Does the CHA2DS2-VASc scale sufficiently predict the risk of left atrial appendage thrombus in patients with diagnosed atrial fibrillation treated with non-vitamin K oral anticoagulants?

The CHA2DS2-VASc scale does not include potential risk factors for left atrial appendage thrombus (LAAT) formation such as a form of atrial fibrillation (AF) and impaired kidney function. The real risk of thromboembolic complications in AF patients is still unclear as well as an optimal anticoagulant treatment in males with a CHA2DS2-VASc score of 1 and females with a CHA2DS2-VASc score of 2.The aim of this study was to compare the predictive value of the CHA2DS2-VASc scale and other scales to estimate the risk of LAAT formation in AF patients treated with non-vitamin K oral anticoagulants (NOACs) and to assess the prevalence of thrombi in patients at intermediate risk of stroke.The observational study included consecutive patients with a diagnosis of non-valvular AF treated with NOACs, admitted to 3 high-reference institutions between 2013 and 2018. All individuals underwent transoesophageal echocardiography before cardioversion or ablation.Out of 1163 enrolled AF patients (62.1% male, mean age 62 years) the LAAT had been detected in 50 individuals (4.3%). Among patients with LAAT, 1 patient (2.0%) was classified as a low-risk category, 9 (18.0%) were at intermediate-risk, and 40 (80.0%) were at high risk of thromboembolic complications according to CHA2DS2-VASc scale. All patients were treated with NOACs: 51.0% rivaroxaban, 47.1% dabigatran, and 1.9% apixaban.Patients at intermediate stroke-risk with detected LAAT had higher R2CHADS2 score (2.1 ±â€Š1.2 vs 1.2 ±â€Š0.8, P = .007), higher CHA2DS2-VASc-RAF score (6.4 ±â€Š4.4 vs 3.7 ±â€Š2.6, P = .027) and more often had an estimated glomerular filtration rate below 56 mL/min/1.73 m (44.4% vs 13.2%, P = .026) compared to patients without LAAT. The receiver operating characteristics revealed that the CHA2DS2-VASc-RAF scale had better predictive ability to distinguish between patients with and without LAAT in the study group than CHA2DS2-VASc (P = .0006), CHADS2 (P = .0006) and R2CHADS2 scale (P = .0140).The CHA2DS2-VASc scale should be supplemented with an assessment of renal function and form of AF to improve stroke risk estimation. The application of additional scales to estimate the risk of LAAT might be especially useful among males with a CHA2DS2-VASc score of 1 and females with a CHA2DS2-VASc score of 2.

Outcome of non-vitamin K oral anticoagulants in the treatment of left atrial/left atrial appendage thrombus in patients with nonvalvular atrial fibrillation.

BACKGROUND: Data comparing dabigatran with rivaroxaban regarding the resolution of left atrial/left atrial appendage (LA/LAA) thrombus in patients with nonvalvular atrial fibrillation (AF) are scarce. This study aimed to compare the efficacy and safety of dabigatran vs rivaroxaban regarding the resolution of LA/LAA thrombus in patients with nonvalvular AF. METHODS: This retrospective study enrolled nonvalvular AF patients scheduled to undergo catheter ablation or cardioversion in Shanghai Ruijin Hospital between January 2014 and January 2019. Altogether, 34 patients with LA/LAA thrombus detected by transesophageal echocardiography (TEE) were enrolled. Among them, 12 patients were treated with dabigatran 150 mg bid and the other 22 with rivaroxaban 20 mg qd. Follow-up TEE was performed within greater than or equal to 3 weeks to less than 6 months of the initial TEE to evaluate the resolution of the LA/LAA thrombus. RESULTS: Baseline patient characteristics were similar in the two groups. Overall, 18 patients (81.8%) in the rivaroxaban group had complete thrombus resolution after 70.3 ± 22.1 treatment days, and 10 patients (83.3%) in the dabigatran group had complete thrombus resolution after 69.3 ± 47.9 treatment days. There was no significant difference between the groups (P = .6). TEE showed that the average length, width, and area of thrombus significantly decreased in both groups after treatment, although there was no significant difference in the amount of change in these parameters between the two groups after treatment (P = .6). Undissolved thrombus in two patients in the rivaroxaban group did dissolve after switching to dabigatran. CONCLUSIONS: The results suggest that both dabigatran and rivaroxaban are potential options for treating LA/LAA thrombus in patients with nonvalvular AF. Dabigatran could be an alternative option for the resolution of LA/LAA thrombus resistant to rivaroxaban.

Cost-Effectiveness of Left Atrial Appendage Closure With the WATCHMAN Device Compared With Warfarin or Non-Vitamin K Antagonist Oral Anticoagulants for Secondary Prevention in Nonvalvular Atrial Fibrillation.

