Sudden Death in Patients With Coronary Heart Disease Without Severe Systolic Dysfunction

The association between GRACE score at admission for myocardial infarction and the incidence of sudden cardiac arrests in long-term follow-up - the MADDEC study

Background. Sudden cardiac arrest (SCA), often also leading to sudden cardiac death (SCD), is a common complication in coronary artery disease. Despite the effort there is a lack of applicable prediction tools to identify those at high risk. We tested the association between the validated GRACE score and the incidence of SCA after myocardial infarction. Material and methods. A retrospective analysis of 1,985 patients treated for myocardial infarction (MI) between January 1st 2015 and December 31st 2018 and followed until the 31st of December of 2021. The main exposure variable was patients' GRACE score at the point of admission and main outcome variable was incident SCA after hospitalization. Their association was analyzed by subdistribution hazard (SDH) model analysis. The secondary endpoints included SCA in patients with no indication to implantable cardioverter-defibrillator (ICD) device and incident SCD. Results. A total of 1985 patients were treated for MI. Mean GRACE score at baseline was 118.7 (SD 32.0). During a median follow-up time of 5.3 years (IQR 3.8-6.1 years) 78 SCA events and 52 SCDs occurred. In unadjusted analyses one SD increase in GRACE score associated with over 50% higher risk of SCA (SDH 1.55, 95% CI 1.29-1.85, p < 0.0001) and over 40% higher risk for SCD (1.42, 1.12-1.79, p = 0.0033). The associations between SCA and GRACE remained statistically significant even with patients without indication for ICD device (1.57, 1.30-1.90, p < 0.0001) as well as when adjusting with patients LVEF and omitting the age from the GRACE score to better represent the severity of the cardiac event. The association of GRACE and SCD turned statistically insignificant when adjusting with LVEF. Conclusions. GRACE score measured at admission for MI associates with long-term risk for SCA.

Characteristics Associated with Ventricular Tachyarrhythmias and Their Prognostic Impact in Heart Failure with Mildly Reduced Ejection Fraction

Background: The occurrence of ventricular tachyarrhythmias represents an established risk factor of mortality in heart failure (HF). However, data concerning their prognostic impact in heart failure with mildly reduced ejection fraction (HFmrEF) is limited. Therefore, the present study aims to investigate patient characteristics associated with ventricular tachyarrhythmias and their prognostic impact in patients with HFmrEF. Methods: Consecutive patients hospitalized with HFmrEF (i.e., left ventricular ejection fraction 41-49% and signs and/or symptoms of HF) were retrospectively included at one institution from 2016 to 2022. The prognosis of patients with HFmrEF and different types of ventricular tachyarrhythmias (i.e., non-sustained ventricular tachycardia (nsVT), sustained VT (sVT), and ventricular fibrillation (VF) was investigated for the primary endpoint of long-term all-cause mortality at 30 months. Secondary endpoints included in-hospital all-cause mortality and long-term HF-related rehospitalization at 30 months. Results: From a total of 2184 patients with HFmrEF, 4.4% experienced ventricular tachyarrhythmias (i.e., 2.0% nsVT, 0.7% sVT, and 1.6% VF). The occurrence of nsVT was associated with higher New York Heart Association (NYHA) functional class, whereas the incidence of sVT/VF was associated with acute myocardial infarction and ischemic heart disease. However, nsVT (25.0%; HR = 0.760; 95% CI 0.419-1.380; p = 0.367) and sVT/VF (28.8%; HR = 0.928; 95% CI 0.556-1.549; p = 0.776) were not associated with a higher risk of long-term all-cause mortality compared to patients with HFmrEF without ventricular tachyarrhythmias (31.5%). In-hospital cardiovascular mortality was more frequently observed in patients with HFmrEF and sVT/VF compared to those with HFmrEF but without sustained ventricular tachyarrhythmias (7.7% vs. 1.5%; p = 0.004). Finally, the risk of rehospitalization for worsening HF was not affected by the presence of ventricular tachyarrhythmias. Conclusions: The occurrence of ventricular tachyarrhythmias in patients hospitalized with HFmrEF was low and not associated with long-term prognosis.

The relationship between CTA performances and cardiac function indicators in myocardial bridge and mural coronary artery

OBJECTIVE

To investigate the relationship between computed tomography angiography (CTA) performances and cardiac function indicators in patients with myocardial bridge and mural coronary artery (MB-MCA).

METHODS

The clinical data of 60 patients with MB-MCA receiving CTA in the First Hospital of Zhangjiakou from January 2021 to February 2022 were analyzed retrospectively. The patients were divided into different groups based on CTA performances, including the degree of stenosis of the left anterior descending (LAD) MCA, whether there was atherosclerosis in the anterior segment of MB of LAD branch, the MB thickness, and the degree of stenosis of the LAD branch. The correlation between these TCA performances and cardiac function indicators including end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV), cardiac output (CO), and left ventricular ejection fraction (LVEF) was analyzed. Besides, the receiver operating characteristic (ROC) curve was used to analyze the predictive performance of cardiac function indicators for the severity of MB-MCA.

RESULTS

ESV, EDV, SV, CO and LVEF were statistically different between the moderate stenosis group and mild stenosis group (all P < 0.05). EDV, SV, CO, and LVEF were statistically different between the atherosclerosis group and non-atherosclerosis group (all P < 0.05). SV, CO, LVEF in the deep group were lower than that in the superficial group (all P < 0.05). EDV, CO, LVEF were different between the LAD moderate stenosis group and LAD mild stenosis group (all P < 0.05). The AUC (areas under the curve) of combined detection of ESV, EDV, SV, CO, and LVEF in predicting the severity of MB-MCA was 0.907, which was higher than the single indicator predictive effect.

