Commotio Cordis in Non-Sport-Related Events: A Systematic Review.

BACKGROUND: Commotio cordis is an increasingly recognized cause of sudden cardiac death. Although commonly linked with athletes, many events occur in non-sport-related settings. OBJECTIVES: The goal of this study was to characterize and compare non-sport-related vs sport-related commotio cordis. METHODS: PubMed and Embase were searched for all cases of commotio cordis from inception to January 5, 2022. RESULTS: Of 334 commotio cordis cases identified, 121 (36%) occurred in non-sport-related contexts, which included assault (76%), motor vehicle accidents (7%), and daily activities (16%). Projectiles were implicated significantly less in non-sport-related events (5% vs 94%, respectively; P < 0.001). Nonprojectile etiologies in non-sport-related events mostly consisted of impacts with body parts (79%). Both categories affected similar younger aged demographic (P = 0.10). The proportion of female victims was significantly higher in non-sport-related events (13% vs 2%, respectively; P = 0.025). Mortality was significantly higher in non-sport-related events (88% vs 66%, respectively; P < 0.001). In non-sport-related events, rates of cardiopulmonary resuscitation (27% vs 97%, respectively; P < 0.001) and defibrillation (17% vs 81%, respectively; P < 0.001) were both lower and resuscitation was more commonly delayed beyond 3 min (80% vs 5%, respectively; P < 0.001). CONCLUSIONS: Commotio cordis occurs across a spectrum of non-sport-related settings including assault, motor vehicle accidents, and daily activities. Both categories affected a younger and male-predominant demographic. Mortality is higher in non-sport-related commotio cordis, likely owing to lower rates of cardiopulmonary resuscitation, defibrillation, automated external defibrillator availability, and extended time to resuscitation. Increased awareness of non-sport-related commotio cordis is essential to develop a means of prevention and mortality reduction, with earlier recognition and prompt resuscitation measures.

Provocation testing in congenital long QT syndrome: A practical guide.

Congenital long QT syndrome (LQTS) is a hereditary cardiac channelopathy with an estimated prevalence of 1 in 2500. A prolonged resting QT interval corrected for heart rate (QTc interval) remains a key diagnostic component; however, the QTc value may be normal in up to 40% of patients with genotype-positive LQTS and borderline in a further 30%. Provocation of QTc prolongation and T-wave changes may be pivotal to unmasking the diagnosis and useful in predicting genotype. LQTS provocation testing involves assessment of repolarization during and after exercise, in response to changes in heart rate or autonomic tone, with patients with LQTS exhibiting a maladaptive repolarization response. We review the utility and strengths and limitations of 4 forms of provocation testing-stand-up test, exercise stress test, epinephrine challenge, and mental stress test-in diagnosing LQTS and provide some practical guidance for performing provocation testing. Ultimately, exercise testing, when feasible, is the most useful form of provocation testing when considering diagnostic sensitivity and specificity.

Association of the Timing and Extent of Cardiac Implantable Electronic Device Infections With Mortality.

Importance: Cardiac implantable electronic device (CIED) infection is a potentially devastating complication with an estimated 12-month mortality of 15% to 30%. The association of the extent (localized or systemic) and timing of infection with all-cause mortality has not been established. Objective: To evaluate the association of the extent and timing of CIED infection with all-cause mortality. Design, Setting, and Participants: This prospective observational cohort study was conducted between December 1, 2012, and September 30, 2016, in 28 centers across Canada and the Netherlands. The study included 19 559 patients undergoing CIED procedures, 177 of whom developed an infection. Data were analyzed from April 5, 2021, to January 14, 2023. Exposures: Prospectively identified CIED infections. Main Outcomes and Measures: Time-dependent analysis of the timing (early [≤3 months] or delayed [3-12 months]) and extent (localized or systemic) of infection was performed to determine the risk of all-cause mortality associated with CIED infections. Results: Of 19 559 patients undergoing CIED procedures, 177 developed a CIED infection. The mean (SD) age was 68.7 (12.7) years, and 132 patients were male (74.6%). The cumulative incidence of infection was 0.6%, 0.7%, and 0.9% within 3, 6, and 12 months, respectively. Infection rates were highest in the first 3 months (0.21% per month), reducing significantly thereafter. Compared with patients who did not develop CIED infection, those with early localized infections were not at higher risk for all-cause mortality (no deaths at 30 days [0 of 74 patients]: adjusted hazard ratio [aHR], 0.64 [95% CI, 0.20-1.98]; P = .43). However, patients with early systemic and delayed localized infections had an approximately 3-fold increase in mortality (8.9% 30-day mortality [4 of 45 patients]: aHR, 2.88 [95% CI, 1.48-5.61]; P = .002; 8.8% 30-day mortality [3 of 34 patients]: aHR, 3.57 [95% CI, 1.33-9.57]; P = .01), increasing to a 9.3-fold risk of death for those with delayed systemic infections (21.7% 30-day mortality [5 of 23 patients]: aHR, 9.30 [95% CI, 3.82-22.65]; P < .001). Conclusions and Relevance: Findings suggest that CIED infections are most common within 3 months after the procedure. Early systemic infections and delayed localized infections are associated with increased mortality, with the highest risk for patients with delayed systemic infections. Early detection and treatment of CIED infections may be important in reducing mortality associated with this complication.

