Prognostic impact of early ventricular fibrillation in patients with ST-elevation myocardial infarction treated with primary PCI

Analysis of the Association between Copy Number Variation and Ventricular Fibrillation in ST-Elevation Acute Myocardial Infarction

Sudden cardiac death due to ventricular fibrillation (VF) during ST-elevation acute myocardial infarction (STEAMI) significantly contributes to cardiovascular-related deaths. Although VF has been linked to genetic factors, variations in copy number variation (CNV), a significant source of genetic variation, have remained largely unexplored in this context. To address this knowledge gap, this study performed whole exome sequencing analysis on a cohort of 39 patients with STEAMI who experienced VF, aiming to elucidate the role of CNVs in this pathology. The analysis revealed CNVs in the form of duplications in the PARP2 and TTC5 genes as well as CNVs in the form of deletions in the MUC15 and PPP6R1 genes, which could potentially serve as risk indicators for VF during STEAMI. The analysis also underscores notable CNVs with an average gene copy number equal to or greater than four in DEFB134, FCGR2C, GREM1, PARM1, SCG5, and UNC79 genes. These findings provide further insight into the role of CNVs in VF in the context of STEAMI.

Sex differences in ventricular arrhythmia, atrial fibrillation and atrioventricular block complicating acute myocardial infarction

Background

Acute myocardial infarction (AMI) complicated by tachyarrhythmias or high-grade atrioventricular block (HAVB) may lead to increased mortality.

Purpose

To evaluate the sex differences in patients with AMI complicated by tachyarrhythmias and HAVB and their associated outcomes.

Materials and methods

We analyzed the incidence rates of arrhythmias following AMI from the Acute Coronary Syndrome Israeli Survey database from 2000 to 2018. We assessed the differences in arrhythmias incidence and the associated mortality risk between men and women.

Results

This cohort of 14,280 consecutive patients included 3,159 (22.1%) women and 11,121 (77.9%) men. Women were less likely to experience early ventricular tachyarrhythmia (VTA), (1.6% vs. 2.3%, p = 0.034), but had similar rates of late VTA (2.3% vs. 2.2%, p = 0.62). Women were more likely to experience atrial fibrillation (AF) (8.6% vs. 5.0%, p < 0.001) and HAVB (3.7% vs. 2.3%, p < 0.001). The risk of early VTAs was similar in men and women [adjusted Odds Ratio (aOR) = 0.76, p = 0.09], but women had a higher risk of AF (aOR = 1.27, p = 0.004) and HAVB (aOR = 1.30, p = 0.03). Early [adjusted hazard ratio (aHR) = 2.84, p < 0.001] and late VTA (aHR =- 4.59, p < 0.001), AF (aHR = 1.52, p < 0.001) and HAVB (aHR = 2.83, p < 0.001) were associated with increased 30-day mortality. Only late VTA (aHR = 2.14, p < 0.001) and AF (aHR = 1.44, p = 0.002) remained significant in the post 30 days period.

Conclusions

During AMI women experienced more AF and HAVB but fewer early VTAs than men. Early and late VTAs, AF, and HAVB were associated with increased 30-day mortality. Only late VTA and AF were associated with increased post-30-day mortality.

Ventricular fibrillation in acute myocardial infarction: 20-year trends in the FAST-MI study

AIMS

Sudden cardiac arrest remains a major complication of acute myocardial infarction (AMI) and is frequently related to ventricular fibrillation (VF). Incidence and impact of VF among patients hospitalized for AMI were evaluated.

METHODS AND RESULTS

Data from the FAST-MI programme consisting of 5 French nationwide prospective cohort studies between 1995 and 2015 were analysed, totally including 14 423 patients with AMI (66 ± 14 years, 72% males, 59% ST-elevation myocardial infarction). Overall, proportion of patients presenting in-hospital VF decreased from 3.9% in 1995 to 1.8% in 2015 (P < 0.001). One-year mortality decreased from 60.7% to 24.6% (P < 0.001). However, compared with patients who did not develop VF, the over-risk of 1-year mortality associated with VF was stable over time [hazard ratio (HR) 6.78, 95% confidence interval (CI) 5.03-9.14 in 1995 and HR 6.64, 95% CI 4.20-10.49 in 2015, P = 0.52]. This increased mortality in the VF group was mainly related to fatal events occurring prior to hospital discharge, representing 86.2% of 1-year mortality, despite the very low rate of implantable cardioverter defibrillator in the VF group (2.6%).

