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Are We Ready for the Upcoming Super-Aging Society?
Article ID: CJ-21-0274
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Article ID: CJ-21-0274
Currently, the COVID-19 pandemic, which began at the end of 2019, is still prevailing worldwide in 2021. Although the mortality rate of COVID-19 itself is a big issue, there is also concern about worsening of comorbid underlying diseases due to refraining from hospital visits. In fact, the weekly numbers of patients with acute coronary syndrome have substantially reduced as compared with the prior year.1
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The year 2021 is another milestone because it has been 10 years since the launch of the first non-vitamin K dependent anticoagulant (VKA), dabigatran, in Japan, and followed by releases of rivaroxaban, apixaban, and edoxaban. Thereafter, anticoagulation for atrial fibrillation (AF) changed drastically from the VKAs to the direct oral anticoagulants (DOACs), which are considered to be superior to VKAs in several aspects, among which is that regular monitoring of blood samples is no longer needed. DOACs contribute to a decrease in the number of hospital visits, which essentially promoted appropriate treatment of AF during the COVID-19 pandemic.
In this issue of the Journal, Okumura et al report a novel risk score predicting ischemic strokes in Japanese nonvalvular AF patients.2 They define the HELT-E2S2 score, which consists of hypertension (H, 1 point), being elderly (75–84 years) (E, 1 point), low body mass index (BMI <18.5 kg/m2) (L, 1 point), persistent/permanent type AF (T, 1 point), being extremely elderly (≥85 years) (E2, 2 points), and a previous stroke (S2, 2 points). Being extremely elderly and having a previous stroke have greater weight than the others. For the risk stratification of stroke in patients with nonvalvular AF, the CHADS2 score3 was initially introduced, but the CHA2DS2-VASc score4 took over and is utilized in the latest USA and EU AF guidelines.5,6 The Japanese Circulation Society AF guidelines still use the CHADS2 score for the stroke risk evaluation of nonvalvular AF patients. The incidence of strokes in nonvalvular AF patients is reported to be less in Japan than in Caucasian countries,7 and a racial and regional difference in the stroke risk of nonvalvular AF exists.8 Hence, a region-specific stroke risk score has been awaited. The HELT-E2S2 score is characterized by waiving the factors of heart failure and diabetes mellitus but including a low BMI and the type of AF, and moreover, the age at risk is set at 10 years older than that for the CHADS2 score (Figure). A meta-analysis showed that being underweight was associated with an increased risk of a stroke or systemic embolism in AF patients.9 Also, patients with persistent AF are reported to have higher rates of strokes or systemic embolisms than those with paroxysmal AF. Hence, inclusion of both a low BMI and the type of AF would be reasonable. Although further external validation might be required, this score system will be welcomed by Japanese physicians. Particularly, in Japan, which has become a super-aged society, the 85-year-old population accounted for more than 6 million people in 2020,10 and thus patients with AF at such an age are not uncommon. This study is highly regarded for revealing the risk of developing ischemic strokes in these super-elderly patients.
Risk scores of stroke and bleeding events in patients with atrial fibrillation. CHADS2, CHA2DS2-VASc, and HELT-E2S2 are stroke risk scores and HAS-BLED is a bleeding risk score. Other risk factors of the HAS-BLED score comprise abnormal renal/liver function (1, 2 points), bleeding (1 point), labile INR (1 point), and drugs (1 point). See text for details.
Because anticoagulants suppress blood clot formation, bleeding events under anticoagulation are common. As the CHADS2 and HAS-BLED scores,11 which are bleeding risk scores, have risk factors including hypertension, stroke, and being elderly (>65 years) in common, patients with a higher stroke risk would have a higher bleeding risk. Although the estimated bleeding risk should not in itself guide treatment decisions for anticoagulation without any contraindication,6 bleeding events cannot be overlooked. Bleeding post-discharge after a percutaneous coronary intervention has a strong relationship with subsequent all-cause death,12 which also could be applied to AF patients. Actually, edoxaban reduces mortality risk as compared with warfarin because of the reduction in bleeding events in patients with nonvalvular AF,13 suggesting bleeding events can affect mortality in AF patients. With society aging, major bleeding events in extremely elderly patients with AF is concerning. As aging is associated with multiple morbidities,14 bleeding, advanced chronic kidney disease, lower body weight, concomitant cancer, surgery, polypharmacy, and cognitive impairment, there are lots of reasons for stopping anticoagulation. Though the efficacy and safety of apixaban is reported to be preserved in patients with multimorbidity,15 the data on extremely elderly patients are still lacking. Presently, the indication for anticoagulation has been determined only from the risk assessment of strokes; however, for extremely elderly patients, the risk of bleeding or the net clinical benefit including mortality, might need to be evaluated as well. Underlying data are needed urgently for the upcoming super-aged society; in particular, the clinical course after developing a stroke or bleeding should be followed until death while taking into account changes in the quality of life over time.
I thank Mr. John Martin for his linguistic support.
S.T. received honoraria from Daiichisankyo, Bayer and Medtronic; research fund from Japan Lifeline.
