Arrhythmia monitoring and outcome after myocardial infarction (BIO|GUARD-MI): a randomized trial.

Objectives: Cardiac arrhythmias predict poor outcome after myocardial infarction (MI). We studied if arrhythmia monitoring with an insertable cardiac monitor (ICM) can improve treatment and outcome. Design: BIO|GUARD-MI was a randomized, international open-label study with blinded outcome assessment. Setting: Tertiary care facilities monitored the arrhythmias, while the follow-up remained with primary care physicians. Participants: Patients after ST-elevation (STEMI) or non-ST-elevation MI with an ejection fraction >35% and a CHA2DS2-VASc score ≥4 (men) or ≥5 (women). Interventions: Patients were randomly assigned to receive or not receive an ICM in addition to standard post-MI treatment. Device-detected arrhythmias triggered immediate guideline recommended therapy changes via remote monitoring. Main outcome measures: MACE, defined as a composite of cardiovascular death or acute unscheduled hospitalization for cardiovascular causes. Results: 790 patients (mean age 71 years, 72% male, 51% non-STEMI) of planned 1,400 pts were enrolled and followed for a median of 31.6 months. At 2 years, 39.4% of the device group and 6.7% of the control group had their therapy adapted for an arrhythmia [hazard ratio (HR) = 5.9, P < 0.0001]. Most frequent arrhythmias were atrial fibrillation, pauses and bradycardia. The use of an ICM did not improve outcome in the entire cohort (HR = 0.84, 95%-CI: 0.65-1.10; P = 0.21). In secondary analysis, a statistically significant interaction of the type of infarction suggests a benefit in the pre-specified non-STEMI subgroup. Risk factor analysis indicates that this may be connected to the higher incidence of MACE in patients with non-STEMI. Conclusions: The burden of asymptomatic but actionable arrhythmias is large in post-infarction patients. However, arrhythmia monitoring with an ICM did not improve outcome in the entire cohort. Post-hoc analysis suggests that it may be beneficial in non-STEMI patients or other high-risk subgroups. Clinical Trial Registration: [https://www.clinicaltrials.gov/ct2/show/NCT02341534], NCT02341534.

Association between Preeclampsia and Long-term Risk of Arrhythmias.

BACKGROUND: Preeclampsia (PE), a pregnancy-induced hypertensive disorder, affects 4-5% of pregnancies worldwide. It is well known that hypertension is associated with an increased risk of arrhythmias; however, data on the association between PE and arrhythmias are sparse. METHODS: In this observational cohort study, we identified all primiparous women who gave birth in Denmark (1997-2016) using Danish nationwide registries. The women were stratified on whether they developed PE during primiparous pregnancy, and followed from primiparous pregnancy to incident arrhythmia, emigration, death, or end of study (December 31, 2018). RESULTS: A total of 523,271 primiparous women with a median age of 28 years were included and 23,367 (4.5%) were diagnosed with PE. During a median follow-up of 10.1 years, women with vs without PE were associated with a higher incidence of arrhythmias (1.42% vs 1.02%): 1) Composite of cardiac arrest, ventricular tachycardia/fibrillation, or ICD implantation (adjusted HR 1.60 [95% CI 1.14-2.24]), 2) Composite of advanced 2nd degree or 3rd degree atrioventricular block, sinoatrial dysfunction, or pacemaker implantation (adjusted HR 1.48 [95% CI 0.97-2.23]), 3) Composite of supraventricular tachyarrhythmias or extra systoles (adjusted HR 1.34 [95% CI 1.19-1.51]), 4) Composite of all the above-mentioned arrhythmias (adjusted HR 1.37 [95% CI 1.23-1.54]). CONCLUSION: Preeclamptic women were associated with a significantly and at hitherto unknown long-term increased rate of arrhythmias. This finding suggests that women with PE may benefit from cardiovascular risk assessment, screening, and preventive education.

This study examined whether preeclampsia, a condition that can occur during pregnancy and cause high blood-pressure, was linked to heart rhythm problems in first-time mothers. Women who had preeclampsia in their first pregnancy were more likely to develop heart rhythm problems later in life.This suggests that women with a history of preeclampsia might need extra attention to prevent future problems.

Asymptomatic children with ventricular pre-excitation/WPW pattern.