CONCLUSION

This study demonstrates that in-hospital VF incidence and mortality in the setting of AMI have significantly decreased over the past 20 years. Nevertheless, VF remained steadily associated with approximately a 10-fold increased relative risk of in-hospital mortality, without an impact on post-discharge mortality. Beyond long-term cardiac defibrillation strategy, these results emphasize the need to identify in-hospital interventions to further reduce mortality in VF patients.

STUDY REGISTRATION

ClinicalTrials.gov Identifier: NCT00673036, NCT01237418, NCT02566200.

Prognostic value of early sustained ventricular arrhythmias in ST-elevation myocardial infarction treated by primary percutaneous coronary intervention: a sub-study of VALIDATE-SWEDEHEART trial

Background

Prognostic assessment of ventricular tachycardia (VT) or ventricular fibrillation (VF) in ST-segment elevation myocardial infarction (STEMI) is based mainly on distinguishing between early (<48 hours) and late arrhythmias, and does not take into account its time distribution with regard to reperfusion, or type of arrhythmia.

Objective

We analyzed the prognostic value of early ventricular arrhythmias (VAs) in STEMI with regard to their type and timing.

Methods

The prespecified analysis of the multicenter prospective Bivalirudin versus Heparin in ST-Segment and Non-ST-Segment Elevation Myocardial Infarctionin Patients on Modern Antiplatelet Therapy in the Swedish Web System for Enhancement and Development of Evidence-based Care in Heart Disease evaluated according to Recommended Therapies Registry Trial included 2886 STEMI patients undergoing primary percutaneous coronary intervention (PCI). VA episodes were characterized regarding their type and timing. Survival status at 180 days was assessed through the population registry.

Results

Nonmonomorphic VT or VF was observed in 97 (3.4%) and monomorphic VT in 16 (0.5%) patients. Only 3 (2.7%) early VA episodes occurred after 24 hours from symptom onset. VA was associated with higher risk of death (hazard ratio 3.59; 95% confidence interval [CI] 2.01-6.42) after adjustment for age, sex, and STEMI localization. VA after PCI was associated with an increased mortality compared with VA before PCI (hazard ratio 6.68; 95% CI 2.90-15.41). Early VA was associated with in-hospital mortality (odds ratio 7.39; 95% CI 3.68-14.83) but not with long-term prognosis in patients discharged alive. The type of VA was not associated with mortality.

Conclusion

VA after PCI was associated with an increased mortality compared with VA before PCI. Long-term prognosis did not differ between patients with monomorphic VT and nonmonomorphic VT or VF, but events were few. VA incidence during 24 to 48 hours of STEMI is negligibly low, thus precluding assessment of its prognostic importance.

Multimodality Imaging of Sudden Cardiac Death and Acute Complications in Acute Coronary Syndrome

Sudden cardiac death (SCD) is a potentially fatal event usually caused by a cardiac arrhythmia, which is often the result of coronary artery disease (CAD). Up to 80% of patients suffering from SCD have concomitant CAD. Arrhythmic complications may occur in patients with acute coronary syndrome (ACS) before admission, during revascularization procedures, and in hospital intensive care monitoring. In addition, about 20% of patients who survive cardiac arrest develop a transmural myocardial infarction (MI). Prevention of ACS can be evaluated in selected patients using cardiac computed tomography angiography (CCTA), while diagnosis can be depicted using electrocardiography (ECG), and complications can be evaluated with cardiac magnetic resonance (CMR) and echocardiography. CCTA can evaluate plaque, burden of disease, stenosis, and adverse plaque characteristics, in patients with chest pain. ECG and echocardiography are the first-line tests for ACS and are affordable and useful for diagnosis. CMR can evaluate function and the presence of complications after ACS, such as development of ventricular thrombus and presence of myocardial tissue characterization abnormalities that can be the substrate of ventricular arrhythmias.

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.

Prognostic Significance of Ventricular Arrhythmias in 13 444 Patients With Acute Coronary Syndrome: A Retrospective Cohort Study Based on Routine Clinical Data (NIHR Health Informatics Collaborative VA-ACS Study)

