An overview of heart rhythm disorders and management in myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is the most common adult form of muscular dystrophy, presenting with a constellation of systemic findings secondary to a CTG triplet expansion of the noncoding region of the DMPK gene. Cardiac involvement is frequent, with conduction disease and supraventricular and ventricular arrhythmias being the most prevalent cardiac manifestations, often developing from a young age. The development of cardiac arrhythmias has been linked to increased morbidity and mortality, with sudden cardiac death well described. Strategies to mitigate risk of arrhythmic death have been developed. In this review, we outline the current knowledge on the pathophysiology of rhythm abnormalities in patients with myotonic dystrophy and summarize available knowledge on arrhythmic risk stratification. We also review management strategies from an electrophysiological perspective, attempting to underline the substantial unmet need to address residual arrhythmic risks for this population.

Risk Prediction Models and Scores in Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) has historically been linked with sudden cardiac death (SCD). Currently, it is well established that only a subset of patients is at the highest risk stratum for such a catastrophic event. Detection of patients belonging to this high-risk category can allow for timely defibrillator implantation, changing the natural history of HCM. Inversely, device implantation in patients deemed at low risk leads to an unnecessary burden of device complications with no apparent protective benefit. Previous studies have identified a series of markers, now considered established risk factors, with genetic testing and newer imaging allowing for the detection of novel, highly promising indices of increased risk for SCD. Despite the identification of a number of risk factors, there is noticeable discrepancy in the utility of such factors for risk stratification between the current American and European guidelines. We sought to systematically review the data available on these two approaches, presenting their rationale and respective predictive capacity, also discussing the potential of novel markers to augment the precision of currently used risk stratification models for SCD in HCM.

The Novel Desmin Variant p.Leu115Ile Is Associated With a Unique Form of Biventricular Arrhythmogenic Cardiomyopathy.

BACKGROUND: Arrhythmogenic cardiomyopathy (AC) is a heritable myocardial disorder and a major cause of sudden cardiac death. It is typically caused by mutations in desmosomal genes. Desmin gene (DES) variants have been previously reported in AC but with insufficient evidence to support their pathogenicity. METHODS: We aimed to assess a large AC patient cohort for DES mutations and describe a unique phenotype associated with a recurring variant in three families. A cohort of 138 probands with a diagnosis of AC and no identifiable desmosomal gene mutations were prospectively screened by whole-exome sequencing. RESULTS: A single DES variant (p.Leu115Ile, c.343C>A) was identified in 3 index patients (2%). We assessed the clinical phenotypes within their families and confirmed cosegregation. One carrier required heart transplantation, 2 died suddenly, and 1 died of noncardiac causes. All cases had right- and left-ventricular (LV) involvement. LV late gadolinium enhancement was present in all, and circumferential subepicardial distribution was confirmed on histology. A significant burden of ventricular arrhythmias was noted. Desmin aggregates were not observed macroscopically, but analysis of the desmin filament formation in transfected cardiomyocytes derived from induced pluripotent stem cells, and SW13 cells revealed cytoplasmic aggregation of mutant desmin. Atomic force microscopy revealed that the mutant form accumulates into short protofilaments and small fibrous aggregates. CONCLUSIONS: DES p.Leu115Ile leads to disruption of the desmin filament network and causes a malignant biventricular form of AC, characterized by LV dysfunction and a circumferential subepicardial distribution of myocardial fibrosis.

Andersen-Tawil Syndrome Presenting with Complete Heart Block.

Andersen-Tawil syndrome (ATS) is a rare autosomal dominant neuromuscular disorder due to mutations in the KCNJ2 gene. The classical phenotype of ATS consists of a triad of periodic paralysis, cardiac conduction abnormalities and dysmorphic features. Episodes of either muscle weakness or cardiac arrhythmia may predominate however, and dysmorphic features may be subtle, masking the true breadth of the clinical presentation, and posing a diagnostic challenge. The severity of cardiac involvement varies but includes reports of life-threatening events or sudden cardiac death, usually attributed to ventricular tachyarrhythmias. We report the first case of advanced atrioventricular (AV) block in ATS and highlight clinical factors that may delay diagnosis.

Dilated cardiomyopathy and arrhythmogenic left ventricular cardiomyopathy: a comprehensive genotype-imaging phenotype study.