Paediatric patients with ventricular pre-excitation/asymptomatic WPW syndrome have a higher risk of atrial fibrillation degenerating into ventricular fibrillation and sudden cardiac death (SCD). In more than half of these patients this can be the first symptom presenting. Hence, it is important to conduct a risk stratification for SCD in asymptomatic patients with pre-excitation/delta wave in the ECGs. In this review, invasive risk stratification by electrophysiologic testing and ablation is recommended when possible. Catheter ablation is reported to have a high rate of success and low risk of complications.

ISE/ISHNE expert consensus statement on the ECG diagnosis of left ventricular hypertrophy: The change of the paradigm.

The ECG diagnosis of LVH is predominantly based on the QRS voltage criteria. The classical paradigm postulates that the increased left ventricular mass generates a stronger electrical field, increasing the leftward and posterior QRS forces, reflected in the augmented QRS amplitude. However, the low sensitivity of voltage criteria has been repeatedly documented. We discuss possible reasons for this shortcoming and proposal of a new paradigm. The theoretical background for voltage measured at the body surface is defined by the solid angle theorem, which relates the measured voltage to spatial and non-spatial determinants. The spatial determinants are represented by the extent of the activation front and the distance of the recording electrodes. The non-spatial determinants comprise electrical characteristics of the myocardium, which are comparatively neglected in the interpretation of the QRS patterns. Various clinical conditions are associated with LVH. These conditions produce considerable diversity of electrical properties alterations thereby modifying the resultant QRS patterns. The spectrum of QRS patterns observed in LVH patients is quite broad, including also left axis deviation, left anterior fascicular block, incomplete and complete left bundle branch blocks, Q waves, and fragmented QRS. Importantly, the QRS complex can be within normal limits. The new paradigm stresses the electrophysiological background in interpreting QRS changes, i.e., the effect of the non-spatial determinants. This postulates that the role of ECG is not to estimate LV size in LVH, but to understand and decode the underlying electrical processes, which are crucial in relation to cardiovascular risk assessment.

Pulmonary Valve Replacement in Tetralogy of Fallot: Procedural Volume and Durability of Bioprosthetic Pulmonary Valves.

BACKGROUND: Robust data on changes in pulmonary valve replacement (PVR) procedural volume and predictors of bioprosthetic pulmonary valve (BPV) durability in patients with tetralogy of Fallot (TOF) are scarce. OBJECTIVES: This study sought to assess temporal trends in PVR procedural volume and BPV durability in a nationwide, retrospective TOF cohort. METHODS: Data were obtained from patient records. Robust linear regression was used to assess temporal trends in PVR procedural volume. Piecewise exponential additive mixed models were used to estimate BPV durability, defined as the time from implantation to redo PVR with death as a competing risk, and to assess risk factors for reduced durability. RESULTS: In total, 546 PVR were performed in 384 patients from 1976 to 2021. The annual number of PVR increased from 0.4 to 6.0 per million population (P < 0.001). In the last decade, the transcatheter PVR volume increased by 20% annually (P < 0.001), whereas the surgical PVR volume did not change significantly. The median BPV durability was 17 years (Q1: 10-Q3: 10 years-not applicable). There was no significant difference in the durability of different BPV after adjustment for confounders. Age at PVR (HR: 0.78 per 10 years from <1 year; 95% CI: 0.63-0.96; P = 0.02) and true inner valve diameter (9-17 mm vs 18-22 mm HR: 0.40; 95% CI: 0.22-0.73; P = 0.003 and 18-22 mm vs 23-30 mm HR: 0.59; 95% CI: 0.25-1.39; P = 0.23) were associated with reduced BPV durability in multivariate models. CONCLUSIONS: The PVR procedural volume has increased over time, with a greater increment in transcatheter than surgical PVR during the last decade. Younger patient age at PVR and a smaller true inner valve diameter predicted reduced BPV durability.

Myocardial scarring and recurrence of ventricular arrhythmia in patients surviving an out-of-hospital cardiac arrest.