Background A minority of acute coronary syndrome (ACS) cases are associated with ventricular arrhythmias (VA) and/or cardiac arrest (CA). We investigated the effect of VA/CA at the time of ACS on long-term outcomes. Methods and Results We analyzed routine clinical data from 5 National Health Service trusts in the United Kingdom, collected between 2010 and 2017 by the National Institute for Health Research Health Informatics Collaborative. A total of 13 444 patients with ACS, 376 (2.8%) of whom had concurrent VA, survived to hospital discharge and were followed up for a median of 3.42 years. Patients with VA or CA at index presentation had significantly increased risks of subsequent VA during follow-up (VA group: adjusted hazard ratio [HR], 4.15 [95% CI, 2.42-7.09]; CA group: adjusted HR, 2.60 [95% CI, 1.23-5.48]). Patients who suffered a CA in the context of ACS and survived to discharge also had a 36% increase in long-term mortality (adjusted HR, 1.36 [95% CI, 1.04-1.78]), although the concurrent diagnosis of VA alone during ACS did not affect all-cause mortality (adjusted HR, 1.03 [95% CI, 0.80-1.33]). Conclusions Patients who develop VA or CA during ACS who survive to discharge have increased risks of subsequent VA, whereas those who have CA during ACS also have an increase in long-term mortality. These individuals may represent a subgroup at greater risk of subsequent arrhythmic events as a result of intrinsically lower thresholds for developing VA.

Relation of Early Monomorphic Ventricular Tachycardia to Long-Term Mortality in ST-Elevation Myocardial Infarction

Early ventricular tachycardia (VT) and ventricular fibrillation (VF) are associated with increased in-hospital mortality but do not influence the long-term prognosis in ST-elevation myocardial infarction (STEMI). Recent data advocate a differential approach to the type of arrhythmia and indicate long-term mortality hazard associated with monomorphic VT. We aimed to evaluate the prognostic value of early monomorphic VT compared to nonmonomorphic VT/VF in a nonselected cohort of STEMI patients. Consecutive STEMI patients admitted for primary percutaneous coronary intervention from 2007 to 2010 were included. Clinical characteristics were obtained from the Swedish national SWEDEHEART registry. The occurrence and type of early VT/VF were verified in medical records. All-cause mortality 8 years after STEMI was assessed using the Swedish Cause of Death Register. A total of 2,277 STEMI patients were included (age 66 ± 12 years, 70% male), among them 35 (1.5%) with early monomorphic VT and 115 (5.1%) with nonmonomorphic VT/VF. Patients with monomorphic VT had similar clinical characteristics compared to those with nonmonomorphic VT/VF. In total, 22 patients (63%) with monomorphic VT and 43 (37%) with nonmonomorphic VT/VF died by 8 years of follow-up (p = 0.011). Monomorphic VT was associated with a higher risk of all-cause mortality compared to nonmonomorphic VT/VF in univariate analysis (HR 2.03, 95% CI 1.21 to 3.39, p = 0.007) and after adjustment for age and history of myocardial infarction (MI) (HR 1.74, 95% CI 1.02 to 2.97, p = 0.041). Early monomorphic VT in STEMI is associated with a higher risk of all-cause mortality compared to nonmonomorphic VT/VF and deserves further studies to refine risk stratification strategies.

Survival after Resuscitated Out-of-Hospital Cardiac Arrest in Patients with Paramedic-Identified ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention

Background: ST-segment elevation myocardial infarction (STEMI) is a common cause of out-of-hospital cardiac arrest (OHCA). For these patients, urgent angiography and revascularization is an important treatment goal. There is a lack of data on the prognosis of STEMI patients after OHCA, who are diagnosed and treated by paramedics prior to hospital transport for primary percutaneous coronary intervention (PCI).Methods: Included were adult STEMI patients identified and treated by paramedics in Queensland (Australia) from January 2016 to December 2019, transported to a hospital for primary PCI, and receiving primary PCI. Patients were grouped into those with resuscitated OHCA and those without OHCA. Clinically-important time intervals, angiographic and clinical profiles, and survival were described.Results: Patients with OHCA had longer time intervals from prehospital STEMI identification to reperfusion than those without OHCA (median 97 versus 87 mins, p = 0.001). The former had higher rates of cardiac arrhythmia history (50.5 versus 12.4%, p < 0.001), classified low left ventricular ejection fraction on admission (64.9 versus 50.1%, p = 0.006), and cardiogenic shock (5.2 versus 1.2%, p = 0.011) than the latter. A significantly higher proportion of patients with OHCA had multiple diseased vessels (16.9 versus 8.3%, p = 0.005). In-hospital, 30-day, and one-year mortality was low, being 4.1%, 4.1% and 5.2%, respectively, for STEMI patients with OHCA. The corresponding figures for those without OHCA were 1.6%, 1.8% and 3.3%, respectively.Conclusions: Survival in paramedic-identified STEMI patients treated with primary PCI following OHCA resuscitation was high. Rapid angiography and reperfusion are critical in these patients.

Association Between Radial Versus Femoral Access for Percutaneous Coronary Intervention and Long-Term Mortality

Background

Percutaneous coronary intervention with radial arterial access has been associated with fewer occurrences of major bleeding. However, published data on the long‐term mortality and major adverse cardiac events after percutaneous coronary intervention with radial or femoral arterial access are inconclusive.

