Exploring the Correlation Between Fibrosis Biomarkers and Clinical Disease Severity in PLN p.Arg14del Patients

Background: Pathogenic variants in phospholamban (PLN, like p. Arg14del), are found in patients diagnosed with arrhythmogenic (ACM) and dilated cardiomyopathy (DCM). Fibrosis formation in the heart is one of the hallmarks in PLN p.Arg14del carriers. During collagen synthesis and breakdown, propeptides are released into the circulation, such as procollagen type I carboxy-terminal propeptide (PICP) and C-terminal telopeptide collagen type I (ICTP).Aim: To investigate if PICP/ICTP levels in blood are correlative biomarkers for clinical disease severity and outcome in PLN p.Arg14del variant carriers.Methods: Serum and EDTA blood samples were collected from 72 PLN p.Arg14del carriers (age 50.5 years, 63% female) diagnosed with ACM (n = 12), DCM (n = 14), and preclinical variant carriers (n = 46). PICP levels were measured with an enzyme-linked immune sorbent assay and ICTP with a radio immuno-assay. Increased PICP/ICTP ratios suggest a higher collagen deposition. Clinical data including electrocardiographic, and imaging results were adjudicated from medical records.Results: No correlation between PICP/ICTP ratios and late gadolinium enhancement (LGE) was found. Moderate correlations were found between the PICP/ICTP ratio and end-diastolic/systolic volume (both rs = 0.40, n = 23, p = 0.06). PICP/ICTP ratio was significantly higher in patients with T wave inversion (TWI), especially in leads V4–V6, II, III, and aVF (p < 0.022) and in patients with premature ventricular contractions (PVCs) during an exercise tolerance test (p = 0.007).Conclusion: High PICP/ICTP ratios correlated with clinical parameters, such as TWI and PVCs. Given the limited size and heterogeneity of the patient group, additional studies are required to substantiate the incremental prognostic value of these fibrosis biomarkers in PLN p.Arg14del patients.

Premature Ventricular Contractions During the Recovery Phase of Exercise Are Only Associated with Increased Cardiovascular Mortality when Present Together with Echocardiographic Abnormalities

Background: Premature ventricular contractions (PVCs) during the recovery of exercise stress testing are associated with increased cardiovascular mortality, but the cause remains unknown. We aimed to evaluate the association of PVCs during recovery with abnormalities on echocardiography, and to evaluate their combined prognostic performance. Methods: Echocardiographic abnormalities (reduced left ventricular (LV) ejection fraction, valvular heart disease, LV dilatation, LV hypertrophy, or increased filling pressures) and the presence of PVCs during recovery (≥1/min) were identified among patients having undergone resting echocardiography within median [interquartile range] 0 [0-2] days of an exercise stress test. The association between such changes and cardiovascular mortality was analyzed using Cox regression adjusted for age, sex, clinical and exercise variables. Results: Among included patients (n=3,106, 219 events, 7.9 [5.4-11.1] years follow-up), PVCs during recovery was found in 1,327 (43%) patients, among which prevalence of echocardiographic abnormalities was increased (58% vs. 43%, p<0.001). Overall, PVCs during recovery was associated with increased cardiovascular mortality (adjusted hazard ratio (HR) [95% confidence interval] 1.6 [1.2-2.1], p<0.001). When combined with echocardiographic abnormalities, PVCs during recovery was only associated with increased risk when such were present (adjusted HR 3.3 [2.0-5.4], p<0.001), and not when absent (adjusted HR 1.4 [0.7-2.6], p=0.26), in reference to those with neither. Conclusion: PVCs during recovery was associated with increased prevalence of echocardiographic abnormalities. Increased risk of cardiovascular mortality was observed only for subjects with PVCs if concomitant echocardiographic abnormalities were present. This provides a structural explanation for the increased long-term cardiovascular risk among patients with PVCs during recovery.

When Should Premature Ventricular Contractions Be Considered as a Red Flag in Children with Cardiomyopathy?

Premature ventricular contractions (PVCs) are common and generally benign in childhood and tend to resolve spontaneously in most cases. When PVCs occur frequently, an arrhythmia-induced cardiomyopathy may be present requiring medical or catheter ablation. PVCs are only rarely the manifestation of a cardiomyopathy. The purpose of this review is to provide some tips and tricks to raise the suspicion of a cardiac disease based on the presence and characteristics of PVCs in children.

