Exercise in hypertrophic cardiomyopathy: restrict or rethink.

The detailed physiological consequences of aerobic training, in patients with hypertrophic cardiomyopathy (HCM), are not well understood. In athletes and nonathletes with HCM, there are two hypothetical concerns with respect to exercise: exercise-related worsening of the phenotype (e.g., promoting hypertrophy and fibrosis) and/or triggering of arrhythmia. The former concern is unproven and animal studies suggest an opposite effect, where exercise has been shown to be protective. The main reason for exercise restriction in HCM is fear of exercise-induced arrhythmia. Although the safety of sports in HCM has been reviewed, even more recent data suggest a substantially lower risk for sudden cardiac death (SCD) in HCM than previously thought, and there is an ongoing debate about restrictions of exercise imposed on individuals with HCM. This review outlines the pathophysiology of HCM, the impact of acute and chronic exercise (and variations of exercise intensity, modality, and athletic phenotype) in HCM including changes in autonomic function, blood pressure, cardiac dimensions and function, and cardiac output, and the underlying mechanisms that may trigger exercise-induced lethal arrhythmias. It provides a critical evaluation of the evidence regarding risk of SCD in athletes and the potential benefits of targeted exercise prescription in adults with HCM. Finally, it provides considerations for personalized recommendations for sports participation based on the available data.

A rare cause of platypnea-orthodeoxia syndrome in a young female due to persistent left superior vena cava.

Platypnea-Orthodeoxia syndrome (POS) is a rare clinical syndrome characterized by shortness of breath in the upright position that is relieved with supine positioning. We present a rare case of persistent left superior vena cava (PLSVC) draining into the left atrium causing a right-to-left shunt and subsequent POS. A 30-year-old female with a past medical history of hypertrophic cardiomyopathy, congenital Long QT syndrome and a left-sided dual chamber implantable cardioverter-defibrillator (ICD) presented with dyspnea and lightheadedness. Prior to presentation, the patient underwent a left-sided ICD extraction due to ICD lead infection and re-implantation from the right side through the cephalic vein. After further investigation, it was concluded that the PLSVC resulted in a physiological right-to-left shunting causing POS, with resolution of her symptoms after surgical ligation. To our knowledge, this is the first case report of PLSVC presenting with POS without anatomical intracardiac shunts following iatrogenic right superior vena cava (RSVC) obstruction.

Hypertrophic Cardiomyopathy-Related Sudden Cardiac Death in Young People in Ontario.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is considered a leading cause of sudden cardiac death (SCD) in younger people. The incidence of HCM-related SCD and its relationship to exercise have not been well studied in large comprehensive studies outside of tertiary care settings. This study sought to estimate the incidence of HCM-related SCD and its association with exercise in a large unselected population. METHODS: Using the Office of the Chief Coroner of Ontario database encompassing all deaths attended by the coroner, we identified all HCM-related SCDs in individuals 10 to 45 years of age between 2005 and 2016 (70 million person-years). Confirmation of HCM was based on typical macroscopic and microscopic features (definite HCM-related SCD). Sudden deaths with a prior clinical diagnosis of HCM but no autopsy were considered probable HCM-related SCDs. Cases with typical features but no myofiber disarray were considered possible HCM. The completeness of data was verified in a subset of patients in the Toronto area with the use of a registry of all emergency medical services-attended cardiac arrests, with an autopsy rate of 94%. To estimate the number of HCM-related aborted cardiac arrests and lives potentially saved by implantable cardioverter-defibrillators, all de novo implantations for secondary prevention and all implantations and appropriate shocks for primary prevention in patients with HCM 10 to 45 years of age, respectively, were identified with the use of a registry containing data on implantable cardioverter-defibrillator implantations from all implanting sites throughout Ontario. RESULTS: Forty-four, 3, and 6 cases of definite, probable, and possible HCM-related SCDs, respectively, were identified, corresponding to estimated annual incidence rates of 0.31 per 1000 HCM person-years (95% CI, 0.24-0.44) for definite HCM-related SCD, 0.33 per 1000 HCM person-years (95% CI, 0.34-0.62) for definite or probable HCM-related SCD, and 0.39 per 1000 HCM person-years (95% CI, 0.28-0.49) for definite, probable, or possible HCM-related SCD (estimated 140 740 HCM person-years of observation). The estimated annual incidence rate for HCM-related SCD plus aborted cardiac arrest and HCM-related life-threatening arrhythmia (SCD, aborted cardiac arrest, and appropriate implantable cardioverter-defibrillator shocks) was 0.84 per 1000 HCM person-years (95% CI, 0.70-1.0). The majority (70%) of SCDs occurred in previously undiagnosed individuals. Most SCDs occurred during rest (64.8%) or light activity (18.5%). CONCLUSIONS: The incidence of HCM-related SCD in the general population 10 to 45 years of age is substantially lower than previously reported, with most cases occurring in previously undiagnosed individuals. SCDs are infrequently related to exercise.