Method and Results

This was a territory‐wide retrospective cohort study including 26 022 patients who underwent first‐ever percutaneous coronary intervention between January 1, 2010 and December 31, 2017 in Hong Kong. Among the 14 614 patients matched by propensity score (7307 patients in each group), 558 (7.6%) and 787 (10.8%) patients died during the observation period in the radial group and femoral group, respectively, resulting in annualized all‐cause mortality rates of 2.69% and 3.87%, respectively. The radial group had a lower risk of all‐cause mortality compared with the femoral group up to 3 years after percutaneous coronary intervention (hazard ratio [HR], 0.70; 95% CI, 0.63–0.78; P<0.001). Radial access was associated with a lower risk of major adverse cardiac events (HR, 0.78; 95% CI, 0.73–0.83, P<0.001), myocardial infarction after hospital discharge (HR, 0.78; 95% CI, 0.70–0.87, P<0.001), and unplanned revascularization (HR, 0.76; 95% CI, 0.68–0.85, P<0.001). The risks of stroke were similar across the 2 groups (HR, 0.96; 95% CI, 0.82–1.13, P=0.655).

Conclusions

Radial access was associated with a significant reduction in all‐cause mortality at 3 years compared with femoral access. Radial access was associated with reduced risks of myocardial infarction and unplanned revascularization, but not stroke. The benefits were sustained beyond the early postoperative period.

Prognosis of the non-ST elevation myocardial infarction complicated with early ventricular fibrillation at higher age

Early ventricular fibrillation (EVF) predicts mortality in ST-segment elevation myocardial infarction (STEMI) patients. Data are lacking about prognosis and management of non-ST-segment elevation myocardial infarction (NSTEMI) EMI with EVF, especially at higher age. In the daily clinical practice, there is no clear prognosis of patients surviving EVF. The present study aimed to investigate the risk factors and factors influencing the prognosis of NSTEMI patients surviving EVF, especially at higher age. Clinical data, including 30-day and 1-year mortality of 6179 NSTEMI patients, were examined; 2.44% (n=151) survived EVF and were further analyzed using chi-square test and uni- and multivariate analyses. Patients were divided into two age groups below and above the age of 70 years. Survival time was compared with Kaplan-Meier analysis. EVF was an independent risk factor for mortality in NSTEMI patients below (HR: 2.4) and above the age of 70 (HR: 2.1). Mortality rates between the two age groups of NSTEMI patients with EVF did not differ significantly: 30-day mortality was 24% vs 40% (p=0.2709) and 1-year mortality was 39% vs 55% (p=0.2085). Additional mortality after 30 days to 1 year was 15% vs 14.6% (p=0.9728). Clinical characteristics of patients with EVF differed significantly from those without in both age groups. EVF after revascularization—within 48 h—had 11.2 OR for 30-day mortality above the age of 70. EVF in NSTEMI was an independent risk factor for mortality in both age groups. Invasive management and revascularization of NSTEMI patients with EVF is highly recommended. Closer follow-up and selection of patients (independent of age) for ICD implantation in the critical first month is essential.

Correlation of Prolonged Corrected QT Interval With Ventricular Arrhythmias and In-Hospital Mortality Among ST-Elevation Myocardial Infarction Patients: A Mystique or Lucidity?

Background Ventricular arrhythmias (VAs) are a frequent cause of cardiovascular mortality, especially in developing countries. Prolongation of corrected QT (QTc) interval predisposes patients to life-threatening VAs. Our study aims to assess the correlation of prolonged QTc interval with VAs and in-hospital mortality among ST-elevation myocardial infarction (STEMI) patients.  Methods This cross-sectional study analyzed the data from 40 patients with a confirmed diagnosis of STEMI and prolonged QTc interval. The patients were evaluated for several characteristics including their electrocardiography (ECG) findings. The frequency of in-hospital mortality and VAs developed after admission were recorded. Spearman correlation was used to assess the correlation of prolonged QTc interval with VAs and in-hospital mortality. Results Out of 40 cases, 30 patients were males and 10 were females with a mean age hovering at 52.95 ± 10.65 years. The mean QTc interval of our patients was 512.02 ± 49.74 milliseconds (ms). A total of 11 (27.5%) patients developed VAs while 14 (35%) of the patients succumbed to the disease complications. Spearman correlation showed a strong significant positive correlation of QTc interval with VAs (rho = 0.658, p < 0.001) and in-hospital mortality (rho = 0.314, p = 0.04). Conclusion Prolonged QTc interval is positively correlated with VAs and in-hospital mortality among STEMI patients. These patients should be regularly monitored and must be managed with caution as they have increased chances to develop VAs and in-hospital mortality. There is an utmost need for curation of guidelines that aid in risk stratification and appropriate management of such patients.