INTRODUCTION: Prediction of recurrent ventricular arrhythmia (VA) in survivors of an out-of-hospital cardiac arrest (OHCA) is important, but currently difficult. Risk of recurrence may be related to presence of myocardial scarring assessed with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Our study aims to characterize myocardial scarring as defined by LGE-CMR in survivors of a VA-OHCA and investigate its potential role in the risk of new VA events. METHODS: Between 2015 and 2022, a total of 230 VA-OHCA patients without ST-segment elevation myocardial infarction had CMR before implantable cardioverter-defibrillator implantation for secondary prevention at Copenhagen University Hospital, Rigshospitalet, and Hospital Clínic, University of Barcelona, of which n = 170 patients had a conventional (no LGE protocol) CMR and n = 60 patients had LGE-CMR (including LGE protocol). Scar tissue including core, border zone (BZ) and BZ channels were automatically detected by specialized investigational software in patients with LGE-CMR. The primary endpoint was recurrent VA. RESULTS: After exclusion, n = 52 VA-OHCA patients with LGE-CMR and a mean left ventricular ejection fraction of 49 ± 16% were included, of which 18 (32%) patients reached the primary endpoint of VA. Patients with recurrent VA in exhibited greater scar mass, core mass, BZ mass, and presence of BZ channels compared with patients without recurrent VA. The presence of BZ channels identified patients with recurrent VA with 67% sensitivity and 85% specificity (area under the ROC curve (AUC) 0.76; 95% CI: 0.63-0.89; p < .001) and was the strongest predictor of the primary endpoint. CONCLUSIONS: The presence of BZ channels was the strongest predictor of recurrent VA in patients with an out of-hospital cardiac arrest and LGE-CMR.

ISE/ISHNE Expert Consensus Statement on ECG Diagnosis of Left Ventricular Hypertrophy: The Change of the Paradigm. The joint paper of the International Society of Electrocardiology and the International Society for Holter Monitoring and Noninvasive Electrocardiology.

The ECG diagnosis of LVH is predominantly based on the QRS voltage criteria, i.e. the increased QRS complex amplitude in defined leads. The classical ECG diagnostic paradigm postulates that the increased left ventricular mass generates a stronger electrical field, increasing the leftward and posterior QRS forces. These increased forces are reflected in the augmented QRS amplitude in the corresponding leads. However, the clinical observations document increased QRS amplitude only in the minority of patients with LVH. The low sensitivity of voltage criteria has been repeatedly documented. We discuss possible reasons for this shortcoming and proposal of a new paradigm.

Global constructive work is associated with ventricular arrhythmias after cardiac resynchronization therapy.

AIMS: Non-invasive left ventricular (LV) pressure-strain loops provide a novel method for quantifying myocardial work by incorporating LV pressure in measurements of myocardial deformation. Early studies suggest that myocardial work parameters such as global constructive work (GCW) could be useful and reliable in arrhythmia prediction, particularly in patients undergoing cardiac resynchronization therapy (CRT). The aim of this study was to evaluate whether the magnitude of GCW was associated with the occurrence of ventricular arrhythmias in patients after CRT. METHODS AND RESULTS: Patients on guideline-recommended treatment with a CRT defibrillator (CRT-D) were evaluated by 2D speckle-tracking echocardiography including measurements of GCW at least 6 months after implantation. The primary outcome was a composite of appropriate defibrillator therapy and sustained ventricular arrhythmia under the monitor zone. A total of 162 patients [mean age 66 years (±10), 122 males (75%)] were included. Sixteen (10%) patients experienced the primary outcome during a median follow-up of 18 months (interquartile range: 12-25) after the performance of index echocardiography. Patients with a below-median GCW (<1473 mmHg%) had a hazard ratio (HR) for the outcome of 8.14 [95% confidence interval (CI): 1.83-36.08], P = 0.006 compared with patients above the median in a univariate model and remained an independent predictor after multivariate adjustment for the estimated glomerular filtration rate and QRS duration [HR 4.75 (95% CI: 1.01-22.28), P < 0.05]. CONCLUSION: In patients treated with CRT-D, a GCW below median level was associated with a five-fold increase in the risk of ventricular arrhythmias.

Treatment-induced increase in total body potassium in patients at high risk of ventricular arrhythmias; a randomized POTCAST substudy.

