Incidence and predictors of sudden cardiac death in patients with reduced left ventricular ejection fraction after myocardial infarction in an era of revascularisation

Sudden cardiac death in long-term follow-up in patients treated with primary percutaneous coronary intervention

Objective. Most studies analyzing predictors of sudden cardiac death (SCD) after acute myocardial infarction included only high-risk patients or index reperfusion had not been performed in all patients. The aim of our study was to analyze the incidence of SCD and determine the predictors of SCD occurrence during 6-year follow-up of unselected patients with ST-elevation myocardial infarction (STEMI), treated with primary percutaneous coronary intervention (pPCI). Method. we analysed 3114 STEMI patients included included in the University Clinical Center of Serbia STEMI Register. Patients presenting with cardiogenic schock were excluded. Echocardiographic examination was performed before hospital discharge. Results. During 6-year follow-up, lethal outcome was registered in 297 (9.5%) patients, of whom 95 (31.9%) had SCD. The highest incidence of SCD was recorded in the first year of follow-up, when SCD was registered in 25 patients, which is 26.3% of the total number of patients who had had SCD, i.e. 0.8% of the patients analyzed. The independent predictors for the occurrence of SCD during 6-year follow-up were EF < 45% (HR 3.07, 95% 1.87-5.02), post-procedural TIMI flow <3 (HR 2.59, 95%CI 1.37-5.14), reduced baseline kidney function (HR 1.87, 95%CI 1.12-2.93) and Killip class >1 at admission (HR 1.69, 95%CI 1.23-2.97). Conclusion. There is a low incidence of SCD in unselected STEMI patients treated with primary PCI. Predictors of SCD occurence during long-term follow-up in analyzed patients are clinical variables that are easily recorded during index hospitalization and include: EF ≤45%, post-procedural flow TIMI < 3, Killip class >1, and reduced baseline kidney function.

Individual Trajectories of Health Status During the First Year of Discharge From Hospitalization for Heart Failure and Their Associations With Death in the Following Years

Background Improving health status is one of the major goals in the management of heart failure (HF). However, little is known about the long-term individual trajectories of health status in patients with acute HF after discharge. Methods and Results We enrolled 2328 patients hospitalized for HF from 51 hospitals prospectively and measured their health status via the Kansas City Cardiomyopathy Questionnaire-12 at admission and 1, 6, and 12 months after discharge, respectively. The median age of the patients included was 66 years, and 63.3% were men. Six patterns of Kansas City Cardiomyopathy Questionnaire-12 trajectories were identified by a latent class trajectory model: persistently good (34.0%), rapidly improving (35.5%), slowly improving (10.4%), moderately regressing (7.4%), severely regressing (7.5%), and persistently poor (5.3%). Advanced age, decompensated chronic HF, HF with mildly reduced ejection fraction, HF with preserved ejection fraction, depression symptoms, cognitive impairment, and each additional HF rehospitalization within 1 year of discharge were associated with unfavorable health status (moderately regressing, severely regressing, and persistently poor) (P<0.05). Compared with the pattern of persistently good, slowly improving (hazard ratio [HR], 1.50 [95% CI, 1.06-2.12]), moderately regressing (HR, 1.92 [1.43-2.58]), severely regressing (HR, 2.26 [1.54-3.31]), and persistently poor (HR, 2.34 [1.55-3.53]) were associated with increased risks of all-cause death. Conclusions One-fifth of 1-year survivors after hospitalization for HF experienced unfavorable health status trajectories and had a substantially increased risk of death during the following years. Our findings help inform the understanding of disease progression from a patient perception perspective and its relationship with long-term survival. Registration URL: https://www.clinicaltrials.gov; unique identifier: NCT02878811.

Cardiac magnetic resonance outperforms echocardiography to predict subsequent implantable cardioverter defibrillator therapies in ST-segment elevation myocardial infarction patients

Background

Implantable cardioverter defibrillators (ICD) are effective as a primary prevention measure of ventricular tachyarrhythmias in patients with ST-segment elevation myocardial infarction (STEMI) and depressed left ventricular ejection fraction (LVEF). The implications of using cardiac magnetic resonance (CMR) instead of echocardiography (Echo) to assess LVEF prior to the indication of ICD in this setting are unknown.