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.

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.

Sex Differences and Utility of Treadmill Testing in Long-QT Syndrome.

Background Diagnosis of congenital long-QT syndrome (LQTS) is complicated by phenotypic ambiguity, with a frequent normal-to-borderline resting QT interval. A 3-step algorithm based on exercise response of the corrected QT interval (QTc) was previously developed to diagnose patients with LQTS and predict subtype. This study evaluated the 3-step algorithm in a population that is more representative of the general population with LQTS with milder phenotypes and establishes sex-specific cutoffs beyond the resting QTc. Methods and Results We identified 208 LQTS likely pathogenic or pathogenic KCNQ1 or KCNH2 variant carriers in the Canadian NLQTS (National Long-QT Syndrome) Registry and 215 unaffected controls from the HiRO (Hearts in Rhythm Organization) Registry. Exercise treadmill tests were analyzed across the 5 stages of the Bruce protocol. The predictive value of exercise ECG characteristics was analyzed using receiver operating characteristic curve analysis to identify optimal cutoff values. A total of 78% of male carriers and 74% of female carriers had a resting QTc value in the normal-to-borderline range. The 4-minute recovery QTc demonstrated the best predictive value for carrier status in both sexes, with better LQTS ascertainment in female patients (area under the curve, 0.90 versus 0.82), with greater sensitivity and specificity. The optimal cutoff value for the 4-minute recovery period was 440 milliseconds for male patients and 450 milliseconds for female patients. The 1-minute recovery QTc had the best predictive value in female patients for differentiating LQTS1 versus LQTS2 (area under the curve, 0.82), and the peak exercise QTc had a marginally better predictive value in male patients for subtype with (area under the curve, 0.71). The optimal cutoff value for the 1-minute recovery period was 435 milliseconds for male patients and 455 milliseconds for femal patients. Conclusions The 3-step QT exercise algorithm is a valid tool for the diagnosis of LQTS in a general population with more frequent ambiguity in phenotype. The algorithm is a simple and reliable method for the identification and prediction of the 2 major genotypes of LQTS.

Latent Causes of Sudden Cardiac Arrest.

Inherited arrhythmia syndromes are a common cause of apparently unexplained cardiac arrest or sudden cardiac death. These include long QT syndrome and Brugada syndrome, with a well-recognized phenotype in most patients with sufficiently severe disease to lead to cardiac arrest. Less common and typically less apparent conditions that may not be readily evident include catecholaminergic polymorphic ventricular tachycardia, short QT syndrome and early repolarization syndrome. In cardiac arrest patients whose extensive testing does not reveal an underlying etiology, a diagnosis of idiopathic ventricular fibrillation or short-coupled ventricular fibrillation is assigned. This review summarizes our current understanding of the less common inherited arrhythmia syndromes and provides clinicians with a practical approach to diagnosis and management.

Congenital Long QT Syndrome.

Congenital long QT syndrome (LQTS) encompasses a group of heritable conditions that are associated with cardiac repolarization dysfunction. Since its initial description in 1957, our understanding of LQTS has increased dramatically. The prevalence of LQTS is estimated to be ∼1:2,000, with a slight female predominance. The diagnosis of LQTS is based on clinical, electrocardiogram, and genetic factors. Risk stratification of patients with LQTS aims to identify those who are at increased risk of cardiac arrest or sudden cardiac death. Factors including age, sex, QTc interval, and genetic background all contribute to current risk stratification paradigms. The management of LQTS involves conservative measures such as the avoidance of QT-prolonging drugs, pharmacologic measures with nonselective ß-blockers, and interventional approaches such as device therapy or left cardiac sympathetic denervation. In general, most forms of exercise are considered safe in adequately treated patients, and implantable cardioverter-defibrillator therapy is reserved for those at the highest risk. This review summarizes our current understanding of LQTS and provides clinicians with a practical approach to diagnosis and management.