CONCLUSIONS

Cardiac function indicators, mainly CO and LVEF are correlated with the CTA performance of MB-MCA patients. The combination of cardiac function indicators has a good effect in predicting the severity of MB-MCA.

Sudden cardiac death after heart transplantation: a population-based study

AIMS

The epidemiology of sudden cardiac death (SCD) after heart transplantation (HTx) remains imprecisely described. We aimed to assess the incidence and determinants of SCD in a large cohort of HTx recipients, compared with the general population.

METHODS AND RESULTS

Consecutive HTx recipients (n = 1246, 2 centres) transplanted between 2004 and 2016 were included. We prospectively assessed clinical, biological, pathologic, and functional parameters. SCD was centrally adjudicated. We compared the SCD incidence beyond the first year post-transplant in this cohort with that observed in the general population of the same geographic area (registry carried out by the same group of investigators; n = 19 706 SCD). We performed a competing risk multivariate Cox model to identify variables associated with SCD. The annual incidence of SCD was 12.5 per 1,000 person-years [95% confidence interval (CI), 9.7-15.9] in the HTx recipients cohort compared with 0.54 per 1,000 person-years (95% CI, 0.53-0.55) in the general population (P < 0.001). The risk of SCD was markedly elevated among the youngest HTx recipients with standardized mortality ratios for SCD up to 837 for recipients ≤30 years. Beyond the first year, SCD was the leading cause of death. Five variables were independently associated with SCD: older donor age (P = 0.003), younger recipient age (P = 0.001) and ethnicity (P = 0.034), pre-existing donor-specific antibodies (P = 0.009), and last left ventricular ejection fraction (P = 0.048).

CONCLUSION

HTx recipients, particularly the youngest, were at very high risk of SCD compared with the general population. The consideration of specific risk factors may help identify high-risk subgroups.

Cardiac Magnetic Resonance as an Etiological Diagnosis Tool in Recovered Sudden Cardiac Death or Unstable Ventricular Arrhythmia Patients

BACKGROUND

Cardiac magnetic resonance (CMR) has an increasing diagnostic relevance in survivors of sudden cardiac death (SCD) or unstable ventricular arrhythmia (UVA) in developed countries.

OBJECTIVE

To evaluate retrospectively the additional role of CMR in a developing country where few resources are available, and should be used more effectively.

METHODS

The study included SCD or UVA survivors admitted between 2009 and 2019 at a tertiary academic institution referred to CMR. Demographic, clinical, and laboratory data were collected from the medical records. CMR images and reports were reviewed and their impact on the final etiological diagnosis was determined. A descriptive analysis was performed and p<0.05 established as significant.

RESULTS

Sixty-four patients, 54.9±15.4 years old, and 42 (71.9%) males. Most events (81.3%) were out of the hospital and ventricular tachycardia was the most common rhythm. Cardiovascular medications were previously used by 55 patients, and beta-blockers were the most used medications (37.5%). Electrocardiogram had electrical inactive areas in 21.9% and all of them had fibrosis at CMR. Mean left ventricular ejection fraction (LVEF) was 44±14%, with 60.9% ≤50% and only 29.7% ≤35%. Late gadolinium enhancement was identified in 71.9%, with a transmural pattern in 43.8%. Chagas cardiomyopathy was the most common etiology (28.1%), followed by ischemic cardiomyopathy (17.2%). Among 26 without a previously identified etiology, CMR could define it (15 patients - 57%).

CONCLUSION

In accordance with previous studies in developed countries, CMR was capable of increasing etiological diagnosis and identifying the arrhythmogenic substrate, allowing better care in half of the underdiagnosed patients.

Sudden death in ischemic heart disease: looking for new predictors: polygenic risk

The phenomenon of sudden death (SD) occurs, in 70% of cases, in people who do not fall within the indications of the guidelines relating to the implantation of the defibrillator. There is a way of inheriting the risk condition by genetic means, the polygenic one, in which mutations are not found, but an increase in alleles of common variations called polymorphisms. The PRE-DETERMINE cohort study has the primary objective of determining whether biological markers, and electrocardiogram can be used to identify individuals more likely to experience SD. Within the study, we investigated the utility of the genome-wide polygenic score for coronary artery disease (GPSCAD) for SD risk stratification in an intermediate-risk population with stable coronary artery disease without severe systolic dysfunction and/or indication for an implantable cardioverter defibrillator in primary prevention. Over a mean follow-up period of 8.0 years, patients in the top decile of GPSCAD were at higher absolute (8.0% vs. 4.8%; P < 0.005) and relative (29% vs. 16%; P < 0.0003) risk of SD compared to the rest of the cohort. No association was found between the highest decile of GPSCAD and other forms of death, cardiac, and non-cardiac. The data on the increase in absolute and relative terms of SD can be used, at this stage, only for a theoretical estimate on the possible efficacy of the defibrillator in the population with chronic coronary artery disease and moderately depressed left ventricular function as number needed to treat and possible reduction of mortality in high-risk patients (those included in the top decile of GPSCAD).