The relationship between the quantitative extent of late gadolinium enhancement and burden of nonsustained ventricular tachycardia in hypertrophic cardiomyopathy: A delayed contrast-enhanced magnetic resonance study.

OBJECTIVES: To examine the relationship between late gadolinium enhancement (LGE) extent and nonsustained ventricular tachycardia (NSVT) characteristics in patients with hypertrophic cardiomyopathy (HCM). BACKGROUND: NSVT has been shown to be independently associated with sudden cardiac death (SCD) in HCM. Previous studies have found LGE on cardiac magnetic resonance (CMR) to be independently associated with NSVT. METHODS: Seventy-three patients who had 14-day Holter monitoring for either risk stratification for SCD (n = 62) or evaluation of atrial fibrillation (n = 11) on a CMR study were included. Areas of LGE in left ventricle (LV) were visually identified and analyzed quantitatively for both high (≥6 SD above the mean signal intensity of normal myocardium) and intermediate (≥4 but <6 SD) LGE signal intensity. RESULTS: Patients with more extensive LGE had longer (P = 0.0028) and more frequent (P = 0.02) episodes of NSVT. In univariate analyses, frequency of NSVT was associated with LGE extent (rs = 0.43, P = 0.001), LV ejection fraction (rs = -0.38, P < 0.001), LV mass (rs = 0.32, P = 0.005), LV maximal wall thickness (rs = 0.28, P = 0.016), and left atrium diameter (rs = 0.29, P = 0.001); maximal length of NSVT was associated with LGE extent (rs = 0.52, P < 0.001), LV ejection fraction (rs = -0.44, P < 0.001), LV mass (rs = 0.37, P = 0.001), and left atrium diameter (rs = 0.3, P < 0.001). In multivariable analyses, LGE extent remained the sole variable independently associated with frequency (P = 0.001) and maximal length of episodes of NSVT (P = 0.001). No significant association was found between the rate of NSVT and LGE extent. CONCLUSIONS: LGE extent is independently associated with a greater burden and longer episodes of NSVT in HCM. These findings support the association between myocardial fibrosis as represented by LGE and ventricular tachyarrhythmias in HCM.

Left atrial remodeling postseptal myectomy for severe obstructive hypertrophic cardiomyopathy: Analysis by two-dimensional speckle-tracking echocardiography.

