Atherosclerosis on CT coronary angiography and the risk of long-term cardiovascular events after liver transplantation.

Computed tomography coronary angiography (CTCA) is increasingly utilized for preoperative risk stratification before liver transplantation (LT). We sought to assess the predictors of advanced atherosclerosis on CTCA using the recently developed Coronary Artery Disease-Reporting and Data System (CAD-RADS) score and its impact on the prediction of long-term major adverse cardiovascular events (MACE) following LT. We conducted a retrospective cohort study of consecutive patients who underwent CTCA for LT work-up between 2011 and 2018. Advanced atherosclerosis was defined as coronary artery calcium scores > 400 or CAD-RADS score ≥ 3 (≥50% coronary artery stenosis). MACE was defined as myocardial infarction, heart failure, stroke, or resuscitated cardiac arrest. Overall, 229 patients underwent CTCA (mean age 66 ± 5 y, 82% male). Of these, 157 (68.5%) proceeded with LT. The leading etiology of cirrhosis was hepatitis (47%), and 53% of patients had diabetes before transplant. On adjusted analysis, male sex (OR 4.6, 95% CI 1.5-13.8, p = 0.006), diabetes (OR 2.2, 95% CI 1.2-4.2, p = 0.01) and dyslipidemia (OR 3.1, 95% CI 1.3-6.9, p = 0.005) were predictors of advanced atherosclerosis on CTCA. Thirty-two patients (20%) experienced MACE. At a median follow-up of 4 years, CAD-RADS ≥ 3, but not coronary artery calcium scores, was associated with a heightened risk of MACE (HR 5.8, 95% CI 1.6-20.6, p = 0.006). Based on CTCA results, 71 patients (31%) commenced statin therapy which was associated with a lower risk of all-cause mortality (HR 0.48, 95% CI 0.24-0.97, p = 0.04). The standardized CAD-RADS classification on CTCA predicted the occurrence of cardiovascular outcomes following LT, with a potential to increase the utilization of preventive cardiovascular therapies.

Correlation of ventricular pacing burden and left ventricular function in patients with heart failure with reduced ejection fraction.

BACKGROUND: Pacemaker-induced cardiomyopathy is a well described phenomenon in patients with preserved ejection fraction at the time of permanent pacemaker implant. One of the identified risk factors for pacemaker-induced cardiomyopathy is the degree of ventricular pacing burden. However, it is unclear how a high right ventricular pacing burden affects patients with depressed left ventricular function at the time of pacemaker implantation. We sought to assess the relationship between right ventricular pacing and change in left ventricular function over time. METHODS: We conducted an analysis of all patients who had received either a single or dual lead cardiac implantable electronic devices, excluding biventricular devices, and had a prior transthoracic echocardiogram demonstrating an ejection fraction of less than 50%. The primary end-point was the correlation between the percentage of ventricular pacing and the change in LV ejection fraction. RESULTS: Fifty eight patients with preceding heart failure had pacemakers implanted and had follow up echocardiograms. There was no correlation between the degree of ventricular pacing and the absolute change in LV function (r = .04, p = .979). None of the previously identified risk factors for pacemaker induced cardiomyopathy were predictive of a significant fall in ejection fraction. CONCLUSION: The degree of RV pacing and other established risk factors for pacemaker-induced cardiomyopathy in patients with normal left ventricular function at the time of implantation do not appear to carry the same risk in patients with pre-existing heart failure who receive either single or dual lead pacemakers.

High spinal cord injury precipitating syncope: a rare indication for pacemaker insertion.

The current evidence for vasovagal syncope management is that cardiac pacing is only indicated in a highly select group of patients where symptoms can be linked to bradycardic episodes. High spinal cord injury can lead to autonomic dysfunction and sympathetic nervous system hypoactivity. A high spinal cord injury can theoretically precipitate profound bradycardia leading to haemodynamic instability and syncope. A patient in his 50s with a history of C2 spinal injury was admitted to our tertiary centre for management of what was initially thought to be septic shock causing hypotension and syncope. With evidence to suggest this patient's presentation may be profound reflex syncope in the context of unopposed parasympathetic signalling, consensus was reached to implant a permanent pacemaker. Remarkably, the patient's haemodynamics stabilised and there were no further episodes of syncope.

