Impact of revascularization in patients with sustained ventricular arrhythmias, prior myocardial infarction, and preserved left ventricular ejection fraction

Ischemia testing and revascularization in patients with monomorphic ventricular tachycardia: A relic of the past?

Testing for myocardial ischemia in patients presenting with sustained monomorphic Ventricular Tachycardia(VT) even without evidence of acute myocardial infarction is a tempting strategy that is frequently utilized in clinical practice. Monomorphic VT is mainly caused by re-entry around chronic myocardial scar and active ischemia has no role in its pathogenesis, thus making testing for ischemia futile, at least in theory. This systematic literature review sought to address the usefulness of ischemia testing (mainly coronary angiography) in patients presenting with monomorphic VT through 8 selected studies after evaluating a total of 130 published manuscripts. Particularly, we sought to unveil whether coronary angiography and possibly concomitant revascularization leads to lesser tachycardia recurrence. Our conclusion can be summarized as follows: this approach whether combined with revascularization or not, does not seem to reduce VT recurrence nor does it affect mortality in such patients. Even though most of the published literature points at this direction, validation from randomized controlled trials is imperative.

Impact of de novo tachyarrhythmias in patients with prior acute coronary syndrome

Although the incidence of acute coronary syndrome (ACS) has increased over the decades, the overall prognosis has improved with newer stents, tailored medication, and better intervention techniques. Atrial fibrillation (AF) and ventricular arrhythmia at the time of ACS diagnosis are known indicators of a poor acute prognosis. However, there is a lack of data regarding the long-term arrhythmic impact of ventricular tachyarrhythmia (VA) on mortality in ACS patients. This study sought to elucidate the impact of tachyarrhythmia on mortality during long-term follow-up in patients with a history of ACS. This retrospective study was conducted in a single university hospital, and it evaluated the clinical outcomes, especially regarding cardiovascular mortality and readmission. The enrolled patients underwent percutaneous coronary intervention (PCI) for ACS between February 2004 and March 2018. Clinical information was attained by a thorough chart review. We retrospectively analyzed 560 ACS patients. We reviewed all electrocardiograms (ECGs) before and immediately after PCI, during hospitalization, and within 3 months of the index PCI. Three months after the index PCI procedure, any Holter monitoring or ECG was also reviewed for arrhythmia diagnosis. During follow-up, 91 patients were diagnosed with AF and 36 patients were diagnosed with VA. Overall mortality was related to the presence of anemia, low body mass index, low left ventricular ejection fraction after PCI, late-diagnosed AF, and any VA during follow-up. Readmission was higher in patients with chronic kidney disease and newly diagnosed AF during the follow-up. Diagnosis of late tachyarrhythmia during follow-up was associated with increased mortality in post-ACS patients.

Improved prediction of electrical storm in patients with prior myocardial infarction and implantable cardioverter defibrillator

AIMS

To evaluate predictors of electrical storm (ES), including chronic total occlusion in an infarct-related coronary artery (infarct-related artery CTO, IRACTO), in a cohort of patients with prior myocardial infarction (MI) and implantable cardioverter-defibrillators (ICD).

METHODS

Multicenter observational cohort study including 643 consecutive patients with prior MI and a first ICD implanted between 2005 and 2018 at three tertiary hospitals. All the patients included in the study had undergone a diagnostic coronary angiography before ICD implantation. The variable prior ventricular arrhythmias (VA+) was positive in patients with secondary prevention ICDs and in those with at least one appropriate ICD therapy after primary prevention implantation.

RESULTS

During a median follow-up of 42 months 59 patients (9%) suffered ES. The presence of at least one IRACTO not revascularized (IRACTO-NR) was associated with a significantly higher cumulative incidence of ES (14.5% vs 4.8%, p < 0.001). IRACTO-NR maintained a significant association with ES after adjustment for potential confounders (HR 2.3, p = 0.005) and was an independent predictor of ES together with VA+ and LVEF. The best cut-off of LVEF to predict ES was ≤38%. A risk-prediction model based on IRACTO-NR, VA+ and LVEF≤38% identified three categories of ES risk (low, intermediate and high), with progressively increasing cumulative incidence of ES (2.2%, 9% and 20%).