Growth differentiation factor-15 is a predictive biomarker in primary ventricular fibrillation: The RUTI-STEMI-PVF study

Background:

Primary ventricular fibrillation is an ominous complication of ST-segment elevation myocardial infarction, and proper biomarkers for risk prediction are lacking. Growth differentiation factor-15 is a marker of inflammation, oxidative stress and hypoxia with well-established prognostic value in ST-segment elevation myocardial infarction patients. We explored the predictive value of growth differentiation factor-15 in a subgroup of ST-segment elevation myocardial infarction patients with primary ventricular fibrillation.

Methods:

Prospective registry of ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention from February 2011–August 2015. Growth differentiation factor-15 concentrations were measured on admission. Logistic regression and Cox proportional regression analyses were used.

Results:

A total of 1165 ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention (men 78.5%, age 62.3±13.1 years) and 72 patients with primary ventricular fibrillation (6.2%) were included. Compared to patients without primary ventricular fibrillation, median growth differentiation factor-15 concentration was two-fold higher in ST-segment elevation myocardial infarction patients with primary ventricular fibrillation (2655 vs 1367 pg/ml, p&lt;0.001). At 30 days, mortality was 13.9% and 3.6% in patients with and without primary ventricular fibrillation, respectively (p&lt;0.001), and median growth differentiation factor-15 concentration in patients with primary ventricular fibrillation was five-fold higher among those who died vs survivors (13,098 vs 2415 pg/ml, p&lt;0.001). In a comprehensive multivariable analysis including age, sex, clinical variables, reperfusion time, left ventricular ejection fraction, N-terminal pro-B-type natriuretic peptide and high-sensitivity troponin T, growth differentiation factor-15 remained an independent predictor of 30-day mortality, with odds ratios of 3.92 (95% confidence interval 1.35–11.39) in patients with primary ventricular fibrillation (p=0.012) and 1.72 (95% confidence interval 1.23–2.40) in patients without primary ventricular fibrillation (p=0.001).

Conclusions:

Growth differentiation factor-15 is a robust independent predictor of 30-day mortality in ST-segment elevation myocardial infarction patients with primary ventricular fibrillation.

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.

ST-segment elevation myocardial infarction

ST-segment elevation myocardial infarction (STEMI) is the most acute manifestation of coronary artery disease and is associated with great morbidity and mortality. A complete thrombotic occlusion developing from an atherosclerotic plaque in an epicardial coronary vessel is the cause of STEMI in the majority of cases. Early diagnosis and immediate reperfusion are the most effective ways to limit myocardial ischaemia and infarct size and thereby reduce the risk of post-STEMI complications and heart failure. Primary percutaneous coronary intervention (PCI) has become the preferred reperfusion strategy in patients with STEMI; if PCI cannot be performed within 120 minutes of STEMI diagnosis, fibrinolysis therapy should be administered to dissolve the occluding thrombus. The initiation of networks to provide around-the-clock cardiac catheterization availability and the generation of standard operating procedures within hospital systems have helped to reduce the time to reperfusion therapy. Together with new advances in antithrombotic therapy and preventive measures, these developments have resulted in a decrease in mortality from STEMI. However, a substantial amount of patients still experience recurrent cardiovascular events after STEMI. New insights have been gained regarding the pathophysiology of STEMI and feed into the development of new treatment strategies.

Progressive increase of the Tpeak-Tend interval is associated with ischaemia-induced ventricular fibrillation in a porcine myocardial infarction model

Aims

Repolarization indices of ECG have been widely assessed as predictors of ventricular arrhythmias. However, little is known of the dynamic changes of these parameters during continuous monitoring in acute ischaemic episodes. The objective of the study was to evaluate repolarization-related predictors of ventricular fibrillation (VF) during progression of experimental myocardial infarction.

Methods and results

Myocardial infarction was induced in 27 pigs by 40-min balloon inflation in the left anterior descending coronary artery, and 12-lead ECG was continuously recorded. Rate-corrected durations of the total Tpeak-Tend intervals measured from the earliest T-wave peak to the latest T-wave end in any lead were determined at baseline and at minute 1, 2, 5, and then every 5th minute of occlusion. There were 7 early (1-3 min) and 10 delayed (15-30 min) VFs in 16 pigs. Baseline Tpeak-Tend did not differ between animals with and without VF. Tpeak-Tend interval rapidly increased immediately after balloon inflation and was greater in VF-susceptible animals at 2-15 min compared with the animals that never developed VF (P < 0.05). Tpeak-Tend was tested as a predictor of delayed VFs. Median Tpeak-Tend at 10th min of occlusion was higher in delayed VF group (n = 10) than in animals without VF (n = 11): 138 [IQR 121-148] ms vs. 111 [IQR 106-127] ms, P = 0.02. Tpeak-Tend  ≥123 ms (10th min) predicted delayed VF episodes with HR = 4.5 95% CI 1.1-17.8, P = 0.031.

