Audrius Aidietis

Atrial fibrillation following cardiac surgery: clinical features and preventative strategies

Atrial fibrillation (AF) is a common complication of cardiac surgery, with an increasing incidence. Post-operative AF results in many complications and increased healthcare resources. Despite substantial interest in the prediction and prevention of post-operative AF, as well as guidelines for the management of this common arrhythmia, there is still some uncertainty about appropriate risk stratification and management. The aim of this review article is to provide an overview of clinical predictive features for the development of AF following cardiac surgery and suitable preventive measures, using both antiarrhythmic and non-antiarrhythmic strategies.

Characterisation and validity of inflammatory biomarkers in the prediction of post-operative atrial fibrillation in coronary artery disease patients

Atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG). We sought to determine the diagnostic validity of plasma biomarkers of i) inflammation (marked by interleukin-6 [IL-6] and high-sensitivity C-reactive protein [hs-CRP]), ii) extracellular matrix remodelling (matrix metalloproteinase [MMP-9], tissue inhibitor of matrix metalloproteinase [TIMP-1]) and iii) the prothrombotic state (tissue factor and von Willebrand factor [vWF]) in the risk prediction of post-operative AF. Samples were obtained preoperatively from peripheral/femoral vein and from intracardiac chambers (right atrium [RA], the right atrial appendage [RAA], the left atrium [LA] and the left atrial appendage [LAA]) amongst 100 consecutive patients free of AF and inflammatory disease undergoing elective CABG. Biomarker concentrations were related to incident AF (30 days). At 30 days post CABG, 30 patients were proven to have had AF. Concentrations of tissue factor (TF) and vWF were unrelated to postoperative AF. Peripheral (p=0.018), and intracardiac levels (RAA (p=0.029) and LA (p=0.026)) of hs-CRP were associated with the presence of AF after CABG. Intracardiac levels of IL-6 in samples from the RAA (p=0.031), LA (p=0.042) and LAA (p=0.006), and MMP-9 in the LAA sample were also associated with AF (p=0.007). Our data suggest that an intra-cardiac inflammatory environment that is manifest peri-operatively may predispose to the development of post-operative AF. This intracardiac inflammatory state was reflected by increased peripheral hs-CRP levels. These differences may indicate local substrate abnormalities contributing to the development of AF post-operatively.

Intracardiac expression of markers of endothelial damage/dysfunction, inflammation, thrombosis, and tissue remodeling, and the development of postoperative atrial fibrillation

Summary.  Background: Atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG), and may have an inflammatory and/or thrombotic etiology. We sought to determine the expression of inflammatory (interleukin [IL]‐6), thrombotic (tissue factor and von Willebrand factor [VWF]) and remodeling (matrix metalloproteinase [MMP]‐9 and tissue inhibitor of metalloproteinase [TIMP]‐1) markers by left atrial appendage (LAA) and right atrial appendage (RAA) tissue in the prediction of postoperative AF. We determined whether the tissue expression of markers of certain different pathophysiologic mechanisms predicted the development of AF after CABG. Methods: LAA and RAA tissue was excised during CABG in 100 patients free of AF and inflammation. Tissue marker expression was quantified by immunohistochemistry and was related to 30‐day postoperative AF. Results: Overall, there were no significant differences in staining intensity of any marker between LAA tissue and RAA tissue. However, more intense expression of VWF by LAA tissue predicted the 30 patients with postoperative AF as compared with those free of AF (P = 0.006). IL‐6, MMP‐9 and TIMP‐1 expression by RAA and LAA epicardial tissue was stronger than expression by endocardium or cardiomyocytes (all P < 0.025) but failed to predict AF. Conclusion: In this study, one of the largest to investigate tissue expression of pathophysiologic markers in relation to postoperative AF, we show that more intense expression of VWF by LAA tissue is a significant predictor of postoperative AF. This points towards a possible role of endothelial damage/dysfunction (as reflected by VWF changes) in the pathogenesis of postoperative AF.