CONCLUSION

In a cohort of patients with prior MI and ICD, IRACTO-NR is an independent predictor of ES. A new risk-prediction model allowed the identification of three categories of risk, with potentially important clinical implications.

Electroanatomical Navigation to Minimize Contrast Medium or X-Rays During Stenting: Insights From an Experimental Model

•

Contrast media and x-rays used in vascular interventional procedures have been linked to health hazards for patients and medical teams.

•

Modified OCT and angioplasty catheters were successful navigated in coronary and carotid arteries using an impedance-sensitive navigation system and used to precisely deliver and implant stents in specified arterial targets without the need for x-ray or contrast medium. Our system achieved an accuracy of 90% and a precision of 1.4mm.

•

This proof-of-principle experiment opens the door to PCI with no contrast medium or X-ray in human through the integration of coronary CT scan and intracoronary imaging technologies within navigation systems.

Stents can be effectively implemented with no x-rays or contrast medium. Modified stents were successfully implanted in 9 of 11 attempted targets (82%) (7 carotid and 4 coronary arteries) using an impedance-sensitive navigation system and optical coherence tomography. Electroanatomical navigation systems can be used to assist interventionalists in performing arterial stenting while minimizing x-ray and contrast use, thereby potentially enhancing safety for both patients and catheterization laboratory staff members.

2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC). With the special contribution of the Heart Failure Association (HFA) of the ESC

Document Reviewers: Rudolf A. de Boer (CPG Review Coordinator) (Netherlands), P. Christian Schulze (CPG Review Coordinator) (Germany), Magdy Abdelhamid (Egypt), Victor Aboyans (France), Stamatis Adamopoulos (Greece), Stefan D. Anker (Germany), Elena Arbelo (Spain), Riccardo Asteggiano (Italy), Johann Bauersachs (Germany), Antoni Bayes-Genis (Spain), Michael A. Borger (Germany), Werner Budts (Belgium), Maja Cikes (Croatia), Kevin Damman (Netherlands), Victoria Delgado (Netherlands), Paul Dendale (Belgium), Polychronis Dilaveris (Greece), Heinz Drexel (Austria), Justin Ezekowitz (Canada), Volkmar Falk (Germany), Laurent Fauchier (France), Gerasimos Filippatos (Greece), Alan Fraser (United Kingdom), Norbert Frey (Germany), Chris P. Gale (United Kingdom), Finn Gustafsson (Denmark), Julie Harris (United Kingdom), Bernard Iung (France), Stefan Janssens (Belgium), Mariell Jessup (United States of America), Aleksandra Konradi (Russia), Dipak Kotecha (United Kingdom), Ekaterini Lambrinou (Cyprus), Patrizio Lancellotti (Belgium), Ulf Landmesser (Germany), Christophe Leclercq (France), Basil S. Lewis (Israel), Francisco Leyva (United Kingdom), AleVs Linhart (Czech Republic), Maja-Lisa Løchen (Norway), Lars H. Lund (Sweden), Donna Mancini (United States of America), Josep Masip (Spain), Davor Milicic (Croatia), Christian Mueller (Switzerland), Holger Nef (Germany), Jens-Cosedis Nielsen (Denmark), Lis Neubeck (United Kingdom), Michel Noutsias (Germany), Steffen E. Petersen (United Kingdom), Anna Sonia Petronio (Italy), Piotr Ponikowski (Poland), Eva Prescott (Denmark), Amina Rakisheva (Kazakhstan), Dimitrios J. Richter (Greece), Evgeny Schlyakhto (Russia), Petar Seferovic (Serbia), Michele Senni (Italy), Marta Sitges (Spain), Miguel Sousa-Uva (Portugal), Carlo G. Tocchetti (Italy), Rhian M. Touyz (United Kingdom), Carsten Tschoepe (Germany), Johannes Waltenberger (Germany/Switzerland) All experts involved in the development of these guidelines have submitted declarations of interest. These have been compiled in a report and published in a supplementary document simultaneously to the guidelines. The report is also available on the ESC website www.escardio.org/guidelines For the Supplementary Data which include background information and detailed discussion of the data that have provided the basis for the guidelines see European Heart Journal online.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered. Structure: Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Coronary revascularisation in patients with ischaemic cardiomyopathy