AIMS: Myocardial scar detected by cardiovascular magnetic resonance has been associated with sudden cardiac death in dilated cardiomyopathy (DCM). Certain genetic causes of DCM may cause a malignant arrhythmogenic phenotype. The concepts of arrhythmogenic left ventricular (LV) cardiomyopathy (ALVC) and arrhythmogenic DCM are currently ill-defined. We hypothesized that a distinctive imaging phenotype defines ALVC. METHODS AND RESULTS: Eighty-nine patients with DCM-associated mutations [desmoplakin (DSP) n = 25, filamin C (FLNC) n = 7, titin n = 30, lamin A/C n = 12, bcl2-associated athanogene 3 n = 3, RNA binding motif protein 20 n = 3, cardiac sodium channel NAv1.5 n = 2, and sarcomeric genes n = 7] were comprehensively phenotyped. Clustering analysis resulted in two groups: 'DSP/FLNC genotypes' and 'non-DSP/FLNC'. There were no significant differences in age, sex, symptoms, baseline electrocardiography, arrhythmia burden, or ventricular volumes between the two groups. Subepicardial LV late gadolinium enhancement with ring-like pattern (at least three contiguous segments in the same short-axis slice) was observed in 78.1% of DSP/FLNC genotypes but was absent in the other DCM genotypes (P < 0.001). Left ventricular ejection fraction (LVEF) and global longitudinal strain were lower in other DCM genotypes (P = 0.053 and P = 0.015, respectively), but LV regional wall motion abnormalities were more common in DSP/FLNC genotypes (P < 0.001). DSP/FLNC patients with non-sustained ventricular tachycardia (NSVT) had more LV scar (P = 0.010), whereas other DCM genotypes patients with NSVT had lower LVEF (P = 0.001) than patients without NSVT. CONCLUSION: DSP/FLNC genotypes cause more regionality in LV impairment. The most defining characteristic is a subepicardial ring-like scar pattern in DSP/FLNC, which should be considered in future diagnostic criteria for ALVC.

Free Cortisol Is a More Accurate Marker for Adrenal Function and Does Not Correlate with Renal Function in Cirrhosis.

BACKGROUND: The accuracy of diagnosis and clinical implications of the hepatoadrenal syndrome, as currently diagnosed using total cortisol, remain to be validated. AIM: The aim of this study was to assess adrenal function using free cortisol in stable cirrhosis and study the potential implications of any abnormalities for renal and/or cardiac function. METHODS: Sixty-one stable consecutively enrolled patients with cirrhosis underwent assessment of adrenal function using the low-dose short Synacthen test, renal function by 51Cr-EDTA glomerular filtration rate (GFR), and cardiac function by two-dimensional echocardiography. RESULTS: Eleven patients (18%) had total peak cortisol (PC) < 500 nmol/L, but no patient had free PC < 33 nmol/L indicating that diagnosis of AI using total cortisol is not confirmed using free cortisol. Free cortisol did not correlate with GFR or parameters of cardiac function. Patients with higher Child-Pugh class had progressively lower free cortisol. Patients with low GFR < 60 mL/min (N = 22) had more frequently grade II-III diastolic dysfunction (66.7% vs. 17.6%; p = 0.005) and had higher Child-Pugh and MELD score compared to those with normal GFR. CONCLUSIONS: Diagnosis of AI using total cortisol is not confirmed using free cortisol and is thus considered unreliable in cirrhosis. Free cortisol is not associated with renal or cardiac dysfunction. Lower free cortisol in more advanced stages of liver disease might be secondary to decreased synthesis due to lower cholesterol levels. Irrespective of free cortisol, parameters of cardiac dysfunction are associated with renal impairment supporting the cardio-renal hypothesis.

Atrial fibrillation in hypertrophic cardiomyopathy: A turning point towards increased morbidity and mortality.

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmic event in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to identify the clinical impact and prognostic significance of AF on a large cohort of patients with HCM. METHODS: Echocardiographic and clinical correlates, risk factors for AF and thromboembolic stroke and the prognostic significance of AF were evaluated in 509 patients with an established diagnosis of HCM. RESULTS: A total of 119 patients (23.4%) were diagnosed with AF during the index evaluation visit. AF patients had a higher prevalence of stroke and presented with worse functional impairment. Left atrial diameter (LA size) was a common independent predictor of the arrhythmia (OR: 2.2, 95% CI 1.6-3.3) and thromboembolic stroke (OR: 1.6, 95% CI 1.01-2.40). AF was an important risk factor for overall mortality (HR=3.4, 95% CI: 1.7-6.5), HCM-related mortality (HR=3.9, 95% CI: 1.8-8.2) and heart failure-related mortality (HR=6.0, 95% CI: 2.0-17.9), even after adjusting for statistically significant clinical and demographic risk factors. However, AF did not affect the risk for sudden death. CONCLUSIONS: LA size is an independent predictor of both AF and thromboembolic stroke. Moreover, patients with AF, regardless of type, have significantly higher mortality rates than patients without AF.