Acute safety and efficacy of the NeoChord procedure

OBJECTIVES Transapical off-pump mitral valve repair using the NeoChord device has been proposed to treat degenerative mitral valve regurgitation. This prospective study sought to evaluate acute safety and efficacy of this innovative, minimally invasive, transcatheter mitral valve repair approach. METHODS Symptomatic patients with severe mitral regurgitation (MR) were selected if they presented a favourable valve anatomy (the presence of leaflet flail/prolapse with consistent overlap of tissue). Early device success was defined as placement of at least two neochordae with residual mitral regurgitation ≤ 2+ after the procedure. The primary acute safety and efficacy end points were evaluated at 30 days. RESULTS Between February 2013 and June 2014, in Padua and Vilnius University Hospitals, a total of 62 patients were treated, with a median age of 66 years (IQR 52-76) and a median EuroSCORE I of 1.9% (IQR 0.9-6). Fifty-six patients (88.9%) presented with a posterior leaflet prolapse, 4 (6%) with an anterior leaflet prolapse and 3 (5%) with a combined disease. Early procedural success was achieved in all patients. Two neochordae were implanted in 2 patients (3%), 3 in 20 (32%), 4 in 28 (44%), 5 in 10 (16%), 6 in 2 (3%) and 7 in 1 (2%). At 30 days, major adverse events included only 1 acute myocardial infarction (2%) successfully treated percutaneously and 2 cases of sepsis (3%). Mitral regurgitation at 30 days was absent in 29 patients (46%), Grade 1+ in 16 (25%), Grade 2+ in 10 (16%), Grade 3+ in 7 (11%) and Grade 4+ in 1 (2%). All 8 patients with MR >2+ were successfully reoperated with conventional surgery or NeoChord reintervention. CONCLUSIONS Initial results with the NeoChord procedure in a small number of patients indicate that transapical off-pump mitral valve repair is feasible and safe. Efficacy is maintained up to the 30-day follow-up with significant clinical benefit for patients.

Hypertension and Cardiac Arrhythmias

Arterial hypertension is a widespread disease and one of important yet under-recognized and under-treated causes of atrial and ventricular arrhythmias. Hypertrophy of cardiac muscle in hypertensive patients is characterized not only by increased myocardial mass, but also by proliferation of fibrous tissue and decreased intercellular coupling, that lead to inhomogeneity of electrical properties and propensity to various arrhythmias. Many trials show the importance of treating hypertension in order to restore normal myocardial function and decrease the number of premature beats, runs of ventricular tachycardia, and attacks of atrial fibrillation. To date, the most convincing data are collected regarding the importance of blockade of renin-angiotensin-aldosterone system (RAAS) in order to avoid arrhythmias in arterial hypertension. Other antihypertensive drug classes (eg beta-blockers, calcium antagonists) are also useful, and investigational compounds that aim at regression of hypertrophy are under search. Polymorphism of genes coding the function of RAAS, pathways of synthesis and degradation of proteins and other cardiac and extracardiac systems involved in regulation of blood pressure, are recognized as promising targets for research.

Pathophysiological insights into atrial fibrillation following cardiac surgery: implications for current pharmaceutical design.

Atrial fibrillation (AF) following cardiac surgery is a common complication, which increases incidence of other complications, hospital and healthcare costs. The reported rate of the occurrence of postoperative AF varies with different studies, depending on population profile, type of surgery, arrhythmia definition and detection methods, design of study. Nonetheless, the precise mechanisms of AF related to cardiac surgery are poorly understood. A diverse variety of reasons have been proposed for the pathogenesis of this common cardiac arrhythmia. The aim of this review article is to provide an overview of pathophysiological processes that lead to the development of AF post-cardiac surgery. These processes are closely inter-related but the most important ones that have bearing on drug design include the RAAS, ion channels, connexins, fibrosis and extracellular matrix turnover, inflammation and oxidative stress. The autonomic nervous system and structural remodeling all influence all these pathophysiological processes, which should not be viewed in isolation. Understanding such processes would have major implications for the approach to current pharmaceutical design, to improve our approach to drug management strategies.

A Double-Orifice Tricuspid Valve Associated With a Divided Right Atrium

Right atrioventricular valve duplication is a rare congenital anomaly with only isolated cases of a double-orifice tricuspid valve having been described. This article presents a case of the surgical repair of a double-orifice tricuspid valve associated with a divided right atrium, a ventricular septal defect, and Wolff-Parkinson-White syndrome.