OBJECTIVE: Hypokalemia is associated with increased risk of arrhythmias and it is recommended to monitor plasma potassium (p-K) regularly in at-risk patients with cardiovascular diseases. It is poorly understood if administration of potassium supplements and mineralocorticoid receptor antagonists (MRA) aimed at increasing p-K also increases intracellular potassium. METHODS: Adults aged≥18 years with an implantable cardioverter defibrillator (ICD) were randomized (1:1) to a control group or to an intervention that included guidance on potassium rich diets, potassium supplements, and MRA to increase p-K to target levels of 4.5-5.0 mmol/l for six months. Total-body-potassium (TBK) was measured by a Whole-Body-Counter along with p-K at baseline, after six weeks, and after six months. RESULTS: Fourteen patients (mean age: 59 years (standard deviation 14), 79% men) were included. Mean p-K was 3.8 mmol/l (0.2), and mean TBK was 1.50 g/kg (0.20) at baseline. After six-weeks, p-K had increased by 0.47 mmol/l (95%CI:0.14;0.81), p = 0.008 in the intervention group compared to controls, whereas no significant difference was found in TBK (44 mg/kg (-20;108), p = 0.17). After six-months, no significant difference was found in p-K as compared to baseline (0.16 mmol/l (-0.18;0.51), p = 0.36), but a significant increase in TBK of 82 mg/kg (16;148), p = 0.017 was found in the intervention group compared to controls. CONCLUSIONS: Increased potassium intake and MRAs increased TBK gradually and a significant increase was seen after six months. The differentially regulated p-K and TBK challenges current knowledge on potassium homeostasis and the time required before the full potential of p-K increasing treatment can be anticipated. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT03833089).

The effect of increased plasma potassium on myocardial function; a randomized POTCAST substudy.

Plasma potassium (p-K) in the high-normal range has been suggested to reduce risk of cardiovascular arrythmias and mortality through electrophysiological and mechanical effects on the myocardium. In this study, it was to investigated if increasing p-K to high-normal levels improves systolic- and diastolic myocardial function in patients with low-normal to moderately reduced left ventricular ejection fraction (LVEF). The study included 50 patients (mean age 58 years (SD 14), 81% men), with a mean p-K 3.95 mmol/l (SD 0.19), mean LVEF 48% (SD 7), and mean Global Longitudinal Strain (GLS) -14.6% (SD 3.1) patients with LVEF 35-55% from "Targeted potassium levels to decrease arrhythmia burden in high-risk patients with cardiovascular diseases trial" (POTCAST). Patients were given standard therapy and randomized (1:1) to an intervention that included guidance on potassium-rich diets, potassium supplements, and mineralocorticoid receptor antagonists targeting high-normal p-K levels (4.5-5.0 mmol/l). Echocardiography was done at baseline and after a mean follow-up of 44 days (SD 18) and the echocardiograms were analyzed for changes in GLS, mechanical dispersion, E/A, e', and E/e'. At follow-up, mean difference in changes in p-K was 0.52 mmol/l (95%CI 0.35;0.69), P<0.001 in the intervention group compared to controls. GLS was improved with a mean difference in changes of -1.0% (-2;-0.02), P<0.05 and e' and E/e' were improved with a mean difference in changes of 0.9 cm/s (0.02;1.7), P = 0.04 and ? 1.5 (-2.9;-0.14), P = 0.03, respectively. Thus, induced increase in p-K to the high-normal range improved indices of systolic and diastolic function in patients with low-normal to moderately reduced LVEF.

Severity of Brugada syndrome disease manifestation and risk of new-onset depression or anxiety: a Danish nationwide study.

AIMS: Reduced psychological health is associated with adverse patient outcomes and higher mortality. We aimed to examine if a Brugada syndrome (BrS) diagnosis and symptomatic disease presentation were associated with an increased risk of new-onset depression or anxiety and all-cause mortality. METHODS AND RESULTS: All Danish patients diagnosed with BrS (2006-2018) with no history of psychiatric disease and available for ≥6 months follow-up were identified using nationwide registries and followed for up to 5 years after diagnosis. The development of clinical depression or anxiety was evaluated using the prescription of medication and diagnosis codes. Factors associated with developing new-onset depression or anxiety were determined using a multivariate Cox proportional hazards regression model. Disease manifestation was categorized as symptomatic (aborted cardiac arrest, ventricular tachycardia, or syncope) or asymptomatic/unspecified at diagnosis. A total of 223 patients with BrS and no history of psychiatric disease were identified (72.6% male, median age at diagnosis 46 years, 45.3% symptomatic). Of these, 15.7% (35/223) developed new-onset depression or anxiety after BrS diagnosis (median follow-up 5.0 years). A greater proportion of symptomatic patients developed new-onset depression or anxiety compared with asymptomatic patients [21/101 (20.8%) and 14/122 (11.5%), respectively, P = 0.08]. Symptomatic disease presentation (HR 3.43, 1.46-8.05) and older age (lower vs. upper tertile: HR 4.41, 1.42-13.63) were significantly associated with new-onset depression or anxiety. All-cause mortality in this group of patients treated according to guidelines was low (n = 4, 1.8%); however, 3/4 developed depression or anxiety before death. CONCLUSION: Approximately, one-sixth of patients with BrS developed new-onset depression or anxiety following a diagnosis of BrS. Symptomatic BrS disease manifestation was significantly associated with new-onset depression or anxiety.

