Causes and prevention of sudden cardiac death in the elderly

The associations of leukocyte telomere length and intermediary cardiovascular phenotype with adverse cardiovascular outcomes in the white population

The evidence about the associations of leukocyte telomere length (LTL) and intermediary cardiovascular phenotypes with adverse cardiovascular outcomes is inconclusive. This study assessed these relationships with cardiovascular imaging, electrocardiography, and the risks of sudden cardiac death (SCD), coronary events, and heart failure (HF) admission. We conducted a cross-sectional analysis of UK Biobank participants enrolled between 2006 and 2010. LTL was measured using quantitative polymerase chain reactions. Electronic health records were used to determine the incidence of SCD, coronary events, and HF admission. Cardiovascular measurements were made using cardiovascular magnetic resonance imaging and machine learning. The associations of LTL with SCD, coronary events, and HF admission and cardiac magnetic resonance imaging, electrocardiogram parameters of 33,043 and 19,554 participants were evaluated by multivariate regression. The median (interquartile range) follow-up period was 11.9 (11.2-12.6) years. Data was analyzed from January to May 2023. Among the 403,382 white participants without coronary artery disease or HF, 181,637 (45.0%) were male with a mean age of 57.1 years old. LTL was independently negatively associated with a risk of SCD (LTL third quartile vs first quartile: hazard ratio [HR]: 0.81, 95% confidence interval [CI]: 0.72-0.92), coronary events (LTL third quartile vs first quartile: HR: 0.88, 95% CI: 0.84-0.92), and HF admission (LTL fourth quartile vs first quartile: HR: 0.84, 95% CI: 0.74-0.95). LTL was also independently positively associated with cardiac remodeling, specifically left ventricular mass index, left-ventricular-end systolic and diastolic volumes, mean left ventricular myocardial wall thickness, left ventricular stroke volume, and with electrocardiogram changes along the negative degree of T-axis. Cross-sectional study results showed that LTL was positively associated with heart size and cardiac function in middle age, but electrocardiography results did not show these associations, which could explain the negative association between LTL and risk of SCD, coronary events, and HF admission in UK Biobank participants.

Efficacy and safety of implantable cardioverter-defibrillator implantation in the elderly-The I-70 Study: A randomized clinical trial

Background

There is conflicting evidence on the efficacy of primary prevention implantable cardioverter-defibrillator (ICD) implantation in the elderly.

Objective

The purpose of this study was to determine the efficacy and safety of ICD implantation in patients 70 years and older.

Methods

Patients (n = 167) aged 70 years or older and eligible for ICD implantation were randomly assigned (1:1) to receive either optimal medical therapy (OMT) (n = 85) or OMT plus ICD (n = 82).

Results

Of the 167 participants (mean age 76.4 years; 165 men), 144 completed the study protocol according to their assigned treatment. Average participant follow-up was 31.5 months. Mortality was similar between the 2 groups: 27 deaths in OMT vs 26 death in ICD (unadjusted hazard ratio 0.92; 95% confidence interval 0.53-1.57), but there was a trend favoring the ICD over the first 36 months of follow-up. Rates of sudden death (7 vs 5; P = .81) and all-cause hospitalization (2.65 events per participant in OMT vs 3.09 in ICD; P = .31) were not statistically significantly different. Eleven participants randomized to ICD received appropriate therapy. Five participants received an inappropriate therapy that included at least 1 ICD shock.

Conclusion

The study did not recruit to target sample size, and accumulated data did not show benefit of ICD therapy in patients 70 years or older. Future studies similar in design might be feasible but will need to contend with patient treatment preference given the large number of patients who do not want an ICD implanted. Further research is needed to determine whether the ICD is effective in prolonging life among elderly device candidates.