BACKGROUND: Septal myectomy relieves left ventricular outflow obstruction (LVOTO) and is associated with excellent long-term outcomes. LVOTO is associated with diastolic dysfunction and increased left atrial (LA) size. We sought to investigate the changes in LA volumes and function postmyectomy and the association between these changes with clinical outcomes postmyectomy. METHODS: Sixty-six hypertrophic cardiomyopathy patients undergoing myectomy were retrospectively studied. Preprocedural and 6- to 18-month postmyectomy follow-up transthoracic echocardiographic images were obtained. LA volumes and strain were assessed by two-dimensional speckle-tracking echocardiography. RESULTS: Left atrial volumes, that is, indexed maximal, minimal, and pre-A volumes reduced postmyectomy, yet remained increased compared to controls (105.6 ± 34.5 mL vs 84.9 ± 26.7 mL, 45.2 ± 25.7 mL vs 35.4 ± 22.6 mL, 70.1 ± 31.4 mL vs 35.4 ± 22.6 mL, respectively, P < 0.05). The total emptying index did not improve postmyectomy and remained lower than controls (58.6 ± 12.4 vs 59.9 ± 12.8, P = NS) whereas atrial contraction improved, yet did not normalize (active emptying index 36.1 ± 14.9 vs 41.1 ± 16.2, P < 0.05). The conduit volume remained reduced postmyectomy (18.6 ± 13.3 mL vs 16.6 ± 15.1 mL, P = NS). LA strain also did not improve postmyectomy (26.8 ± 7.3 vs 28.5 ± 8.8, P = NS). A multivariable logistic regression identified preprocedural E/e' ratio and indexed maximal LA volume, as independent predictors for LA volume reduction ≥20% postmyectomy. During a mean follow-up of 4.9 ± 2.3 years postmyectomy, 24.2% of the patients developed atrial fibrillation and <5% of patients were severely symptomatic. We found no associations between LA volumes/function and atrial fibrillation or symptoms postmyectomy. CONCLUSION: Postmyectomy LA volumes decreased, and the contractile function improved. There was no association between LA volumes/function and clinical outcomes postmyectomy. Notably, the LA remained enlarged (though to a lesser degree) with reduced strain and emptying fraction, suggesting possible atrial myopathy.

Prevention of sudden death in hypertrophic cardiomyopathy: bridging the gaps in knowledge.

Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM). Although the annual rate of SCD in the general HCM population is <1% per year according to contemporary series, there is still a small subset of patients who are at increased risk of SCD. The greatest challenge in the management of HCM is identifying those at increased risk as an implantable cardioverter defibrillator is a potentially life-saving therapy. In this review, we sought to summarize the available data on SCD in HCM and provide a clinical perspective on the current differing and somewhat conflicting European and American recommendations on risk stratification, with balanced guidance with regards to rational clinical decision making. Additionally, we sought to learn more on the actual implementation of the guidelines by HCM experts worldwide.

The Effect of Mineralocorticoid Receptor Antagonists on Recruitment and Function of Endothelial Progenitor Cells in Patients with Congestive Heart Failure.

BACKGROUND: Circulating endothelial progenitor cells have an important role in the process of vascular repair. Impaired recruitment and function of endothelial progenitor cells is related to the pathophysiology of congestive heart failure. Endothelial progenitor cells have been shown to express the mineralocorticoid receptor. OBJECTIVES: To investigate the effect of mineralocorticoid receptor antagonists on endothelial progenitor cells in patients with heart failure. METHODS: Twenty-four patients with compensated heart failure, who were not under mineralocorticoid receptor antagonist therapy, were recruited. Either eplerenone (n=8) or spironolactone (n=16) therapy was initiated. Circulating endothelial progenitor cell level, identified as the proportion of mononuclear cells expressing vascular endothelial growth factor receptor 2 (VEGFR-2), CD133, and CD34, was evaluated by flow cytometry at baseline and after 8 weeks. Following 7 days of culture, colonies were counted by microscopy and MTT assay was performed on randomly selected patients (n=12) to estimate viability. RESULTS: Both median CD34+/VEGFR2+ and median CD133+/VEGFR2+ increased significantly (P = 0.04 and 0.02, respectively). However, the number of colonies and viability of the cells after therapy (as assessed by the MTT assay) was not significantly different compared with the baseline. CONCLUSIONS: These preliminary results suggest that mineralocorticoid receptor blockade may enhance endothelial progenitor cells recruitment in patients with compensated heart failure.

