Sudden Cardiac Arrest Survivors Research Articles

The Dutch Idiopathic Ventricular Fibrillation Registry: progress report on the quest to identify the unidentifiable.

Idiopathic ventricular fibrillation (iVF) is arare cause of sudden cardiac arrest and, by definition, adiagnosis of exclusion. Due to the rarity of the disease, previous and current studies are limited by their retrospective design and small patient numbers. Even though the incidence of iVF has declined owing to the identification of new disease entities, an important subgroup of patients remains. To expand the existing Dutch iVF Registry into alarge nationwide cohort of patients initially diagnosed with iVF, to reveal the underlying cause of iVF in these patients, and to improve arrhythmia management. The Dutch iVF Registry includes sudden cardiac arrest survivors with an initial diagnosis of iVF. Clinical data and outcomes are collected. Outcomes include subsequent detection of adiagnosis other than 'idiopathic', arrhythmia recurrence and death. Non-invasive electrocardiographic imaging is used to investigate electropathological substrates and triggers of VF. To date, 432 patients have been included in the registry (median age at event 40years (interquartile range 28-52)), 61% male. During amedian follow-up of 6(2-12) years, 38patients (9%) received adiagnosis other than 'idiopathic'. Eleven iVF patients were characterised with electrocardiographic imaging. The Dutch iVF Registry is currently the largest of its kind worldwide. In this heterogeneous population of index patients, we aim to identify common functional denominators associated with iVF. With the implementation of non-invasive electrocardiographic imaging and other diagnostic modalities (e.g. echocardiographic deformation, cardiac magnetic resonance), we advance the possibilities to reveal pro-fibrillatory substrates.

Idiopathic ventricular fibrillation: is it acase for genetic testing?

Idiopathic ventricular fibrillation (IVF) is adiagnosis of exclusion in sudden cardiac arrest (SCA) survivors. Although there are clear guidelines on the clinical work-up of SCA survivors, less than one in five patients receives acomplete work-up. This increases the chances of erroneously labelling these patients as having IVF, while 10-20% of them have an inherited cardiac condition (ICC). Diagnoses of ICC increase over time due to (additional) deep phenotyping or as a result of spontaneous expression of ICC over time. As SCA survivors can also harbor (likely) pathogenic variants in cardiomyopathy-associated genes in the absence of aphenotype, or can have another ICC without aclear cardiac phenotype, the question arises as to whether genetic testing in this group should be routinely performed. Family history (mainly in the case of sudden death) can increase suspicion of an ICC in an SCA victim, but does not add great value when adults underwent acomplete cardiological work-up. The diagnosis of ICC has treatment consequences not only for the patient but also for their family. Genetic diagnostic yield does not appear to increase with larger gene panels, but variants of unknown significance (VUS) do. Although VUS can be confusing, careful and critical segregation analysis in the family can be performed when discussed in amultidisciplinary team at acenter of expertise with at least acardiologist as well as aclinical and laboratory geneticist, thereby degrading or promoting VUS. When to introduce genetic testing in SCA survivors remains amatter of debate, but the combination of quick, deep phenotyping with additional genetic testing for the unidentifiable phenotypes, especially in the young, seems preferable.

Prolonged follow-up after apparently unexplained sudden cardiac arrest: A retrospective study