Preoperative Risk Prediction Score for and In-Hospital Clinical Outcomes of Reperfusion Ventricular Fibrillation After Release of Aortic Cross-Clamps: A Retrospective Study

Reperfusion ventricular fibrillation (VF) is a common arrhythmia after cardiac surgery. Predictors of reperfusion VF and its relationships with the adverse prognosis are still unclear. This study aimed to identify a risk score model to predict reperfusion VF and its effect on in-hospital outcomes. The authors enrolled 1,024 consecutive patients undergoing cardiac surgery, and a total of 823 patients were included in the study. A novel risk score model was developed following logistic regression analysis of the predictors of reperfusion VF. The receiver operating characteristic curve was used to validate this model, and the effect of VF on prognosis was later identified in multivariate or Kaplan-Meier analyses. Risk factors for reperfusion VF occurrence included weight >55 kg, preoperative left ventricular ejection fraction <50%, prior stroke, hypertension, aortic valve replacement, HTK solution, and the use of ≥3 grafts in coronary artery bypass grafting. A novel risk score model was developed using the abovementioned variables, and points were assigned to each risk factor according to its odds ratio. A high score (>6) predicted greater than 65% of patients with VF occurrence. Reperfusion VF increased the risk of in-hospital cardiovascular death (p = 0.03) and renal replacement therapy postoperatively (p = 0.022). More attention should be given to reperfusion VF due to an adverse postoperative prognosis, and the developed risk score model may predict this risk.

Catheter ablation in patients with ventricular fibrillation by purkinje de-networking

Background

Ventricular fibrillation (VF) is a leading cause of cardiovascular death worldwide. However, recurrence rates of arrhythmia are high leading to mortality and morbidity. Recently, Purkinje fibers have been identified as potential sources of VF initiation and maintenance.

Aim

The study analyzes the feasibility and effectiveness of catheter ablation in patients with recurrent VF by specific Purkinje de-networking (PDN).

Methods

Consecutive patients with recurrent VF undergoing PDN were included in this observational study. The procedural endpoint was the non-inducibility of sustained ventricular arrhythmia. A three-dimensional -anatomical mapping was conducted, and the specific cardiac conduction system and Purkinje fibers were tagged. All detectable Purkinje signals were ablated in the left ventricle (LV). Additional right ventricular (RV) PDN was performed in case of VF inducibility after LV ablation. Follow-up was performed by patient visits at our outpatient clinic including device interrogation and by telephone interviews.

Results

Eight patients were included in the study. Six patients were females (75%); the median age during the procedure was 43 [37;57] years and the median body mass index was 24 [23;33] kg/m². Four patients (50%) had known structural heart disease with two cases of ischemic cardiomyopathy and two cases of dilated cardiomyopathy. In four patients (50%), no underlying structural heart disease could be identified. The median LV ejection fraction was 42 ± 16.4%. All patients had an implantable cardioverter-defibrillator (ICD) prior to ablation with documentation of recurrent VF. The median number of ICD shocks before the ablation was 5 [3;7]. LV PDN was performed in all patients. In two patients (25%), an additional RV PDN was performed. Non-inducibility of any ventricular arrhythmia was achieved in all patients after PDN. Two patients showed complete left bundle branch block post-ablation. The median follow-up duration was 264 [58;421] days. Two patients (25%) experienced ventricular arrhythmia recurrence with recurrent ICD-shock delivery. One patient died during follow-up with an unknown cause of death. Six patients (75%) experienced no arrhythmia recurrence during follow-up.

Conclusion

Purkinje de-networking represents a novel treatment option for patients with recurrent VF without arrhythmia substrate or specific arrhythmia triggers with promising results in terms of efficiency and feasibility. Larger and more prospective studies are needed for a systematic evaluation.

A meta-analysis of wenxin granule and metoprolol for the treatment of coronary heart disease and arrhythmia

BACKGROUND

This meta-analysis aimed to systematically and comprehensively assess the effectiveness and safety of wenxin granule (WXG) and metoprolol in the treatment of elderly patients with coronary heart disease (CHD) and arrhythmia.

METHODS

We searched the electronic databases of the Cochrane Library, PUBMED, EMBASE, CNKI, Wangfang, and CBM from initiation to May 1, 2022, and selected a set of clinical indicators for WXG and metoprolol for CHD and arrhythmia. The methodological quality of the included studies was analyzed using the Cochrane risk-of-bias tool. Data were pooled using a fixed-effects or random-effects model, and a meta-analysis was conducted.