Evaluation of Prolonged QT Interval: Structural Heart Disease Mimicking Long QT Syndrome.

BACKGROUND: In about 20-25% of patients with congenital long QT syndrome (LQTS) a causative pathogenic mutation is not found. The aim of this study was to explore the prevalence of alternative cardiac diagnoses among patients exhibiting prolongation of QT interval with negative genetic testing for LQTS genes. METHODS: We conducted a retrospective analysis of 239 consecutive patients who were evaluated in the inherited arrhythmia clinic at the Toronto General Hospital between July 2013 and December 2015 for possible LQTS. A detailed review of the patients' charts, electrocardiograms, and imaging was carried out. RESULTS: The analysis included 56 gene-negative patients and 61 gene-positive patients. Of the gene-negative group, 25% had structural heart disease compared to only 1.6% of gene-positive patients (P < 0.001). Structural heart disease was more likely if only one abnormal QTc parameter was found in the course of the evaluation (35.2% vs 9.1%, P = 0.01). The most common structural cardiac pathology was bileaflet mitral valve prolapse (8.9%). No gene-positive patient had episodes of nonsustained ventricular tachycardia, compared to seven of the gene-negative patients (0% vs 12.5%, P = 0.005). CONCLUSIONS: Structural pathology was detected in a quarter of gene-negative patients evaluated for possible LQTS. Hence, cardiac imaging and Holter monitoring should be strongly encouraged to rule out structural heart disease in this population.

Determinants of Left Ventricular Mass Regression in Patients with Severe Symptomatic Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation.

BACKGROUND AND AIM OF THE STUDY: The dynamics of left ventricular mass (LVM) regression following the relief of chronic left ventricular pressure overload are prone to variation. The study aim was to identify determinants of LVM regression following transcatheter aortic valve implantation (TAVI). METHODS: A total of 134 patients undergoing TAVI was identified. A retrospective analysis was performed of LVM indexed to body surface area (LVMi), calculated using transthoracic echocardiography at baseline and at six to 12 months post-TAVI. RESULTS: At six to 12 months after TAVI, there was a significant reduction in mean LVMi (from 118.2 ± 26.67 g/m2 to 103.4 ± 27.07 g/m2; p < 0.001) driven by a decrease in left ventricular wall thickness. The relative wall thickness (RWT) was decreased (0.54 ± 0.10 cm versus 0.51 ± 0.09 cm; p = 0.006), whereas the prevalence of concentric remodeling (RWT ≥ 0.42) remained unchanged (85.1% versus 80.6%; p = 0.3). However, 47 patients (35.1%) demonstrated significant LVMi regression, but had a lower baseline LVMi than patients who demonstrated significant regression (109.8 ± 25.8 g/m2 versus 122 ± 26.1 g/m2; p = 0.008) but had otherwise similar characteristics. A greater magnitude of LVMi reduction was associated with a greater baseline LVMi (r = 0.39; p < 0.001), where patients with LVMi in the highest quartile had the most substantial reduction in LVMi (p < 0.001). Multivariable analysis identified pre-TAVI LVMi as the sole independent predictor of LVMi regression at six to 12 months post-TAVI (P = 0.45; 95% confidence interval 0.255-0.534; p < 0.001). CONCLUSION: LVM regression at six to months post-TAVI was variable, with about one-third of patients not showing a significant regression. Only baseline LVM predicted LVM regression; patients with a higher baseline LVM demonstrated a greater regression.

The Impact of Transcatheter Aortic Valve Implantation on Mitral Regurgitation Regression in High-Risk Patients with Aortic Stenosis.