Materials and methods

We evaluated 52 STEMI patients (56.6 ± 11 years, 88.5% male) treated with ICD in primary prevention who underwent echocardiography and CMR prior to ICD implantation. ICD implantation was indicated based on the presence of heart failure and depressed LVEF (≤ 35%) by echocardiography, CMR, or both. Prediction of ICD therapies (ICD-T) during follow-up by echocardiography and CMR before ICD implantation was assessed.

Results

Compared to echocardiography, LVEF was lower by cardiac CMR (30.2 ± 9% vs. 37.4 ± 7.6%, p < 0.001). LVEF ≤ 35% was detected in 24 patients (46.2%) by Echo and in 42 (80.7%) by CMR. During a mean follow-up of 6.1 ± 4.2 years, 10 patients received appropriate ICD-T (3.16 ICD-T per 100 person-years): 5 direct shocks to treat very fast ventricular tachycardia or ventricular fibrillation, 3 effective antitachycardia pacing (ATP) for treatment of ventricular tachycardia, and 2 ineffective ATP followed by shock to treat ventricular tachycardia. Echo-LVEF ≤ 35% correctly predicted ICD-T in 4/10 (40%) patients and CMR-LVEF ≤ 35% in 10/10 (100%) patients. CMR-LVEF improved on Echo-LVEF for predicting ICD-T (area under the curve: 0.76 vs. 0.48, p = 0.04).

Conclusion

In STEMI patients treated with ICD, assessment of LVEF by CMR outperforms Echo-LVEF to predict the subsequent use of appropriate ICD therapies.

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.

Incidence and Predictors of Sudden Cardiac Death After a Major Non-Fatal Cardiovascular Event

BACKGROUND

Sudden cardiac death (SCD) still accounts for the majority of deaths from the four major cardiovascular events (myocardial infarction (MI), heart failure (HF), atrial fibrillation (AF), and stroke) despite substantial progress on prevention.

METHODS

Four separate cohorts (one for each of the four major cardiovascular conditions) were captured through person-linked hospital morbidity and mortality data collections between 2000 and 2009 and followed-up for 11.5 years. The incidence rate for each cohort was total SCD cases divided by sum of follow-up time for each individual alive. Kaplan-Meier survival curve was used to calculate unadjusted risk of SCD. Predictors of SCD were identified by fitting multivariable adjusted Cox regression models in each of the cohorts.

RESULTS

There were 1,174 cases of SCD from 53,614 total CVD events across the cohorts (35.6% for MI, 15.6% for HF, 22.4% for AF, 26.4% for stroke). The incidence rate and unadjusted risk of SCD were both highest after incident hospitalisation for HF, followed by MI, stroke and AF. The elevated risk of SCD was independently associated with MI, HF, arrhythmias, peripheral artery disease, diabetes, chronic kidney disease, and prior coronary heart disease (hazard ratios ranging from 1.1 to 2.8). Early revascularisation is protective in 28-day survivors after an incident MI event.

CONCLUSIONS

An appreciable incidence of SCD following an incident event of MI, HF, AF and stroke deserves greater prevention efforts. Major medical conditions such as MI, HF, peripheral artery disease, and arrhythmias are risk markers of SCD and coronary revascularisation is protective.

The Role of the Cardioversion Defibrillator in Post Myocardial Infarction Sudden Cardiac Death: A Systematic Review of Clinical Trials and Observational Studies

