Chahal, Choudhary Anwar A

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and sleep disordered breathing (SDB) is a treatable risk factor that has been seen to occur concurrently, and is known to propagate mortality and morbidity in a number of cardiovascular disease states including heart failure, and indeed hypertrophic cardiomyopathy. In this review, we summarize past studies that explored the simultaneous occurrence of HCM and SDB, and the pathophysiology of SDB in relation to heart failure, arrhythmias, cardiac ischemia and pulmonary hypertension in HCM. The current therapeutic modalities, with the effect of obstructive sleep apnea (OSA) treatment on HCM, are then discussed along with potential future directions.

Background Sudden unexpected death in epilepsy ( SUDEP ) is the leading cause of epilepsy‐related death. SUDEP shares many features with sudden cardiac death and sudden unexplained death in the young and may have a similar genetic contribution. We aim to systematically review the literature on the genetics of SUDEP . Methods and Results PubMed, MEDLINE Epub Ahead of Print, Ovid Medline In‐Process & Other Non‐Indexed Citations, MEDLINE , EMBASE , Cochrane Database of Systematic Reviews, and Scopus were searched through April 4, 2017. English language human studies analyzing SUDEP for known sudden death, ion channel and arrhythmia‐related pathogenic variants, novel variant discovery, and copy number variant analyses were included. Aggregate descriptive statistics were generated; data were insufficient for meta‐analysis. A total of 8 studies with 161 unique individuals were included; mean was age 29.0 (± SD 14.2) years; 61% males; ECG data were reported in 7.5% of cases; 50.7% were found prone and 58% of deaths were nocturnal. Cause included all types of epilepsy. Antemortem diagnosis of Dravet syndrome and autism (with duplication of chromosome 15) was associated with 11% and 9% of cases. The most frequently detected known pathogenic variants at postmortem were in Na + and K + ion channel subunits, as were novel potentially pathogenic variants (11%). Overall, the majority of variants were of unknown significance. Analysis of copy number variant was insignificant. Conclusions SUDEP case adjudication and evaluation remains limited largely because of crucial missing data such as ECG s. The most frequent pathogenic/likely pathogenic variants identified by molecular autopsy are in ion channel or arrhythmia‐related genes, with an ≈11% discovery rate. Comprehensive postmortem examination should include examination of the heart and brain by specialized pathologists and blood storage.

SummaryObjectiveWe aimed to determine the frequency of probable obstructive sleep apnea (pOSA) in refractory epilepsy monitoring unit inpatients and clinical features associated with pOSA, including risk for sudden unexpected death in epilepsy (SUDEP).MethodsWe prospectively recruited 49 consecutive adult patients admitted to the Mayo Clinic Epilepsy Monitoring Unit with focal, generalized, or unclassified epilepsy syndromes. pOSA was identified using oximetric oxyhemoglobin desaturation index (ODI) and the Sleep Apnea–Sleep Disorders Questionnaire (SA‐SDQ) and STOP‐BAG screening tools. Revised SUDEP Risk Inventory (rSUDEP‐7) scores were calculated, and epilepsy patients with and without pOSA were compared with Wilcoxon signed‐rank tests. Correlation and regression analyses were utilized to determine relationships between pOSA and rSUDEP‐7 scores.ResultsThirty‐five percent of patients had pOSA, with a mean ODI of 11.3 ± 5.1/h (range = 5.1‐22.8). Patients with pOSA were older and heavier, and more frequently had a focal epilepsy syndrome and longer epilepsy duration, with higher SA‐SDQ and STOP‐BAG scores (all P < 0.05). Median rSUDEP‐7 score was 3 ± 1.4 (range = 0‐6). Higher rSUDEP‐7 scores were positively correlated with higher ODI (P = 0.036). rSUDEP‐7 score ≥ 5 was associated with pOSA by ODI, SA‐SDQ, and STOP‐BAG questionnaire criteria (P < 0.05).SignificanceOur pilot study identified a high frequency of pOSA in refractory epilepsy monitoring patients, finding that pOSA patients were older and heavier, with higher screening symptoms for sleep apnea and more frequent focal seizures with a longer epilepsy duration. We also found a possible association between OSA and SUDEP risk. Identification and treatment of OSA in patients with epilepsy could conceivably provide a novel approach toward preventing the risk of SUDEP. Future studies with polysomnography are needed to confirm predictive features for OSA in epilepsy populations, and to determine whether OSA is associated with SUDEP risk.

Background Excessive daytime sleepiness ( EDS ), a common symptom among patients with sleep‐disordered breathing, is closely associated with the development of cardiovascular diseases, but its long‐term prognostic value is not completely understood. The aim of this study was to investigate whether EDS would be an independent prognostic factor after myocardial infarction. Methods and Results We prospectively recruited 112 post–myocardial infarction patients. The Epworth Sleepiness Scale was completed before polysomnography, and EDS was defined as a score ≥11. After exclusion of 8 patients who accepted treatment with continuous positive airway pressure, 104 patients were followed up for 48 months. The primary composite end point was major adverse cardiac events. Patients with EDS had higher rates of major adverse cardiac events (48.4% versus 27.4%, χ 2 =5.27, P =0.022) and reinfarction (29.0% versus 5.5%, χ 2 =13.51, P =0.0002) compared with those without EDS . In the Cox proportional hazards model, patients with EDS had 2.15 times (95% confidence interval, 1.08–4.18; P =0.030) higher crude risk of major adverse cardiac events, with prognostic significance persisting after adjusting for age, diabetes mellitus, depression, left ventricular ejection fraction, apnea–hypopnea index, and nocturnal nadir oxygen saturation (hazard ratio: 2.13, 95% confidence interval, 1.04–4.26, P =0.039). Furthermore, among participants with moderate to severe sleep‐disordered breathing, the presence of EDS was associated with higher risk of major adverse cardiac events than those without EDS , after adjusting for age and nadir oxygen saturation (hazard ratio: 3.17, 95% confidence interval, 1.22–7.76, P =0.019). Conclusions EDS may be an independent prognostic factor of adverse outcome in post–myocardial infarction patients with moderate to severe sleep‐disordered breathing. Evaluation of EDS may shed new light on risk stratification and identify treatment responders for this patient population.