Heart failure resulting from ischaemic heart disease is associated with a poor prognosis despite optimal medical treatment. Despite this, patients with ischaemic cardiomyopathy have been largely excluded from randomised trials of revascularisation in stable coronary artery disease. Revascularisation has multiple potential mechanisms of benefit, including the reversal of myocardial hibernation, suppression of ventricular arrhythmias and prevention of spontaneous myocardial infarction. Coronary artery bypass grafting is considered the first-line mode of revascularisation in these patients; however, evidence from the Surgical Treatment of Ischaemic Heart Failure (STICH) trial showed a reduction in mortality, though this only became apparent with extended follow-up due to an excess of early adverse events in the surgical arm. There is currently no randomised controlled trial evidence for percutaneous coronary intervention in patients with ischaemic cardiomyopathy; however, the REVIVED-BCIS2 trial has recently completed recruitment and will address this gap in the evidence. Future directions include (1) clinical trials of revascularisation in patients hospitalised with heart failure, (2) defining the role of viability and ischaemia testing in heart failure, (3) studies to enhance the understanding of the mechanistic effects of revascularisation and (4) generating models to refine pre- and post-revascularisation risk prediction.

Impact of revascularization in patients with post-infarction left ventricular aneurysm and ventricular tachyarrhythmia

Background

Ventricular arrhythmia is a leading cause of cardiac death among patients with post‐infarction left ventricular aneurysm (PI‐LVA). The effect of coronary revascularization in PI‐LVA patients with ventricular tachyarrhythmia remains unknown. This study aims to investigate the impact of revascularization therapy on clinical outcomes in these patients.

Methods

A total of 238 PI‐LVA patients were enrolled, and 59 patients were presented with sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Patients were classified into 4 groups by treatment strategies (medical or revascularization) and the presence of VT/VF: group 1 (n = 57): VT/VF− and revascularization−; group 2 (n = 122): VT/VF− and revascularization+; group 3 (n = 34): VT/VF+ and revascularization+; and group 4 (n = 25): VT/VF+ and revascularization‐. The clinical outcomes were compared, and the primary endpoint was cardiac death or heart transplantation.

Results

Patients were followed up for 45 ± 16 months, and 41 patients (17.2%) reached the primary endpoint. Kaplan–Meier analysis showed that in VT/VF− patients, revascularization associated with higher cardiac survival compared with medical therapy (log‐rank p = .002), but in VT/VF+ patients, revascularization did not predict better cardiac outcome (log‐rank p = .901). Cox regression analysis revealed PET‐EF (HR 4.41, 95% CI: 1.72–11.36, p = .002) and moderate/severe mitral regurgitation (HR 2.32, 95% CI: 1.02–5.30, p = .046) as independent predictors of adverse cardiac outcome in patients with VT/VF.

Conclusion

PI‐LVA patients with VT/VF are at high risk of adverse cardiac outcome, and coronary revascularization does not mitigate this risk, although revascularization was associated with higher cardiac survival in PI‐LVA patients without VT/VF.