Conclusion

Tpeak-Tend prolongation during ischaemia progression predicts VF in the experimental porcine myocardial infarction model and warrants further testing in clinical settings of acute coronary syndromes.

Primary Ventricular Fibrillation in the Primary Percutaneous Coronary Intervention ST-Segment Elevation Myocardial Infarction Era (from the "Codi IAM" Multicenter Registry)

Primary ventricular fibrillation (PVF) is a dreadful complication of ST segment elevation myocardial infarction (STEMI). Scarce data are available regarding PVF prognosis since primary percutaneous coronary intervention (PPCI) became routine practice in STEMI. Our aim was to compare 30-day and 1-year mortality for patients with and without PVF (including out-of-hospital and in-hospital PVF) within a regional registry of PPCI-treated STEMI patients. This prospective multicenter registry included all consecutive STEMI patients treated with PPCI from January 2010 to December 2014. Patients were classified as non-PVF or PVF, with further subdivision into out-of-hospital and in-hospital PVF. We analyzed 30-day and 1-year all-cause mortality in groups. The registry included 10,965 patients. PVF occurred in 949 patients (8.65%), including 74.2% out-of-hospital and 25.8% in-hospital PVF. Compared with the non-PVF group, PVF patients were younger; less commonly diabetic; more frequently had anterior wall STEMI, higher Killip-Kimball class, and left main disease; and showed significantly higher 24-hour (5.1% vs 1.1%), 30-day (18.5% vs 4.7%), and 1-year mortality (23.2% vs 7.9%) (all p <0.001). Mortality did not differ in out-of-hospital versus in-hospital PVF. After multivariable adjustment, PVF remained associated with all-cause 30-day (2.32, 95% CI: 1.91 to 2.82, p <0.001) and 1-year (HR: 1.59, 95% CI: 1.13 to 2.24, p = 0.008) mortality. In conclusion, we present the largest registry of PVF patients in the era of routine PPCI in STEMI. Although overall STEMI mortality has declined, PVF emerged as a predictor of both 30-day and 1-year mortality. These data warrant prospective validation and proper identification and protection of high-risk patients.

Prognostic implications of early monomorphic and non-monomorphic tachyarrhythmias in patients discharged with acute coronary syndrome

BACKGROUND

The prognostic implication of early ventricular tachyarrhythmias (VTs) after acute coronary syndrome (ACS) remains unclear.

OBJECTIVE

We sought to investigate the clinical outcomes of early monomorphic and non-monomorphic VTs that occur within 48 hours in patients after ACS.

METHODS

We retrospectively reviewed the clinical outcomes of 2033 [mean age 67.0 ± 13.4 years; 1486 (73.1%) men] consecutive patients who presented with ACS from 2004 to 2015.

RESULTS

A total of 67 (3.3%) and 90 (4.4%) patients developed early monomorphic or non-monomorphic VT, respectively. Killip class IV (odds ratio [OR] 3.05; 95% confidence interval [CI] 1.47-6.36; P < .01), creatine kinase level (OR 1.01; 95% CI 1.00-1.02 per 100 IU/L; P = .01), and left ventricular ejection fraction (OR 0.96; 95% CI 0.94-0.99; P < .01) were independently associated with early monomorphic VT, whereas age (OR 0.98; 95% CI 0.97-0.99; P = .04), ST elevated myocardial infarction (OR 3.53; 95% CI 1.71-7.27; P < .01), Killip class IV (OR 4.91; 95% CI 2.76-8.74; P < .01), diabetes mellitus (OR 0.48; 95% CI 0.28-0.81; P < .01), and left ventricular ejection fraction (OR 0.97; 95% CI 0.95-0.99; P < .01) were independently associated with early non-monomorphic VT. More patients with early monomorphic VT (n = 22 [32.8%]) died in hospital than those with non-monomorphic VT (n = 16 [17.8%]) or without early VT (n = 133 [7.1%]; P < .01). After a mean follow-up of 67.8 ± 43.2 months, 21 patients with early monomorphic VT (46.7%), 22 patients with early non-monomorphic VT (29.7%), and 552 patients without early VT (31.7%) died. Both early monomorphic and non-monomorphic VTs were associated with a long-term increase in sudden arrhythmic deaths and recurrent VTs. Nevertheless, only early monomorphic VT was shown to independently predict overall survival (hazard ratio 1.62; 95% CI 1.03-2.55; P = .04).