BackgroundWe hypothesized that a prolonged follow-up of survivors of unexplained sudden cardiac arrest (USCA) would subsequently unmask electrical heart disorders in a significant proportion of cases. Patients and methodsWe retrospectively analyzed all out-of-hospital cardiac arrest (OHCA) admitted alive in our cardiac arrest center over 20-years (2002–2022). The diagnosis of USCA was made when no etiology was found after thorough initial hospital investigations. We identified all the new diagnoses established during follow-up, and compared outcomes according to underlying heart diseases. ResultsOut of the 2482 OHCA patients, 68 (2.7%) were initially classified as USCA and 30 (1.2%) with electrical heart disorders. Compared to other cardiac etiologies of OHCA, both USCA and electrical heart disorders patients were younger (mean age 48.5 and 43.5 year-old respectively, versus 62.5 year-old; p < 0.0001), with a higher rate of family history of SCA (17.6 and 23.3% respectively versus 9.2%; p = 0.003). Six patients in each group were lost to follow-up at discharge (6/68, 8.8% in the USCA group, 6/30 20% in the electrical heart disorders group). During a mean follow-up of 8.1 ± 6.3 years, a diagnosis was eventually established in 24.3% of USCA patients (9/35), most of them as electrical heart disorders (55.6%, 5/9). No post-discharge death occurred in both USCA and electrical heart disorders groups, with approximately 10% of appropriate therapy delivered by the implantable cardioverter defibrillator. ConclusionOur findings emphasized that approximately a quarter of patients who had been initially considered as having apparently USCA after index hospital stay actually reveal heart conditions, especially electrical heart disorders.

Impact of Preexisting Depression and Anxiety on Hospital Readmission and Long-Term Survival After Cardiac Arrest.

While sudden cardiac arrest (CA) survivors are at risk for developing psychiatric disorders, little is known about the impact of preexisting mental health conditions on long-term survival or postacute healthcare utilization. We examined the prevalence of preexisting psychiatric conditions in CA patients who survived hospital discharge, characterized incidence and reason for inpatient psychiatry consultation during these patients' acute hospitalizations, and determined the association of pre-CA depression and anxiety with hospital readmission rates and long-term survival. We hypothesized that prior depression or anxiety would be associated with higher hospital readmission rates and lower long-term survival. We conducted a retrospective cohort study including patients resuscitated from in- and out-of-hospital CA who survived both admission and discharge from a single hospital between January 1, 2010, and December 31, 2017. We identified patients from our prospective registry, then performed a structured chart review to abstract past psychiatric history, prescription medications for psychiatric conditions, and identify inpatient psychiatric consultations. We used administrative data to identify readmissions within 1 year and vital status through December 31, 2020. We used multivariable Cox regressions controlling for patient demographics, medical comorbidities, discharge Cerebral Performance Category and disposition, depression, and anxiety history to predict long-term survival and hospital readmission. We included 684 subjects. Past depression or anxiety was noted in 24% (n = 162) and 19% (n = 129) of subjects. A minority of subjects (n = 139, 20%) received a psychiatry consultation during the index hospitalization. Overall, 262 (39%) subjects had at least 1 readmission within 1 year. Past depression was associated with an increased hazard of hospital readmission (hazard ratio 1.50, 95% CI 1.11-2.04), while past anxiety was not associated with readmission. Neither depression nor anxiety were independently associated with long-term survival. Depression is an independent risk factor for hospital readmission in CA survivors.

The Impact of Body Mass Index on In-Hospital Mortality in Post-Cardiac-Arrest Patients-Does Sex Matter?

A number of factors influence mortality in post-cardiac-arrest (CA) patients, nutritional status being one of them. The aim of this study was to assess whether there are sex differences in the prognostic impact of BMI, as calculated on admission to an intensive care unit, on in-hospital mortality in sudden cardiac arrest (SCA) survivors. We carried out a retrospective analysis of data of 129 post-cardiac-arrest patients with return of spontaneous circulation (ROSC) admitted to the Intensive Care Unit (ICU) of the University Teaching Hospital in Wrocław between 2017 and 2022. Female patients were significantly older than male patients (68.62 ± 14.77 vs. 62.7 ± 13.95). The results of univariable logistic regression analysis showed that BMI was not associated with the odds of in-hospital death in either male or female patients. In an age-adjusted model, age was an independent predictor of the odds of in-hospital death only in male patients (OR = 1.034). In our final multiple logistic regression model, adjusted for the remaining variables, none of the traits analysed were a significant independent predictor of the odds of in-hospital death in female patients, whereas an initial rhythm of ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) was an independent predictor of the odds of in-hospital death in male patients (OR = 0.247). BMI on admission to ICU is not a predictor of the odds of in-hospital death in either male or female SCA survivors.