Cardiac arrhythmias in the emergency settings of acute coronary syndrome and revascularization: an European Heart Rhythm Association (EHRA) consensus document, endorsed by the European Association of Percutaneous Cardiovascular Interventions (EAPCI), and European Acute Cardiovascular Care Association (ACCA)

Despite major therapeutic advances over the last decades, complex supraventricular and ventricular arrhythmias (VAs), particularly in the emergency setting or during revascularization for acute myocardial infarction (AMI), remain an important clinical problem. Although the incidence of VAs has declined in the hospital phase of acute coronary syndromes (ACS), mainly due to prompt revascularization and optimal medical therapy, still up to 6% patients with ACS develop ventricular tachycardia and/or ventricular fibrillation within the first hours of ACS symptoms. Despite sustained VAs being perceived predictors of worse in-hospital outcomes, specific associations between the type of VAs, arrhythmia timing, applied treatment strategies and long-term prognosis in AMI are vague. Atrial fibrillation (AF) is the most common supraventricular tachyarrhythmia that may be asymptomatic and/or may be associated with rapid haemodynamic deterioration requiring immediate treatment. It is estimated that over 20% AMI patients may have a history of AF, whereas the new-onset arrhythmia may occur in 5% patients with ST elevation myocardial infarction. Importantly, patients who were treated with primary percutaneous coronary intervention for AMI and developed AF have higher rates of adverse events and mortality compared with subjects free of arrhythmia. The scope of this position document is to cover the clinical implications and pharmacological/non-pharmacological management of arrhythmias in emergency presentations and during revascularization. Current evidence for clinical relevance of specific types of VAs complicating AMI in relation to arrhythmia timing has been discussed.

The effect of revascularization on mortality and risk of ventricular arrhythmia in patients with ischemic cardiomyopathy

Background

There is clear evidence that patients with prior myocardial infarction and a reduced ejection fraction benefit from implantation of a cardioverter-defibrillator (ICD). It is unclear whether this benefit is altered by whether or not revascularization is performed prior to ICD implantation.

Methods

This was a retrospective cohort study following patients who underwent ICD implantation from 2002 to 2014. Patients with ischemic cardiomyopathy and either primary or secondary prevention ICDs were selected for inclusion. Using the electronic medical record, cardiac catheterization data, revascularization status (percutaneous coronary intervention or coronary bypass surgery) were recorded. The outcomes were mortality and ventricular arrhythmia.

Results

There were 606 patients included in the analysis. The mean age was 66.3 ± 10.1 years, 11.9% were women, and the mean LVEF was 30.5 ± 12.0, 58.9% had a primary indication for ICD, 82.0% of the cohort had undergone coronary catheterization prior to ICD implantation. In the overall cohort, there were fewer mortality and ventricular arrhythmia events in patients who had undergone prior revascularization. In patients who had an ICD for secondary prevention, revascularization was associated with a decrease in mortality (HR 0.46, 95% CI (0.24, 0.85) p = 0.015), and a trend towards fewer ventricular arrhythmia (HR 0.62, 95% CI (0.38, 1.00) p = 0.051). There was no association between death or ventricular arrhythmia with revascularization in patients with primary prevention ICDs.

Conclusion

Revascularization may be beneficial in preventing recurrent ventricular arrhythmia, and should be considered as adjunctive therapy to ICD implantation to improve cardiovascular outcomes.

Factors associated with recurrent postinfarction ventricular tachycardia following ablation

INTRODUCTION

Ablation of ventricular tachycardia is the main therapy for patients with drug-refractory ventricular tachycardia (VT). Although evidence suggests that VT ablation could lower the incidence of recurrent VT, many cases still develop VT in follow-up. In this study, we performed a systematic review and meta-analysis to examine risk factors for recurrent VT in patients with postinfarction VT who underwent VT ablation.

EVIDENCE ACQUISITION

We comprehensively searched the databases of MEDLINE and EMBASE from inception to March 2020. Included studies were cohort studies, experimental trials, or randomized controlled trials that evaluate the risk of recurrent VT in postinfarction VT patients who underwent VT ablation. Data from each study were combined using random-effects.