BACKGROUND AND AIM OF THE STUDY: In patients with aortic stenosis, mitral regurgitation (MR) is a common finding. Little is known regarding outcomes of MR in patients undergoing transcatheter aortic valve implantation (TAVI). The study aim was to characterize the short- and mid-term impact of the TAVI procedure on MR grade. METHODS: A total of 261 patients (59% females; mean age 82.1 +/- 6.9 years) undergoing TAVI was assessed for rates of significant MR and the severity of MR at baseline, and at one month and six months after the procedure. RESULTS: In patients with moderate MR or above at baseline (n = 26, 10% of the cohort), there was a mean reduction in grade of 1.5 +/- 1.1 and 1.8 +/- 1.4 after one and six months, respectively (p < 0.01). Reduction in MR grade (1+) at six months was identified in 54.1% (40/74) of patients with mild-moderate MR or greater, and in 88.5% (23/26) of those with moderate MR or above, and was associated with an improved NYHA functional class (correlation coefficient r = -0.294, p < 0.001). Multivariate analysis identified low pulmonary pressure and tricuspid regurgitation as independent predictors of improvements in MR. CONCLUSION: Among the present cohort of patients undergoing TAVI, those with MR at baseline showed an improvement in the severity of their MR. Patients with moderate MR regurgitation or above demonstrated the greatest improvement.

Comparison of platelet inhibition by prasugrel versus ticagrelor over time in patients with acute myocardial infarction.

High on-treatment platelet reactivity (HTPR) despite use of P2Y12 antagonists is associated with adverse cardiac events. The long-term variability in response to prasugrel and ticagrelor is unclear. Our aim was to assess residual platelet reactivity (PR) and rates of HTPR during treatment with prasugrel versus ticagrelor in patients with myocardial infarction (MI). 114 patients with MI treated with percutaneous coronary intervention (PCI) were included. Sixty-two patients were treated with prasugrel (mean age 58 ± 8 years, 21 % women, 29 % diabetes), and 52 patients with ticagrelor (mean age 63 ± 9, 19 % women, 37 % diabetes). Patients were tested for PR at 2-4 days and 30 days post-PCI, using the VerifyNow P2Y12 assay and the multiple-electrode aggregometry. Our results show a higher residual PR in patients treated with prasugrel than those treated with ticagrelor (VerifyNow: 65.4 ± 60.6 vs. 26.0 ± 24.2 P2Y12 reaction units, p < 0.001 at 2-4 days, and 67.3 ± 62.5 vs. 21.1 ± 26.1, p < 0.001 at follow-up). HTPR rates were higher in the prasugrel group (8.1-11.3 % vs. none with ticagrelor in the early test, and 8.7-10.9 % vs. none with ticagrelor at follow-up). In conclusion, in patients with MI undergoing PCI, treatment with ticagrelor resulted in greater platelet inhibition and lower HTPR rates compared with prasugrel, up to 30 days after the event.

Establishment of a Dedicated Inherited Cardiomyopathy Clinic: From Challenges to Improved Patients' Outcome.

Background Inherited cardiomyopathies (ICs) are relatively rare. General cardiologists have little experience in diagnosing and managing these conditions. International societies have recognized the need for dedicated IC clinics. However, only few reports on such clinics are available. Methods and Results Clinical data of patients referred to our clinic during its first 2 years for a personal or family history of (possible) IC were analyzed. A total of 207 patients from 196 families were seen; 13% of probands had their diagnosis changed. Diagnosis was most commonly altered in patients referred for possible arrhythmogenic dominant right ventricular cardiomyopathy (62.5%). A total of 90% of probands had genetic testing, of whom 27.3% harbored a likely pathogenic or pathogenic variant. Of patients with confirmed hypertrophic cardiomyopathy, 31 (28.7%) were treated for left ventricular outflow tract obstruction, including septal reduction in 13. Patients with either hypertrophic cardiomyopathy or left ventricular noncompaction and a history of atrial fibrillation were started on oral anticoagulation. Oral anticoagulation was also discussed with all patients with hypertrophic cardiomyopathy and apical aneurysm. Patients with a definite diagnosis of arrhythmogenic dominant right ventricular cardiomyopathy were started on ß-blockers and given restrictive exercise prescriptions. A total of 17 patients with hypertrophic cardiomyopathy and 5 patients with likely pathogenic or likely variants in arrhythmogenic genes received primary prevention implantable cardioverter-defibrillators. No implantable cardioverter-defibrillators were warranted for arrhythmogenic dominant right ventricular cardiomyopathy. A total of 76 family members from 24 families had cascade screening, 32 of whom carried the familial variant. A total of 21 members from 13 gene-elusive families were evaluated by clinical screening, 3 of whom had positive screening. Conclusions Specialized IC clinics may improve diagnosis, management, and outcomes of patients with (possible) IC and their family members.