Importance of exercise stress testing in evaluation of unexplained cardiac arrest survivor.

In sudden cardiac arrest survivors without an immediately identifiable cause, additional extensive yet individualised testing is required. We describe 3survivors of sudden cardiac arrest in whom exercise stress testing was not performed during the initial hospital admission. All 3patients were incorrectly diagnosed with long QT syndrome based on temporary sudden cardiac arrest-related heart rate-corrected QT interval prolongation, and exercise stress testing was not performed during the initial work-up. When they were subjected to exercise stress testing during follow-up, adelayed diagnosis of catecholaminergic polymorphic ventricular tachycardia (CPVT) was made. As aresult, these patients were initially managed inappropriately, and their family members were initially not screened for CPVT. In sudden cardiac arrest survivors without an immediately identifiable cause, omission of exercise stress testing or erroneous interpretation of the results can lead to adelayed or missed diagnosis of CPVT, which may have considerable implications for survivors and their family.

Parametric mapping by cardiovascular magnetic resonance imaging in sudden cardiac arrest survivors.

Etiology of sudden cardiac arrest (SCA) is identified in less than 30% of survivors without coronary artery disease. We sought to assess the diagnostic role of myocardial parametric mapping using cardiovascular magnetic resonance (CMR) in identifying SCA etiology. Consecutive SCA survivors undergoing CMR with myocardial parametric mapping were included in the study. The determination if CMR was decisive or contributory in identifying SCA etiology was made if the diagnosis was unclear prior to CMR, and the discharge diagnosis was consistent with the CMR result. Parametric mapping was considered essential for establishing probable SCA etiology by CMR if the SCA cause could not have been determined without its utilization. If the CMR diagnosis could have been potentially based on the combination of cine and LGE imaging, parametric mapping was considered contributory. Of the 35 patients (mean age 46.9 ± 14.1years; 57% males) included, SCA diagnosis was based on CMR in 23 (66%) patients. Of those, parametric mapping was essential for the diagnosis of myocarditis and tako-tsubo cardiomyopathy (11/48%) and contributed to the diagnosis in 10 (43%) additional cases. Inclusion of quantitative T1 and T2 parametric mapping in the SCA CMR protocol has the potential to increase diagnostic yield of CMR and further specify SCA etiology, especially myocarditis.

PO-05-163 INCIDENCE AND RHYTHM PRESENTATION OF IN-HOSPITAL VERSUS OUT-OF-HOSPITAL SUDDEN CARDIAC ARREST AND PREDICTORS OF READMISSION AT 90 DAYS