RESULTS

Eight randomized controlled trials involving 722 patients with CHD and arrhythmia were included. Our findings showed that WXG and metoprolol showed better effects than metoprolol alone on electrocardiogram change (odds ratio [OR] = 7.21, 95% confidence interval [CI] [1.48, 35.07]), clinical symptom improvement (OR = 5.83, 95% CI [1.52, 22.35]), overall clinical effect (OR = 5.51, 95% CI [2.65, 11.44], P < .001), atrial premature beat (mean difference [MD] = -109.85, 95% CI [-171.25, -48.46], P < .001), ventricular premature beat (MD = -195.43, 95% CI [-334.09, -56.77], P < .001), borderline premature beat (MD = -42.92, 95% CI [-77.18, -8.67], P = .01), short-burst ventricular tachycardia (MD = -35.98, 95% CI [-39.66, -32.30], P < .001), ST segment reduction (MD = -0.47, 95% CI [-0.54, -0.40], P < .001), ST segment decrease duration (MD = -0.76, 95% CI [-0.95, -0.57], P < .001). However, no significant differences were observed in adverse reactions (OR = 0.54, 95% CI [0.27, 1.09], P = .09).

CONCLUSION

Compared to metoprolol alone, WXG and metoprolol can more effectively manage patients with CHD and arrhythmia. However, additional large-scale, multicenter, rigorous, and high-quality randomized controlled trials are warranted to verify the present findings.

Sudden unexpected death in Parkinson's disease: Insights from clinical practice

Classified as the second most common neurodegenerative disorder associated with aging after Alzheimer's disease, Parkinson's disease (PD) is the most common movement disorder. In the last decade, despite advances in treatment, mortality rates linked with PD continued to reach significant figures. Available studies have shown that compared with healthy controls, patients with PD are accompanied by high rates of premature death. This is usually caused by factors such as pneumonia and cerebrovascular and cardiovascular diseases. Recently, it has been demonstrated that a significant proportion of patients with PD die suddenly. This is referred to as a sudden and unexpected death in PD (SUDPAR). Here, we focus on the magnitude of SUDPAR. Finally, it is important to learn more about SUDPAR for the implementation of effective prevention strategies.

Cardiac Implantable Electronic Devices: Reoperations and the Competing Risk of Death

BACKGROUND

The use of cardiac implantable electronic devices (CIED), which includes pacemakers, implantable cardioverter-defibrillators (ICD), cardiac resynchronisation therapy pacemakers (CRT-P) and cardiac resynchronisation therapy defibrillators (CRT-D) has increased over the past 20 years, but there is a lack of real world evidence on the longevity of these devices in the older population which is essential to inform health care delivery and support clinical decisions.

METHODS AND RESULTS

We conducted a retrospective cohort study using data from the Australian Government Department of Veterans' Affairs database. The cohort consisted of people who had a CIED procedure between 2005 and 2015. The cumulative risk of generator replacement/reoperations was estimated accounting for the competing risk of death. A total of 16,662 patients were included. In pacemaker recipients with an average age of 85 years, the 5-year risk of reoperation ranged from 2.8% in single chamber, 3.6% in dual chamber to 7.6% in CRT-P recipients, while the 5-year risk of dying with the index pacemaker in situ was 63% in single chamber, 46% in dual chamber and 56% in CRT-P recipients. In defibrillator recipients with an average age of 80 years, the 5-year risk of reoperation ranged from 11% in single chamber, 13% in dual chamber to 24% in CRT-D recipients, while the 5-year risk of dying with the index defibrillator in situ was 46% in single chamber, 40% in dual chamber and 41% in CRT-D recipients.

CONCLUSION

In this cohort of older patients the 5-year risk of generator reoperation was low in pacemaker recipients whereas up to one in four CRT-D recipients would have a reoperation within 5 years.

Development and Validation of a Risk Prediction Model for Ventricular Arrhythmia in Elderly Patients with Coronary Heart Disease

BACKGROUND

Sudden cardiac death is a leading cause of death from coronary heart disease (CHD). The risk of sudden cardiac death (SCD) increases with age, and sudden arrhythmic death remains a major cause of mortality in elderly individuals, especially ventricular arrhythmias (VA). We developed a risk prediction model by combining ECG and other clinical noninvasive indexes including biomarkers and echocardiology for VA in elderly patients with CHD.