Hypertrophic Mesenteric Adipose Tissue May Play a Role in Atherogenesis in Inflammatory Bowel Diseases.

BACKGROUND: Adipokines released by the adipose tissue are known to play a role in atherogenesis. The hypertrophic mesenteric fat in patients with inflammatory bowel diseases (IBD) also produces adipokines that are considered to play a role in intestinal inflammation. Whether they also contribute to accelerated atherosclerosis in IBD is unknown. The aim of this study was to assess the role of 2 adipokines, resistin and adiponectin, in IBD. METHODS: We previously published data on 3 markers of cardiovascular risk, carotid intima-media thickness, carotid-femoral pulse wave velocity, and lipoprotein-associated phospholipase A2, in 44 patients with IBD and 44 controls matched for established cardiovascular risk factors. In this study, we measured resistin and adiponectin levels, and assessed their correlations with carotid intima-media thickness, pulse wave velocity, and lipoprotein-associated phospholipase A2. RESULTS: Resistin levels were significantly higher in patients with IBD (13.7 versus 10 ng/mL; P = 0.022), but there was no difference in adiponectin levels. Resistin levels were significantly higher in patients with active disease compared with those in remission (18.9 versus 11.3 ng/mL; P = 0.014). Adiponectin levels were significantly lower in Crohn's disease compared with ulcerative colitis (6736.3 ± 3105 versus 10,476.1 ± 5575.7 ng/mL; P = 0.026). Adiponectin correlated inversely with pulse wave velocity (rho = -0.434; P < 0.0005) and carotid intima-media thickness (rho = -0.255; P = 0.021). CONCLUSIONS: This is the first study to suggest that adipokines produced by the hypertrophic mesenteric fat in IBD may play a role not only in intestinal inflammation but also in atherogenesis. Resistin has mainly pro-inflammatory properties, whereas adiponectin likely exerts an angioprotective effect.

Treating Heart Failure with Preserved Ejection Fraction Related to Arterial Stiffness. Can we Kill Two Birds With One Stone?

Heart failure with preserved ejection fraction (HFpEF). Arterial hypertension (AH), arterial stiffness (AS), older age, and female gender are the main determinants of HFpEF, but several cardiac or extra-cardiac pathologies are also possible causes. The combined ventricular-vascular stiffening (abnormal left atrium-left ventricle coupling related to AS) is the main contributor of the increased prevalence of HFpEF in elderly persons, particularly elderly women, and in younger persons with AH. The hospitalization and mortality rates of HFpEF are similar to those of heart failure with reduced EF (HFrEF). However, although the prognosis of HFrEF has been substantially improved during the last 2 decades, the effective treatment of HFpEF remains an unmet need. Regimens effective in HFrEF have no substantial effect on HFpEF, because of different pathophysiologies of the 2 syndromes. Pipeline drugs seem promising, but it will take some years before they are commercially available. Aggressive treatment of noncardiac comorbidities seems to be the only option at hand. Treatment of anaemia, sleep disorders, chronic kidney disease (CKD), non-alcoholic fatty liver (NAFLD), atrial fibrillation, diabetes, and careful use of diuretics to reduce preload are effective to some degree. Statin treatment, despite the presence of dyslipidaemia, deserves special attention because it has been proven, mainly in small studies or post hoc analyses of trials, that it offers a substantial improvement in quality of life and a reduction in mortality rates. We need to urgently utilize these recourses to relieve a considerable part of the general population suffering from HFpEF, a deadly disease.

Lipoprotein-associated phospholipase A2 and arterial stiffness evaluation in patients with inflammatory bowel diseases.

