Thrombogenesis in atrial fibrillation contributing mechanisms and natural history

Risk Factors of Acute Ischemic Stroke and Mortality Among Adults With Endocardial Fibroelastosis

OBJECTIVES

Endocardial fibroelastosis (EFE) is a rare form of restrictive cardiomyopathy associated with high morbidity and mortality. The literature is sparse on information pertaining to risk stratification. Thus, we sought to highlight the risk factors of acute ischemic stroke (AIS) and mortality in adults with EFE.

METHODS

The National Inpatient Sample (NIS) database was queried from 2001 to 2020 using the International Classification of Diseases 9th Revision (ICD-9) and 10th Revision (ICD-10) codes for adult patients with EFE. Factors associated with AIS and mortality were identified.

RESULTS

In all, 18495 cases of EFE fit the inclusion criteria, of which 2370 (12.82%) had AIS. The mean ages for patients with and without AIS were 62.37 and 54.24, respectively. Multivariate regression suggested greater odds of AIS in patients with hypertension (aOR 2.329, P<0.01), dyslipidemia (aOR: 1.566, P<0.01), peripheral vascular disease (PVD) (aOR: 1.736, P<0.01), alcohol abuse (aOR: 1.817, P<0.01), age >60 y (aOR: 1.646, P<0.01), females (vs. males, aOR: 1.238, P<0.01), and smokers (aOR: 1.697, P<0.01). Patients with cirrhosis (aOR: 0.174, P<0.01), CKD (aOR: 0.369, P<0.01), COPD (aOR: 0.402, P<0.01), atrial fibrillation (aOR: 0.542, P<0.01) had lower odds of AIS. 3.1% of EFE patients with AIS died. Diabetes (aOR: 11.665, P<0.01) and COPD (aOR: 3.201, P=0.017) were associated with the greatest odds of all-cause mortality. Dyslipidemia (aOR: 0.387, P=0.010) and females (vs. males, aOR: 0.432, P=0.012) had reduced odds of all-cause mortality.

CONCLUSION

Several risk factors are associated with AIS in EFE, while diabetes, COPD, and being male are associated with mortality in EFE.

An illustrative case of endocardial fibroelastosis and recalcitrant intracardiac thrombosis: a case report

Background

Endocardial Fibroelastosis is diffuse, accentuated proliferation of ventricular endocardium causing a rare form of restrictive cardiomyopathy in both children and adults. It is an incompletely understood cause of heart failure predominantly in Sub-Saharan Africa associated with high morbidity and mortality. Atrial fibrillation and thrombus formation are common accompanying complications and portend a poor prognosis. Due to rarity of the condition in the developed countries and lack of evidence based options, the optimal strategy for anticoagulation is unclear.

Case presentation

Herein, we describe a relatively asymptomatic patient with endocardial fibroelastosis who has been found to have atrial fibrillation and a large thrombus in the right atrium. Currently, there is no evidence-based strategy in the management of endocardial fibroelastosis-associated intracardiac thrombus. This case report illustrates a scenario by which the use of apixaban potentially benefited or prevented the thrombus formation compared with warfarin as demonstrated by imaging findings.

Conclusions

The patients with endocardial fibroelastosis are at risk of developing intracardiac thrombus due to sticky substrate lining cardiac chambers while being relatively asymptomatic. No directed therapy is known for the management of heart failure and any complications of subsequent arrhythmias. The general recommendations follow those of same conditions in other hosts. Novel oral anticoagulant agents can be considered in the treatment of atrial thrombus in the appropriate settings.

EARLY: a pilot study on early diagnosis of atrial fibrillation in a primary healthcare centre

AIM

Atrial fibrillation (AF) is associated with high morbidity and mortality. Early diagnosis is likely to improve therapy and prognosis. The study objective was to evaluate the usefulness of a programme for early diagnosis of AF in patients from an urban primary care centre.

METHODS AND RESULTS

Participants were recruited from a randomized sample of patients not diagnosed with AF but having relevant risk factors: age ≥ 65 years, ischaemic and/or valvular heart disease, congestive heart failure, hypertension, and/or diabetes. Patients were randomly assigned to the intervention group (IG) or control group (CG). The intervention included (i) initial visit with clinical history, electrocardiogram, and instruction about pulse palpation and warning signs and (ii) electrocardiogram every 6 months during a 2-year follow-up. The main endpoint of the study was the proportion of new cases diagnosed at 6 months. Secondary endpoints were number of new AF diagnoses and complications associated with the arrhythmia in both groups. A total of 928 patients were included (463 IG and 465 CG). At 6 months, AF was diagnosed in 8 IG patients and 1 CG patient (1.7 vs. 0.2%, respectively, P = 0.018). After 2 years of follow-up, 11 IG patients and 6 CG patients had newly diagnosed AF (2.5 vs. 1.3%, respectively, P = 0.132). Time to first diagnosis of AF was shorter in IG patients [median (inter-quartile range): 7 (192) days vs. 227 (188.5) days in CG, P = 0.029].