Sudden cardiac arrest (SCA) may culminate in sudden cardiac death (SCD) if resuscitation efforts are unsuccessful or absent. The pathogenesis and system of care for in-hospital and out-of-hospital cardiac arrest (IHCA and OHCA) are different. We sought to determine predictors of readmission in these patients presenting with SCA and surviving to discharge. All patients >18 years of age presenting with sudden cardiac arrest from 2016-2019 were included. Data were abstracted using the International Classification of Diseases 10th Revision-Clinical Modification from the Nationwide Readmissions Database (NRD). Patient demographics, presence of comorbidities, presenting rhythm, and predictors of readmission were evaluated. Out of 51,998,206 admissions between 2016 to 2019, 35,050 (0.07%) presented with SCA. IHCA was commoner than OHCA [21,347 (60.9%) vs 13,703 (39.1%)]. Patients presenting with OHCA were younger [67 vs 69 years, p <0.0001] and had overall lower systemic comorbidities [Charlson’s comorbidity index (CCI) – OHCA: 2.0 (1.0-3.0) vs IHCA: 2.0 (1.0-4.0) points, P<0.0001]. Pulseless electrical activity (PEA) was the predominant presenting rhythm overall but much higher in the OHCA group [overall: 68.6%, IHCA: 51.5% vs OHCA: 95.4%, p<0.0001]. Ventricular arrhythmia (VA) [ventricular tachycardia (VT), ventricular fibrillation (VF)] were commoner in IHCA as compared to OHCA [OHCA: 2,878 (29.9%) vs IHCA: 6,761 (70.1%), p<0.0001]. Of the patients getting admitted with SCA, 26,080 (74.41%) died at the first admission, with a higher mortality in the OHCA group [IHCA 15,690 (73.5% mortality) vs OHCA 10,390 (75.82% mortality), p<0.0001]. At 90-day follow-up, a much higher percentage of the OHCA group had PEA as compared to IHCA [OHCA: 3,012 (90.9%) vs. IHCA: 2,573 (45.5%), p<0.0001] similar to the first admission. Young age predicted higher readmissions in the IHCA group whereas the presence of diabetes mellitus and renal diseases predicted higher readmission rates in both the groups (P<0.0001). PEA was the predominant presenting rhythm irrespective of the type of cardiac arrest (IHCA or OHCA) at the first admission as well as at readmission. Younger patients (<60 years) with IHCA were more likely to get readmitted, which is alarming and needs a proper evaluation of this cohort to prevent recurrences and reduce mortality among sudden cardiac arrest survivors.

MP-453090-5 SUDDEN CARDIAC ARREST AS THE FIRST MANIFESTATION OF HEART DISEASE IN THE GENERAL POPULATION

The subgroup of individuals who present with sudden cardiac arrest (SCA) as the first manifestation of heart disease (FM-SCA) present the greatest challenge to effective clinical risk stratification, but population-based data in the current era is lacking. We hypothesized that improved awareness and access to health care has resulted in a reduction in prevalence of FM-SCA. We compared the prevalence secular trends of FM-SCA in two geographically distinct US populations and evaluated distinguishing characteristics. Consecutive cases of SCA were ascertained prospectively from 2 large ongoing US studies, the Oregon Sudden Unexpected Death Study (OreSUDS, Portland OR, USA, 2002-2018) and Prediction of Sudden Death in Multi-ethnic Communities (PRESTO, Ventura CA, USA, 2015-2022), total population 1.85 million residents. All out-of-hospital SCA events attended by emergency medical services were determined following an established multi-source ascertainment and adjudication process, and a detailed review of the comprehensive lifetime clinical records was conducted for each individual. Both SCA survivors and non-survivors were included. FM-SCA cases were defined as SCA with no prior heart disease diagnosis. A multi-variable model using combined data from both cohorts was used to identify distinguishing characteristics of FM-SCA vs. other SCA. A total of 3390 SCA cases (age 64.3 ± 18.8, female 34%) were identified in OreSUDS and n=2318 (age 71.6 ± 15.7, female 36%) in PRESTO. In OreSUDS, prevalence of FM-SCA was 39% (n=1282, age 58.6 ± 21.7, 32% female) and decreased modestly over time (Figure; 37% in 2002-06 to 33% in 2014-18; p=0.001 for trend). In PRESTO, overall prevalence of FM-SCA was 41% (n=949, age 68.3 ± 17.6, 33% female) and did not change significantly over time (Figure; 2015-2022; p=0.06 for trend). In multivariate comparisons of FM-SCA vs. other SCA performed in the subset of individuals with healthcare visits, younger age, male sex and lower rates of diabetes, hypertension, seizure disorder, chronic obstructive pulmonary disease and chronic renal insufficiency were associated with FM-SCA (p <0.0001). There was a modest reduction in prevalence over time, but 33-41% of individuals continued to present with FM-SCA and were distinguished by younger age, male sex and lower rates of co-morbid conditions. These findings suggest the need to develop and investigate user-friendly and cost-effective pre-screening methods to reduce FM-SCA in the general population.