Efficacy of intravenous magnesium for the management of non-post operative atrial fibrillation with rapid ventricular response: A systematic review and meta-analysis.

BACKGROUND: Intravenous magnesium (IV Mg), a commonly utilized therapeutic agent in the management of atrial fibrillation (AF) with rapid ventricular response, is thought to exert its influence via its effect on cellular automaticity and prolongation of atrial and atrioventricular nodal refractoriness thus reducing ventricular rate. We sought to undertake a systematic review and meta-analysis of the effectiveness of IV Mg versus placebo in addition to standard pharmacotherapy in the rate and rhythm control of AF in the nonpostoperative patient cohort given that randomized control trials (RCTs) have shown conflicting results. METHODS: Randomized controlled trials comparing IV Mg versus placebo in addition to standard of care were identified via electronic database searches. Nine RCTs were returned with a total of 1048 patients. Primary efficacy endpoints were study-defined rate control and rhythm control/reversion to sinus rhythm. The secondary endpoint was patient experienced side effects. RESULTS: Our analysis found IV Mg in addition to standard care was successful in achieving rate control (odd ratio [OR] 1.87, 95% confidence interval [CI] 1.13-3.11, p = .02) and rhythm control (OR 1.45, 95% CI 1.04-2.03, p = .03). Although not well reported among studies, there was no significant difference between groups regarding the likelihood of experiencing side effects. CONCLUSIONS: IV Mg, in addition to standard-of-care pharmacotherapy, increases the rates of successful rate and rhythm control in nonpostoperative patients with AF with rapid ventricular response and is well tolerated.

Development of a carpark cardiac implantable electronic device clinic to improve time efficiency and patient satisfaction in the context of restrictions imposed by the COVID-19 pandemic.

INTRODUCTION: We evaluated time efficiency and patient satisfaction of a "car park clinic" (CPC) compared to traditional face-to-face (F2F) during the COVID-19 pandemic. METHODS: Consecutive patients attending CPC between September 2020 and November 2021 were surveyed. CPC time was recorded by staff. F2F time was reported by patients and administrative data. RESULTS: A total of 591 patients attended the CPC. A total of 176 responses were collected for F2F clinic. Regarding satisfaction, 90% of CPC patients responded "happy" or "very happy." 96% reported feeling "safe" or "very safe." Patients spent significantly less time in CPC compared to F2F (17 ± 8 vs. 50 ± 24 min, p < .001). CONCLUSION: CPC had excellent patient satisfaction and superior time efficiency compared to F2F.

Ventricular fibrillation episodes related to managed ventricular pacing algorithm in a patient with mitral valve prolapse - "Arrhythmic MVP due to MVP".

We report a case of an implant cardiac defibrillator (ICD) patient who an ICD implanted for ventricular fibrillation (VF) related to mitral valve prolapse. He has 2 episodes of VF in his device lives. First episode of VF in year 2016 was initiated after a pause related to the MVP™ algorithm with a critically timed PVC. MVP™ was turned off which prevented further VF episodes. However, MVP™ was turned back on at the device replacement in 2018. A second VF episode developed with similar mechanism in 2021 and MVP™ was subsequently turned off with no further VF recorded. This case highlights the importance of recognizing the mechanism of initiation of tachy-arrhythmia episodes and serves as an important reminder regarding optimization of device settings at the time of replacement.

Diabetes mellitus is an independent predictor of obstructive coronary artery disease in patients presenting with atrial fibrillation and elevated troponin.

Atrial fibrillation can present with symptoms of myocardial infarction and elevated troponin, even in the absence of obstructive coronary artery disease (CAD). We sought to determine the characteristics that predict underlying obstructive CAD. Obstructive CAD was far more likely in those with troponin elevation. In those with elevated troponin, diabetes mellitus was an independent predictor of obstructive CAD.