METHOD

In the retrospective study, a total of 2231 consecutive elderly patients (≥60 years old) with CHD hospitalized were investigated, and finally 1983 patients were enrolled as the model group. The occurrence of VA within 12 months was mainly collected. Study parameters included clinical characteristics (age, gender, height, weight, BMI, and past medical history), ECG indexes (QTcd, Tp-e/QT, and HRV indexes), biomarker indexes (NT-proBNP, Myo, cTnT, CK-MB, CRP, K+, and Ca2+), and echocardiology indexes. In the respective study, 406 elderly patients (≥60 years old) with CHD were included as the verification group to verify the model in terms of differentiation and calibration.

RESULTS

In the multiparameter model, seven independent predictors were selected: LVEF, LAV, HLP, QTcd, sex, Tp-e/QT, and age. Increased HLP, Tp-e/QT, QTcd, age, and LAV were risk factors (RR > 1), while female and increased LVEF were protective factors (RR < 1). This model can well predict the occurrence of VA in elderly patients with CHD (for model group, AUC: 0.721, 95% CI: 0.669∼0.772; for verification group, AUC: 0.73, 95% CI: 0.648∼0.818; Hosmer-Lemeshow χ 2 = 13.541, P=0.095). After adjusting the predictors, it was found that the combination of clinical indexes and ECG indexes could predict VA more efficiently than using clinical indexes alone.

CONCLUSIONS

LVEF, LAV, QTcd, Tp-e/QT, gender, age, and HLP were independent predictors of VA risk in elderly patients with CHD. Among these factors, the echocardiology indexes LVEF and LAV had the greatest influence on the predictive efficiency of the model, followed by ECG indexes, QTcd and Tp-e/QT. After verification, the model had a good degree of differentiation and calibration, which can provide a certain reference for clinical prediction of the VA occurrence in elderly patients with CHD.

Changes in Cardiovascular Health Status and Risk of Sudden Cardiac Death in Older Adults

PURPOSE

Cardiovascular health (CVH) status is associated with several cardiovascular outcomes; however, correlations between changes in CVH status and risk of sudden cardiac death (SCD) are unknown. We aimed to evaluate associations between changes in CVH status and risk of SCD and all-cause death in older adults.

MATERIALS AND METHODS

We used data from the Korea National Health Insurance Service-Senior cohort database (2005-2012). Six metrics from the American Heart Association (smoking, body mass index, physical activity, blood pressure, total cholesterol, and fasting blood glucose) were used to calculate CVH scores. Changes in CVH status between two health checkups were categorized as low to low, low to high, high to low, and high to high.

RESULTS

We included 105200 patients whose CVH status for an initial and follow-up health checkup (2-year interval) was available. During a median of 5.2 years of follow-up after a second health checkup, 688 SCDs occurred. Compared to patients with a persistent low CVH status, those with a consistently high CVH status had a reduced risk of SCD [adjusted hazard ratio (HR), 0.69; 95% confidence interval (CI), 0.56-0.86] and all-cause death (adjusted HR, 0.74; 95% CI, 0.69-0.78). The risk of all-cause death followed similar trends. However, an inconsistent linear relationship was observed for changes in CVH status and the risk of SCD, but not of all-cause death.

CONCLUSION

Maintaining a high CVH status was associated with future risks of SCD and all-cause death among an older adult population.

Mortality in patients with psychogenic nonepileptic seizures

Objective

To investigate the hypothesis that patients diagnosed with psychogenic nonepileptic seizures (PNES) on video-EEG monitoring (VEM) have increased mortality by comparison to the general population.

Methods

This retrospective cohort study included patients evaluated in VEM units of 3 tertiary hospitals in Melbourne, Australia, between January 1, 1995, and December 31, 2015. Diagnosis was based on consensus opinion of experienced epileptologists and neuropsychiatrists at each hospital. Mortality was determined in patients diagnosed with PNES, epilepsy, or both conditions by linkage to the Australian National Death Index. Lifetime history of psychiatric disorders in PNES was determined from formal neuropsychiatric reports.

Results

A total of 5,508 patients underwent VEM. A total of 674 (12.2%) were diagnosed with PNES, 3064 (55.6%) with epilepsy, 175 (3.2%) with both conditions, and 1,595 (29.0%) received other diagnoses or had no diagnosis made. The standardized mortality ratio (SMR) of patients diagnosed with PNES was 2.5 (95% confidence interval [CI] 2.0–3.3). Those younger than 30 had an 8-fold higher risk of death (95% CI 3.4–19.8). Direct comparison revealed no significant difference in mortality rate between diagnostic groups. Among deaths in patients diagnosed with PNES (n = 55), external causes contributed 18%, with 20% of deaths in those younger than 50 years attributed to suicide, and “epilepsy” was recorded as the cause of death in 24%.