BACKGROUND AND AIMS: The association between inflammatory bowel diseases (IBD) and cardiovascular disease (CVD) remains equivocal. Arterial stiffness, as assessed by pulse wave velocity (PWV), and lipoprotein-associated phospholipase A2 (Lp-PLA2) are surrogates of CVD risk. AIM: The aim of this study was to assess carotid-femoral PWV and Lp-PLA2 in patients with IBD without history of CVD. METHODS: Established CVD risk factors, IBD characteristics, PWV and Lp-PLA2 activity were assessed in 44 patients with IBD, 29 with Crohn's disease (CD) and 15 with ulcerative colitis (UC), and 44 matched controls. RESULTS: IBD patients had lower total and low density lipoprotein cholesterol (LDL-C) levels. There was no difference in PWV between patients and controls (6.8 vs. 6.4m/s), but patients with CD had higher PWV compared to those with UC (7 vs. 6.3m/s; p=0.044), and to controls. Smoking rates were significantly higher among CD patients. Factors associated with PWV were age, mean arterial pressure and smoking. Lp-PLA2 activity was significantly lower in patients with IBD (46.8 vs. 53.9 nmol/mL/min; p=0.011). There was no difference in Lp-PLA2 between CD and UC patients. LDL-C was the only significant predictor of Lp-PLA2. CONCLUSIONS: Our study showed lower Lp-PLA2 activity in patients with IBD compared with controls, reflecting lower LDL-C in the former. There was no difference in PWV between the two groups. Arterial stiffness was higher in patients with CD, which is likely related to higher smoking rates. These findings challenge a possible association between IBD and CVD, but further studies are required.

Renal denervation: transition from pathophysiology to clinical practice.

Resistant hypertension, defined as failure to reach blood pressure (BP) goals despite treatment with ≥3 antihypertensive agents, one of which is a diuretic, bears a significant risk of cardiovascular complications. Strong evidence exists, implicating the overactivation of the sympathetic nervous system (SNS) in the pathogenesis of resistant hypertension through complex neurohormonal interactions. Renal denervation is a novel attractive option to achieve adequate blockade of the sympathetic system, with subsequent BP reductions in patients with resistant hypertension. Data have shown promising results regarding the efficacy of the procedure, maintaining a favorable safety profile. As such, the paradigm of resistant hypertension has expanded in other conditions involving a hyperadrenergic state such as the metabolic syndrome, heart failure, arrhythmias, sleep apnea, and renal failure. This review focuses on the pathophysiological rationale of modifying SNS tone and the evidence of the benefits of such intervention beyond BP control.

Is there an association between inflammatory bowel diseases and carotid intima-media thickness? Preliminary data.

Inflammation is a predictor of cardiovascular disease (CVD). Thus, inflammatory bowel diseases (IBD) may be associated with CVD. We assessed carotid intima-media thickness (cIMT; an indicator of CVD risk) in 42 patients with IBD, free of CVD or diabetes; 26 with Crohn's disease (CD) and 16 with ulcerative colitis (UC). The cIMT was significantly greater in patients with IBD compared to 42 healthy controls (0.62 ± 0.08 vs 0.52 ± 0.06 mm; P < .0005). The cIMT did not differ between patients with CD and UC or between the different disease activity and treatment groups. Factors associated with cIMT were age, body mass index, and IBD, with the latter making a greater contribution. The IBD is a predictor of cIMT, even when other CVD risk factors are considered. These findings suggest an association between early arterial wall alterations and IBD. Such an association should be proven in larger studies that should assess the incidence of CVD in patients with IBD.

Carotid intima-media thickness in patients with inflammatory bowel disease: a systematic review.

We systematically reviewed the available data on carotid intima-media thickness (cIMT) in patients with inflammatory bowel diseases (IBDs) without history of cardiovascular disease (CVD) and its associated factors. A total of 6 studies met the inclusion criteria including 217 patients with Crohn's disease (CD) and 85 with ulcerative colitis (UC). Two studies included only patients with CD. The prevalence of traditional CVD risk factors and the inflammatory burden (IBD duration and activity) varied greatly among patients and studies. Factors that correlated with cIMT were age, male gender, body mass index, arterial hypertension, as well as cholesterol and homocysteine levels. The current data on cIMT in patients with IBD are inconclusive. This is probably due to small number of patients, population heterogeneity with regard to inflammatory burden and smoking habits, and lack of strict matching with controls. In order to elucidate any potential association between IBD and CVD risk, larger prospective studies are required.

Statins and cardiovascular outcomes in elderly and younger patients with coronary artery disease: a post hoc analysis of the GREACE study.