Sudden cardiac death related to physical exercise in the young: a nationwide cohort study of Australia.

BACKGROUND: Sudden cardiac death (SCD) during physical exercise is devastating. AIMS: To evaluate causes and circumstances of exercise-related SCD in the young in Australia. METHODS: We reviewed the National Coronial Information System database for deaths in Australia relating to cardiovascular disease in cases aged 10-35 years between 2000 and 2016. Cases who had undertaken physical exercise at the time of the event were included. We collected demographics, circumstances of death, type of physical exercise, bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use prior to ambulance arrival. RESULTS: Over a 17-year period, 1925 SCD cases were identified, of which 110 (6%) cases (median age 27 years (interquartile range 21-32 years); 92% male) were related to sports/physical exercise. Thirteen (12%) cases occurred in active athletes. Most common causes were coronary artery disease (CAD; 37%) and sudden arrhythmic death syndrome (SADS; 20%). Among Aboriginal and Torres Strait Islanders (n = 10), all deaths were related to CAD. Australian Rules Football (24%), running/jogging (14%) and soccer (14%) were the most frequent physical exercise activities. Prior symptoms were present in 39% (chest pain 37%, pre-syncope/syncope 26%). Most (87%) were witnessed, with bystander CPR in 70%. AED use prior to ambulance arrival was 8%. CONCLUSIONS: The present study demonstrates the high occurrence of CAD and SADS in SCD in the young related to physical exercise. Aboriginal and Torres Strait Islanders were disproportionately affected by CAD. Although events were commonly witnessed, AED was seldom used prior to ambulance arrival and highlights an important opportunity to improve outcomes in the post-arrest chain of survival.

Atrial Tachyarrhythmias and Stroke: Temporal Relationship and Stroke Subtypes.

BACKGROUND AND PURPOSE: Research into the temporal relationship between atrial tachyarrhythmias (atrial tachycardia [AT] and atrial fibrillation [AF]) and stroke has produced conflicting findings. Systematic categorization of stroke subtypes may help clarify the discussion. OBJECTIVES: The objective of the study was to examine the presence and timing of AT/AF in relation to ischemic stroke subtypes, categorized as either cardioembolic (CE) or non-CE. METHODS: Consecutive patients presenting to the Austin Hospital with acute stroke from 2012 to 2019 and a cardiac implantable electronic device (CIED) were identified. Using a case-control design, the temporal proximity of AT/AF episodes in the 90 days prior to stroke was compared in the CE and non-CE stroke groups. RESULTS: 5,591 patients presented to the Austin Hospital with acute stroke from 2012 to 2019, of whom 31 patients with an ischemic stroke and a CIED with ≥90 days of monitoring were identified. Twelve strokes were adjudicated as CE and 19 as non-CE by a stroke neurologist. Six of the 12 CE stroke patients (50%) experienced AT/AF within 30 days preceding their stroke, while none of the 19 non-CE stroke patients recorded any AT/AF in the same period (p = 0.001). Four CE stroke patients (33%) had no AT/AF preceding their strokes at any time. The odds ratio for CE stroke was highest (39; 95% confidence interval [CI]: 1.92-791.5) when AT/AF occurred in the 30 days prior, declining to 20.65 (95% CI: 1.00-427.66) and 6.07 (95% CI: 0.94-39.04) in the subsequent 31-60- and 61-90-day windows, respectively. CONCLUSIONS: CE strokes were associated with a significantly higher proportion of preceding AT/AF compared with non-CE strokes. These findings support a potential temporal relationship between AT/AF and CE stroke and demonstrate that stroke subtyping can better characterize the relationship between AF and ischemic stroke. However, this study's findings are limited by its sample size and small number of informative cases.

Comparison of 2 Smart Watch Algorithms for Detection of Atrial Fibrillation and the Benefit of Clinician Interpretation: SMART WARS Study.