AbstractBackgroundCardiovascular implantable electronic devices (CIEDs) can be life‐saving. However, complications from CIED infection can be life‐threatening, often requiring device removal. Despite publication of CIED infection management guidelines, there remains marked variation in clinical practice.ObjectiveTo better understand and quantify these differences, we conducted a multinational survey of practitioners of CIED management.MethodsAn electronic survey was sent to Heart Rhythm Society members, spanning 70 countries across six continents. All responses were collected anonymously.Results227 out of 3,600 (6.3%) responded to the survey. The majority of surveys were completed by practitioners from the United States (168; 68.3%) and 53.8% of these practiced in academic medical centers. The large majority (92.7%) of sites had protocols to ensure appropriate timing of prophylactic antibiotics. Superficial (incisional) site infections were treated with antibiotics alone 52.5% of the time (consistent with guidelines); in contrast, deep pocket infections were treated with antibiotics (with device removal) in accordance to guidelines only 37.4% of the time. Almost all providers (98.7%) were inclined to perform complete hardware removal in cases of CIED‐related endocarditis. In contrast, 82.2% of survey participants suggested complete CIED system removal in patients with an occult Gram‐positive bacteremia, 65.5% with occult Gram‐negative bacteremia, and 59.3% with prolonged bacteremia due to a source other than CIED.ConclusionsThese data suggest wide variability in clinical practice in managing CIED infection with significant deviations from published guidelines. There is critical need to increase awareness and develop institutional protocols to ensure adherence with evidence‐based guidelines to optimize outcomes.

Introduction The role of cardiac implantable electronic device (CIED) therapy in patients with ATTR-wt (senile) amyloid is not very well defined. It is unknown whether there is mortality benefit or harm with the implantation of CIEDs. Methods We performed a retrospective analysis of a prospectively collected registry of patients with biopsy proven ATTR-wt amyloid with cardiac involvement. These patients were followed up at Mayo Clinic, Rochester, Minnesota between Jan 1, 1985 to Sep 30, 2015. The follow-up of these patients was done via personal communication (written or verbal) and entered into the database. During analysis these patients were subdivided on the basis of the presence or absence of a CIED, cardiac involvement or not, and all-cause mortality analysed. The implantation of a CIED was analysed as a time-dependent covariate in the survival of these patients and Kaplan-Meier (K-M) survival plots created. Comparison between groups with CIED and those without CIED was made. In addition, CIEDs were subdivided into permanent pacemakers (PPM), defibrillators (ICDs) and cardiac resynchronization devices (CRT-P/D). Mortality among the patients with each device subtype was estimated and compared to overall mortality. Results 409 patients with ATTR-wt and cardiac involvement were reviewed with CIEDs implanted in 101 (25%) patients. The median follow-up (25th, 75th centile) was 2.4 (1.1, 4.3) years. Utilisation of ICDs in this population was higher than the general community in Olmsted county. There was no association in the overall survival or evidence of harm with CIED utilisation in patients with ATTR amyloidosis and cardiac involvement. Conclusions CIEDs utilisation remains high in ATTR-wt with cardiac involvement. Due diligence is needed in selecting the optimal patient for benefit prior to the implantation of CIEDs in this cohort. Further research is required to pool multi-centre amyloid registry data and determine if there is mortality benefit.

Objective Sudden cardiac arrest (SCA) is the most devastating outcome in hypertrophic cardiomyopathy (HCM). We evaluated repolarisation features on the surface electrocardiogram (ECG) to identify the potential risk factors for SCA. Methods Data was collected from 52 patients with HCM who underwent implantable cardioverter defibrillator (ICD) implantation. Leads V2 and V5 from the ECG closest to the time of ICD implant were utilised for measuring the Tpeak-Tend interval (Tpe), QTc, Tpe/QTc, T-wave duration and T-wave amplitude. The presence of the five traditional SCA-associated risk factors was assessed, as well as the HCM risk-SCD score. Results 16 (30%) patients experienced aborted cardiac arrest over 8.5±4.1 years, with 9 receiving an ICD shock and 7 receiving ATP. On univariate analysis, T-wave amplitude was associated with appropriate ICD therapy (HR per 0.1 mV 0.79, 95% CI 0.56 to 0.96, p=0.02). Aborted SCA was not associated with a greater mean QTc duration, Tpeak-Tend interval, T-wave duration, or Tpe/QT ratio. Multivariate analysis (adjusting for cardinal HCM SCA-risk factors) showed T-wave amplitude in Lead V2 was an independent predictor of risk (adjusted HR per 0.1 mV 0.74, 95% CI 0.57 to 0.97, p=0.03). Addition of T-wave amplitude in Lead V2 to the traditional risk factors resulted in significant improvement in risk stratification (C-statistic from 0.65 to 0.75) but did not improve the performance of the HCM SCD-risk score. Conclusions T-wave amplitude is a novel marker of SCA in this high risk HCM population and may provide incremental predictive value to established risk factors. Further work is needed to define the role of repolarisation abnormalities in predicting SCA in HCM.