Time Trend in Incidence of Sudden Cardiac Death After Percutaneous Coronary Intervention from 2009 to 2017 (from the Japanese Multicenter Registry)

The advances in the integrated management of patients with coronary artery disease undergoing percutaneous coronary intervention (PCI) have reduced subsequent cardiovascular events. Nonetheless, sudden cardiac death (SCD) remains a major concern. Therefore, we aimed to investigate the time trend in SCD incidence after PCI and to identify the clinical factors contributing to SCD. From a prospective, multicenter cohort registry in Japan, 8,723 consecutive patients with coronary artery disease undergoing PCI between 2009 and 2017 were included. We evaluated the SCD incidence 2 years after PCI; all death events were adjudicated, and SCD was defined as unexpected death without a noncardiovascular cause in a previously stable patient within 24 hours from the onset. The Fine and Gray method was used to identify the factors associated with SCD. Overall, the mean age of the patients was 68.3 ± 11.3 years, and 1,173 patients (13.4%) had heart failure (HF). During the study period, the use of second-generation drug-eluting stents increased. The 2-year cumulative incidence of all-cause mortality and SCD was 4.29% and 0.45%, respectively. All-cause mortality remained stable during the study period (p for trend = 0.98), whereas the crude incidence of SCD tended to decrease over the study period (p for trend = 0.052). HF was the strongest predictor associated with the risk of SCD (crude incidence [vs non-HF] 2.13% vs 0.19%; p <0.001). In conclusion, the incidence of SCD after PCI decreased over the last decade, albeit the high incidence of SCD among patients with HF remains concerning.

Heart Failure Burden by Autopsy, Guideline-Directed Medical Therapy, and ICD Utilization Among Sudden Deaths

BACKGROUND

Studies of heart failure with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF) report high sudden cardiac death (SCD) rates but presume cardiac cause. Underlying causes, guideline-directed medical therapy (GDMT), and implantable cardioverter-defibrillator (ICD) use in community sudden deaths with heart failure (HF) are unknown.

OBJECTIVES

This study aims to assess the burden of HF, GDMT, and ICD use among autopsied sudden deaths in the POST SCD (Postmortem Systematic Investigation of Sudden Cardiac Death) study, a countywide postmortem study of all presumed SCDs.

METHODS

Incident WHO-defined (presumed) SCDs for individuals of ages 18 to 90 years were autopsied via prospective surveillance of consecutive out-of-hospital deaths in San Francisco County from February 1, 2011, to March 1, 2014. Sudden arrhythmic deaths (SADs) had no identifiable nonarrhythmic cause (eg, pulmonary embolism), and are thus considered potentially rescuable with ICD.

RESULTS

Of 525 presumed SCDs, 100 (19%) had HF. There were 85 patients with known HF (31 HFpEF, 54 HFrEF) and 15 with subclinical HF (postmortem evidence of cardiomyopathy and pulmonary edema without HF diagnosis). SADs comprised 56% (293 of 525) of all presumed SCDs, and 69% (69 of 100) of HF SCDs. The rates were similar in HFrEF (40 of 54 [74%]) and HFpEF (19 of 31 [61%], P = 0.45). Four SAD patients (4%) had ICDs, 3 of which experienced device failure. Twenty-eight SCDs had ejection fraction ≤35%: 22 (79%) with arrhythmic and 6 (21%) with noncardiac causes. Of the 22 SAD patients, 8 (36%) had no identifiable barrier to ICD referral. Complete use of GDMT in HFrEF was 6%.

CONCLUSIONS

One in 5 community sudden deaths had HF; two-thirds had autopsy-confirmed arrhythmic causes. ICD prevention criteria captured only 8% (22 of 293) of all SAD cases countywide; GDMT and ICD use remain important targets for HF sudden death prevention.

Polygenic Risk Score Predicts Sudden Death in Patients With Coronary Disease and Preserved Systolic Function

BACKGROUND

A familial predisposition to sudden and/or arrhythmic death (SAD) in the setting of coronary artery disease (CAD) exists; however, the genetic basis is poorly understood.

OBJECTIVES

The purpose of this study was to determine whether a genome-wide polygenic score for coronary artery disease (GPSCAD) might have utility in SAD risk stratification in CAD patients without severe systolic dysfunction.

METHODS

A previously validated GPSCAD was generated utilizing genome-wide genotyping in 4,698 PRE-DETERMINE participants of European ancestry with CAD and left ventricular ejection fraction >30%-35%. The population was dichotomized according to top GPSCAD decile as defined by the general population, and absolute, proportional, and relative risks for SAD and non-SAD were estimated using competing risk analyses.

RESULTS

Over a median follow-up of 8.0 years, participants in the top GPSCAD decile were at elevated absolute SAD risk (8.0%; 95% CI: 5.1%-12.4% vs 4.8%; 95% CI: 3.3%-7.0%; P = 0.005) and proportional SAD risk (29% vs 16%; P = 0.0003) compared with the remainder. After controlling for left ventricular ejection fraction, clinical factors, and electrocardiogram parameters, the top GPSCAD decile was associated with SAD (subdistribution HR: 1.77; 95% CI: 1.23-2.54; P = 0.002) but not non-SAD (subdistribution HR: 1.00; 95% CI: 0.80-1.25; P = 0.98) (P for Δ = 0.003). The addition of the top GPSCAD decile to the multivariable model significantly improved net reclassification indexes (NRIs) (continuous NRI: 14.0%; P = 0.024; and categorical NRI: 6.6%; P = 0.005) but not the C-index (difference in C-index: 0.007; P = 0.143).

CONCLUSIONS

Among CAD patients without severe systolic dysfunction, high GPSCAD specifically predicted SAD and enriched for both absolute and proportional SAD risk, identifying a population who might benefit from defibrillator therapy.

Catheter ablation of well tolerated ventricular tachycardia in patients with structural heart disease and without automatic defibrillator implantation: long term follow-up

BACKGROUND

The occurrence of a sustained monomorphic ventricular tachycardias (SMVT) in patients with underlying structural heart disease (SHD) is considered related to poor prognosis. The purpose of our work was to evaluate if these patients could benefit from radiofrequency (RF) ablation, and the defibrillator (ICD) implantation could be deferred during follow-up.