BACKGROUND: Smart watches and wearable technology capable of heart rhythm assessment have increased in use in the general population. The Apple Watch Series 4 (AW4) and KardiaBand (KB) are devices capable of obtaining single-lead electrocardiographic recordings, presenting a novel opportunity for the detection of paroxysmal arrhythmias. OBJECTIVES: The aim of this study was to assess the diagnostic utility of the AW4 and KB in an elderly outpatient population. METHODS: Consecutive recordings were taken from patients attending cardiology outpatient clinic from the AW4 and KB concurrently with 12-lead electrocardiography. Automated diagnoses and blinded single-lead electrocardiographic tracing interpretations by 2 cardiologists were analyzed. Analysis was also conducted to assess the effect of combined device and clinician interpretation. RESULTS: One hundred twenty-five patients were prospectively recruited (mean age 76 ± 7 years, 62% men). The accuracy of the automated rhythm assessment was higher with the KB than the AW4 (74% vs 65%). For the detection of atrial fibrillation, the sensitivity and negative predictive value of the KB were 89% and 97%, respectively, and of the AW4 were 19% and 82%, respectively. Using hybrid automated and clinician interpretation, the overall accuracy of the KB and AW4 was 91% and 87%, respectively. CONCLUSIONS: The KB automated algorithm outperformed the AW4 in its accuracy and sensitivity for detecting atrial fibrillation in the outpatient setting. Clinician assessment of the single-lead electrocardiogram improved accuracy. These findings suggest that although these devices' tracings are of sufficient quality, automated diagnosis alone is not sufficient for making clinical decisions about atrial fibrillation diagnosis and management.

A prospective natural history study of coronary atherosclerosis following liver transplantation.

BACKGROUND & AIMS: Cardiovascular disease remains a leading cause of mortality following liver transplantation (LT). Whether it may be partially attributable to accelerated development of subclinical coronary artery disease is unclear. We sought to assess the longitudinal effect of LT on coronary plaque burden. METHODS: A prospective observational study was conducted in 30 asymptomatic patients who underwent computed tomographic coronary angiography (CTCA) pre- and a median 4-years following LT. Serial changes were quantified using coronary artery calcium score (CACS) and semi-quantitative CTCA scores, in a blinded fashion. High-risk plaque (HRP) characteristics were also assessed. Plaque progression was defined using prognostically significant cut-offs. RESULTS: In the study population (age 59.8 ± 8 years, 80% male), 93 of 459 coronary segments had plaque at baseline. On follow-up CTCA, 68 (+73.1%) new lesions appeared in segments without plaque initially. Nineteen (63.3%) patients demonstrated a clinically significant rise in plaque burden on CACS and semi-quantitative indices on CTCA (all p<0.001). CAD-RADS score rose to ≥4 (≥70% stenosis) in 9 (30%) patients, necessitating ischemia-guided revascularization in 3 (10%) patients. While the absence of coronary calcification or plaque pre-LT was protective, presence of HRP and development of post-transplant metabolic syndrome were both strong independent predictors of atherosclerosis progression. CONCLUSIONS: Our findings suggest that LT is associated with early progression of coronary atherosclerosis. Accelerated progression was noted particularly in those with HRP and post-transplant metabolic syndrome. Understanding the mechanisms of this novel observation and the potential role of preventive cardiovascular therapies in this population merit further study.

Role of renin-angiotensin system antagonists on long-term mortality post-percutaneous coronary intervention in reduced and preserved ejection fraction.