The circle of reentry: Characteristics of trigger-substrate interaction leading to sudden cardiac arrest.

Sudden cardiac death is often caused by ventricular arrhythmias driven by reentry. Comprehensive characterization of the potential triggers and substrate in survivors of sudden cardiac arrest has provided insights into the trigger-substrate interaction leading to reentry. Previously, a "Triangle of Arrhythmogenesis", reflecting interactions between substrate, trigger and modulating factors, has been proposed to reason about arrhythmia initiation. Here, we expand upon this concept by separating the trigger and substrate characteristics in their spatial and temporal components. This yields four key elements that are required for the initiation of reentry: local dispersion of excitability (e.g., the presence of steep repolarization time gradients), a critical relative size of the region of excitability and the region of inexcitability (e.g., a sufficiently large region with early repolarization), a trigger that originates at a time when some tissue is excitable and other tissue is inexcitable (e.g., an early premature complex), and which occurs from an excitable region (e.g., from a region with early repolarization). We discuss how these findings yield a new mechanistic framework for reasoning about reentry initiation, the "Circle of Reentry." In a patient case of unexplained ventricular fibrillation, we then illustrate how a comprehensive clinical investigation of these trigger-substrate characteristics may help to understand the associated arrhythmia mechanism. We will also discuss how this reentry initiation concept may help to identify patients at risk, and how similar reasoning may apply to other reentrant arrhythmias.

Highlights From the Circulation Family of Journals.

Highlights From the Circulation Family of Journals.

Pre-percutaneous coronary intervention sudden cardiac arrest in ST-elevation myocardial infarction: Incidence, predictors, and related outcomes.

ST-segment elevation myocardial infarction (STEMI) is a frequent cause of sudden cardiac arrest (SCA) and early percutaneous coronary intervention (PCI) is associated with increased survival. Despite constant improvements in SCA management, survival remains poor. We aimed to assess pre-PCI SCA incidence and related outcomes in patients admitted with STEMI. This was a prospective cohort study of patients admitted with STEMI in a tertiary university hospital over 11 years. All patients were submitted to emergency coronary angiography. Baseline characteristics, details of the procedure, reperfusion strategies, and adverse outcomes were assessed. The primary outcome was in-hospital mortality. The secondary outcome was 1-year mortality after hospital discharge. Predictors of pre-PCI SCA was also assessed. During the study period 1,493 patients were included; the mean age was 61.1 years (±12), and 65.3% were male. Pre-PCI SCA was present in 133 (8.9%) patients. In-hospital mortality was higher in the pre-PCI SCA group (36.8% vs. 8.8%, p < 0.0001). In multivariate analysis, anterior MI, cardiogenic shock, age, pre-PCI SCA and lower ejection fraction remained significantly associated with in-hospital mortality. When we analyzed the interaction between pre-PCI SCA and cardiogenic shock upon admission there is a further increase in mortality risk when both conditions are present. For predictors of pre-PCI SCA, only younger age and cardiogenic shock remained significantly associated after multivariate analysis. Overall 1-year mortality rates were similar between pre-PCI SCA survivors and non-pre-PCI SCA group. In a cohort of consecutive patients admitted with STEMI, pre-PCI SCA was associated with higher in-hospital mortality, and its association with cardiogenic shock further increases mortality risk. However, long-term mortality among pre-PCI SCA survivors was similar to non-SCA patients. Understanding characteristics associated with pre-PCI SCA may help to prevent and improve the management of STEMI patients.

Near-death experiences and the change of worldview in survivors of sudden cardiac arrest: A phenomenological and hermeneutical study.