EVIDENCE SYNTHESIS

Thirteen studies involving 1803 postinfarction patients who underwent VT ablation were included. Inducibility after the procedure (pooled HR=1.71, P<0.001), lower baseline left ventricular ejection fraction (LVEF) (pooled HR=0.98, P<0.001) and higher baseline New York Heart Association (NYHA) classification (pooled HR=1.34, P=0.003) were significantly associated with VT recurrence during the follow-up. There was no significant association between age, gender or diabetes mellitus and VT recurrence.

CONCLUSIONS

Our meta-analysis demonstrated that inducibility after the procedure, lower baseline LVEF and higher baseline NYHA classification were associated with an increased risk of VT recurrence in postinfarction VT patients who underwent VT ablation.

Acute management of ventricular tachycardia

Acute management of patients with ventricular arrhythmia (VA) is aimed at immediate VA termination if the patient is hemodynamically instable and early termination after initial diagnostic work-up if tolerated. Prolonged episodes of VA may lead to hemodynamic and metabolic decompensation and early resumption of normal ventricular activation is warranted. Termination is best performed by electrical cardioversion, anti-tachycardia pacing (if available, in cases with an implanted defibrillator [ICD]) or defibrillation. Antiarrhythmic drug treatment may lead to rhythm stabilization in cases of VA recurrence. Scrutinizing the electrocardiogram (ECG) of VA is extremely helpful to differentiate potential mechanisms, underlying cardiac pathologies and identify treatment options, as well as a differential diagnosis if a ventricular origin is unclear. In general, structural VA should be differentiated from idiopathic and non-structural (idiopathic) VA. On the other hand, based on ECG morphology VA should be classified into monomorphic versus polymorphic ventricular tacyhcardia (VT)/ventricular fibrillation (VF). Polymorphic VT/VF may be related to reversible causes as well as genetically determined arrhythmia syndromes and a specialized treatment pathway may be chosen: (1) VA termination, (2) evaluation and treatment of potential VA causes, (3) acute (medical treatment) and chronic (interventional treatment using catheter ablation) prevention of recurrence and (4) treatment of underlying heart disease, if identified, are crucial pillars of VA management. These patients can be managed in dedicated VT units and by multispecialty teams integrating all potential aspects of rhythm stabilization and treating underlying cardiac abnormalities. Heart failure management in patients with reduced left ventricular function may be crucial for the long-term prognosis.

Relationship of non-invasive quantification of myocardial blood flow to arrhythmic events in patients with implantable cardiac defibrillators

BACKGROUND

Ischemia contributes to arrhythmogenesis though its role is incompletely understood. Abnormal myocardial perfusion measured by PET imaging may predict ventricular arrhythmias (VAs) in a high-risk population.

METHODS

Patients with implantable cardiac defibrillators who had undergone rubidium-82 cardiac PET imaging were identified. Patients were stratified by median MBF and MFR values for analysis. The Cox proportional hazards model was used to assess the impact of myocardial perfusion on survival free of VT independent of critical covariates.

RESULTS

A total of 159 patients (124 (78%) males, median age 65.9 years, IQR [56.76-72.63]) were followed for 1.43 years IQR [0.83-2.21]. VA occurred in 29 patients (23.7%). After adjustment for ejection fraction, age, and sex, impaired stress MBF was associated with an increased risk of VA (adjusted HR per ml/min/g 1.52, 95% CI (1.01-2.31), P = 0.04). Summed rest and stress scores were not predictive of VA. Among patients with severe LV dysfunction, stress MBF remained an independent predictor of VA (adjusted HR per 1 ml/min/g HR 1.69, 95% CI (1.03-11.36), P = 0.03), while residual EF, summed rest, and summed stress scores were not (P > 0.05).

CONCLUSIONS

Impaired stress myocardial blood flow was associated with less survival free of ventricular arrhythmias.

Effect of coronary revascularization on long-term clinical outcomes in patients with ischemic cardiomyopathy and recurrent ventricular arrhythmia

BACKGROUND

Patients with ventricular tachycardia (VT) postmyocardial infarction (MI) are a higher risk group with significant morbidity and mortality. We examined the impact of prior coronary revascularization on clinical outcomes in patients with ischemic cardiomyopathy and VT.