Sudden cardiac death (SCD) accounts for approximately half of all the deaths attributed to cardiovascular disease in the United States. Survivors of an acute myocardial infarction (AMI) are at high risk of SCD, largely due to cardiac arrhythmias and severe left ventricular (LV) systolic dysfunction. The implantable cardioverter defibrillator (ICD) or automated implantable cardioverter defibrillator (AICD) is a device that is implantable inside the body, able to perform cardioversion, defibrillation, and (in modern versions) pacing of the heart. According to a study included in our review, patients who received an ICD contributed to an adjusted 44% reduction (hazard ratio [HR] 0.56, 95% CI: 0.32-1.01; P = 0.053) of all-cause mortality compared to those with a comparable baseline. Patients with an ICD implant three months after a myocardial infarction (MI) demonstrated a non-significantly higher mortality than patients who did not receive an ICD. The factors favoring ICD implantation were multiple MIs, increased resting heart rate, occurrence of non-sustained ventricular tachycardia, QRS duration = 120 ms, syncope events, anti-arrhythmic drug treatment (mostly Class III), and an index MI of more than one year. The likelihood of receiving an ICD diminished with the patient's age. Increased periodic repolarization dynamics were a significant predictor of mortality. It can be concluded that cardioverter defibrillators help reduce not only all-cause mortality but also sudden cardiac death. It is important to note that ICDs are only significant if implanted after a sufficient time-gap post-MI.

Thyroid-stimulating hormone within the normal range and risk of major adverse cardiovascular events in nonischemic dilated cardiomyopathy patients with severe left ventricular dysfunction

BACKGROUND

The association between thyroid-stimulating-hormone (TSH) and prognosis of nonischemic dilated cardiomyopathy (NIDCM) in patients with normal thyroid function remains unclear.

HYPOTHESIS

Our aim was to investigate the association between TSH and major adverse cardiovascular events in euthyroid NIDCM patients.

METHODS

The original cohort consisted of 216 consecutive euthyroid NIDCM patients, with left ventricular ejection fraction (LVEF) ≤35%, who were observed from 2010 to 2013. Patients with persistent ventricular arrhythmia (VA) histories, amiodarone taken for VA prevention, or on heart transplant list within 1 year were excluded. A follow-up evaluation was performed, and VA events, heart failure (HF) exacerbation/heart transplant, cardiac death, or death from any cause were separately evaluated.

RESULTS

A total of 184 patients were enrolled, and 97.8% (180/184) ultimately received follow-up evaluations. During the median 4.6-year follow-up, 24 VA events, 28 cardiac deaths, 30 all-cause deaths, 40 HF exacerbations, and 11 heart transplant events occurred. Serum TSH levels showed good predictive efficacies for VA events (area under the curve [AUC] = 0.702, 95% confidence interval [CI]: 0.629-0.767), and the risk of VA events increased, according to serum TSH quarters, as determined by Kaplan-Meier analysis (2.2% vs 13.4% vs 21.0% vs 30.0%, Q1-Q4, P = 0.011). Multivariable Cox analysis showed that patients at the Q4 level of serum TSH (>2.67 mIU/L) suffered an increased risk of VA events, compared with those at the Q1 level of TSH (hazard ratio [HR] = 15.88, 95% CI: 2.01-65.15) or those at the other three quarters (HR = 3.17, 95% CI: 1.38-7.26). However, the Q4 TSH level was not associated with other adverse cardiac events.

CONCLUSION

An association between TSH levels and the risk of VA events may exist in euthyroid NIDCM patients.

High incidence of ventricular arrhythmias in patients with left ventricular enlargement and moderate left ventricular dysfunction

BACKGROUND

Left ventricular ejection fraction (LVEF) ≤35% is the cutoff value used to identify patients at high risk of sudden cardiac death. However, whether patients who have moderate left ventricular dysfunction and left ventricular enlargement (LVE) have a high risk of ventricular arrhythmias (VAs) and cardiac death is unclear.

HYPOTHESIS

Patients with moderate left ventricular dysfunction and LVE may have a high risk of VAs.

METHODS

This study retrospectively analyzed the data of 853 patients who have an implantable cardioverter-defibrillator/cardiac resynchronization therapy cardioverter-defibrillator equipped with home monitoring. The patients were divided into 4 groups: group A, 35% < LVEF ≤ 45% and left ventricular end-diastolic dimension (LVEDD) ≥60 mm; group B, LVEF ≤35% and LVEDD <60 mm; group C, 35% < LVEF ≤ 45% and LVEDD <60 mm; and group D, LVEF ≤35% and LVEDD ≥60 mm.