AIMS: The use of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II-receptor blockers (ARBs) post-myocardial infarction (MI) is supported by evidence based on trials performed in the thrombolysis era. This was prior to primary percutaneous coronary intervention (PCI) being routine practice, and with little direct evidence for the use of these medications in patients with preserved left ventricular (LV) function. This study sought to determine whether there is an association between ACEi/ARB use after PCI for acute coronary syndrome (ACS) and long-term all-cause mortality, with a particular focus on patients with preserved LV function. METHODS: This multicentre, observational study evaluated prospectively collected data of 21,388 patients (> 18 years old) that underwent PCI for NSTEMI and STEMI between 2005 and 2018, and were alive at 30 day follow-up. RESULTS: In total, 83.8% of patients were using ACEi/ARBs. Kaplan-Meier analysis demonstrated ACEi/ARB use was associated with a significantly lower mortality in the entire cohort (15.0 vs. 22.7%; p < 0.001) with a mean follow-up of 5.58 years; and independently associated with 24% lower mortality by Cox proportional hazards modelling (HR 0.76, CI 0.67-0.85, p < 0.001). ACEi/ARB therapy was also associated with significantly lower mortality in patients with reduced or preserved LV function, with greater survival benefit with worse LV dysfunction. CONCLUSION: ACEi/ARB therapy post-PCI is associated with significantly lower long-term mortality in patients with reduced and preserved LV function. These findings provide contemporary evidence for using these agents in the current era of routine primary PCI, including those with preserved EF.

Angiotensin-Converting Enzyme 2 Activity Is Associated With Embolic Stroke of Undetermined Source.

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Relationship between QT interval prolongation and structural abnormalities in cirrhotic cardiomyopathy: A change in the current paradigm.

It is postulated that cardiac structural abnormalities observed in cirrhotic cardiomyopathy (CCM) contribute to the electrophysiologic abnormality of QT interval (QTc) prolongation. We sought to evaluate whether QTc prolongation is associated with intrinsic abnormalities in cardiac structure and function that characterize CCM. Consecutive patients undergoing liver transplant work-up between 2010 and 2018 were included. Measures of cardiac function on stress testing including cardiac reserve and chronotropic incompetence were collected prospectively and a corrected QTc ≥ 440 ms was considered prolonged. Overall, 439 patients were included and 65.1% had a prolonged QTc. There were no differences in markers of left ventricular and atrial remodeling, or resting systolic and diastolic function across QTc groups. The proportion of patients that met the criteria for a low cardiac reserve (39.2 vs 36.6%, p = .66) or chronotropic incompetence (18.1 vs 21.3%, p = .52) was not different in those with a QTc ≥ 440 vs <440 ms. Further, there was no association between QTc prolongation and CCM by either the 2005 World College of Gastroenterology or modified 2020 Cirrhotic Cardiomyopathy Consortium criteria. QT interval prolongation was not associated with structural or functional cardiac abnormalities that characterize CCM. These findings suggest that CCM and QT interval prolongation in cirrhosis may be two separate entities with distinct pathophysiological origins.

The role of CHA2DS2-VASc score in evaluating patients with atrial fibrillation undergoing percutaneous coronary intervention.

OBJECTIVE: The aim of the review was to assess whether CHA2DS2-VASc score is predictive of mortality in patients with atrial fibrillation undergoing percutaneous coronary intervention (PCI). BACKGROUND: The CHA2DS2-VASc score is validated in predicting stroke risk in atrial fibrillation. The optimum management strategy for these patients undergoing PCI is still debated. METHODS: The CHA2DS2-VASc score was calculated in consecutive patients with atrial fibrillation undergoing PCI in a large Australian registry between 2007 and 2013. Patients were divided into low (1-2), intermediate (3-4) and high (≥5) groups. Clinical and procedural data, 30-day, 1-year and long-term outcomes were compared between the groups. RESULTS: A total of 564 patients were included in our analysis. Patients with high CHA2DS2-VASc scores had higher mortality rates at 1-year (2, 8, 15; P = 0.002) and long-term (6, 20, 37; P < 0.001). High-risk patients were more likely to have renal impairment and multivessel disease. Increasing CHA2DS2-VASc score was associated with increased risk of stroke (0, 2, 6; P = 0.03). However, only 41.9% received anticoagulation, with no difference across the risk groups. When compared to low-risk, intermediate [HR 3.57; 95% confidence interval (CI), 1.28-9.92; P = 0.015] and high (hazard ratio 7.82; 95% CI, 2.88-21.24; P < 0.001) CHA2DS2-VASc scores were significant predictors of long-term mortality. CONCLUSIONS: Higher CHA2DS2-VASc scores in patients with atrial fibrillation undergoing PCI are associated with significantly worse outcomes. Despite being high-risk, the patients in this cohort are likely undertreated with anticoagulation. Close clinical follow-up with greater utilization of anticoagulation and optimal medical therapy has the potential to improve long-term outcomes.

