Hot Line 9: STROKESTOP II, GUARD-AF and MIRACLE-AF
01 Sep 2024
Novel, large-scale approaches to atrial fibrillation (AF) screening and management were assessed in Hot Line 9.
Doctor Katrin Kemp Gudmundsdottir (Karolinska Institutet Danderyd Hospital - Stockholm, Sweden) presented the STROKESTOP II trial – a randomised mass screening AF programme of all 75- to 76-year-olds in the Stockholm region in Sweden – to examine whether being invited for screening would reduce the risk of thromboembolic events compared to a control group, who were not invited for screening. Of those invited to screening, 6,843 (49%) accepted the invitation. Participants without previously known AF had N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels analysed before being stratified into high-risk (NT-proBNP 125 ng/L or higher) and low-risk (less than 125 ng/L) groups. Those considered low risk (40%) received one episode of screening with a single-lead ECG, while those classed as high risk (60%) had more intensive home screening (4-times a day for 2 weeks) using a handheld single-lead ECG device. New AF was detected in 2.4% of all participants.
After a median follow-up of 5 years, no difference was noted in the risk of stroke or systemic embolism between the intervention group (including both participants that came for screening and the ones invited but did not attend) and the control group. Further sub-analyses found that the risk of stroke or systemic embolism was 41% lower among participants with low levels of NT-proBNP compared with controls (0.61 vs. 1.03 events per 100 years). In the high-risk group (with elevated levels of NT-proBNP), individuals had more than double the risk of developing new AF in the 5 years, and the risk of ischaemic stroke or systemic embolism was 57% higher than in the low-risk group (0.95 vs. 0.61 events per 100 years). Dr. Kemp Gudmundsdottir said: “Our findings do not support this way of systematic screening for AF in older adults, but they indicate that it may be safe not to concentrate screening efforts at those individuals with low levels of NT-proBNP, although this needs confirmation in further studies.”
Next, Professor Renato Lopes (Duke University Medical Center - Durham, USA) revealed results from GUARD-AF – another screening trial, but this time using a 14-day continuous ECG patch monitor (Zio XT) to assess whether identifying older adults with undiagnosed AF results in a reduced rate of stroke compared with usual care. In total, 11,905 participants from primary care sites across the US were randomised to screening or usual care. “Our study showed a 52% increase in the number of cases of AF diagnosed over a maximum of 2.5 years of follow-up, an increase in the initiation of oral anticoagulants with no increase in rates of hospitalisation for bleeding, but no significant reduction in the rate of hospitalisations for all stroke compared with usual care,” said Prof. Lopes. “Despite being the largest study using a 14-day, patch-based continuous ECG monitor, our findings should not be considered conclusive due to early termination as a result of the COVID-19 pandemic and lower than expected number of clinical events. Further studies with longer follow-up and including participants at higher risk for stroke are needed to establish the true potential of AF screening in reducing rates of strokes.” He concluded: “Our results add to the body of evidence around AF screening and highlight the challenges in determining the impact of AF screening on clinical outcomes. Until we have clear information on who should be screened, how and for how long, and its real impact in stroke prevention, AF screening should not be routinely recommended.”
The final presentation, by Professor Minglong Chen (The First Affiliated Hospital of Nanjing Medical University - Nanjing, China), described the MIRACLE-AF randomised cluster trial, which assessed a digital health support platform to help village doctors in China provide integrated AF care. The study included 1,039 adults with AF, aged 65 years or older, from 30 village clinics in Jiangsu Province in rural China. Clinics were randomised to telemedicine integrated care (the intervention group) or enhanced usual care (the control group). Treatment in both groups was the responsibility of the doctors, all of whom had received intensified training on integrated care management according to the Atrial fibrillation Better Care (ABC) pathway. However, only doctors in the intervention group had access to the telemedicine platform.
After 1 year, 33% of patients in the intervention group and 8.8% in the control group met all three criteria for the ABC pathway – a group difference of around 24%. By 3 years, this had increased to almost 42% of patients in the intervention group and around 10% in the control group (a difference of 31%). After 3 years, rates of the composite primary outcome (CV death, all strokes, hospitalisation due to worsening of heart failure or acute coronary syndrome [ACS] and emergency visits due to AF) were 36% lower with the intervention vs. control (6.21% vs. 9.62% per year). Specifically, the risk of CV death was 50% lower in the intervention group, while the risks of any stroke and hospitalisation due to worsening of heart failure or ACS were 36% and 31% lower, respectively, compared with controls. However, clinically relevant non-major bleeding was higher (9 vs. 3 events) in the intervention group. “The magnitude of the reduction in serious CV events in patients in the intervention group is impressive,” said Prof. Chen. “Our results indicate that the telemedicine-based, village doctor-led, AF specialist-supported intervention was effective and is a feasible and sustainable implementation strategy that could be scaled-up to improve the management of AF in the older population across rural China and in other low-and-middle income countries with limited healthcare access.”
