Risk profiles for ventricular arrhythmias in hypertrophic cardiomyopathy through clustering analysis including left ventricular strain.

AIMS: The prediction of ventricular arrhythmia (VA) in hypertrophic cardiomyopathy (HCM) remains challenging. We sought to characterize the VA risk profile in HCM patients through clustering analysis combining clinical and conventional imaging parameters with information derived from left ventricular longitudinal strain analysis (LV-LS). METHODS: A total of 434 HCM patients (65% men, mean age 56 years) were included from two referral centers and followed longitudinally (mean duration 6 years). Mechanical and temporal parameters were automatically extracted from the LV-LS segmental curves of each patient in addition to conventional clinical and imaging data. A total of 287 features were analyzed using a clustering approach (k-means). The principal endpoint was VA. RESULTS: 4 clusters were identified with a higher rhythmic risk for clusters 1 and 4 (VA rates of 26%(28/108), 13%(13/97), 12%(14/120), and 31%(34/109) for cluster 1,2,3 and 4 respectively). These 4 clusters differed mainly by LV-mechanics with a severe and homogeneous decrease of myocardial deformation for cluster 4, a small decrease for clusters 2 and 3 and a marked deformation delay and temporal dispersion for cluster 1 associated with a moderate decrease of the GLS (p < 0.0001 for GLS comparison between clusters). Patients from cluster 4 had the most severe phenotype (mean LV mass index 123 vs. 112 g/m2; p = 0.0003) with LV and left atrium (LA) remodeling (LA-volume index (LAVI) 46.6 vs. 41.5 ml/m2, p = 0.04 and LVEF 59.7 vs. 66.3%, p < 0.001) and impaired exercise capacity (% predicted peak VO2 58.6 vs. 69.5%; p = 0.025). CONCLUSION: Processing LV-LS parameters in HCM patients 4 clusters with specific LV-strain patterns and different rhythmic risk levels are identified. Automatic extraction and analysis of LV strain parameters improves the risk stratification for VA in HCM patients.

The saga of dyssynchrony imaging: Are we getting to the point.

Cardiac resynchronisation therapy (CRT) has an established role in the management of patients with heart failure, reduced left ventricular ejection fraction (LVEF < 35%) and widened QRS (>130 msec). Despite the complex pathophysiology of left ventricular (LV) dyssynchrony and the increasing evidence supporting the identification of specific electromechanical substrates that are associated with a higher probability of CRT response, the assessment of LVEF is the only imaging-derived parameter used for the selection of CRT candidates. This review aims to (1) provide an overview of the evolution of cardiac imaging for the assessment of LV dyssynchrony and its role in the selection of patients undergoing CRT; (2) highlight the main pitfalls and advantages of the application of cardiac imaging for the assessment of LV dyssynchrony; (3) provide some perspectives for clinical application and future research in this field. Conclusion: the road for a more individualized approach to resynchronization therapy delivery is open and imaging might provide important input beyond the assessment of LVEF.

Could echocardiographic left atrial characterization have additive value for detecting risks of atrial arrhythmias and stroke in patients with hypertrophic cardiomyopathy?

AIMS: Atrial arrhythmia (AA) is considered a turning point for prognosis in patients with hypertrophic cardiomyopathy (HCM). We sought to assess whether the occurrence of AA and stroke could be estimated by an echocardiographic evaluation. METHODS AND RESULTS: A total of 216 patients with HCM (52 ± 16 years old) were analysed. All patients underwent transthoracic echocardiography for the evaluation of left atrial volume (LAV), peak left atrial strain (PLAS), and peak atrial contraction strain. The patients were followed for 2.9 years for the occurrence of a composite endpoint including AA and/or stroke and peripheral embolism. Among the 216 patients, 78 (36%) met the composite endpoint. These patients were older (57.1 ± 14.4 vs. 50.3 ± 16.7 years; P = 0.0035), had a higher prevalence of arterial hypertension (62.3 vs. 42.3%; P = 0.005), and had higher NT-proBNP. The LAV (47 ± 20 vs. 37.2 ± 15.7 mL/m²; P = 0.0001) was significantly higher in patients who met the composite endpoint, whereas PLAS was significantly impaired (19.3 ± 9.54 vs. 26.6 ± 9.12%; P < 0.0001). After adjustment, PLAS was independently associated with events with an odds ratio of 0.42 (95% confidence interval 0.29-0.61; P < 0.0001). Stroke occurred in 67% of the patients without any clinical AA. The PLAS with a cut-off of under 15.5% provided event prediction with 91% specificity. Using a 15% cut-off, PLAS also demonstrated a predictive value for new-onset of AA. CONCLUSION: The decrease in PLAS was strongly associated with the risk of stroke, even in patients without any documented AA. Its value for guiding the management of patients with HCM requires further investigation.