients with venous thromboembolism treated with vitamin K antagonists: Findings from the RIETE registry

BACKGROUND

The time in therapeutic range (TTR) of patients with venous thromboembolism (VTE) treated with vitamin K antagonists (VKA) is usually below recommended, leading to higher frequency of vascular events, bleeding and mortality. The SAMe-TT2R2 prediction score discriminates those patients with high or low probability of obtaining poor INR control and its use is recommended in patients with atrial fibrillation. Its usefulness has been evaluated in patients with VTE, with conflicting results.

METHOD

We included consecutive patients enrolled in Registro Informatizado Enfermedad TromboEmbolica (RIETE), a prospective multicenter VTE registry, treated with VKA for >90 days and a minimum of 3 INR determinations. We analyzed the relationship between the SAMe-TT₂R₂ score and TTR, determined by the Rosendaal method and by the percentage of INR determinations (after excluding the first month). A ROC curve was calculated considering a cut-off point of TTR ≥65% for good anticoagulation control.

RESULTS

3893 patients were included and classified in high (1411 patients) or low (2482 patients) probability of obtaining poor INR control according to the total score obtained (0-1 points versus 2 points, respectively). TTR, calculated by direct method and Rosendaal method, was 51.2 (±23.4) and 55.4 (±25.9) in the high probability group; and 54.4 (±23.0) and 58.2 (±25.6) in the low probability group, respectively (p < 0.001 for both comparisons). The outcomes were similar between groups. The predictive capacity of the SAMe-TT2R2 score showed an area under the ROC curve of 0.54 (CI 95% 0.52-0.56) and 0.53 (CI 95% 0.51-0.55).

CONCLUSIONS

In patients with VTE treated with VKA, the SAMe-TT2R2 score discriminated those patients with high probability of obtaining poor INR control, but with a low predictive capacity. Further studies are required to assess the usefulness of the score in clinical decision-making.

Is the time in therapeutic range on coumarins predicted by previous time in therapeutic range?

BACKGROUND

The benefit of vitamin K antagonists depends on the time within the therapeutic range (TTR). A patient's previous TTR could be a factor in the decision to change the anticoagulation regimen. However, the predictive value of a previous TTR for a future TTR is not well established, nor is it clear which TTR should prompt action.

OBJECTIVES

To investigate the predictive performance of a TTR and identify a threshold below which no recovery of TTR should be expected.

PATIENTS/METHODS

From 18 031 patients who used acenocoumarol in a first-line anticoagulation clinic, a TTR was calculated over multiple periods of 90, 180, and 365 days each. We assessed the correlation between baseline and later TTR and the separation between groups by quintile of baseline TTR. We describe the proportion of patients who obtain a TTR≥ 70% conditional on baseline TTR.

RESULTS

The correlation between baseline and later TTR was 0.25 (95% confidence interval [CI], 0.24-0.26), 0.27 (95% CI, 0.26-0.28) and 0.34 (95% CI, 0.32-0.35) for analyses over 90, 180, and 365 days. Corresponding c statistics for discrimination by baseline group were 0.60, 0.61, and 0.63. The probability to obtain a TTR ≥70% increased with baseline TTR: from 42% with a baseline TTR of 50%-65% when TTR was 100% (TTR calculated over 180 days).

CONCLUSIONS

We conclude that a current TTR hardly predicts a future TTR. Physicians and patients should deliberate together which probabilities to accept, take measures to improve TTR, and consider potential alternatives.

SAMe-TT2R2 score for prediction of suboptimal time in therapeutic range in a Thai population with atrial fibrillation

INTRODUCTION

International normalised ratio (INR) control is an important factor in patients with non-valvular atrial fibrillation (NVAF) being treated with warfarin. INR control was previously reported to be poorer among Asians compared to Westerners. We aimed to validate the SAMe-TT2R2 score for prediction of suboptimal INR control (defined as time in therapeutic range [TTR] < 65% in the Thai population) and to investigate TTR among Thai NVAF patients being treated with warfarin.

METHODS

INR data from patients enrolled in a multicentre NVAF registry was analysed. Clinical and laboratory data was prospectively collected. TTR was calculated using the Rosendaal method. Baseline data was compared between patients with and without suboptimal INR control. Univariate and multivariate analyses were performed to identify variables independently associated with suboptimal INR control.

RESULTS

A total of 1,669 patients from 22 centres located across Thailand were included. The average age was 69.1 ± 10.7 years, and 921 (55.2%) were male. The mean TTR was 50.5% ± 27.5%; 1,125 (67.4%) had TTR < 65%. Univariate analysis showed hypertension, diabetes mellitus, heart failure, renal disease and SAMe-TT2R2 score to be significantly different between patients with and without optimal TTR. The SAMe-TT2R2 score was the only factor that remained statistically significant in multivariate analysis. The C-statistic for the SAMe-TT2R2 score in the prediction of suboptimal TTR was 0.54.

CONCLUSION

SAMe-TT2R2 score was the only independent predictor of suboptimal TTR in NVAF patients being treated with warfarin. However, due to the low C-statistic, the score may have limited discriminative power.

The SAMe-TT2R2 Score Predicts Warfarin Control in an Australian Population with Atrial Fibrillation

BACKGROUND

Warfarin requires regular monitoring with the time in therapeutic range (TTR), a common indicator of control and TTR > 70% is indicative of efficient anticoagulation. The SAMe-TT2R2 (sex, age, medical history, treatment, tobacco use, race) model has been utilised as a predictor of warfarin control, with a score ≥ 2 indicative of poor control. However, it has been suggested that race may be over-represented in this model. To date, no Australian studies have applied this model, possibly because race is not routinely recorded. Therefore, the aim of this study was to apply the SAMe-TT2R2 model in an Australian population on warfarin managed by both a warfarin care program (WCP) and general practitioner (GP).

METHODS

Retrospective data was collected for patients receiving warfarin via a WCP in Queensland and whilst being managed by a GP. Patient data was used to calculate the SAMe-TT2R2 score and the TTR for each patient. Mean TTR was used for analysis and comparison with the categorised SAMe-TT2R2 score.

RESULTS

Of the 3911 patients managed by a WCP, there was a significantly lower mean TTR for patients with a SAMe-TT2R2 score ≥ 2 compared to 0-1 (78.6 ± 10.7% vs. 80.9 ± 9.5%, p < 0.0001). Of these patients, 200 were analysed whilst managed by a GP and the categorised SAMe-TT2R2 score did not result in a statistically different mean TTR (69.3 ± 16.3% with 0-1 vs. 63.6 ± 15.0% with ≥2, p = 0.089), but a score ≥2 differentiated patients with a TTR less than 65%.

CONCLUSIONS

The SAMe-TT2R2 model differentiated Australian patients with reduced warfarin control, despite the exclusion of race. In Australia, the SAMe-TT2R2 score could assist clinicians in identifying Australian patients who may obtain reduced warfarin control and benefit from additional interventions such as a dedicated WCP.