Near-death experiences (NDEs) can occur during episodes of unconsciousness from life-threatening conditions, such as sudden cardiac arrests (SCAs). This study is based on interviews with patients who had an NDE. The interviews were analyzed with phenomenological hermeneutical method for their lived experiences and the meaning for the view of life and death. Four participants were interviewed 10 weeks after their NDE. Four themes emerged: being on the other side, in another dimension; not dreaming, this is a real experience; being in a non-physical condition without my body; and comparing views of life and death before and after the NDEs. The participants described the NDEs as an experience of another realm as non-physical in nature and existing beyond space and time. This study shows that this experience of another state of being, through the lived experiences of NDEs, gave the participants an entirely new meaning on life and death. To them, death was no longer viewed as an end but a passage into something else and that life continues after death. This realization instantly changed their worldview.

Explaining the Unexplained: A Practical Approach to Investigating the Cardiac Arrest Survivor.

Sudden cardiac arrest (SCA) is a common cause of death. The majority of SCA is caused by ventricular arrhythmia due to underlying CHD. Aborted SCA with no apparent diagnosis after initial assessment with ECG, echocardiography and coronary assessment is referred to as unexplained cardiac arrest (UCA). Systematic evaluation of such patients may reveal a specific diagnosis in up to half of patients before a diagnosis of idiopathic VF is assigned. Specific diagnoses include inherited cardiac conditions, such as latent cardiomyopathies or inherited primary electrical disease. Identifying the cause of UCA is therefore not only critical for appropriate management of the SCA survivors to prevent recurrence, but also for their family members who may be at risk of the same condition. This review provides a tiered, systematic approach for the investigation of UCA.

A panel of blood biomarkers unique to sudden cardiac arrest

The identification of circulating biomarkers specific for sudden cardiac arrest (SCA) could enhance risk prediction. Of particular interest are biomarkers specific to SCA, independent of coronary artery disease (CAD). The purpose of this study was to identify biomarkers of SCA obtained close to the SCA event. Twenty cases (survivors of SCA) and 40 age- and sex-matched controls were compared, with a replication analysis of 29 cases matched to 57 controls. A secondary analysis compared 20 SCA cases to 20 controls with CAD. Blood samples were obtained from SCA survivors at a median of 11 months after the SCA event. Proteins were analyzed on a mass spectrometer using data-independent acquisition; a subset of cytokines were analyzed using immunoassays; and 1153 lipids (13 classes) were analyzed. A false discovery rate P value of <.05 identified associated proteins. Patients had a mean age of 58 years (range 25-87 years), and 70% were male. A total of 26 protein biomarkers associated with SCA when cases were compared with controls, of which 20 differentiated SCA from CAD. The replication analysis identified 8 of 26 biomarkers, of which 6 were not overlapping with CAD. The top identified biological processes involved the extracellular matrix, coagulation cascades, and platelet activation. Lipids in the lysophosphatidylcholine class were implicated in SCA through the CAD pathway. We identified a panel of novel blood biomarkers specifically associated with SCA, including several that may be involved outside the CAD pathway. These biomarkers could have mechanistic significance and the potential to enhance clinical prediction of SCA.

The aftermath of surviving a sudden cardiac arrest for young exercisers - a qualitative study in Norway

BackgroundWhen surviving a sudden cardiac arrest (SCA), physical, cognitive, and emotional effects of surviving may be present for months or years. The survivors' family and colleagues are also highly affected by the incident. There is little knowledge about experiences of surviving SCA in individuals who prior to the incident were young and reported to exercise regularly. Consequently, the aim of this study was to explore the aftermath of surviving a SCA in young, regular exercisers.MethodsThe study had a qualitative design, conducting in-depth individual interviews with SCA survivors < 50 years of age reporting to exercise ≥ 5 h/week and/or who suffered SCA during or less than 60 min after exercise. The data were analysed using systematic text condensation in-line with recommendations from Malterud.Results18 of 31 eligible participants were included in the study. Through analysis we identified ‘Establishing a new everyday life’ as superordinate category, with subordinate categories a) being part of my surroundings, b) expecting normality but facing a new reality and c) lucky to be alive!ConclusionThis study adds knowledge about young and regular exercisers’ experiences after surviving a SCA. The obligations of everyday life in young survivors of SCA often imply a high work load and complex tasks, e.g. due to being in the beginning of their career or even still studying. Healthcare personnel, as well as the society, need to acknowledge that although lucky to be alive and apparently well-functioning, young survivors of SCA may have persistent challenges that cause frustration and reduced quality of life.