INTRODUCTION: The effect of cardiovascular disease (CVD) prevention measures aimed at elderly patients requires further evidence. We investigated the effect of statin treatment (targeted to achieve guideline goals) on CVD outcomes in different age groups to determine whether statins are more beneficial in the elderly. MATERIAL AND METHODS: The primary endpoint of this post hoc analysis of the GREek Atorvastatin and Coronary-heart-disease Evaluation (GREACE) study (n = 1,600 patients with established coronary heart disease (CHD), mean follow-up 3 years) was the absolute and relative CVD event (a composite of death, myocardial infarction, revascularization, unstable angina, heart failure and stroke) risk reduction in age quartiles (each n = 200). Patients on "structured care" with atorvastatin (n = 800) followed up by the university clinic and treated to lipid goal were compared with the corresponding quartiles on "usual care" (n = 800) followed up by specialists or general practitioners of the patient's choice outside the hospital. RESULTS: In the elderly (mean age 69 ±4 and 70 ±3 years in the "structured" and "usual care", respectively) the absolute CVD event reduction between "structured" and "usual care" was 16.5% (p < 0.0001), while in the younger patients (mean age 51 ±3 years and 52 ±3 years in the "structured" and "usual care", respectively) this was 8.5% (p = 0.016); relative risk reduction (RRR) 60% (p < 0.0001) vs. 42% respectively (p = 0.001). The elderly had higher rates of chronic kidney disease and higher uric acid levels, plus an increased prevalence of diabetes, metabolic syndrome and non-alcoholic fatty liver disease. These factors might contribute to the increased CVD risk in older patients. CONCLUSIONS: All age groups benefited from statin treatment, but the elderly on "structured care" had a greater absolute and relative CVD risk reduction than the younger patients when compared with the corresponding patients assigned to "usual care". These findings suggest that we should not deprive older patients of CVD prevention treatment and lipid target achievement.

Left ventricular hypertrophy caused by a novel nonsense mutation in FHL1.

Emery Dreifuss muscular dystrophy (EDMD) is a hereditary muscular disorder, characterized by contractures, progressive muscular wasting and cardiac involvement. The majority of EDMD patients harbor mutations in the lamin A/C (LMNA) and emerin (STA) genes. Emerging data implicate mutations in FHL1 (four and a half LIM protein 1) gene, located in chromosome Xq26, in EDMD pathogenesis. FHL1 is mainly expressed in striated and cardiac muscle, and plays an important role in sarcomeric protein synthesis, maintenance of cellular integrity, intracellular signaling and genetic transcription pathways. We report the identification of a novel nonsense mutation in FHL1 gene, associated with left ventricular hypertrophy and a family history of stroke and sudden cardiac death. The management implications of this diagnosis are also discussed.

The impact of smoking on cardiovascular outcomes and comorbidities in statin-treated patients with coronary artery disease: a post hoc analysis of the GREACE study.

BACKGROUND: Smoking adversely affects cardiovascular disease (CVD) morbidity and mortality; however the effect of long-term statin treatment in high risk smokers is not entirely clear. The primary endpoint of this post hoc analysis of the GREek Atorvastatin and Coronary Heart Disease Evaluation (GREACE) study (n=1,600 patients with established coronary heart disease, mean follow-up 3-years) was the incidence of major CVD events, a composite of death, myocardial infarction, revascularization, unstable angina, heart failure, and stroke in statin-treated patients (n=880) who continued to smoke (n=129) compared with ex-smokers (n=309) and never smokers (n=442) as well as on patients not treated with a statin (n=720) of all smoking categories. Secondary endpoints were the effect of smoking on chronic kidney disease (CKD) and on non-alcoholic fatty liver disease (NAFLD), two major and common independent CVD risk factors. RESULTS: Among statin treated patients the hazard ratio (HR) for current smokers compared with never smokers was 1.86 [95% confidence interval-(CI) 1.19-2.10); similar was the HR for current smokers compared with ex-smokers. Absolute (16.3%) and relative (45.6%) CVD risk reduction was great in current smokers on statins compared with those not on a statin; however they still had the highest absolute CVD event incidence (19.4%). Low high density lipoprotein cholesterol and higher triglycerides may account, at least in part, for this. The highest risk of CVD events in any of the 6 groups was in the smokers not on a statin (35.7%). CKD and NAFLD were not negatively affected by smoking and they do not appear to be implicated in the adverse effect of smoking on CVD event rate in patients on a statin. CONCLUSIONS: Statins reduce CVD morbidity and mortality in current smokers with CVD, but these remain high in terms of absolute incidence compared with ex- and never smokers. CKD and NAFLD are not affected by smoking and do not seem to contribute to this high CVD event incidence. These make smoking cessation imperative in high risk patients even if they are on statins.