Reduced inferior wall longitudinal strain is associated with malignant arrhythmias in non-ischemic heart failure.

BACKGROUND: Reduced systolic myocardial function in the inferior region of the left ventricle has been suggested to be associated with malignant arrhythmias. We tested this hypothesis in patients with non-ischemic heart failure. METHODS: Patients with non-ischemic heart failure (left ventricular ejection fraction [LVEF] < 35%) were evaluated by 2D-speckle-tracking echocardiography. The regional longitudinal strain was calculated for each of the six left ventricular walls. The reduced regional function was defined as strain below the median. The outcome was a composite of sudden cardiac death, admission with sustained ventricular arrhythmia, resuscitated cardiac arrest, and appropriate therapy from a primary prophylactic implantable cardioverter defibrillator. Time-to-first-event analysis was performed using a Cox model. RESULTS: From two centers, 401 patients were included (median age: 63 years, 72% male) with a median LVEF of 25% (interquartile range [IQR] 20;30), and a median inferior wall strain of -9.0% (-12.5; -5.4). During a median follow-up of 4.0 years, 52 outcomes occurred. After multivariate adjustment for clinical and electrocardiographic parameters, inferior wall strain was independently associated with the outcome (HR 2.50 [1.35; 4.62], p = .003). No independent association was found between the composite outcome and reduced strain in any of the other left ventricular walls, Global Longitudinal Strain (HR 1.66 [0.93; 2.98], p = .09), or LVEF (HR 1.33 [0.75; 2.33], p = .33). CONCLUSIONS: Below median strain in the left ventricular inferior region was independently associated with a 2.5-fold increase in the risk of malignant arrhythmias and sudden cardiac death in patients with non-ischemic heart failure.

Use of Nonrecommended Drugs in Patients With Brugada Syndrome: A Danish Nationwide Cohort Study.

Background Patients with Brugada syndrome (BrS) are recommended to avoid drugs that may increase their risk of arrhythmic events. We examined treatment with such drugs in patients with BrS after their diagnosis. Methods and Results All Danish patients diagnosed with BrS (2006-2018) with >12 months of follow-up were identified from nationwide registries. Nonrecommended BrS drugs were grouped into drugs to "avoid" or "preferably avoid" according to http://www.brugadadrugs.org. Cox proportional hazards analyses were performed to identify factors associated with any nonrecommended BrS drug use, and logistic regression analyses were performed to examine associated risk of appropriate implantable cardioverter defibrillator therapy, mortality, and a combined end point indicating an arrhythmic event of delayed implantable cardioverter defibrillator implantation, appropriate implantable cardioverter defibrillator therapy, and mortality. During a median follow-up of 6.8 years, 93/270 (34.4%) patients with BrS (70.4% male, median age at diagnosis 46.1 years [interquartile range, 32.6-57.4]) were treated with ≥1 nonrecommended BrS drugs. No difference in any nonrecommended BrS drug use was identified comparing time before BrS diagnosis (12.6%) with each of the 5 years following BrS diagnosis (P>0.05). Factors associated with any nonrecommended BrS drug use after diagnosis were female sex (hazard ratio [HR]) 1.83 [95% CI, 1.15-2.90]), psychiatric disease (HR, 3.63 [1.89-6.99]), and prior use of any nonrecommended BrS drug (HR, 4.76 [2.45-9.25]). No significant association between any nonrecommended BrS drug use and implantable cardioverter defibrillator therapy (n=20/97, odds ratio [OR], 0.7 [0.2-2.4]), mortality (n=10/270, OR, 3.4 [0.7-19.6]), or the combined end point (n=38/270, OR, 1.7 [0.8-3.7]) was identified. Conclusions One in 3 patients with BrS were treated with a nonrecommended BrS drug after BrS diagnosis, and a BrS diagnosis did not change prescription patterns. More awareness of nonrecommended drug use among patients with BrS is needed.