METHODS

We reviewed consecutive patients with well-tolerated SMVT, SHD and left ventricular ejection fraction over 30%. These patients were treated by RF ablation and were discharged without ICD. The primary outcome was a composite of all-cause death and recurrence of SMVT; the secondary outcome was death from all causes.

RESULTS

62 patients were selected. After a median follow-up of 38.8 months, the primary outcome occurred in 24 (38.7%) and the secondary in 11 (17.7%) patients. The annual mortality rate was 4.3% and no patient died from sudden death.

CONCLUSIONS

RF ablation as a first-choice therapy seems to represent an effective and beneficial therapeutic approach.

Arrhythmic sudden death survival prediction using deep learning analysis of scarring in the heart

Sudden cardiac death from arrhythmia is a major cause of mortality worldwide. Here, we develop a novel deep learning (DL) approach that blends neural networks and survival analysis to predict patient-specific survival curves from contrast-enhanced cardiac magnetic resonance images and clinical covariates for patients with ischemic heart disease. The DL-predicted survival curves offer accurate predictions at times up to 10 years and allow for estimation of uncertainty in predictions. The performance of this learning architecture was evaluated on multi-center internal validation data and tested on an independent test set, achieving concordance index of 0.83 and 0.74, and 10-year integrated Brier score of 0.12 and 0.14. We demonstrate that our DL approach with only raw cardiac images as input outperforms standard survival models constructed using clinical covariates. This technology has the potential to transform clinical decision-making by offering accurate and generalizable predictions of patient-specific survival probabilities of arrhythmic death over time.

Diabetes and Risk of Sudden Death in Coronary Artery Disease Patients Without Severe Systolic Dysfunction

OBJECTIVES

This study sought to determine the absolute and relative associations of diabetes mellitus (DM) and hemoglobin A1c (HbA1c) with sudden and/or arrhythmic death (SAD) versus other modes of death in patients with coronary artery disease (CAD) who do not qualify for implantable cardioverter-defibrillators.

BACKGROUND

Patients with CAD and DM are at elevated risk for SAD; however, it is unclear whether these patients would benefit from implantable cardioverter-defibrillators given competing causes of death and/or whether HbA1c might augment SAD risk stratification.

METHODS

In the PRE-DETERMINE study of 5,764 patients with CAD with left ventricular ejection fraction (LVEF) of >30% to 35%, competing risk analyses were used to compare the absolute and relative risks of SAD versus non-SAD by DM status and HbA1c level and to identify risk factors for SAD among 1,782 patients with DM.

RESULTS

Over a median follow-up of 6.8 years, DM and HbA1c were significantly associated with SAD and non-SAD (P < 0.05 for all comparisons); however, the cumulative incidence of non-SAD (19.2%; 95% CI: 17.3%-21.2%) was almost 4 times higher than SAD (4.8%; 95% CI: 3.8%-5.9%) in DM patients. A similar pattern of absolute risk was observed across categories of HbA1c. In analyses limited to patients with DM, HbA1c was not associated with SAD, whereas low LVEF, atrial fibrillation, and electrocardiogram measurements were associated with higher SAD risk.

CONCLUSIONS

In patients with CAD and LVEF of >30% to 35%, patients with DM and/or elevated HbA1c are at much higher absolute risk of dying from non-SAD than SAD. Clinical risk markers, and not HbA1c, were associated with SAD risk in patients with DM. (PRE-DETERMINE: Biologic Markers and MRI SCD Cohort Study; NCT01114269).

Ventricular Arrhythmias in Ischemic Cardiomyopathy-New Avenues for Mechanism-Guided Treatment

Ischemic heart disease is the most common cause of lethal ventricular arrhythmias and sudden cardiac death (SCD). In patients who are at high risk after myocardial infarction, implantable cardioverter defibrillators are the most effective treatment to reduce incidence of SCD and ablation therapy can be effective for ventricular arrhythmias with identifiable culprit lesions. Yet, these approaches are not always successful and come with a considerable cost, while pharmacological management is often poor and ineffective, and occasionally proarrhythmic. Advances in mechanistic insights of arrhythmias and technological innovation have led to improved interventional approaches that are being evaluated clinically, yet pharmacological advancement has remained behind. We review the mechanistic basis for current management and provide a perspective for gaining new insights that centre on the complex tissue architecture of the arrhythmogenic infarct and border zone with surviving cardiac myocytes as the source of triggers and central players in re-entry circuits. Identification of the arrhythmia critical sites and characterisation of the molecular signature unique to these sites can open avenues for targeted therapy and reduce off-target effects that have hampered systemic pharmacotherapy. Such advances are in line with precision medicine and a patient-tailored therapy.

Cardiac resynchronization therapy with or without defibrillator in patients with heart failure

Aims

Randomized data on the efficacy/safety of cardiac resynchronization therapy with vs. without defibrillator (CRT-D,-P) in heart failure with reduced ejection fraction (HFrEF) are scarce. We aimed to evaluate survival associated with use of CRT-D vs. CRT-P in a contemporary cohort with HFrEF.