METHODS

The VANISH trial randomized 259 patients with prior MI and antiarrhythmic drug-refractory VT to receive escalated medical therapy or catheter ablation. Clinical outcomes were compared according to whether patients have undergone prior revascularization procedures. The primary outcome was a composite of death, appropriate implantable cardiac defibrillator (ICD) shock, or VT storm. The secondary outcomes included elements of the primary outcome, hospitalization, and any ventricular arrhythmia.

RESULTS

190 patients (73%) had prior coronary revascularization. Revascularization group had more men (97% vs 83%; P  =  0.0003) and patients in that group were older (mean age 69.3 ± 7.6 vs 66.7 ± 9.2; P  =  0.04), had more renal insufficiency (22.6% vs 8.7%; P  =  0.01), and were more likely to have an implanted cardiac resynchronization device (23% vs 10%, P  =  0.03) as compared with the nonrevascularized patients. There were no significant differences in baseline medication use. There was a trend toward fewer hospitalizations in the revascularization group (64% vs 77%; P  =  0.07); there were no differences in the individual outcomes of mortality, VT storm, ICD shocks, recurrent MI, or cardiac failure.

CONCLUSIONS

In this cohort of patients with an ischemic cause for VT, a history of prior coronary revascularization was not associated with a reduction in ventricular arrhythmia or mortality.

Clinical and Echocardiographic Predictors of Arrhythmias Detected With 24-Hour Holter Electrocardiography Among Hypertensive Heart Failure Patients in Nigeria

Background

Hypertensive heart failure (HHF) is the commonest form of heart failure in Nigeria. There is paucity of data in Nigeria on 24-hour Holter electrocardiography (24-HHECG) and important predictors of arrhythmias among HHF patients.

Objectives

To determine the 24-HHECG characteristics among HHF patients. To determine the clinical and echocardiographic predictors of arrhythmias detected using 24-HHECG among HHF patients.

Methods

A total of 100 HHF patients as well as 50 age-matched and sex-matched apparently healthy controls were prospectively recruited over a period of 1 year. They all had baseline laboratory tests, echocardiography, and 24-HHECG.

Results

Hypertensive heart failure patients had significantly higher counts of premature ventricular contractions (PVCs) than the controls (P ≤ .001). Ventricular tachycardia (VT) was recorded in 29% of HHF patients as compared with controls who had no VT on 24-HHECG. The standard deviation of all normal to normal sinus RR intervals over 24 hours (SDNN) was abnormally reduced among HHF patients when compared with controls (P = .046). There was positive correlation between atrial fibrillation (AF) and the following parameters: PVCs (r = .229, P = .015), New York Heart Association (NYHA) (r = .196, P = .033), and VT (r = .223, P = .018). Following multiple linear regression, left ventricular ejection fraction (LVEF) (P ≤ .001) and serum urea (P = .037) were predictors of PVCs among HHF patients. Serum creatinine (P ≤ .001), elevated systolic blood pressure (SBP) (P = .005), and PVCs (P ≤ .001) were important predictors of VT among HHF patients.

Conclusions

Renal dysfunction and reduced LVEF were important predictors of ventricular arrhythmias. High counts of PVCs and elevated SBP were predictive of the occurrence of VT among HHF patients. The NYHA class and ventricular arrhythmias have a significant positive correlation with AF. The SDNN is reduced in HHF patients.