Conclusions

Patients diagnosed with PNES have a SMR 2.5 times above the general population, dying at a rate comparable to those with drug-resistant epilepsy. This emphasizes the importance of prompt diagnosis, identification of risk factors, and implementation of appropriate strategies to prevent potential avoidable deaths.

Idiopathic Ventricular Fibrillation: Diagnosis, Ablation of Triggers, Gaps in Knowledge, and Future Directions

Idiopathic ventricular fibrillation (IVF) is a diagnosis of exclusion made when no underlying cause is identified in a cardiac arrest survivor. Although the frequency of this diagnosis has declined over time due to advances in diagnostic techniques, it remains a substantial cause of sudden cardiac arrest. Further, IVF tends to recur. This article reviews the criteria for diagnosis, patient characteristics, the two primary arrhythmic phenotypes—short-coupled variant of torsades de pointes and recurrent paroxysmal IVF—and the electrophysiologic features, treatment, and ablation of premature ventricular complexes that can trigger IVF.

Influence of Multimorbidity on Burden and Appropriateness of Implantable Cardioverter-Defibrillator Therapies

OBJECTIVE

To determine whether burden of multiple chronic conditions (MCCs) influences the risk of receiving inappropriate vs appropriate device therapies.

DESIGN

Retrospective cohort study.

SETTING

Seven US healthcare delivery systems.

PARTICIPANTS

Adults with left ventricular systolic dysfunction receiving an implantable cardioverter-defibrillator (ICD) for primary prevention.

MEASUREMENTS

Data on 24 comorbid conditions were captured from electronic health records and categorized into quartiles of comorbidity burden (0-3, 4-5, 6-7 and 8-16). Incidence of ICD therapies (shock and antitachycardia pacing [ATP] therapies), including appropriateness, was collected for 3 years after implantation. Outcomes included time to first ICD therapy, total ICD therapy burden, and risk of inappropriate vs appropriate ICD therapy.

RESULTS

Among 2235 patients (mean age = 69 ± 11 years, 75% men), the median number of comorbidities was 6 (interquartile range = 4-8), with 98% having at least two comorbidities. During a mean 2.2 years of follow-up, 18.3% of patients experienced at least one appropriate therapy and 9.9% experienced at least one inappropriate therapy. Higher comorbidity burden was associated with an increased risk of first inappropriate therapy (adjusted hazard ratio [HR] = 1.94 [95% confidence interval {CI} = 1.14-3.31] for 4-5 comorbidities; HR = 2.25 [95% CI = 1.25-4.05] for 6-7 comorbidities; and HR = 2.91 [95% CI = 1.54-5.50] for 8-16 comorbidities). Participants with 8-16 comorbidities had a higher total burden of ICD therapy (adjusted relative risk [RR] = 2.12 [95% CI = 1.43-3.16]), a higher burden of inappropriate therapy (RR = 3.39 [95% CI = 1.67-6.86]), and a higher risk of receiving inappropriate vs appropriate therapy (RR = 1.74 [95% CI = 1.07-2.82]). Comorbidity burden was not significantly associated with receipt of appropriate ICD therapies. Patterns were similar when separately examining shock or ATP therapies.

CONCLUSIONS

In primary prevention ICD recipients, MCC burden was independently associated with an increased risk of inappropriate but not appropriate device therapies. Comorbidity burden should be considered when engaging patients in shared decision making about ICD implantation.

Inhibition of the sodium-glucose co-transporter 2 in the elderly: clinical and mechanistic insights into safety and efficacy