CONCLUSION

The simple screening proposed could be useful for the early detection of AF in primary care.

New oral antithrombotics: focus on dabigatran, an oral, reversible direct thrombin inhibitor for the prevention and treatment of venous and arterial thromboembolic disorders

Venous thromboembolism, presenting as deep vein thrombosis or pulmonary embolism, is a major challenge for health care systems. It is the third most common vascular disease after coronary heart disease and stroke, and many hospitalized patients have at least one risk factor. In particular, patients undergoing hip or knee replacement are at risk, with an incidence of asymptomatic deep vein thrombosis of 40%–60% without thromboprophylaxis. Venous thromboembolism is associated with significant mortality and morbidity, with patients being at risk of recurrence, post-thrombotic syndrome, and chronic thromboembolic pulmonary hypertension. Arterial thromboembolism is even more frequent, and atrial fibrillation, the most common embolic source (cardiac arrhythmia), is associated with a five-fold increase in the risk of stroke. Strokes due to atrial fibrillation tend to be more severe and disabling and are more often fatal than strokes due to other causes. Currently, recommended management of both venous and arterial thromboembolism involves the use of anticoagulants such as coumarin and heparin derivatives. These agents are effective, although have characteristics that prevent them from providing optimal anticoagulation and convenience. Hence, new improved oral anticoagulants are being investigated. Dabigatran is a reversible, direct thrombin inhibitor, which is administered as dabigatran etexilate, the oral prodrug. Because it is the first new oral anticoagulant that has been licensed in many countries worldwide for thromboprophylaxis following orthopedic surgery and for stroke prevention in patients with atrial fibrillation, this compound will be the main focus of this review. Dabigatran has been investigated for the treatment of established venous thromboembolism and prevention of recurrence in patients undergoing hip or knee replacement, as well as for stroke prevention in atrial fibrillation patients with a moderate and high risk of stroke.

Recent Advances in Percutaneous Cardioscopy

Percutaneous cardioscopy, using high-resolution fiberoptic imaging, enables direct visualization of the cardiac interior, thereby enabling macroscopic pathological diagnosis. Percutaneous cardioscopy has demonstrated that the endocardial surface exhibits various colors characteristic of different heart diseases. This imaging modality can now be used for evaluation of the severity of myocardial ischemia, and staging of myocarditis. Myocardial blood flow recovery induced by vasodilating agents or percutaneous coronary interventions can be clearly visualized. Morphological and functional changes in the cardiac valves can also be evaluated. Cardioscope-guided endomyocardial biopsy enables pin-point biopsy of the diseased myocardium. Recently, dye-image cardioscopy and fluorescence cardioscopy were developed for evaluation of the subendocardial microcirculation. Cardioscope-guided intracardiac therapies such as myotomy, myectomy, valvulotomy, and transendocardial angiogenic and myogenic therapy have been trialed using animal models in anticipation of future clinical applications. Percutaneous cardioscopy has the potential to contribute to our understanding of heart disease, and to assist in guidance for intracardiac therapies.

Cardioscopic detection of left ventricular thrombi. -With special reference to a comparison with left ventriculography and echocardiography-

BACKGROUND

Thrombosis occurs in the left ventricle and causes ischemic cerebral attacks. However, differences in the incidence of left ventricular thrombi (LVT) among various categories of heart diseases are not known.

METHODS AND RESULTS

From April 2000 to 31 March 2008, 258 patients (104 females and 154 males; age 63 ± 6 years) with a heart disease underwent cardioscopy of the left ventricle. LVT were detected by cardioscopy in 78 of 258 patients; 12.5% of 57 patients with stable angina, 0% of 9 with unstable angina, 45.2% of 42 with acute myocardial infarction, 23.2% of 43 with old myocardial infarction, 61.9% of 21 with idiopathic acute myocarditis, 44.3% of 68 with idiopathic chronic myocarditis, 33.3% of 6 with rheumatic valvular disease, 25.7% of 31 with idiopathic dilated cardiomyopathy and in 8.0% of 12 with idiopathic hypertrophic cardiomyopathy. Nine of 78 thrombi were globular and 69 were mural. The detection rate of LVT by cardioscopy, left venticulography, non-contrast and contrast echocardiography was 30.2%, 2.7%, 1.9% and 7.0%, respectively.

CONCLUSIONS

LVT were frequently detected by cardioscopy in patients with heart diseases. Although invasive, cardioscopy was more sensitive in detecting LVT than left ventriculography, and non-contrast and contrast echocardiography.