430 Diagnosis and management of a case of biventricular arrhythmogenic cardiomyopathy: a case report

Arrhythmogenic cardiomyopathy (ACM) is a genetically determined heart muscle disorder characterized by fibro-fatty replacement of myocardium which may affect the right ventricle (‘dominant right’ variant), the left ventricle (‘dominant left’ variant) or both (‘biventricular disease’ variant). Despite of ACM is one of the main causes of sudden cardiac death (SCD) in young people and athletes as well, the diagnosis of this complex clinical entity still remains a challenge. We report on a case of a 29 years old non-athletic woman with family history of SCD and a long-standing personal history of palpitations leading to frequent accesses to the Accident & Emergency Department. Her echocardiogram was normal while twelve leads ECG revealed negative T waves in the right precordial leads (V1–V3) and post-excitation epsilon waves. ECG Holter monitoring recorded frequent (up to 17 000 in 24 h) polymorphic premature ventricular contractions (PVCs) seldom organized in couplets or triplets. She was followed-up in our clinic and started on Propanolol 40 mg bid with slight relief of symptoms and reduction of PVCs. Cardiac magnetic resonance (CMR) showed regional dyskinesia of both ventricles and RV dilatation. Moreover, tissue characterization findings revealed the presence of diffuse subepicardial late gadolinium enhancement (LGE) of the LV. Genetic analysis was performed and a variant of uncertain significance (VUS) in Desmoplakin was identified. Non sustained monomorphic ventricular tachycardia was induced during electrophysiologic study by programmed ventricular stimulation. In light of these results, we diagnosed biventricular ACM and, after carefully discussion with the patient, a subcutaneous implantable cardioverter defibrillator (ICD) was implanted. The present case should be a persisting reminder that must be considered more than just a single diagnostic tool when dealing with arrhythmic presentations especially in young patients and the importance of contrast CMR along with genetic testing in order to aid clinicians in the demanding selection of the best candidates for ICD implantation.

Abiraterone Induced Refractory Hypokalemia and Torsades de Pointes in a Patient with Metastatic Castration-Resistant Prostate Carcinoma: A Case Report

Background Abiraterone, an androgen deprivation therapy (ADT), has been used in the treatment of metastatic castration-resistant prostate cancer (mCRPC). It has been associated with increased risks of hypokalemia and cardiac disorders. We report a case of torsades de pointes (TdP) associated with abiraterone use and refractory hypokalemia in a man with mCRPC. Case summary A 78-year-old man with mCRPC presented to the emergency room for generalized weakness. Laboratory results revealed a potassium level of 2.2 mmol/L (3.5-5.0), magnesium level of 2.4 mg/dl (1.6-2.5), and normal kidney and hepatic functions. Initial EKG showed atrial fibrillation with rapid ventricular rate of 106 b.p.m., frequent premature ventricular contractions (PVCs), and a QTc of 634 ms. The patient had multiple episodes of TdP, became pulseless and underwent advanced cardiac life support, including defibrillation. Despite a total of 220 mEq of intravenous potassium chloride, his potassium level only improved to 2.8 mmol/L. He received spironolactone and amiloride to promote urinary potassium reabsorption in addition to hydrocortisone, in an effort to reduce abiraterone’s effect on increasing mineralocorticoid synthesis. Discussion Abiraterone has been widely used in mCRPC since its approval by the FDA in 2011. Regulatory guidelines and standardized close QTc and electrolyte monitoring in patients may help prevent fatal arrhythmias associated with abiraterone.

Inflammation and Immune Response in Arrhythmogenic Cardiomyopathy: State-of-the-Art Review

Arrhythmogenic cardiomyopathy (ACM) is a primary disease of the myocardium, predominantly caused by genetic defects in proteins of the cardiac intercalated disc, particularly, desmosomes. Transmission is mostly autosomal dominant with incomplete penetrance. ACM also has wide phenotype variability, ranging from premature ventricular contractions to sudden cardiac death and heart failure. Among other drivers and modulators of phenotype, inflammation in response to viral infection and immune triggers have been postulated to be an aggravator of cardiac myocyte damage and necrosis. This theory is supported by multiple pieces of evidence, including the presence of inflammatory infiltrates in more than two-thirds of ACM hearts, detection of different cardiotropic viruses in sporadic cases of ACM, the fact that patients with ACM often fulfill the histological criteria of active myocarditis, and the abundance of anti–desmoglein-2, antiheart, and anti-intercalated disk autoantibodies in patients with arrhythmogenic right ventricular cardiomyopathy. In keeping with the frequent familial occurrence of ACM, it has been proposed that, in addition to genetic predisposition to progressive myocardial damage, a heritable susceptibility to viral infections and immune reactions may explain familial clustering of ACM. Moreover, considerable in vitro and in vivo evidence implicates activated inflammatory signaling in ACM. Although the role of inflammation/immune response in ACM is not entirely clear, inflammation as a driver of phenotype and a potential target for mechanism-based therapy warrants further research. This review discusses the present evidence supporting the role of inflammatory and immune responses in ACM pathogenesis and proposes opportunities for translational and clinical investigation.