Methods and results

Patients from Swedish HF Registry treated with CRT-D/CRT-P and fulfilling criteria for primary prevention defibrillator use were included. Logistic regression was used to evaluate predictors of CRT-D non-use. All-cause mortality was compared in CRT-D vs. CRT-P by Cox regression in a 1 : 1 propensity-score-matched cohort. Of 1988 patients with CRT, 1108 (56%) had CRT-D and 880 (44%) CRT-P. Older age, higher ejection fraction (EF), female sex, and the lack of referral to HF nurse-led outpatient clinic were major determinants of CRT-D non-use. After matching, 645 CRT-D patients were compared with 645 with CRT-P. The CRT-D use was associated with lower 1- and 3-year all-cause mortality [hazard ratio (HR):0.76, 95% confidence interval (CI):0.58–0.98; HR: 0.82, 95% CI: 0.68–0.99, respectively]. Results were consistent in all pre-specified subgroups except for CRT-D use being associated with lower 3-year mortality in patients with an EF < 30% but not in those with an EF ≥ 30% (HR: 0.73, 95% CI: 0.59–0.89 and HR: 1.24, 95% CI: 0.83–1.85, respectively; P-interaction = 0.02).

Conclusion

In a contemporary HFrEF cohort, CRT-D was associated with lower mortality compared with CRT-P. The CRT-D use was less likely in older patients, females, and in patients not referred to HF nurse-led outpatient clinic. Our findings support the use of CRT-D vs. CRT-P in HFrEF, in particular with severely reduced EF.

Factors Predisposing to Survival After Resuscitation for Sudden Cardiac Arrest

BACKGROUND

In the POST SCD study, the authors autopsied all World Health Organization (WHO)-defined sudden cardiac deaths (SCDs) and found that only 56% had an arrhythmic cause; resuscitated sudden cardiac arrests (SCAs) were excluded because they did not die suddenly. They hypothesized that causes underlying resuscitated SCAs would be similarly heterogeneous.

OBJECTIVES

The aim of this study was to determine the causes and outcomes of resuscitated SCAs.

METHODS

The authors identified all out-of-hospital cardiac arrests (OHCAs) from February 1, 2011, to January 1, 2015, of patients aged 18 to 90 years in San Francisco County. Resuscitated SCAs were OHCAs surviving to hospitalization and meeting WHO criteria for suddenness. Underlying cause was determined by comprehensive record review.

RESULTS

The authors identified 734 OHCAs over 48 months; 239 met SCA criteria, 133 (55.6%) were resuscitated to hospitalization, and 47 (19.7%) survived to discharge. Arrhythmic causes accounted for significantly more resuscitated SCAs overall (92 of 133, 69.1%), particularly among survivors (43 of 47, 91.5%), than WHO-defined SCDs in POST SCD (293 of 525, 55.8%; p < 0.004 for both). Among resuscitated SCAs, arrhythmic cause, ventricular tachycardia/fibrillation initial rhythm, and white race were independent predictors of survival. None of the resuscitated SCAs due to neurologic causes survived.

CONCLUSIONS

In this 4-year countywide study of OHCAs, only one-third were sudden, of which one-half were resuscitated to hospitalization and 1 in 5 survived to discharge. Arrhythmic cause predicted survival and nearly one-half of nonsurvivors had nonarrhythmic causes, suggesting that SCA survivors are not equivalent to SCDs. Early identification of nonarrhythmic SCAs, such as neurologic emergencies, may be a target to improve OHCA survival.

Sudden Cardiac Death in Patients with Heart Disease and Preserved Systolic Function: Current Options for Risk Stratification

Sudden cardiac death (SCD) is the leading cause of cardiovascular mortality in patients with coronary artery disease without severe systolic dysfunction and in heart failure with preserved ejection fraction. From a global health perspective, while risk may be lower, the absolute number of SCDs in patients with left ventricle ejection fraction >35% is higher than in those with severely reduced left ventricle ejection fraction (defined as ≤35%). Despite these observations and the high amount of available data, to date there are no clear recommendations to reduce the sudden cardiac death burden in the population with mid-range or preserved left ventricle ejection fraction. Ongoing improvements in risk stratification based on electrophysiological and imaging techniques point towards a more precise identification of patients who would benefit from ICD implantation, which is still an unmet need in this subset of patients. The aim of this review is to provide a state-of-the-art approach in sudden cardiac death risk stratification of patients with mid-range and preserved left ventricular ejection fraction and one of the following etiologies: ischemic cardiomyopathy, heart failure, atrial fibrillation or myocarditis.

Long-Term Outcome of the Randomized DAPA Trial

Background:

The randomized DAPA trial (Defibrillator After Primary Angioplasty) aimed to evaluate the survival benefit of prophylactic implantable cardioverter defibrillator (ICD) implantation in early selected high-risk patients after primary percutaneous coronary intervention for ST-segment–elevation myocardial infarction.

Methods:

A randomized, multicenter, controlled trial compared ICD versus conventional medical therapy in high-risk patients with primary percutaneous coronary intervention, based on one of the following factors: left ventricular ejection fraction <30% within 4 days after ST-segment–elevation myocardial infarction, primary ventricular fibrillation, Killip class ≥2 or TIMI (Thrombolysis in Myocardial Infarction) flow <3 after percutaneous coronary intervention. ICD was implanted 30 to 60 days after MI. Primary end point was all-cause mortality at 3 years follow-up. The trial prematurely ended after inclusion of 266 patients (38% of the calculated sample size). Additional survival assessment was performed in February 2019 for the primary end point.

Results:

A total of 266 patients, 78.2% males, with a mean age of 60.8±11.3 years, were enrolled. One hundred thirty-one patients were randomized to the ICD arm and 135 patients to the control arm. All-cause mortality was significant lower in the ICD group (5% versus 13%, hazard ratio, 0.37 [95% CI, 0.15–0.95]) after 3 years follow-up. Appropriate ICD therapy occurred in 9 patients at 3 years follow-up (5 within the first 8 months after implantation). After a median long-term follow-up of 9 years (interquartile range, 3–11), total mortality (18% versus 38%; hazard ratio, 0.58 [95% CI, 0.37–0.91]), and cardiac mortality (hazard ratio, 0.52 [95% CI, 0.28–0.99]) was significant lower in the ICD group. Noncardiac death was not significantly different between groups. Left ventricular ejection fraction increased ≥10% in 46.5% of the patients during follow-up, and the extent of improvement was similar in both study groups.