Arrhythmogenic Right Ventricular Cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) encompasses a group of conditions characterized by right ventricular fibrofatty infiltration, with a predominant arrhythmic presentation. First described in the late 1970s and early 1980s, it is now frequently recognized to have biventricular involvement. The prevalence is ∼1:2,000 to 1:5,000, depending on geographic location, and it has a slight male predominance. The diagnosis of ARVC is determined on the basis of fulfillment of task force criteria incorporating electrophysiological parameters, cardiac imaging findings, genetic factors, and histopathologic features. Risk stratification of patients with ARVC aims to identify those who are at increased risk of sudden cardiac death or sustained ventricular tachycardia. Factors including age, sex, electrophysiological features, and cardiac imaging investigations all contribute to risk stratification. The current management of ARVC includes exercise restriction, ß-blocker therapy, consideration for implantable cardioverter-defibrillator insertion, and catheter ablation. This review summarizes our current understanding of ARVC and provides clinicians with a practical approach to diagnosis and management.

Brugada Syndrome.

Brugada syndrome (BrS) is an "inherited" condition characterized by predisposition to syncope and cardiac arrest, predominantly during sleep. The prevalence is ∼1:2,000, and is more commonly diagnosed in young to middle-aged males, although patient sex does not appear to impact prognosis. Despite the perception of BrS being an inherited arrhythmia syndrome, most cases are not associated with a single causative gene variant. Electrocardiogram (ECG) findings support variable extent of depolarization and repolarization changes, with coved ST-segment elevation ≥2 mm and a negative T-wave in the right precordial leads. These ECG changes are often intermittent, and may be provoked by fever or sodium channel blocker challenge. Growing evidence from cardiac imaging, epicardial ablation, and pathology studies suggests the presence of an epicardial arrhythmic substrate within the right ventricular outflow tract. Risk stratification aims to identify those who are at increased risk of sudden cardiac death, with well-established factors being the presence of spontaneous ECG changes and a history of cardiac arrest or cardiogenic syncope. Current management involves conservative measures in asymptomatic patients, including fever management and drug avoidance. Symptomatic patients typically undergo implantable cardioverter defibrillator insertion, with quinidine and epicardial ablation used for patients with recurrent arrhythmia. This review summarizes our current understanding of BrS and provides clinicians with a practical approach to diagnosis and management.

Epidemiology of cardiac implantable electronic device infections: incidence and risk factors.

Cardiac implantable electronic device (CIED) infection is a potentially devastating complication of CIED procedures, causing significant morbidity and mortality for patients. Of all CIED complications, infection has the greatest impact on mortality, requirement for re-intervention and additional hospital treatment days. Based on large prospective studies, the infection rate at 12-months after a CIED procedure is approximately 1%. The risk of CIED infection may be related to several factors which should be considered with regards to risk minimization. These include technical factors, patient factors, and periprocedural factors. Technical factors include the number of leads and size of generator, the absolute number of interventions which have been performed for the patient, and the operative approach. Patient factors include various non-modifiable underlying comorbidities and potentially modifiable transient conditions. Procedural factors include both peri-operative and post-operative factors. The contemporary PADIT score, derived from a large cohort of CIED patients, is useful for the prediction of infection risk. In this review, we summarize the key information regarding epidemiology, incidence and risk factors for CIED infection.

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.

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.

Prediction of Perioperative Cardiovascular Events in Liver Transplantation.

BACKGROUND: Hepatorenal syndrome (HRS) is a serious complication of liver cirrhosis with poor survival in the absence of liver transplantation (LT). HRS represents a state of profound circulatory and cardiac dysfunction. Whether it increases risk of perioperative major adverse cardiovascular events (MACE) following LT remains unclear. METHODS: We performed a retrospective cohort study of 560 consecutive patients undergoing cardiac workup for LT of whom 319 proceeded to LT. All patients underwent standardized assessment including dobutamine stress echocardiography. HRS was defined according to International Club of Ascites criteria. RESULTS: Primary outcome of 30-day MACE occurred in 74 (23.2%) patients. A significantly higher proportion of patients with HRS experienced MACE (31 [41.9%] versus 54 [22.0%]; P = 0.001). After adjusting for age, model for end-stage liver disease score, cardiovascular risk index, history of coronary artery disease, and a positive stress test, HRS remained an independent predictor for MACE (odds ratio [OR], 2.44; 95% confidence interval [CI], 1.13-5.78). Other independent predictors included poor functional status (OR, 3.38; 95% CI, 1.41-8.13), pulmonary hypertension (OR, 3.26; 95% CI, 1.17-5.56), and beta-blocker use (OR, 2.56; 95% CI, 1.10-6.48). Occurrence of perioperative MACE was associated with a trend toward poor age-adjusted survival over 3.6-year follow-up (hazard ratio, 2.0; 95% CI, 0.98-4.10; P = 0.057). CONCLUSIONS: HRS, beta-blocker use, pulmonary hypertension, and poor functional status were all associated with over a 2-fold higher risk of MACE following LT. Whether inclusion of these variables in routine preoperative assessment can facilitate cardiac risk stratification warrants further study.

Effect of QT interval prolongation on cardiac arrest following liver transplantation and derivation of a risk index.