Temporal changes in the surgical management of patients with tetralogy of Fallot in Denmark: a nationwide cohort study.

OBJECTIVES: To assess temporal changes in the surgical management of patients with tetralogy of Fallot including the timing of interventions, surgical techniques, reinterventions and survival in a nationwide cohort. METHODS: Patients with tetralogy of Fallot in Denmark were divided into 3 eras based on their year of birth: early (1977-1991), intermediate (1992-2006) and late (2007-2021). RESULTS: The cohort consisted of 745 patients. Median follow-up was 21.2 years (13.7-30.5). There was a temporal trend towards less shunt palliation (-0.3% per year, 95% CI -0.05 to -0.1). Median age at intracardiac repair was 2.9 years (1.8-5.0), 0.8 years (0.5-1.3) and 0.5 years (0.4-0.7) (P < 0.001) in the early, intermediate and late era, respectively. There was a temporal trend towards less valve-sparing repair (-0.7% per year, 95% CI -0.5 to -1.0) and more repair with transannular patches (0.7% per year, 95% CI 0.5-1.0). Survival at 10 years was 79% (64-76), 90% (87-93) and 95% (92-98) (P < 0.001) and pulmonary valve replacement within the first 10 years after intracardiac repair was performed in 3% (1-6), 12% (8-16) and 21% (13-29) (P < 0.001) in the early, intermediate and late era, respectively. CONCLUSIONS: There was a temporal trend towards less shunt palliation and intracardiac repair at a younger age with more use of transannular patches. While survival throughout childhood and adolescence has improved, more patients undergo pulmonary valve replacement during the first 10 years after intracardiac repair.

Incidence of thyroid dysfunction following initiation of amiodarone treatment in patients with and without heart failure: a nationwide cohort study.

AIMS: Thyroid dysfunction is considered the most frequent complication to amiodarone treatment, but data on its occurrence outside clinical trials are sparse. The present study aimed to examine the incidence of thyroid dysfunction following initiation of amiodarone treatment in a nationwide cohort of patients with and without heart failure (HF). METHODS AND RESULTS: In Danish registries, we identified all patients with first-time amiodarone treatment during the period 2000-18, without prior thyroid disease or medication. The primary outcome was a composite of thyroid diagnoses and initiation of thyroid drugs. Outcomes were assessed at 1-year follow-up, and for patients free of events in the first year, in a landmark analysis for the subsequent 5 years. We included 43 724 patients with first-time amiodarone treatment, of whom 16 939 (38%) had HF. At 1-year follow-up, the cumulative incidence and adjusted hazard ratio (HR) of the primary outcome were 5.3% and 1.37 (95% confidence interval 1.25-1.50) in patients with a history of HF and 4.2% in those without HF (reference). In the 1-year landmark analysis, the subsequent 5-year cumulative incidences and adjusted HRs of the primary outcome were 5.3% (reference) in patients with 1-year accumulated dose <27.38 g [corresponding to average daily dose (ADD <75 mg)], 14.0% and HR 2.74 (2.46-3.05) for 27.38-45.63 g (ADD 75-125 mg), 20.0% and HR 4.16 (3.77-4.59) for 45.64-63.88 g (ADD 126-175 mg), and 24.5% and HR 5.30 (4.82-5.90) for >63.88 g (ADD >175 mg). CONCLUSION: Among patients who initiated amiodarone treatment, around 5% had thyroid dysfunction at 1-year follow-up, with a slightly higher incidence in those with HF. A dose-response relationship was observed between the 1-year accumulated amiodarone dose and the subsequent 5-year cumulative incidence of thyroid dysfunction.

Scar border zone mass and presence of border zone channels assessed with cardiac magnetic resonance imaging are associated with ventricular arrhythmia in patients with ST-segment elevation myocardial infarction.