Small Intestinal Inflammatory Myofibroblastic Metastasis in the Left Ventricle

Inflammatory myofibroblastic tumors (IMTs) are rare and usually appear in childhood and adolescence. These tumors often take a benign course, but tend to reoccur in a quarter of cases and metastasize locally. Distant IMT metastases are extremely uncommon. To our knowledge, metastatic spread to the heart has not been reported. We present a case of a 43-year-old woman with small intestinal IMT metastatic spread to the cavity of the left ventricle, stomach, liver, vertebra, and pelvic bones. The cardiac tumor was resected, and the patient survived for 9 months. She dies because the progression of IMT at other sites.

Pacemaker-Mediated Programmable Hypertension Control Therapy

Background Many patients requiring a pacemaker have persistent hypertension with systolic blood pressures above recommended levels. We evaluated a pacemaker‐based Programmable Hypertension Control (PHC) therapy that uses a sequence of variably timed shorter and longer atrioventricular intervals. Methods and Results Patients indicated for dual‐chamber pacing with office systolic blood pressure (oSBP) >150 mm Hg despite stable medical therapy were implanted with a Moderato™ pulse generator that delivers PHC therapy. Patients were followed for 1 month (Run‐In period) with conventional pacing; those with persistent oSBP >140 mm Hg were included in the study and had PHC therapy activated. The co‐primary efficacy end points were changes in 24‐hour ambulatory systolic blood pressure and oSBP between baseline and 3 months. Safety was assessed by tracking adverse events. Thirty‐five patients met the initial inclusion criteria and underwent Moderato implantation. At 1 month, oSBP was <140 mm Hg in 7 patients who were excluded. PHC was activated in the remaining 27 patients with baseline office blood pressure 166±11/80±10 mm Hg despite an average of 3.2 antihypertensive medications. During the Run‐In period, oSBP and 24‐hour ambulatory systolic blood pressure decreased by 8±13 and 5±12 mm Hg (P<0.002), respectively. Compared with pre‐PHC activation measurements, oSBP decreased by another 16±15 mm Hg and 24‐hour ambulatory systolic blood pressure decreased by an additional 10±13 mm Hg (both P<0.01) at 3 months. No device‐related serious adverse effects were noted. Conclusions In pacemaker patients with persistent hypertension despite medical therapy, oSBP and 24‐hour ambulatory systolic blood pressure are decreased by PHC therapy. Initial indications are that this therapy is a safe and promising therapy for such patients. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT02282033.

An early European experience with transapical off-pump mitral valve repair with NeoChord implantation†

OBJECTIVES Transapical off-pump NeoChord repair is a novel minimally invasive surgical procedure to treat degenerative mitral valve regurgitation. The aim was to evaluate 1-year clinical results of the NeoChord procedure in a consecutive cohort of patients. METHODS Between February 2013 and July 2016, 213 patients were enrolled in the NeoChord Independent International Registry. All patients presented severe mitral regurgitation due to flail/prolapse of 1 or both leaflets, and they all completed postoperative echocardiographic assessment up to 1 year. We identified the primary end point as composed of procedural success, freedom from mortality, stroke, reintervention, recurrence of severe mitral regurgitation, rehospitalization and decrease of at least 1 New York Heart Association functional class at 1-year follow-up. We also compared outcomes according to the anatomical classification (Type A: isolated central posterior leaflet disease; Type B: posterior multisegment disease; Type C: anterior, bileaflet, paracommissural disease with/without leaflet/annular calcifications). RESULTS The median age was 68 years (interquartile range 56-77), and the median EuroSCORE II was 1.05% (interquartile range 0.67-1.76). The number of Type A, B and C patients was 82 (38.5%), 98 (46%) and 33 (15.5%), respectively. Procedural success was achieved in 206 (96.7%) patients. At 1-year follow-up, overall survival was 98 ± 1%. Composite end point was achieved in 84 ± 2.5% for the overall population and 94 ± 2.6%, 82.6 ± 3.8% and 63.6 ± 8.4% in Type A, Type B and Type C patients, respectively (P < 0.0001). CONCLUSIONS These results demonstrate that the NeoChord procedure is safe, effective and reproducible. Clinical and echocardiographic efficacy is maintained up to 1 year with significant differences among the anatomical groups. Specific anatomical selection criteria are necessary to achieve stable results.