The prevalence of type 2 diabetes mellitus (T2DM) in the elderly grew sharply over the last decade. Reduced insulin sensitivity and secretory capacity, weight gain, sarcopenia, and elevated adiposity are all common metabolic and body changes in the aging population that favor an increased risk of hypoglycemia, frailty syndrome, falls, and cognitive dysfunction. First line antidiabetic therapy is frequently not safe in older individuals because of its high risk of hypoglycemia and prevalent co-morbid diseases, such as chronic kidney disease, osteoporosis, cardiovascular disease, and obesity. Sodium-glucose cotransporter 2 inhibitor (SGLT2i) is a new class of antidiabetic therapy that inhibits glucose and sodium reabsorption on renal proximal convoluted tubule. Its effect is well demonstrated in various clinical scenarios in the younger population. This review and metanalysis describe particularities of the SGLT2i on the elderly, with mechanistic insights of the potential benefit and remaining challenges about the use of these drugs in this important age group. Further, we will present a meta-analysis of the main effects of SGLT2i reported in post-hoc studies in which the median age of the subgroups analyzed was over 60 years. Despite the absence of specific clinical trials for this population, our findings suggest that SGLT2i therapy on older individuals is effective to lower glucose and maintain its effect on systolic blood pressure and body weight.

Increasing age does not affect time to appropriate therapy in primary prevention ICD/CRT-D: a competing risks analysis

Aims

To evaluate the impact of age on the clinical outcomes in a primary prevention implantable cardioverter defibrillator (ICD)/cardiac resynchronization therapy defibrillator (CRT-D) population.

Methods and Results

A retrospective, multicentre analysis of patients aged 60 years and over with primary prevention ICD/CRT-D devices implanted between 1 January 2006 and 1 November 2014 was performed. Survival to follow-up with no therapy (T1), death prior to follow-up with no therapy (T2), delivery of appropriate therapy with survival to follow-up (T3), and delivery of appropriate therapy with death prior to follow-up (T4) were measured. In total, 424 patients were eligible for inclusion in the analysis, mean follow-up of 32.6 months during which time 44 patients (10.1%) received appropriate therapy. The sub-hazard ratio (SHR) for the cumulative incidence of appropriate therapy (T3) according to age at implant was 1.00 (P = 0.851; 95% CI 0.96–1.04). The SHR for cumulative incidence of death (T2) according to age at implant was 1.06 (P < 0.001; 95% CI 1.03–1.01). Age at implant, ischaemic aetiology, baseline haemoglobin, and the presence of diabetes mellitus were predictors of all-cause mortality.

Conclusion

Age has no impact on the time to appropriate therapy, but risk of death prior to therapy increases by 6% for every year increment. As the ICD population ages, the proportion who die without receiving appropriate therapy increases due to competing risks. Characterizing competing risks predictive of death independent of ICD indication would focus therapy on those with potential to benefit and reduce unnecessary exposure to ICD-related morbidity.

Myocyte repolarization modulates myocardial function in aging dogs

Studies of myocardial aging are complex and the mechanisms involved in the deterioration of ventricular performance and decreased functional reserve of the old heart remain to be properly defined. We have studied a colony of beagle dogs from 3 to 14 yr of age kept under a highly regulated environment to define the effects of aging on the myocardium. Ventricular, myocardial, and myocyte function, together with anatomical and structural properties of the organ and cardiomyocytes, were evaluated. Ventricular hypertrophy was not observed with aging and the structural composition of the myocardium was modestly affected. Alterations in the myocyte compartment were identified in aged dogs, and these factors negatively interfere with the contractile reserve typical of the young heart. The duration of the action potential is prolonged in old cardiomyocytes contributing to the slower electrical recovery of the myocardium. Also, the remodeled repolarization of cardiomyocytes with aging provides inotropic support to the senescent muscle but compromises its contractile reserve, rendering the old heart ineffective under conditions of high hemodynamic demand. The defects in the electrical and mechanical properties of cardiomyocytes with aging suggest that this cell population is an important determinant of the cardiac senescent phenotype. Collectively, the delayed electrical repolarization of aging cardiomyocytes may be viewed as a critical variable of the aging myopathy and its propensity to evolve into ventricular decompensation under stressful conditions.

Individual patient data network meta-analysis of mortality effects of implantable cardiac devices

OBJECTIVE

Implantable cardioverter defibrillators (ICD), cardiac resynchronisation therapy pacemakers (CRT-P) and the combination therapy (CRT-D) have been shown to reduce all-cause mortality compared with medical therapy alone in patients with heart failure and reduced EF. Our aim was to synthesise data from major randomised controlled trials to estimate the comparative mortality effects of these devices and how these vary according to patients' characteristics.

METHODS

Data from 13 randomised trials (12 638 patients) were provided by medical technology companies. Individual patient data were synthesised using network meta-analysis.