Recurrent Out-of-Hospital Sudden Cardiac Arrest: Prevalence and Clinical Factors.

Despite improvements in management following survival from sudden cardiac arrest (SCA) and wide availability of implantable cardioverter defibrillators for secondary prevention, a subgroup of individuals will suffer multiple distinct episodes of SCA. The objective of this study was to characterize and evaluate the burden of recurrent out-of-hospital SCA among survivors of SCA in a single large US community. SCA cases were prospectively ascertained in the Oregon Sudden Unexpected Death Study. Individuals that experienced recurrent SCA were identified both prospectively and retrospectively. We ascertained 6649 individuals with SCA (2002-2020) and 924 (14%) survived to hospital discharge. Of these, 88 survivors (10%) experienced recurrent SCA. Of the nonsurvivors (n=5725), 35 had suffered a recurrent SCA. Of the total 123 SCA cases with recurrent SCA, >60% occurred at least 1 year after the initial SCA (median 23 months, range: 6 days to 31 years). SCA occurred despite a secondary prevention implantable cardioverter defibrillator in 22% (n=26). Prevalence of coronary disease (36% versus 25%), hypertension (69% versus 43%), diabetes (44% versus 21%), and chronic kidney disease (35% versus 14%) was significantly higher in recurrent SCA versus single SCA survivors (n=80, P=0.01). Among individuals with no secondary prevention implantable cardioverter defibrillators before recurrent SCA, the majority had apparently reversible etiologies identified at initial SCA, with one-quarter undergoing coronary revascularization and over half diagnosed with noncoronary cardiac etiologies. At least 10% of SCA survivors had recurrent SCA, and a large subgroup suffered their repeat SCA despite treatment for an apparently reversible etiology. A renewed focus on careful assessment of cardiac substrate as well as management of coronary disease, hypertension, diabetes, and chronic kidney disease in SCA survivors could reduce recurrent SCA.

Abstract 12083: Highly Caffeinated Energy Drinks and Genetic Heart Disease-Associated Sudden Cardiac Arrest

Background: Highly caffeinated energy drinks (HCEDs) can trigger life-threatening cardiac arrhythmias in individuals with and without an underlying genetic predisposition. Though the mechanism(s) responsible for these events remain unclear, it has been postulated that high caffeine may alter heart rate, blood pressure, cardiac contractility, and cardiac repolarization in a manner that is pro-arrhythmic. Objective: To describe our experience regarding sudden cardiac arrest (SCA) events occurring in proximity to HCED consumption in patients with underling genetic heart diseases. Methods: All SCA survivors referred to the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic for clinical and/or molecular evaluation were reviewed to identify those with a history of HCED consumption prior to their event. Patient demographics, clinical characteristics, documented HCED consumption, and temporal relationship of HCED consumption to SCA were extracted from the electronic medical record. Results: Among 144 SCA survivors with a structurally normal heart, 8 (6 females; mean age at event 28 ± 8 years) experienced an unexplained SCA associated temporally with HCED consumption. Of these, 5 (63%) had either long QT syndrome (n=3) or catecholaminergic polymorphic ventricular tachycardia (n=2). The remaining 3 were diagnosed with unexplained SCA/idiopathic ventricular fibrillation after a comprehensive evaluation. Three patients (37%) were habitual HCED consumers while 5 (63%) imbibed for the first time with consumption ranging from several hours to a few minutes before the SCA. Seven patients (88%) required a rescue shock (average 2 ± 2 shocks/patient) while 1 was manually resuscitated. Upon follow-up, 6 (75%) were dismissed with an implantable cardioverter defibrillator, 1 (13%) on pharmacologic therapy, and 1 (13%) underwent denervation surgery. All SCA survivors have quit drinking HCEDs and have been event-free since. Conclusion: Overall, 8/144 (5.6%) of SCA survivors evaluated in our program experienced a SCA in proximity to consuming a HCED. Although larger cohort studies are needed to elucidate the precise mechanism for HCED-triggered/associated SCA and quantify its precise pro-arrhythmic risk, it seems prudent to sound an early warning.