CONCLUSION

Early monomorphic VT, but not early non-monomorphic VT, independently predicted all-cause mortality in patients with ACS who survived to hospital discharge.

Sudden Cardiac Death in Acute Coronary Syndromes

Sudden cardiac death in acute coronary syndromes mostly results from complex ventricular arrhythmias. Although the incidence has fallen with contemporary management, they still pose a threat for many patients. Treatment consists of immediate termination by electrical cardioversion and prompt coronary revascularization for relief of ischemia. Beta-blockers administered prophylactically have a protective effect. For recurrent episodes, pharmacologic treatment consists of beta-blockers and amiodarone, or, in nonresponsive patients, lidocaine. Other antiarrhythmic drugs play only a marginal role. Catheter ablation performed in qualified centers can be effective in recurrent episodes of ventricular tachycardia or ventricular fibrillation triggered by premature ventricular contractions.

Ventricular Arrhythmia after Acute Myocardial Infarction: 'The Perfect Storm'

Ventricular tachyarrhythmias (VAs) commonly occur early in ischaemia, and remain a common cause of sudden death in acute MI. The thrombolysis and primary percutaneous coronary intervention era has resulted in the modification of the natural history of an infarct and subsequent VA. Presence of VA could independently influence mortality in patients recovering from MI. Appropriate risk assessment and subsequent treatment is warranted in these patients. The prevention and treatment of haemodynamically significant VA in the post-infarct period and of sudden cardiac death remote from the event remain areas of ongoing study.

Very low risk ST-segment elevation myocardial infarction? It exists and may be easily identified

BACKGROUND

Early discharge protocols have been proposed for ST-segment elevation myocardial infarction (STEMI) low risk patients despite the existence of few but significant cardiovascular events during mid-term follow-up. We aimed to identify a subgroup of patients among those considered low-risk in which prognosis would be particularly good.

METHODS

We analyzed 30-day outcomes and long-term follow-up among 1.111 STEMI patients treated with reperfusion therapy.

RESULTS

Multivariate analysis identified seven variables as predictors of 30-day outcomes: Femoral approach; age>65; systolic dysfunction; postprocedural TIMI flow<3; elevated creatinine level>1.5mg/dL; stenosis of left-main coronary artery; and two or higher Killip class (FASTEST). A total of 228 patients (20.5%), defined as very low-risk (VLR), had none of these variables on admission. VLR group of patients compared to non-VLR patients had lower in-hospital (0% vs. 5.9%; p<0.001) and 30-day mortality (0% vs. 6.25%: p<0.001). They also presented fewer in-hospital complications (6.6% vs. 39.7%; p<0.001) and 30-day major adverse events (0.9% vs. 4.5%; p=0.01). Significant mortality differences during a mean follow-up of 23.8±19.4months were also observed (2.2% vs. 15.2%; p<0.001). The first VLR subject died 11months after hospital discharge. No cardiovascular deaths were identified in this subgroup of patients during follow-up.

CONCLUSIONS

About a fifth of STEMI patients have VLR and can be easily identified. They have an excellent prognosis suggesting that 24-48h in-hospital stay could be a feasible alternative in these patients.

Predictors of ventricular fibrillation at reperfusion in patients with acute ST-elevation myocardial infarction treated by primary percutaneous coronary intervention

Ventricular fibrillation (VF) during reperfusion (rVF) in ST-segment elevation myocardial infarction (STEMI) is an infrequent but serious event that complicates coronary interventions. The aim of this study was to analyze clinical predictors of rVF in an unselected population of patients with STEMI treated with percutaneous coronary intervention (PCI). Consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2012 were retrospectively assessed for the presence of rVF. Admission electrocardiograms, stored in a digital format, were analyzed for a maximal ST-segment elevation in a single lead and the sum of ST-segment deviations in all leads. Clinical, electrocardiographic, and angiographic characteristics were tested for associations with rVF using logistic regression analysis. Among 3,724 patients with STEMI admitted from 2007 to 2012, 71 (1.9%) had rVF. In univariate analysis, history of myocardial infarction, aspirin and β-blocker use, VF before PCI, left main coronary artery disease, inferior myocardial infarction localization, symptom-to-balloon time <360 minutes, maximal ST-segment elevation in a single lead >300 μV, and sum of ST-segment deviations in all leads >1,500 μV were associated with increased risk for rVF. In a multivariate analysis, sum of ST-segment deviations in all leads >1500 μV (odds ratio 3.7, 95% confidence interval 1.45 to 9.41, p = 0.006) before PCI remained an independent predictor of rVF. In-hospital mortality was 18.3% in the rVF group and 3.3% in the group without VF (p <0.001), but rVF was not an independent predictor of in-hospital death. In conclusion, the magnitude of ST-segment elevation before PCI for STEMI independently predicts rVF and should be considered in periprocedural arrhythmic risk assessment. Despite higher in-hospital mortality in patients with rVF, rVF itself has no independent prognostic value for prognosis.

