Publications

It is now well established that infection with SARS-CoV-2 resulting in COVID-19 disease includes a severely symptomatic subset of patients in whom an aggressive and/or dysregulated host immune response leads to cytokine storm syndrome (CSS) that may be further complicated by thrombotic events, contributing to the severe morbidity and mortality observed in COVID-19. This review provides a brief overview of cytokine storm in COVID-19, and then presents a mechanistic discussion of how cytokine storm affects integrated pathways in thrombosis involving the endothelium, platelets, the coagulation cascade, eicosanoids, auto-antibody mediated thrombosis, and the fibrinolytic system.

The association between the cumulative hypertension burden and the development of atrial fibrillation (AF) is unclear. We aimed to investigate the relationship between hypertension burden and the development of incident AF. Using the Korean National Health Insurance Service database, we identified 3 726 172 subjects who underwent 4 consecutive annual health checkups between 2009 and 2013, with no history of AF. During the median follow-up of 5.2 years, AF was newly diagnosed in 22 012 patients (0.59% of the total study population; 1.168 per 1000 person-years). Using the blood pressure (BP) values at each health checkup, we determined the burden of hypertension (systolic BP ≥130 mm Hg or diastolic BP ≥80 mm Hg), stratified as 0 to 4 per the hypertension criteria. The subjects were grouped according to hypertension burden scale 1 to 4: 20% (n=742 806), 19% (n=704 623), 19% (n=713 258), 21% (n=766 204), and 21% (n=799 281). Compared with normal people, subjects with hypertension burdens of 1, 2, 3, and 4 were associated with an 8%, 18%, 26%, and 27% increased risk of incident AF, respectively. On semiquantitative analyses with further stratification of stage 1 (systolic BP of 130-139 mm Hg or diastolic BP of 80-89 mm Hg) and stage 2 (systolic BP ≥140 mm Hg or diastolic BP ≥90 mm Hg) hypertension, the risk of AF increased with the hypertension burden by up to 71%. In this study, both a sustained exposure and the degree of increased BP were associated with an increased risk of incident AF. Tailored BP management should be emphasized to reduce the risk of AF.

Postural orthostatic tachycardia syndrome (POTS) is a common accompaniment of a variety of chronic, inflammatory diseases, including long COVID, as are small, insoluble, 'fibrinaloid' microclots. We here develop the argument, with accompanying evidence, that fibrinaloid microclots, through their ability to block the flow of blood through microcapillaries and thus cause tissue hypoxia, are not simply correlated with but in fact, by preceding it, may be a chief intermediary cause of POTS, in which tachycardia is simply the body's exaggerated 'physiological' response to hypoxia. Similar reasoning accounts for the symptoms bundled under the term 'fatigue'. Amyloids are known to be membrane disruptors, and when their targets are nerve membranes, this can explain neurotoxicity and hence the autonomic nervous system dysfunction that contributes to POTS. Taken together as a system view, we indicate that fibrinaloid microclots can serve to link POTS and fatigue in long COVID in a manner that is at once both mechanistic and explanatory. This has clear implications for the treatment of such diseases.

In patients treated with dabigatran undergoing CIED surgery, interruption of dabigatran is associated with similar or lower incidence of pocket hematoma, when compared with warfarin interruption without or with heparin bridging, respectively. Whether uninterrupted dabigatran can reduce pocket hematoma or ischemic stroke remains to be evaluated.

Adequate secondary prevention in survivors of intracerebral hemorrhage (ICH) who also have atrial fibrillation (AF) is a long-standing clinical dilemma because these patients are at increased risk of recurrent ICH as well as of ischemic stroke. The efficacy and safety of oral anticoagulation, the standard preventive medication for ischemic stroke patients with AF, in ICH patients with AF are uncertain. PRESTIGE-AF is an international, phase 3b, multi-center, randomized, open, blinded end-point assessment (PROBE) clinical trial that compared the efficacy and safety of direct oral anticoagulants (DOACs) with no DOAC (either no antithrombotic treatment or any antiplatelet drug). Randomization occurred in a 1:1 ratio and stratification was based on ICH location and sex. The two co-primary binary endpoints included ischemic stroke and recurrent ICH which will be analyzed hierarchically according to the intention-to-treat principle. Secondary efficacy endpoints encompassed all-stroke and systemic embolism, all-cause and cardiovascular mortality, major adverse cardiac events, and net clinical benefit. Secondary safety endpoints included any major hemorrhage and intracranial hemorrhage. All outcome events were adjudicated by an independent committee. Results of PRESTIGE-AF are expected to support risk-adjusted secondary prevention in ICH survivors with AF and to inform clinical guideline recommendations.

Three simple clinical risk factors (age, sex, and BMI) and two biomarkers (elevated BNP and elevated FGF-23) identify patients with AF. Further research is warranted to elucidate FGF-23 dependent mechanisms of AF.

Among adults with NVAF receiving anticoagulation, the use of dabigatran compared with warfarin was associated with a lower risk of osteoporotic fracture. Additional study, perhaps including randomized clinical trials, may be warranted to further understand the relationship between use of dabigatran vs warfarin and risk of fracture.