AIMS: Late gadolinium enhancement cardiac magnetic resonance (CMR) permits characterization of left ventricular ischaemic scars. We aimed to evaluate if scar core mass, border zone (BZ) mass, and BZ channels are risk markers for subsequent ventricular arrhythmia (VA) in ST-segment elevation myocardial infarction (STEMI). METHODS AND RESULTS: A sub-study of the DANish Acute Myocardial Infarction-3 multi-centre trial and Danegaptide phase II proof-of-concept clinical trial in which a total of 843 STEMI patients had a 3-month follow-up CMR. Of these, 21 patients subsequently experienced VA during 100 months of follow-up and were randomly matched 1:5 with 105 controls. A VA event was defined as: ventricular tachycardia, ventricular fibrillation, or sudden cardiac death. Ischaemic scar characteristics were automatically detected by specialized software. We included 126 patients with a median left ventricular ejection fraction of 51.0 ± 11.6% in cases with VA vs. 55.5 ± 8.5% in controls (P = 0.10). Cases had a larger mean BZ mass and more often BZ channels compared to controls [BZ mass: 17.2 ± 10.3 g vs. 10.3 ± 6.0 g; P = 0.0002; BZ channels: 17 (80%) vs. 44 (42%); P = 0.001]. A combination of ≥17.2 g BZ mass and the presence of BZ channels was five times more prevalent in cases vs. controls (P ≤ 0.00001) with an odds ratio of 9.40 (95% confidence interval 3.26-27.13; P ≤ 0.0001) for VA. This identified cases with 52% sensitivity and 90% specificity. CONCLUSION(S): Scar characterization with CMR indicates that a combination of ≥17.2 g BZ mass and the presence of BZ channels had the strongest association with subsequent VA in STEMI patients. CLINICALTRIALS.GOV: Unique identifier: NCT01435408 (DANAMI 3-iPOST and DANAMI 3-DEFER), NCT01960933 (DANAMI 3-PRIMULTI), and NCT01977755 (Danegaptide).

Long-term risk of new-onset arrhythmia in ST-segment elevation myocardial infarction according to revascularization status.

AIMS: Emerging data show that complete revascularization (CR) reduces cardiovascular death and recurrent myocardial infarction in ST-segment elevation myocardial infarction (STEMI). However, the influence of revascularization status on development of arrhythmia in the long-term post-STEMI phase is poorly described. We hypothesized that incomplete revascularization (ICR) compared with CR in STEMI is associated with an increased long-term risk of new-onset arrhythmia. METHODS AND RESULTS: Patients with STEMI treated with primary percutaneous coronary intervention (PPCI) at Copenhagen University Hospital, Rigshospitalet, Denmark, with CR or ICR were identified via the Eastern Danish Heart registry from 2009 to 2016. Using unique Danish administrative registries, the outcomes were assessed. The primary outcome was new-onset arrhythmia defined as a composite of atrial fibrillation/flutter (AF), sinoatrial block, advanced second- or third-degree atrioventricular block, ventricular tachycardia/fibrillation (VT), or cardiac arrest (CA), with presentation >7 days post-PPCI. Secondary outcomes were the components of the primary outcome and all-cause mortality. A total of 5103 patients (median age: 62.0 years; 76% men) were included, of whom 4009 (79%) and 1094 (21%) patients underwent CR and ICR, respectively. Compared with CR, ICR was associated with a higher risk of new-onset arrhythmia [hazard ratio (HR), 1.33; 95% confidence interval (CI), 1.07-1.66; P = 0.01], AF (HR, 1.29; 95% CI, 1.00-1.66; P = 0.05), a combined outcome of VT and CA (HR, 1.77; 95% CI, 1.10-2.84; P = 0.02) and all-cause mortality (HR, 1.27; 95% CI, 1.05-1.53; P = 0.01). All HRs adjusted. CONCLUSION: Among patients with STEMI, ICR was associated with an increased long-term risk of new-onset arrhythmia and all-cause mortality compared with CR.

Use of torsades de pointes risk drugs among patients with out-of-hospital cardiac arrest and likelihood of shockable rhythm and return of spontaneous circulation: A nationwide study.