Conclusions:

In this prematurely terminated and thus underpowered randomized trial, early prophylactic ICD implantation demonstrated lower total and cardiac mortality in patients with high-risk ST-segment–elevation myocardial infarction treated with primary percutaneous coronary intervention.

Registration:

URL: https://www.trialregister.nl ; Unique identifier: Trial NL74 (NTR105).

Arrhythmic risk stratification in heart failure mid-range ejection fraction patients with a non-invasive guiding to programmed ventricular stimulation two-step approach

BACKGROUND

Although some post myocardial infarction (post-MI) and dilated cardiomyopathy (DCM) patients with mid-range ejection fraction heart failure (HFmrEF/40%-49%) face an increased risk for arrhythmic sudden cardiac death (SCD), current guidelines do not recommend an implantable cardiac defibrilator (ICD). We risk stratified hospitalized HFmrEF patients for SCD with a combined non-invasive risk factors (NIRFs) guiding to programmed ventricular stimulation (PVS) two-step approach.

METHODS

Forty-eight patients (male = 83%, age = 64 ± 14 years, LVEF = 45 ± 5%, CAD = 69%, DCM = 31%) underwent a NIRFs screening first-step with electrocardiogram (ECG), SAECG, Echocardiography and 24-hour ambulatory ECG (AECG). Thirty-two patients with presence of one of three NIRFs (SAECG ≥ 2 positive criteria for late potentials, ventricular premature beats ≥ 240/24 hours, and non-sustained ventricular tachycardia [VT] episode ≥ 1/24 hours) were further investigated with PVS. Patients were classified as either low risk (Group 1, n = 16, NIRFs-), moderate risk (Group 2, n = 18, NIRFs+/PVS-), and high risk (Group 3, n = 14, NIRFs+/PVS+). All in Group 3 received an ICD.

RESULTS

After 41 ± 18 months, 9 of 48 patients, experienced the major arrhythmic event (MAE) endpoint (clinical VT/fibrillation = 3, appropriate ICD activation = 6). The endpoint occurred more frequently in Group 3 (7/14, 50%) than in Groups 1 and 2 (2/34, 5.8%). Logistic regression model adjusted for PVS, age, and LVEF revealed that PVS was an independent MAE predictor (OR: 21.152, 95% CI: 2.618-170.887, P = .004). Kaplan-Meier curves diverged significantly (log rank, P < .001) while PVS negative predictive value was 94%.

CONCLUSIONS

In hospitalized HFmrEF post-MI and DCM patients, a NIRFs guiding to PVS two-step approach efficiently detected the subgroup at increased risk for MAE.

Secondary prevention of sudden cardiac death

The prevention and treatment of sudden cardiac death (SCD) remains a significant public health challenge. For patients with a history of sudden death attributable to ventricular arrhythmia, implantable cardioverter-defibrillator (ICD) therapy is a mainstay of treatment, although these patients remain at high risk for recurrent ventricular arrhythmia and defibrillator therapies. In this review, we summarize landmark clinical trials evaluating the efficacy of ICD therapy in secondary prevention patients, review clinical outcomes including mode of death in survivors of SCD, and highlight the role for systematic diagnostic evaluation. We additionally discuss the invasive electrophysiological management of these patients, including ICD selection and programming as well as the role and timing of antiarrhythmic drug therapy and catheter ablation. Finally, we frame future challenges and needs to advance the care for secondary prevention patients.

Simple electrocardiographic measures improve sudden arrhythmic death prediction in coronary disease

AIMS

To determine whether the combination of standard electrocardiographic (ECG) markers reflecting domains of arrhythmic risk improves sudden and/or arrhythmic death (SAD) risk stratification in patients with coronary heart disease (CHD).

METHODS AND RESULTS

The association between ECG markers and SAD was examined in a derivation cohort (PREDETERMINE; N = 5462) with adjustment for clinical risk factors, left ventricular ejection fraction (LVEF), and competing risk. Competing outcome models assessed the differential association of ECG markers with SAD and competing mortality. The predictive value of a derived ECG score was then validated (ARTEMIS; N = 1900). In the derivation cohort, the 5-year cumulative incidence of SAD was 1.5% [95% confidence interval (CI) 1.1-1.9] and 6.2% (95% CI 4.5-8.3) in those with a low- and high-risk ECG score, respectively (P for Δ < 0.001). A high-risk ECG score was more strongly associated with SAD than non-SAD mortality (adjusted hazard ratios = 2.87 vs. 1.38 respectively; P for Δ = 0.003) and the proportion of deaths due to SAD was greater in the high vs. low risk groups (24.9% vs. 16.5%, P for Δ = 0.03). Similar findings were observed in the validation cohort. The addition of ECG markers to a clinical risk factor model inclusive of LVEF improved indices of discrimination and reclassification in both derivation and validation cohorts, including correct reclassification of 28% of patients in the validation cohort [net reclassification improvement 28 (7-49%), P = 0.009].

CONCLUSION

For patients with CHD, an externally validated ECG score enriched for both absolute and proportional SAD risk and significantly improved risk stratification compared to standard clinical risk factors including LVEF.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT01114269. ClinicalTrials.gov ID NCT01114269.