BACKGROUND AND PURPOSE: Once a patient with atrial fibrillation experiences an embolic event, the risk of a recurrent event increases 2.6-fold. New treatments have emerged as viable treatment alternatives to warfarin for stroke risk reduction in secondary prevention populations. This analysis sought to assess the cost-effectiveness of left atrial appendage closure (LAAC) compared with warfarin and the non-vitamin K antagonist oral anticoagulants dabigatran 150 mg, apixaban and rivaroxaban in the prevention of stroke in nonvalvular atrial fibrillation patients with a prior stroke or transient ischemic attack. METHODS: A Markov model was constructed using data from the secondary prevention subgroup analyses of the non-vitamin K antagonist oral anticoagulant and LAAC pivotal trials. Costs were from 2016 US Medicare reimbursement rates and the literature. The cost-effectiveness analysis was conducted from a US Medicare perspective over a lifetime (20 years) horizon. The model was populated with a cohort of 10 000 patients aged 70 years with a CHA2DS2-VASc score of 7 (annual stroke risk=9.60%) and HAS-BLED score of 3 (annual bleeding risk=3.74%). RESULTS: LAAC achieved cost-effectiveness relative to dabigatran at year 5 and warfarin and apixaban at year 6. At 10 years, LAAC had more quality-adjusted life years (4.986 versus 4.769, 4.869, 4.888, and 4.810) and lower costs ($42 616 versus $53 770, $58 774, $55 656, and $58 655) than warfarin, dabigatran, apixaban, and rivaroxaban, respectively, making LAAC the dominant (more effective and less costly) stroke risk reduction strategy. LAAC remained the dominant strategy over the lifetime analysis. CONCLUSIONS: Upfront procedure costs initially make LAAC higher cost than warfarin and the non-vitamin K antagonist oral anticoagulants, but within 10 years, LAAC delivers more quality-adjusted life years and has lower total costs, making LAAC the most cost-effective treatment strategy for secondary prevention of stroke in atrial fibrillation.

Initial Experience With Novel Oral Anticoagulants During the First 45 Days After Left Atrial Appendage Closure With the Watchman Device.

BACKGROUND: The use of oral anticoagulation or dual antiplatelet therapy (DAPT) is recommended within the first 45 days after left atrial appendage (LAA) closure using the Watchman device because of incomplete device endothelialization. This study reports for the first time the feasibility of novel oral anticoagulants (NOAC) in these patients. HYPOTHESIS: NOAC therapy is safe and effective after LAA closure. METHODS: Interventional LAA closure was performed successfully in 45 patients. Of these, 18 patients received NOAC during the first 45 days after implantation and 27 patients received DAPT. Transesophageal echocardiography was conducted 45 days after implantation. The primary study endpoint was abnormal thrombus apposition 45 days after implantation. Secondary study endpoints were death from any cause, major adverse cardiac and cerebrovascular events (MACCE), and major bleedings. RESULTS: After 45 days, transesophageal echocardiography revealed no abnormal thrombus apposition. During a follow-up of 417 ± 323 days, 7 patients died. No stroke or transient ischemic attack occurred. Nonfatal myocardial infarction occurred in 1 patient. There was a nonsignificant trend for lower all-cause mortality (P = 0.159) and occurrence of MACCE (P = 0.096) in the NOAC group compared with the DAPT group. Overall, 6 patients suffered from a major bleeding (NOAC, n = 3; DAPT, n = 3). In NOAC group, major bleedings (at day 205, 688, and 736) occurred long after termination of NOAC therapy. There was no significant difference in the frequency of major bleedings in different groups. CONCLUSIONS: Our pilot study suggests that NOAC therapy within the first 45 days after interventional LAA closure is safe and effective.

Hypotensive activity of the ethanol extract of Pavetta crassipes leaves.

Pavetta crassipes leaf is routinely used locally in Nigeria for the management of respiratory disorders and hypertension. The hypotensive and other cardiovascular effects of Pavetta crassipes were investigated in cats and rats. The effects of the extract on rat and cat blood pressures, isolated rat atria, rat portal vein, isolated rat aorta and rat vas deferens were studied. Specific receptor antagonists (atropine, mepyramine, phentolamine, propranolol) were used to elucidate the underlying mechanism(s) involved in the cardiovascular changes induced by P. crassipes. The results revealed that the ethanolic extract of Pavetta crassipes lowered the blood pressures of cats and rats in a dose dependent manner. The extract also caused a concentration-dependent decrease in the force of contraction of the isolated rat atria and rat portal vein. The decreases in blood pressure values were attenuated in the presence of a beta-adrenoceptor antagonist, propranolol. The extract also attenuated isoprenaline-induced contraction of the rat atria. However, the extract did not affect contractions evoked by KCl, norepinephrine and 5-HT on the rat aorta. Pavetta crassipes contains biologically active substances that may be useful in the management of hypertension.

Cardiovascular effects of isorhamnetin and quercetin in isolated rat and porcine vascular smooth muscle and isolated rat atria.

Isorhamnetin and quercetin produced endothelium-independent vasodilator effects in rat aorta, rat mesenteric arteries, rat portal vein and porcine coronary arteries. The effects of the two flavonoids were similar in arteries stimulated by noradrenaline, KCl, U46619 or phorbol esters but the two flavonoids were more potent in the coronary arteries than in the aorta. At high concentrations, they also induced a positive inotropic effect in isolated rat atria. Therefore, at least part of the in vivo effects of quercetin may result from its conversion to isorhamnetin which is the main metabolite of quercetin found in plasma. The arterial, venous and coronary vasodilator effects may contribute to the protective effects of flavonoids in ischaemic heart disease observed in epidemiological studies.