AIM: Treatment with certain drugs can augment the risk of developing malignant arrhythmias (e.g. torsades de pointes [TdP]). Hence, we examined the overall TdP risk drug use before out-of-hospital cardiac arrest (OHCA) and possible association with shockable rhythm and return of spontaneous circulation (ROSC). METHODS: Patients ≥18 years with an OHCA of cardiac origin from the Danish Cardiac Arrest Registry (2001-2014) and TdP risk drug use according to www.CredibleMeds.org were identified. Factors associated with TdP risk drug use and secondly how use may affect shockable rhythm and ROSC were determined by multivariable logistic regression. RESULTS: We identified 27,481 patients with an OHCA of cardiac origin (median age: 72 years [interquartile range 62.0, 80.0 years]). A total of 37% were in treatment with TdP risk drugs 0-30 days before OHCA compared with 33% 61-90 days before OHCA (p < 0.001). Most commonly used TdP risk drugs were citalopram (36.1%) and roxithromycin (10.7%). Patients in TdP risk drug treatment were older (75 vs 70 years) and more comorbid compared with those not in treatment. Subsequently, TdP risk drug use was associated with less likelihood of the presenting rhythm being shockable (odds ratio [OR] = 0.63, 95% confidence interval [CI]:0.58-0.69) and ROSC (OR = 0.73, 95% CI:0.66-0.80). CONCLUSION: TdP risk drug use increased in the time leading up to OHCA and was associated with reduced likelihood of presenting with a shockable rhythm and ROSC in an all-comer OHCA setting. However, patients in TdP risk drug treatment were older and more comorbid than patients not in treatment.

Targeted potassium levels to decrease arrhythmia burden in high risk patients with cardiovascular diseases (POTCAST): Study protocol for a randomized controlled trial.

BACKGROUND: Low plasma potassium (p-K) is associated with increased risk of malignant arrhythmia and observational studies indicate protective effects of p-K in the upper reference level. However, randomized clinical studies are needed to document whether actively increasing p-K to high-normal levels is possible and safe and improves cardiovascular outcomes. OBJECTIVE: To investigate if increased p-K reduces the risk of malignant arrhythmia and all-cause death in high-risk patients with a cardiovascular disease treated with an implantable cardioverter defibrillator (ICD) for primary or secondary preventive causes. Secondly, to investigate whether high-normal p-K levels can be safely reached and maintained using already available medications and potassium-rich dietary guidance. METHODS: This is a prospective, randomized, and open-labelled study enrolling patient at high-risk of malignant arrhythmias. According to sample size calculations, 1,000 patients will be randomized 1:1 to either an investigational regiment that aims to increase and maintain p-K at high-normal levels (4.5-5.0 mmol/L) or to usual standard of care and followed for an expected four years. The trial will run until a total of 291 events have occurred providing an α = 0.05 and 1-ß = 0.80. The composite primary endpoint includes ventricular tachycardia >125 bpm lasting >30 seconds, any appropriate ICD-therapy, and all-cause mortality. At present, 739 patients have been randomized. CONCLUSIONS: We present the rationale for the design of the POTCAST trial. The inclusion was initiated 2019 and is expected to be finished 2022. The study will show if easily available treatments to increase p-K may be a new treatment modality to protect against malignant arrythmias.

Comparison of the Anterior Septal Line and Mitral Isthmus Line for Perimitral Atrial Flutter Ablation Using Robotic Magnetic Navigation.

BACKGROUND: Perimitral atrial flutter (PMAFL) is one of the most common macro-reentrant left atrial tachycardias. Mitral isthmus (MI) linear ablation is a common strategy for the treatment of PMAFLs, and anterior septum (AS) linear ablation has emerged as a novel ablation approach. We aimed at assessing the effectiveness of AS linear ablation using robotic magnetic navigation for PMAFL ablation. METHODS: In this retrospective study, a total of 36 consecutive patients presented with AFL as the unique arrhythmia or accompanied with atrial fibrillation (AF) who underwent catheter ablation were enrolled. Patients were classified into two groups according to the different ablation strategies, the MI line group (10 patients) and the AS line group (26 patients). RESULTS: The clinical baseline characteristics of patients in the two groups were nearly identical. There were no significant differences in procedure time (148.7 ± 46.1 vs. 123.2 ± 30.1 min, P=0.058) or radiofrequency ablation time (25.9 ± 11.4 vs. 23.5 ± 12.6 min) between the two groups. Fluoroscopy time was longer in the MI line group (8.0 ± 4.4 vs. 5.1 ± 2.7 min, P=0.024), and the acute success rate was higher in the AS line group versus the MI line group (96.2% vs. 70%, P=0.025). The long-term freedom from arrhythmia survival rate was higher in the AS line group (73%) than in the MI line group (40%) after a mean follow-up time of 37.4 months with a 3-month blanking period (P=0.049). CONCLUSIONS: AS linear ablation is an effective and safe strategy for PMAFL ablation using robotic magnetic navigation.