RESULTS

Unadjusted analyses found CRT-D to be the most effective treatment (reduction in rate of death vs medical therapy: 42% (95% credible interval: 32-50%), followed by ICD (29% (20-37%)) and CRT-P (28% (15-40%)). CRT-D reduced mortality compared with CRT-P (19% (1-33%)) and ICD (18% (7-28%)). QRS duration, left bundle branch block (LBBB) morphology, age and gender were included as predictors of benefit in the final adjusted model. In this model, CRT-D reduced mortality in all subgroups (range: 53% (34-66%) to 28% (-1% to 49%)). Patients with QRS duration ≥150 ms, LBBB morphology and female gender benefited more from CRT-P and CRT-D. Men and those <60 years benefited more from ICD.

CONCLUSIONS

These data provide estimates for the mortality benefits of device therapy conditional upon multiple patient characteristics. They can be used to estimate an individual patient's expected relative benefit and thus inform shared decision making. Clinical guidelines should discuss age and gender as predictors of device benefits.

Implantable cardioverter defibrillators in octogenarians: clinical outcomes from a single center

AIMS

Limited data exist on outcomes in very elderly ICD recipients. We describe outcomes in new ICD and Cardiac Resynchronisation Therapy with Defibrillator (CRT-D) implants in octogenarians at our institution.

METHODS

Patients aged 80 years and above who underwent de novo ICD or CRT-D implantation from January 2006 to July 2012 were identified. Clinical data were collected from the procedural record, medical and ICD notes. Baseline characteristics were compared using independent sample t test for continuous variables and Fisher's exact test for categorical variables. Kaplan-Meier curves were constructed.

RESULTS

Ten per cent of all new ICD/CRT-D implants were aged 80 years and over. Median age was 83.0 years. Median follow-up was 29 months. Death occurred in 17 (34%). Median time to death was 23 months. Three deaths (6%) occurred within 12 months of ICD implantation. Appropriate therapy (ATP or shock) occurred in 19 (38%). Inappropriate therapy occurred in 6 (12%). Rates of appropriate shocks and inappropriate therapy (shocks and ATP) and significant valvular incompetence were higher amongst deceased patients (P=0.03 OR 5.9 95% CI 1.3-27) and (P=0.02 OR 12 95% CI 1.3-112). Univariate analysis identified diuretic use (P=0.008 95% C.I. 0.05 to 0.63) and appropriate shock (P= 0.025 95% C.I. 1.25 to 26.3) as predictors of mortality.

CONCLUSION

Octogenarians make up a small but increasing number of ICD recipients. This study highlights high survival rates at one year with acceptable rates of appropriate and inappropriate device therapy. Ongoing debate regarding the appropriateness of ICD in very elderly patients is warranted.

Mortality and neurological outcome in the elderly after target temperature management for out-of-hospital cardiac arrest

AIM

To assess older age as a prognostic factor in patients resuscitated from out-of-hospital-cardiac arrest (OHCA) and the interaction between age and level of target temperature management.

METHODS AND RESULTS

950 patients included in the target temperature management (TTM) trial were randomly allocated to TTM at 33 or 36 °C for 24h. We assessed survival and cerebral outcome (cerebral performance category, CPC and modified Rankin scale, mRS) using age as predictor, dividing patients into 5 age groups: ≤ 65 (median), 66-70, 71-75, 76-80 and >80 years of age. Shockable rhythm decreased with higher age groups, p = 0.001, the same was true for ST segment elevation on ECG at admission, p < 0.01. Increasing age was associated with a higher mortality rate (HR = 1.04 per year, 95% CI = 1.03-1.06, p < 0.001) after adjusting for confounders. Octogenarians had an increased mortality (HR = 3.5, CI: 2.5-5.0, p < 0.001) compared to patients ≤ 65 years of age. Favorable vs. unfavorable outcome measured by CPC and mRS in survivors was different between age groups with adverse outcomes more prevalent in higher age groups (CPC: p = 0.04, mRS: p = 0.001). The interaction between age and target temperature allocation was not statistically significant for either mortality or neurological outcome.

CONCLUSION

Increasing age is associated with significantly increased mortality after OHCA, but mortality rate is not influenced by level of target temperature. Risk of poor neurological outcome also increases with age, but is not modified by level of target temperature.