Sudden death in heart failure with preserved ejection fraction and beyond: an elusive target

Heart failure (HF) with preserved ejection fraction (HFpEF) represents half of HF patients, who are more likely older, women, and hypertensive. Mortality rates in HFpEF are higher compared with age- and comorbidity-matched non-HF controls and lower than in HF with reduced ejection fraction (HFrEF); the majority (50-70%) are cardiovascular (CV) deaths. Among CV deaths, sudden death (SD) (~ 35%) and HF-death (~ 20%) are the leading cardiac modes of death; however, proportionally, CV deaths, SD, and HF-deaths are lower in HFpEF, while non-CV deaths constitute a higher proportion of deaths in HFpEF (30-40%) than in HFrEF (~ 15%). Importantly, the underlying mechanism of SD has not been clearly elucidated and non-arrhythmic SD may be more prominent in HFpEF than in HFrEF. Furthermore, there is no specific strategy for identifying high-risk patients, probably due to wide heterogeneity in presentation and pathophysiology of HFpEF and a plethora of comorbidities in this population. Thus, the management of HFpEF remains problematic due to paucity of data on the clinical benefits of current therapies, which focus on symptom relief and reduction of HF-hospitalization by controlling fluid retention and managing risk-factors and comorbidities. Matching a specific pathophysiology or mode of death with available and novel therapies may improve outcomes in HFpEF. However, this still remains an elusive target, as we need more information on determinants of SD. Implantable cardioverter-defibrillators (ICDs) have changed the landscape of SD prevention in HFrEF; if ICDs are to be applied to HFpEF, there must be a coordinated effort to identify and select high-risk patients.

Mode of Death Among Japanese Adults With Heart Failure With Preserved, Midrange, and Reduced Ejection Fraction

IMPORTANCE

Despite intensive treatment, hospitalized patients with acute decompensated heart failure (ADHF) have a substantial risk of postdischarge mortality. Limited data are available on the possible differences in the incidence and mechanisms of death among patients with heart failure with reduced ejection fraction (HFrEF), heart failure with midrange ejection fraction (HFmrEF), and heart failure with preserved ejection fraction (HFpEF).

OBJECTIVES

To examine the incidences and mode of postdischarge mortality among patients with ADHF and to compare the risk profile among patients with HFrEF, HFmrEF, and HFpEF.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study of 4056 patients hospitalized for ADHF analyzed data from 3717 patients who were discharged from October 1, 2014, to March 31, 2016. Data analysis was performed from April 1 to August 31, 2019.

EXPOSURES

Death among patients with ADHF after hospital discharge.

MAIN OUTCOMES AND MEASURES

All-cause death and cause of postdischarge mortality after the index hospitalization by left ventricular ejection fraction (LVEF) subgroup.

RESULTS

A total of 3717 patients (mean [SD] age, 77.7 [12.0] years; 2049 [55.1%] male) were included in the study. The mean (SD) LVEF at baseline was 46.4% (16.2%). Among 3717 enrolled patients, 1383 (37.2%) were categorized as having HFrEF (LVEF, <40%), 703 (18.9%) as having HFmrEF (LVEF, 40%-49%), and 1631 (43.9%) as having HFpEF (LVEF, ≥50%). The incidence and causes of death were evaluated after discharge from the index hospitalization. The median follow-up period was 470 days (interquartile range, 357-649 days), and the 1-year follow-up rate was 96%. During follow-up, all-cause death occurred in 848 patients (22.8%; HFrEF group: 298 [21.5%; 95% CI, 19.5%-23.8%]; HFmrEF group: 158 [22.5%; 95% CI, 19.5%-25.7%]; and HRpEF group: 392 [24.0%; 95% CI, 22.0%-26.2%]; P = .26), cardiovascular deaths occurred in 523 patients (14.1%; HFrEF group: 203 [14.7%; 95% CI, 12.9%-16.6%]; HFmrEF group: 97 [13.8%; 95% CI, 11.4%-16.5%]; and HFpEF group: 223 [13.7%; 95% CI, 12.1%-15.4%]; P = .71), and sudden cardiac death occurred in 98 patients (2.6%; HFrEF group: 44 [3.2%; 95% CI, 2.4%-4.2%]; HFmrEF group: 14 [2.0%; 95% CI, 1.2%-3.3%]; and HFpEF group: 40 [2.5%; 95% CI, 1.8%-3.3%]; P = .23). The risks of causes of death were similar among the subtypes.

CONCLUSIONS AND RELEVANCE

The mode of death was similar among the heart failure subtypes. Given the nonnegligible incidence of sudden cardiac death in patients with HFpEF found in this study, further studies appear to be warranted to identify a high-risk subset in this population.

Prediction of major adverse cardiac, cerebrovascular events in patients with diabetes after acute coronary syndrome

BACKGROUND AND OBJECTIVES

The risk of major adverse cardiac and cerebrovascular events following acute coronary syndrome is increased in people with diabetes. Predicting out-of-hospital outcomes upon follow-up remains difficult, and no simple, well-validated tools exist for this population at present. We aim to evaluate several factors in a competing risks model for actionable evaluation of the incidence of major adverse cardiac and cerebrovascular events in diabetic outpatients following acute coronary syndrome.

METHODS

Retrospective analysis of consecutive patients admitted for acute coronary syndrome in two centres. A Fine-Gray competing risks model was adjusted to predict major adverse cardiac and cerebrovascular events and all-cause mortality. A point-based score is presented that is based on this model.