Liver transplantation (LT) has a 4-fold higher risk of periprocedural cardiac arrest and ventricular arrhythmias (CA/VAs) compared with other noncardiac surgeries. Prolongation of the corrected QT interval (QTc) is common in patients with liver cirrhosis. Whether it is associated with an increased risk of CA/VAs following LT is unclear. Rates of 30-day CA/VAs post-LT were assessed in consecutive adults undergoing LT between 2010 and 2017. Pretransplant QTc was measured by a cardiologist blinded to clinical outcomes. Among 408 patients included, CA/VAs occurred in 26 patients (6.4%). QTc was significantly longer in CA/VA patients (475 ± 34 vs 450 ± 34 ms, P < .001). Optimal QTc cut-off for prediction of CA/VAs was ≥480 ms. After adjustment, QTc ≥480 ms remained the strongest predictor for the occurrence of CA/VAs (odds ratio [OR] 5.2, 95% confidence interval [CI] 2.2-12.6). A point-based cardiac arrest risk index (CARI) was derived with the bootstrap method for yielding optimism-corrected coefficients (2 points: QTc ≥480, 1 point: Model for End-Stage Liver Disease [MELD] ≥30, 1 point: age ≥65, and 1 point: male). CARI score ≥3 demonstrated moderate discrimination (c-statistic 0.79, optimism-corrected c-statistic 0.77) with appropriate calibration. QTc ≥480 ms was associated with a 5-fold increase in the risk of CA/VAs. The CARI score may identify patients at higher risk of these events. Whether heightened perioperative cardiac surveillance, avoidance of QT prolonging medications, or beta blockers could mitigate the risk of CA/VAs in this population merits further study.

Sudden cardiac death following liver transplantation: Incidence, trends and risk predictors.

BACKGROUND: Cardiovascular events are a leading cause of mortality following liver transplantation (LT). Although a preponderance of sudden cardiac death (SCD) in this population has been reported, there is a paucity of data evaluating the incidence, timing and predictors of SCD following LT. METHODS: Using the prospectively collected Australian and New Zealand Liver Transplant Registry, a cohort study of all adult LTs from 1985 to 2017 was performed to ascertain the incidence and predictors of SCD. Recipient cause of death was adjudicated by an interdisciplinary panel. RESULTS: 4265 LT patients were followed-up for 37,409 person-years. SCD was the leading mode of cardiovascular death with an incidence rate of 165 per 100,000 person-years. There was a significant increase in the hazard of SCD in the contemporary (1996-2017) vs early era (1985-1995) (hazard ratio [HR] 2.42, 95%CI 1.10-5.40; p = 0.02). On Cox regression after adjusting for significant univariate predictors including age, coronary artery disease and non-alcoholic steatohepatitis, pre-transplant diabetes was the only independent predictor of SCD (HR 2.5 95%CI 1.1-6.0). CONCLUSION: SCD is the leading mode of cardiovascular cause-specific mortality following LT and diabetes was associated with a two-fold higher risk for its occurrence. Given the escalating cardiovascular risk factor profile of LT candidates, targeted therapies especially in patients with diabetes are needed to mitigate risk of post-transplant SCD.

Effect of liver transplantation on QT-interval prolongation and impact on mortality.

BACKGROUND: QT-interval prolongation is considered the electrophysiological hallmark of cirrhotic cardiomyopathy. However, the significance of QT-interval prolongation and how it is affected by liver transplantation (LT) remains unclear. METHODS: Consecutive inpatients undergoing LT between 2010 and 2017 at a state-wide liver transplant center in Australia were included. Preoperative, early postoperative and long-term follow-up corrected QT-intervals (QTc) were manually measured by a cardiologist. QTc was calculated using the Bazett formula and QTc ≥440 milliseconds (ms) was considered prolonged. RESULTS: Overall, 1111 ECG tracings among 408 patients (mean age 57 ± 12 years) were assessed. Pre-LT, 265 patients (65.0%) had QTc ≥440 ms and 24 patients (5.9%) had QTc ≥500 ms. In the early postoperative period, there was a significant increase in QTc compared to pre-LT (471 ± 39 vs. 452 ± 31 ms, p < 0.001) and 80 patients (20.3%) had QTc ≥500 ms. At a median of six months post-LT, there was significant reduction in mean QTc compared to pre-LT (430 ± 32 vs. 452 ± 31 ms; p < 0.001) with the QTc shortening in 73% of patients. QT-interval prolongation was not associated with postoperative complications or mortality at any time-point. CONCLUSION: QT-interval prolongation is common in patients with liver cirrhosis and this metric normalized in the majority within six months post-LT. A significant increase in QTc was noted early post-LT, with over 20% demonstrating QTc ≥500 ms. QT-interval prolongation was not associated with post-transplant complications or mortality. Resolution of QT-interval prolongation suggests that this feature of cirrhotic cardiomyopathy may reverse post-transplantation.