Should targeted temperature management be used in cardiogenic shock patients? Systematic review and meta-analysis.

Therapeutic hypothermia, or targeted temperature management (TTM), is a strategy of reducing the core body temperature of survivors of sudden cardiac arrest, cardiogenic shock (CS) or stroke. Therefore, a systematic literature review and meta-analysis were performed to tackle the question about whether the implementation of TTM is actually beneficial for patients with CS. Study was designed as a systematic review and meta-analysis. PubMed, Cochrane Library, Web of Science and Scopus were searched from these databases inception to July 17, 2022. Eligible studies were those comparing TTM and non-TTM treatment in CS patients. Data were pooled with the Mantel-Haenszel method. Thirty-day mortality was reported in 3 studies. Polled analysis of 30-day mortality was 44.2% for TTM group and 48.9% for non-TTM group (risk ratio: 0.90; 95% confidence interval: 0.75 to 1.08; p = 0.27). Other mortality follow-up periods showed also no statistically significant differences (p > 0.05). The occurrence of adverse events in the studied groups also did not show statistically significant differences between TTM and non-TTM groups (p > 0.05 for myocardial infarction, stent thrombosis, sepsis, pneumonia, stroke or bleeding events). The present analysis shows no significant benefit of TTM in patients with CS. Moreover, no statistically significant increase of the incidence of adverse effects was found. However, further randomized studies with higher sample size and greater validity are needed to determine if TTM is worth implementing in CS patients.

Survivors of Sudden Cardiac ArrestPresenting With Pulseless ElectricalActivity: Clinical Substrate, Triggers, Long-Term Prognosis.

The proportion of sudden cardiac arrest (SCA) presenting as pulseless electrical activity (PEA) is rising, and survival remains low. The pathophysiology of PEA-SCA is poorly understood, and current clinical practice lacks specific options for the management of survivors. In this study, the authors sought to investigate clinical profile, triggers, and long-term prognosis in survivors of SCA presenting with PEA. The community-based Oregon SUDS (Sudden Unexpected Death Study) (since 2002) and Ventura PRESTO (Prediction of Sudden Death in Multi-ethnic Communities) (since 2015) studies prospectively ascertain all out-of-hospital SCAs of likely cardiac etiology. Lifetime clinical history and detailed evaluation of SCA events is available. We evaluated all SCA survivors with PEA as the presenting rhythm. The study population included 201 PEA-SCA survivors. Of these, 97 could be contacted for access to their clinical records. Among the latter, the mean age was 67 ± 17 years and 58 (60%) were male. After in-hospital examinations, 29 events (30%) were associated with acute myocardial infarction, and 5 (5%) had bradyarrhythmias. Among the remaining 63 patients (65%), specific triggers remained undetermined, although 31 (49%) had a previous history of heart failure. Of the 201 overall survivors, 91 (45%) were deceased after a mean follow-up of 4.2 ± 4.0 years. Survivors under the age of 40 years had an excellent long-term prognosis. Survivors of PEA-SCA are a heterogeneous group with high prevalence of multiple comorbidities, especially heart failure. Surprisingly good long-term survival was observed in young individuals. Acute myocardial infarction as the precipitating event was common, but triggers remained undetermined in the majority. Provision of individualized care to PEA survivors requires a renewed investigative focus on PEA-SCA.