RESULTS

Out of the 1400 patients, there were 783 (55.9%) with at least one major adverse cardiac and cerebrovascular event (417 deaths). Of them, 143 deaths were due to non-major adverse cardiac and cerebrovascular events. Predictive Fine-Gray models show that the 'PG-HACKER' risk factors (gender, age, peripheral arterial disease, left ventricle function, previous congestive heart failure, Killip class and optimal medical therapy) were associated to major adverse cardiac and cerebrovascular events.

CONCLUSION

The PG-HACKER score is a simple and effective tool that is freely available and easily accessible to physicians and patients. The PG-HACKER score can predict major adverse cardiac and cerebrovascular events following acute coronary syndrome in patients with diabetes.

Sudden Arrhythmic Death at the Higher End of the Heart Failure Spectrum

The risk of sudden cardiac death (SCD) is high in heart failure (HF) patients. Sudden arrhythmic death (SAD) is a frequent cause of exit in HF patients at the lower end of the HF spectrum, and implantable cardioverter–defibrillators have been recommended to prevent these life-threatening rhythm disturbances in select patients. However, less is known regarding the cause of SCD in patients at the upper end of the HF spectrum, despite the fact that the majority of out-of-hospital SCD victims have unknown or near-normal/normal left ventricular ejection fraction (LVEF). In this review, we report the epidemiology, summarize the mechanisms, discuss the diagnostic challenges, and propose a stepwise approach for the prevention of SAD in HF with near-normal/normal LVEF.

Circulating miRNAs and Risk of Sudden Death in Patients With Coronary Heart Disease

OBJECTIVES

This study evaluated whether plasma miRNAs were specifically associated with sudden cardiac and/or arrhythmic death (SCD) in a cohort of patients with coronary heart disease (CHD), most of whom were without primary prevention implantable cardioverter-defibrillators.

BACKGROUND

Novel biomarkers for sudden death risk stratification are needed in patients with CHD to more precisely target preventive therapies, such as implantable cardioverter-defibrillators. miRNAs have been implicated in regulating inflammation and cardiac fibrosis in cells, and plasma miRNAs have been shown to predict cardiovascular death in patients with CHD.

METHODS

We performed a nested case control study within a multicenter cohort of 5,956 patients with CHD followed prospectively for SCD. Plasma levels of 18 candidate miRNAs previously associated with cardiac remodeling were measured in 129 SCD cases and 258 control subjects matched on age, sex, race, and left ventricular ejection fraction.

RESULTS

miR-150-5p, miR-29a-3p, and miR-30a-5p were associated with increased SCD risk (odds ratios and 95% confidence intervals: 2.03 [1.12 to 3.67]; p = 0.02; 1.93 [1.07 to 3.50]; p = 0.02; 0.55 [0.31 to 0.97]; p = 0.04, respectively, for third vs. first tertile miRNA level). Unfavorable levels of all 3 miRNAs was associated with a 4.8-fold increased SCD risk (1.59 to 14.51; p = 0.006). A bioinformatics-based approach predicted miR-150-5p, miR-29a-3p, and miR-30a-5p to be involved in apoptosis, fibrosis, and inflammation.

CONCLUSIONS

These findings suggest that plasma miRNAs may regulate pathways important for remodeling and may be useful in identifying patients with CHD at increased risk of SCD.

Refining the World Health Organization Definition: Predicting Autopsy-Defined Sudden Arrhythmic Deaths Among Presumed Sudden Cardiac Deaths in the POST SCD Study

BACKGROUND

Conventional definitions of sudden cardiac death (SCD) presume cardiac cause. We studied the World Health Organization-defined SCDs autopsied in the POST SCD study (Postmortem Systematic Investigation of SCD) to determine whether premortem characteristics could identify autopsy-defined sudden arrhythmic death (SAD) among presumed SCDs.

METHODS

Between January 2, 2011, and January 4, 2016, we prospectively identified all 615 World Health Organization-defined SCDs (144 witnessed) 18 to 90 years in San Francisco County for medical record review and autopsy via medical examiner surveillance. Autopsy-defined SADs had no extracardiac or acute heart failure cause of death. We used 2 nested sets of premortem predictors-an emergency medical system set and a comprehensive set adding medical record data-to develop Least Absolute Selection and Shrinkage Operator models of SAD among witnessed and unwitnessed cohorts.

RESULTS

Of 615 presumed SCDs, 348 (57%) were autopsy-defined SAD. For witnessed cases, the emergency medical system model (area under the receiver operator curve 0.75 [0.67-0.82]) included presenting rhythm of ventricular tachycardia/fibrillation and pulseless electrical activity, while the comprehensive (area under the receiver operator curve 0.78 [0.70-0.84]) added depression. If only ventricular tachycardia/fibrillation witnessed cases (n=48) were classified as SAD, sensitivity was 0.46 (0.36-0.57), and specificity was 0.90 (0.79-0.97). For unwitnessed cases, the emergency medical system model (area under the receiver operator curve 0.68 [0.64-0.73]) included black race, male sex, age, and time since last seen normal, while the comprehensive (area under the receiver operator curve 0.75 [0.71-0.79]) added use of β-blockers, antidepressants, QT-prolonging drugs, opiates, illicit drugs, and dyslipidemia. If only unwitnessed cases <1 hour (n=59) were classified as SAD, sensitivity was 0.18 (0.13-0.22) and specificity was 0.95 (0.90-0.97).

CONCLUSIONS

Our models identify premortem characteristics that can better specify autopsy-defined SAD among presumed SCDs and suggest the World Health Organization definition can be improved by restricting witnessed SCDs to ventricular tachycardia/fibrillation or nonpulseless electrical activity rhythms and unwitnessed cases to <1 hour since last normal, at the cost of sensitivity.