Impact of out-of-hospital cardiac arrest due to ventricular fibrillation in patients with ST-elevation myocardial infarction admitted for primary percutaneous coronary intervention: Impact of ventricular fibrillation in STEMI patients

OBJECTIVE

Pre-hospital life-threatening ventricular tachycardia/fibrillation (VT/VF) is relatively common in the acute phase of ST-elevation myocardial infarction (STEMI). We evaluated the prognostic impact of out-of-hospital cardiac arrest (OHCA) due to VT/VF in non-selected patients with STEMI admitted for primary percutaneous coronary intervention (PCI).

METHODS

Prospective hospital registry was used to collect data of consecutive STEMI patients admitted to our hospital between 2005 and 2010. Patients with OHCA were identified from this registry, and their medical records were reviewed.

RESULTS

During the study period, 4653 patients were admitted with STEMI. Data regarding OHCA due to VT/VF was available in 4643 patients (99.8%). A total of 326 patients (7.0%) had OHCA due to VT/VF. Patients with OHCA were younger (60.3 ± 11.8 vs. 64.1 ± 12.9 year, p<0.001), less often had diabetes (5.2% vs. 12.4%, p<0.001) but more often presented with signs of heart failure (Killip class >1:17.5% vs. 7.7%, p<0.001) and cardiogenic shock (29.6% vs. 2.5%, p<0.001). Coronary angiography was performed in 97.5% of the patients. Coronary angiography and primary PCI were performed equally in both groups. In patients with OHCA, the left main artery (2.3% vs. 1.0%, p=0.04) and LAD (49.2% vs. 41.2%, p=0.01) were more often the culprit artery. In-hospital mortality was significantly higher among patients with OHCA (13.80% vs. 3.4%, p<0.001). However, in patients who were discharged alive from the hospital, the one-year mortality and the combined incidence of death and appropriate ICD therapy were similar in patients with and without OHCA.

CONCLUSION

In a large non-selected STEMI patient population admitted for primary PCI, OHCA due to VT/VF was associated with higher in-hospital mortality but did not affect the long-term prognosis.

Transient and rapid QRS-widening associated with a J-wave pattern predicts impending ventricular fibrillation in experimental myocardial infarction

BACKGROUND

Certain types of the early repolarization phenomenon, previously considered to be benign, have been reported to be associated with ventricular fibrillation (VF), both in population-based studies and in the myocardial infarction (MI) settings.

OBJECTIVE

To analyze whether QRS widening and appearance of a J-wave pattern in experimental MI settings is predictive of VF.

METHODS

MI was induced in 32 pigs by 40-minute inflation of an angioplasty balloon in the left descending artery, and electrocardiogram was continuously recorded. Multilead QRS boundaries were computed, and QRS duration was calculated on a beat-to-beat basis during the occlusion period for each pig. An association between QRS widening and subsequent VF was studied using receiver operating characteristic curve analysis. Electrocardiograms at maximum QRS duration were reviewed for the presence of a J-wave pattern.

RESULTS

Sixteen animals had VF episodes during the occlusion period. Two peaks of QRS widening were found in all animals: the first peak immediately on left descending artery occlusion and the second peak 19.1 ± 4.0 minutes later. The magnitude of changes in the QRS width over time had significant interindividual differences. A QRS widening of ≥28 ms during a 3-minute time window was observed in 14 animals and predicted impending VF (selectivity 80%, specificity 73%, positive predictive value 57%, and negative predictive value 89%; P = .008). In 10 of 14 (71%) pigs, a J-wave pattern appeared at maximal QRS duration. The appearance of a J-wave pattern predicted VF with selectivity 80%, specificity 68%, positive predictive value 53%, and negative predictive value 88% (P = .02).

CONCLUSION

Transient QRS widening, commonly associated with a J-wave pattern, appears to predict impending VF in acute ischemia settings and motivates further clinical studies for monitoring immediate risk of VF in MI.