Secondary Findings Using Broad Pan Cardiomyopathy and Arrhythmia Panels in Patients With a Personal or Family History of Inherited Cardiomyopathy or Arrhythmia Syndrome.

With broad panels and whole exome or genome sequencing, there is the potential for secondary findings, which include pathogenic/likely pathogenic variants or variants of uncertain significance in genes that are unrelated to the primary clinical indication for the testing. No study examined the frequency and implications of secondary findings when using a broad panel for inherited cardiomyopathy or arrhythmia syndromes. We performed a retrospective review of the primary indications for genetic testing, tests performed, and genetic test results to identify secondary findings in patients seen in the Inherited Cardiovascular Disease Clinic for a personal or family history of (possible) inherited cardiomyopathy, inherited arrhythmia syndrome, previous cardiac arrest, or family history of sudden cardiac death. Of 325 probands and 20 family members who had genetic testing, with no-cost broad cardiomyopathy and arrhythmia panel, 4 probands (1.2%) and 4 family members (5%) had pathogenic/likely pathogenic variants in autosomal dominant genes, unrelated to the primary reason for testing. In conclusion, the prevalence of secondary findings using broad cardiomyopathy and arrhythmia panel in patients with personal or family history of inherited cardiomyopathy or arrhythmia was ∼2.2%. Our findings suggest that with appropriate genetic counseling, broad panels might be considered over disease-specific panels because of the relatively high prevalence of secondary findings that positively affect patient care and would not have been identified with more targeted testing.

Arrhythmia Monitoring for Risk Stratification in Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy, presenting significant clinical heterogeneity. Arrhythmia risk stratification and detection are critical components in the evaluation and management of all cases of HCM. The 2020 American Heart Association/American College of Cardiology HCM guidelines provide new recommendations for periodic 24-48-hour ambulatory electrocardiogram monitoring to screen for atrial and ventricular arrhythmias. A strategy of more frequent or prolonged monitoring would lead to earlier arrhythmia recognition and the potential for appropriate treatment. However, whether such a strategy in patients with HCM results in improved outcomes is not yet established. The available evidence, knowledge gaps, and potential merits of such an approach are reviewed. Cardiac implantable electronic devices provide an opportunity for early arrhythmia detection, with the potential to enable early management strategies in order to improve outcomes.

La cardiomyopathie hypertrophique (CMH) qui est la cardiomyopathie héréditaire la plus fréquente présente une hétérogénéité clinique importante. La stratification du risque d'arythmies et leur détection sont des composantes essentielles de l'évaluation et de la prise en charge de tous les cas de CMH. Les lignes directrices 2020 de l'American Heart Association et de l'American College of Cardiology en matière de CMH fournissent les nouvelles recommandations sur la surveillance périodique de l'électrocardiogramme ambulatoire de 24-48 heures pour dépister les arythmies auriculaires et ventriculaires. Une stratégie de surveillance plus fréquente et prolongée permettrait de dépister plus précocement l'arythmie et pourrait mener au traitement approprié. Toutefois, il n'a pas encore été établi qu'une telle stratégie chez les patients atteints de CMH entraînait de meilleurs résultats cliniques. Les données probantes actuelles, les lacunes en matière de connaissances et les mérites potentiels d'une telle approche sont passés en revue. Les dispositifs cardiaques électroniques implantables offrent la possibilité de détecter précocement l'arythmie et le potentiel de favoriser des stratégies de prise en charge précoce pour améliorer les résultats cliniques.