[Diagnosis of ischemia and revascularization in patients with ventricular tachyarrhythmia]

Sustained ventricular tachyarrhythmia usually occurs on the basis of structural heart disease, particularly coronary heart disease (CAD). Although monomorphic ventricular tachycardia (VT) appears mainly in patients with CAD, it is typically not triggered by acute ischemia, in contrast to polymorphic VT or ventricular fibrillation (VF). To judge if VT is caused by acute ischemia is even more difficult in context with an elevated highly sensitive troponin T which is generally elevated in sustained VT because tachycardia in chronic stable coronary artery sclerosis causes a mismatch between increased oxygen demand and limited oxygen supply. Therefore, acute coronary angiography and revascularization may frequently not be necessary in monomorphic VT, will usually not improve rhythm stabilization, and may lead to misinterpretation of monomorphic VT being caused by a coronary stenosis. This can lead to withholding antiarrhythmic therapy after revascularization since it is assumed that the cause of VT has been treated. On the other hand, acute coronary angiography and revascularization are useful in polymorphic VT/VF, ECG signs of ischemia, or typical chest pain before occurrence of VT/VF. Coronary angiography should also be performed in patients with VT with newly diagnosed reduced left ventricular function and before catheter ablation.

Allopurinol and the risk of ventricular arrhythmias in the elderly: a study using US Medicare data

BACKGROUND

There are no published human studies investigating whether the use of allopurinol, the most commonly used medication for the treatment of hyperuricemia in gout, the most common type of inflammatory arthritis in adults, has any beneficial effects on ventricular electrophysiology. The objective of our study was to assess whether allopurinol use is associated with a reduction in the risk of ventricular arrhythmias (VA).

METHODS

We used the 5% random sample of Medicare beneficiaries from 2006-2012 to examine new allopurinol use and the risk of incident VA. Multivariable Cox regression analyses were adjusted for demographics (age, race, sex), comorbidity, cardiac medications, and conditions associated with VA. We calculated hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Of the 28,755 episodes of new allopurinol use, 2538 were associated with incident VA (8.8%). Among patients with incident VA, 54% were male, 78% were White, 75% had gout as the underlying diagnosis, and the mean Charlson-Romano comorbidity score was 4.8. The crude incidence of VA per 1,000,000 person-days declined as the duration of allopurinol use increased: 1-180 days, 151; 181 days to 2 years, 105; and > 2 years, 85. In multivariable-adjusted analyses, compared to non-use, allopurinol use was associated with lower HR of VA of 0.82 (95% CI, 0.76-0.90). Compared to allopurinol non-use, longer allopurinol use durations were significantly associated with lower multivariable-adjusted HR for VA: 1-180 days, 0.96 (95% CI, 0.85-1.08); 181 days to 2 years, 0.76 (95% CI, 0.68-0.85); and > 2 years, 0.72 (95% CI, 0.60-0.87). Multiple sensitivity analyses adjusting for cardiac conditions, anti-arrhythmic drugs and alternate definitions confirmed our findings with minimal/no attenuation of estimates.

CONCLUSION

Allopurinol use and use duration of more than 6 months were independently associated with a lower risk of VA. Future studies need to assess the pathophysiology of this potential benefit.

Aneurysm-related ischemic ventricular tachycardia: safety and efficacy of catheter ablation

Left ventricular aneurysm (LVA) postmyocardial infarction (MI) might be an arrhythmogenic substrate. We examined the safety and efficacy of catheter ablation of LVA-related ventricular tachycardia (VT).Thirty-three consecutive patients who underwent primary catheter ablation of ischemic VT were divided into LVA group (11 patients, mean age 61.9 years, 10 men) and none LVA group. Acute procedural outcomes, complications, and long-term outcomes were assessed.In LVA group, average number of induced VTs were 3.2 ± 2.6 (range 1-7), clinical VTs were located in the ventricular septum scar zone in 4 (36.4%) patients, acute success was achieved in 7 (63.6%) patients, partial success in 3 (27.3%) and failure in 1 patient, while none LVA group showing a statistically similar distribution of acute procedural outcomes (P = 0.52). There were no major or life-threatening complications. VT-free survival rate at median 19 (1-44) months follow-up was numerically but not significantly lower in LVA versus none LVA group (48.5% vs 62.8%, log-rank P = 0.40).Catheter ablation of ischemic VT in the presence of LVA appears feasible and effective, with about one-third of cases having septal ablation targets. Further studies are warranted.