Administration of Adenosine Triphosphate Provides Additional Value Over Programmed Electrophysiologic Study in Confirmation of Successful Ablation of Atrioventricular Accessory Pathways

Objectives: To study the benefit of adenosine triphosphate (ATP) in evaluating ablation endpoints of accessory pathways (AP) and subsequent long-term prognosis.Methods: We reviewed consecutive patients with supraventricular tachycardias due to APs that underwent radiofrequency catheter ablation (RFCA) from January 2016 to September 2018 in our center. The patients were divided into two groups: the ATP group (who had passed both the ATP test and PES after ablation as the endpoint) and the non-ATP group (who had passed PES only after ablation as the endpoint). We reviewed the patients' intra-cardiac electrograms and analyzed their long-term outcomes.Results: In total, 1,343 patients underwent successful RFCA. There were 215 patients in the ATP group with one lost to follow-up. There were 1,128 patients in the non-ATP group with 39 lost to follow-up. Twenty-three patients in the ATP group demonstrated additional electrophysiological entities due to ATP administration, including reappearance of the ablated APs in 16 patients, discovery of PES-undetected APs in 5, induction of atrial fibrillation in 5, premature atrial contractions in 1, and premature ventricular contractions in another. During the 7 to 39 months (average 24.4 ± 9.5 months) follow-up, the recurrence rate was 8.41% (18/214) in the ATP group and 6.80% (74/1,084) in the non-ATP group. In subjects with recurrence, 14 patients (14/18 = 77.8%) in the ATP group and 50 patients (50/74 = 67.6%) in the non-ATP group accepted redo ablations. Among the ATP-group, all the 14 redo APs were the old ones as before. Among the non-ATP-group, redo ablations confirmed that 39 APs were the old ones, while 20 APs were newly detected ones which had been missed previously. The difference in recurrent AP locations confirmed by redo procedures between the two groups was significant (p = 0.008). In the non-ATP group, 20 (40%) of redo cases were proven to have multiple APs, while 33 (3.3%) cases who did not suffer from recurrence had multiple APs. Existences of multiple APs in recurred cases were significantly higher than that in non-recurred ones in the non-ATP group (p &lt; 0.001), while there was no such difference in the ATP group (p = 0.114).Conclusions: The existence of multiple APs was more common in recurrent cases if ATP was not used for confirmation of ablation endpoints. ATP probably has additional value over PES alone by detecting weak AP conductions. ATP can evoke atrial and ventricular arrhythmias.

Incidence of Arrhythmias and Their Prognostic Value in Patients With Multiple Myeloma

Background: Arrhythmias are common cardiovascular complications in multiple myeloma (MM) patients and are related to a poor prognosis.Objective: This study aimed to assess the burden of arrhythmias and their prognostic value in patients with MM.Methods: This was a retrospective study of patients with MM between January 2015 and April 2020 at the First Affiliated Hospital of Xi'an Jiaotong University. The incidence of arrhythmia and associated risk factors were evaluated. The relationship between the type of arrhythmia and survival was analyzed.Results: A total of 319 patients with MM were identified, and 48.0% (153/319) had arrhythmias. The most common type of arrhythmia was sinus tachycardia (ST) (15.0%, 48/319), followed by sinus bradycardia (SB) (14.4%, 46/319), premature atrial contractions (PACs) (6.3%, 20/319), conduction disorders (CDs) (6.0%, 19/319), atrial fibrillation (AF) (6.0%, 19/319), premature ventricular contractions (PVCs) (4.4%, 14/319) and paroxysmal supraventricular tachycardia (PSVT) (0.6%, 2/319). The patients with arrhythmias had higher levels of log NT-proBNP and creatinine, greater bortezomib use, and a higher incidence of diabetes than those without arrhythmias (P &lt; 0.05). The all-cause mortality rates of patients without arrhythmias and those with AF, ST, PACs, CDs, SB, and PVCs were 50.6% (84/166), 73.7% (14/19), 60.4% (29/48), 60.0% (12/20), 52.6% (10/19), 34.8% (16/46), and 28.6% (4/14), respectively. In a subgroup analysis of patients experiencing different types of arrhythmias, patients with SB had lower all-cause mortality than patients with AF (P &lt; 0.01). Univariate and multivariate Cox analyses showed that there was a positive statistically significant association between SB and survival (HR: 0.592 [0.352–0.998], P = 0.049) in a subgroup analysis of different arrhythmias.Conclusions: Patients with MM had a heavy arrhythmia burden, and in this study, approximately half of MM patients had arrhythmias. MM patients with SB were associated with lower all-cause mortality than those with AF. SB might be an independent positive factor for prognosis.