Postoperative Atrial Fibrillation and Long-Term Risk of Stroke in Patients Undergoing Liver Transplantation.

BACKGROUND AND PURPOSE: Postoperative atrial fibrillation (POAF) is the commonest cardiovascular complication following liver transplantation (LT). This study sought to assess a possible association of POAF with subsequent thromboembolic events in patients undergoing LT. METHODS: A retrospective cohort study of consecutive adults undergoing LT between 2010 and 2018 was undertaken. Patients were classified as POAF if atrial fibrillation (AF) was documented within 30 days of LT without a prior history of AF. Cases of ischemic stroke or systemic embolism were adjudicated by a panel of 2 independent physicians. RESULTS: Among the 461 patients included, POAF occurred in 47 (10.2%) a median of 3 days following transplantation. Independent predictors of POAF included advancing age, postoperative sepsis and left atrial enlargement. Over a median follow-up of 4.9 (interquartile range, 2.9-7.2) years, 21 cases of stroke and systemic embolism occurred. Rates of thromboembolic events were significantly higher in patients with POAF (17.0% versus 3.1%; P<0.001). After adjustment, POAF remained a strong independent predictor of thromboembolic events (hazard ratio, 8.36 [95% CI, 2.34-29.79]). Increasing CHA2DS2VASc score was also an independent predictor of thromboembolic events (hazard ratio, 1.58 [95% CI, 1.02-2.46]). A model using POAF and a CHA2DS2VASc score ≥2 alone yielded a C statistic of 0.77, with appropriate calibration for the prediction of thromboembolic events. However, POAF was not an independent predictor of long-term mortality. CONCLUSIONS: POAF following LT is associated with an 8-fold increased risk of thromboembolic events and the use of the CHA2DS2VASc score may facilitate risk stratification of these patients. Prospective studies are warranted to assess whether the use of oral anticoagulants can reduce the risk of thromboembolism following LT.

Systematic quantification of histologic ventricular fibrosis in isolated mitral valve prolapse and sudden cardiac death.

BACKGROUND: Cardiac fibrosis in mitral valve prolapse (MVP) is implicated in the development of sudden cardiac death (SCD); however, the pattern remains poorly characterized. OBJECTIVE: The purpose of this study was to systematically quantify left and right ventricular fibrosis in individuals with isolated MVP and SCD (iMVP-SCD), whereby other potential causes of death are excluded, compared to a control cohort. METHODS: Individuals with iMVP-SCD were identified from the Victorian Institute of Forensic Medicine, Australia, and matched for age, sex, and body mass index to control cases with noncardiac death. Cardiac tissue sections were analyzed to determine collagen deposition in the left ventricular free wall (anterior, lateral, and posterior portions), interventricular septum, and right ventricle. Within the iMVP-SCD cases, the endocardial-to-epicardial distribution of fibrosis within the left ventricle was specifically characterized. RESULTS: Seventeen cases with iMVP-SCD were matched 1:1 with 17 controls, yielding 149 samples and 1788 histologic regions. The iMVP-SCD group had increased left ventricular (anterior, lateral, and posterior; all P <.001) and interventricular septum fibrosis (P <.001), but similar amounts of right ventricular fibrosis (P = .62) compared to controls. In iMVP-SCD, left ventricular fibrosis was significantly higher in the lateral and posterior walls compared to the anterior wall and interventricular septum (all P <.001). Within the lateral and posterior walls, iMVP-SCD cases had a significant endocardial-to-epicardial gradient of cardiac fibrosis (P <.01) similar to other known conditions that cause cardiac remodeling. CONCLUSION: Our study indicates that nonuniform left ventricular remodeling with both localized and generalized left ventricular fibrosis is important in the pathogenesis of SCD in individuals with MVP.