Predictors of ventricular tachyarrhythmia in patients with implantable cardioverter-defibrillator and non-ischemic systolic heart failure.

BACKGROUND: The benefit derived from implantable cardioverter-defibrillators (ICD) in subjects with non-ischemic systolic HF (NICM) is less well-established. AIM: The study aimed to determine the incidence, predictors, and prognostic impact of ventricular arrhythmias in patients with ICD and NICM. METHODS: The study sample included 377 consecutive patients with ICD or cardiac resynchronization cardioverter-defibrillators (CRT-D, 74% of patients) and NICM implanted and monitored remotely in a university hospital. RESULTS: During the median (interquartile range [IQR]) follow-up of 1645 (960-2675) days, sustained ventricular arrhythmia occurred in 92 patients (24.4%). Of those, ventricular fibrillation (VF), ventricular tachycardia (VT), and both VT and VF occurred in 10 (10.9%), 72 (78.3%), and 10 (10.9%) patients, respectively. Patients with vs. those without ventricular arrhythmia differed concerning sex, left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF), post-inflammatory etiology, atrial fibrillation/flutter occurrence, and supraventricular arrhythmia (SVT) other than AF/AFL during follow-up. In multivariable Cox regression, LVEDD (hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.003-1.09; P = 0.03), AF/AFL (HR, 1.86; 95% CI, 1.21-2.85; P = 0.004), and SVT (HR, 1.77; 95% CI, 1.10-2.87; P = 0.02) were independent predictors of sustained VT, while AF/AFL (HR, 1.65; 95% CI, 1.07-2.56; P = 0.02) was independent predictor of VF. All-cause mortality in patients with VT/VF was significantly higher than in subjects without sustained ventricular arrhythmias (35.9% vs. 22.4%; P = 0.01). CONCLUSIONS: Ventricular arrhythmia occurred in every fourth patient with NICM and ICD during 4.5 years of observation and was associated with significantly worse prognosis than in subjects free of VT/VF. Higher LVEDD, atrial fibrillation/atrial flutter, and supraventricular tachycardia flag patients at risk of ventricular arrhythmia.

Predictive factors of left ventricular ejection fraction improvement after myocardial infarction treated invasively.

Introduction: One indication for the implantation of a cardioverter-defibrillator is a reduction in the left ventricular ejection fraction (LVEF) ≤ 35%. However, in certain patients following an acute myocardial infarction (AMI) a gradual improvement in LVEF has been observed. The factors determining this increase in LVEF have not been conclusively determined. Aim: To ascertain the independent predictors associated with the improvement of LVEF in patients following AMI who underwent invasive treatment, while observing their progress over a 6-month follow-up period. Material and methods: Among 665 patients with AMI, a population with LVEF ≤ 35% was selected. After 6 months, a follow-up echocardiogram was performed. Further analysis compared patients with at least 5% improvement in LVEF (Group I) with those without an increase (Group II). Results: Group I consisted of 34 individuals out of 80 patients (43%) with LVEF ≤ 35%. The factors linked to a reduced probability of LVEF improvement were: higher levels of cardiac troponin T (cTnT) (OR 0.841 for 1 ng/ml increase in cTnT, CI 0.715-0.989; p = 0.037), presence of diabetes mellitus (OR = 0.217, 95% CI: 0.058-0.813, p = 0.023) and moderate or severe mitral regurgitation (OR = 0.178, 95% CI: 0.053-0.597; p = 0.005). Conclusions: The study findings indicate that the presence of severe or moderate mitral regurgitation is the most significant factor contributing to the lack of LVEF improvement following AMI. Moreover, the extent of myocardial damage, as indicated by elevated cTnT values, along with compromised adaptation to hypoxia in patients with diabetes, are identified as independent factors associated with reduced chances of an increase in LVEF.

ECHOCARDIOGRAPHIC METHODS FOR ASSESSING LEFT VENTRICULAR SYSTOLIC FUNCTION.

Transthoracic echocardiography (TTE) is the recommended primary method of assessing cardiac function. The measurement of LVEF determines the strategy for treatment of patients, as well as influences their prognosis. 3D echocardiography has higher accuracy and reproducibility than 2D echocardiography; hence it is currently recommended for volume and LVEF measurements. New echocardiographic techniques: global longitudinal strain measured by speckle tracking and myocardial work allow earlier detection of myocardial abnormalities. In addition, they have greater sensitivity in detecting ischemia, fibrosis and left ven¬tricular systolic dyssynchrony. In some myocardial pathologies, such as amyloidosis, hypertrophic cardiomyopathy or Chagas disease, we observe characteristic patterns of myocardial deformation (strain), which are their hallmarks. Myocardial work, on the other hand, allows assessment of contractility independent of the effect of afterload. The new echocardiographic techniques provide additional diagnostic tools for assessing left ventricular systolic function and informa¬tion on prognosis, and hence their use can be expected to become more widespread in daily clinical practice.

TRIMETHYLAMINE OXIDE - FACTOR IN THE DEVELOPMENT OF ATHEROSCLEROSIS AND A POTENTIAL TARGET FOR DIETARY AND PHARMACOLOGICAL INTERVENTIONS.

Atherosclerotic Cardiovascular Diseases (ASCVD) are the most common cause of death worldwide. Among the well-known con¬tributors to atherosclerosis are less common ones, such as trimethylamine oxide (TMAO). This substance is formed from the oxida¬tion of trimethylamine (TMA) with the participation of flavin oxidases in the liver. TMA is produced with the involvement of the intestinal microbiota from foods rich in choline and carnitine. TMAO promotes the production of foam cells, enhances platelet aggregation, affects endothelial inflammation, and promotes atherosclerosis development. However, further research is needed to determine the effect of dietary changes on reducing TMAO levels and thus reducing incident ASCVD.

Novel Genetic Triggers and Genotype-Phenotype Correlations in Patients With Left Ventricular Noncompaction.

BACKGROUND: Left ventricular noncompaction (LVNC) is a genetically and phenotypically heterogeneous disease and, although increasingly recognized in clinical practice, there is a lack of widely accepted diagnostic criteria. We sought to identify novel genetic causes of LVNC and describe genotype-phenotype correlations. METHODS AND RESULTS: A total of 190 patients from 174 families with left ventricular hypertrabeculation (LVHT) or LVNC were referred for cardiac magnetic resonance and whole-exome sequencing. A total of 425 control individuals were included to identify variants of interest (VOIs). We found an excess of 138 VOIs in 102 (59%) unrelated patients in 54 previously identified LVNC or other known cardiomyopathy genes. VOIs were found in 68 of 90 probands with LVNC and 34 of 84 probands with LVHT (76% and 40%, respectively; P<0.001). We identified 0, 1, and ≥2 VOIs in 72, 74, and 28 probands, respectively. We found increasing number of VOIs in a patient strongly correlated with several markers of disease severity, including ratio of noncompacted to compacted myocardium (P<0.001) and left ventricular ejection fraction (P=0.01). The presence of sarcomeric gene mutations was associated with increased occurrence of late gadolinium enhancement (P=0.004). CONCLUSIONS: LVHT and LVNC likely represent a continuum of genotypic disease with differences in severity and variable phenotype explained, in part, by the number of VOIs and whether mutations are present in sarcomeric or nonsarcomeric genes. Presence of VOIs is common in patients with LVHT. Our findings expand the current clinical and genetic diagnostic approaches for patients with LVHT and LVNC.