RESULTS

During a mean follow-up period of 30 ± 13 months, 324 patients (38%) experienced VAs and 125 patients (14.7%) experienced cardiac death. Based on multivariate Cox regression modeling, group A had an increased risk of VAs (A vs B, hazard ratio [HR]: 1.563, 95% confidence interval [CI]: 1.029-2.375, P = 0.036; A vs C, HR: 1.661, 95% CI: 1.204-2.294, P = 0.002) and cardiac death (A vs B, HR: 1.845, 95% CI: 1.013-3.356; A vs C, HR: 2.041, 95% CI: 1.136-3.731, P = 0.021).

CONCLUSIONS

Patients with moderate left ventricular dysfunction and LVE have a high risk of VAs and cardiac death.

Long-term efficacy of implantable cardiac resynchronization therapy plus defibrillator for primary prevention of sudden cardiac death in patients with mild heart failure: an updated meta-analysis

Previous studies of implantable cardiac resynchronization therapy plus defibrillator (CRT-D) therapy used for primary prevention of sudden cardiac death have suggested that CRT-D therapy is less effective in patients with mild heart failure and a wide QRS complex. However, the long-term benefits are variable. We performed a meta-analysis of randomized trials identified in systematic searches of MEDLINE, EMBASE, and the Cochrane Database. Three studies (3858 patients) with a mean follow-up of 66 months were included. Overall, CRT-D therapy was associated with significantly lower all-cause mortality than was implantable cardioverter defibrillator (ICD) therapy (OR, 0.78; 95 % CI, 0.63-0.96; P = 0.02; I (2) = 19 %). However, the risk of cardiac mortality was comparable between two groups (OR, 0.74; 95 % CI, 0.53-1.01; P = 0.06). CRT-D treatment was associated with a significantly lower risk of hospitalization for heart failure (OR, 0.67; 95 % CI, 0.50-0.89; P = 0.005; I (2) = 55 %). The composite outcome of all-cause mortality and hospitalization for heart failure was also markedly lower with CRT-D therapy than with ICD treatment alone (OR, 0.67; 95 % CI, 0.57-0.77; P < 0.0001; I (2) = 0 %). CRT-D therapy decreased the long-term risk of mortality and heart failure events in patients with mild heart failure with a wide QRS complex. However, long-term risk of cardiac mortality was similar between two groups. More randomized studies are needed to confirm these findings, especially in patients with NYHA class I heart failure or patients without LBBB.

The clinical challenge of preventing sudden cardiac death immediately after acute ST-elevation myocardial infarction

Unfortunately, of all patients experiencing acute myocardial infarction (MI), usually in the form of ST-elevation MI, 25-35% will die of sudden cardiac death (SCD) before receiving medical attention, most often from ventricular fibrillation. For patients who reach the hospital, prognosis is considerably better and has improved over the years. Reperfusion therapy, best attained with primary percutaneous coronary intervention compared to thrombolysis, has made a big difference in reducing the risk of SCD early and late after ST-elevation MI. In-hospital SCD due to ventricular tachyarrhythmias is manageable, with either preventive measures or drugs or electrical cardioversion. There is general agreement for secondary prevention of SCD post-MI with implantation of a cardioverter defibrillator (ICD) when malignant ventricular arrhythmias occur late (>48 h) after an MI, and are not due to reversible or correctable causes. The major challenge remains that of primary prevention, that is, how to prevent SCD during the first 1-3 months after ST-elevation MI for patients who have low left ventricular ejection fraction and are not candidates for an ICD according to current guidelines, due to the results of two studies, which did not show any benefits of early (<40 days after an MI) ICD implantation. Two recent documents may provide direction as to how to bridge the gap for this early post-MI period. Both recommend an electrophysiology study to guide implantation of an ICD, at least for those developing syncope or non-sustained ventricular tachycardia, who have an inducible sustained ventricular tachycardia at the electrophysiology study. An ICD is also recommended for patients with indication for a permanent pacemaker due to bradyarrhythmias, who also meet primary prevention criteria for SCD.