Primary prevention implantable cardioverter-defibrillators in hypertrophic cardiomyopathy-Are there predictors of appropriate therapy?

BACKGROUND: Identifying patients with hypertrophic cardiomyopathy (HCM) who warrant a primary prevention implantable cardioverter-defibrillator (ICD) is crucial. ICDs are effective in terminating life-threatening arrhythmias; however, ICDs carry risks of complications. OBJECTIVE: The purpose of this study was to assess the incidence and predictors of appropriate ICD therapies, inappropriate shocks, and device-related complications in patients with HCM and primary prevention ICDs. METHODS: All patients with HCM who underwent primary prevention ICD implantation at Toronto General Hospital between September 2000 and December 2017 were identified. Therapies (shocks or antitachycardia pacing) for ventricular tachycardia >180 beats/min or ventricular fibrillation were considered appropriate. RESULTS: Three hundred two patients were followed for a mean 6.1 ± 4.3 years (1801 patient-years of follow-up). Thirty-eight patients (12.6%) received at least 1 appropriate ICD therapy (2.3%/y); the 5-year cumulative probability of receiving appropriate ICD therapy was 9.6%. None of the conventional risk factors nor the European Society of Cardiology risk score was associated with appropriate ICD therapy. In multivariable analysis, age < 40 years at implantation and atrial fibrillation were independent predictors of appropriate ICD therapy. In a subgroup of patients who had undergone cardiac magnetic resonance imaging before ICD implantation, severe late gadolinium enhancement was the strongest predictor of appropriate ICD therapies. ICD-related complications or inappropriate shocks occurred in 87 patients (28.8%), with an inappropriate shock rate of 2.1%/y; the 5-year cumulative probability was 10.7%. CONCLUSION: The incidence of appropriate ICD therapies in patients with HCM and primary prevention ICDs is lower than previously reported; a high proportion of patients suffer from an ICD-related complication. Traditional risk factors have low predictive utility. Severe late gadolinium enhancement, atrial fibrillation, and young age are important predictors of ventricular tachyarrhythmias in HCM.

Characterization and long-term outcomes of patients with myocarditis: a retrospective observational study.

INTRODUCTION: There is limited data on the long-term follow-up of patients with myocarditis. AIM: To investigate the long-term follow-up of patients with myocarditis. MATERIAL AND METHODS: We performed a retrospective observational analysis on the clinical long-term outcomes of patients with myocarditis over a 10-year period. The primary outcome was mortality. We identified risk factors for mortality and adverse clinical outcomes. We also compared the characteristics and outcomes of patients presenting with fulminant myocarditis to those presenting with non-fulminant myocarditis. RESULTS: Between May 2004 and December 2014, 203 patients with myocarditis or perimyocarditis were admitted to our center. Most patients were male (87.7%) with a median age at presentation of 33 years (interquartile range: 25.4-38.9). The median follow-up period was 56.9 months (interquartile range 25.3-87.3 months), during which the overall mortality was 4.4% (9 patients). Fifteen patients presented with fulminant myocarditis. After multivariable analysis, older age (HR = 1.11, 95% CI: 1.05-1.16, p < 0.001) and a poorer New York Heart Association (NYHA) function class (HR = 4.6, 95% CI: 1.18-18, p = 0.028) were found to be independently associated with a higher risk of mortality, whereas higher albumin levels at presentation (HR = 0.2, 95% CI: 0.07-0.56, p = 0.002) were associated with decreased mortality. The group presenting with fulminant myocarditis had a more severe course of disease and a higher in-hospital mortality (13.3% vs. 0%, p = 0.005). CONCLUSIONS: The overall prognosis of patients with myocarditis is good - in terms of both survival and recovery without residual left ventricular dysfunction.