Inductive and Deductive Approaches to Acute Cell Injury

Many clinically relevant forms of acute injury, such as stroke, traumatic brain injury, and myocardial infarction, have resisted treatments to prevent cell death following injury. The clinical failures can be linked to the currently used inductive models based on biological specifics of the injury system. Here we contrast the application of inductive and deductive models of acute cell injury. Using brain ischemia as a case study, we discuss limitations in inductive inferences, including the inability to unambiguously assign cell death causality and the lack of a systematic quantitative framework. These limitations follow from an overemphasis on qualitative molecular pathways specific to the injured system. Our recently developed nonlinear dynamical theory of cell injury provides a generic, systematic approach to cell injury in which attractor states and system parameters are used to quantitatively characterize acute injury systems. The theoretical, empirical, and therapeutic implications of shifting to a deductive framework are discussed. We illustrate how a deductive mathematical framework offers tangible advantages over qualitative inductive models for the development of therapeutics of acutely injured biological systems.

Sudden cardiac death and diabetes mellitus

Sudden cardiac death (SCD) affects a significant percentage of diabetic patients. SCD in these patients can be due to several factors, such as diastolic dysfunction, heart failure, altered platelet function, inflammation, sympathetic nervous stimulation and other factors. In the present review, we discuss the association between diabetes mellitus and SCD.

Influence of healthy candidate bias in assessing clinical effectiveness for implantable cardioverter-defibrillators: cohort study of older patients with heart failure

OBJECTIVE

To assess the potential contribution of unmeasured general health status to patient selection in assessments of the clinical effectiveness of implantable cardioverter-defibrillator (ICD) therapy.

DESIGN

Retrospective cohort study.

SETTING

Linked data from an ICD registry, heart failure registry, and Medicare claims data for ICDs implanted in 2005 through 2009.

PARTICIPANTS

29,426 patients admitted to hospital with heart failure aged 66 years or older and eligible for ICD therapy for primary prevention.

MAIN OUTCOME MEASURES

Non-traumatic hip fracture, admission to a skilled nursing facility, and 30 day mortality-outcomes unlikely to be improved by ICD therapy.

RESULTS

Compared with 17,853 patients without ICD therapy, 11,573 patients with ICD therapy were younger and had lower ejection fraction and more cardiac admissions to hospital but fewer non-cardiac admissions to hospital and comorbid conditions. Patients with ICD therapy had greater freedom from unrelated events after adjusting for age and sex: hip fracture (hazard ratio 0.77, 95% confidence interval 0.64 to 0.92), skilled nursing facility admission (0.53, 0.50 to 0.55), and 30 day mortality (0.12, 0.10 to 0.15).

CONCLUSIONS

Lower risks of measured outcomes likely reflect unmeasured differences in comorbidity and frailty. The findings highlight potential pitfalls of observational comparative effectiveness research and support physician consideration of general health status in selecting patients for ICD therapy.

The chromosome 9p21 variant not predicting long-term cardiovascular mortality in Chinese with established coronary artery disease: an eleven-year follow-up study

INTRODUCTION

We examined whether the variant at chromosome 9p21, rs4977574, was associated with long-term cardiovascular mortality in Han Chinese patients with coronary artery disease (CAD).

METHODOLOGY

Subjects who underwent coronary angiography for chest pain were consecutively enrolled. Fasting blood samples were collected for laboratory and genotype assessments. The information was correlated with data collected from the national death database.

RESULTS

There were 925 cases with CAD and 634 without CAD enrolled in the present study. The G allele conferred a significant increase in risk of CAD (odds ratio = 1.47, P = 0.003 in the dominant model; odds ratio = 1.36, P = 0.018 in the recessive model). During a median of 11 years (inter-quartile range between 5.2 and 12.5 years) of follow-up, neither the total nor the cardiovascular mortality was different among CAD subjects with different genotypes. Using Cox regression analysis, genotypes of rs4977574 still failed to predict cardiovascular mortality (hazard ratio = 1.25, P = 0.138 in the dominant model; hazard ratio = 1.05, P = 0.729 in the recessive model).

CONCLUSIONS

The rs4977574 at chromosome 9p21 is associated with presence of CAD in Han Chinese. However, rs4977574 could not predict cardiovascular mortality in these CAD subjects during the eleven-year period of the study.