Predictors of future onset of atrial fibrillation in hypertrophic cardiomyopathy.

BACKGROUND: Novel predictors of atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) are desirable. AIM: To detect new multimodality imaging variables predictive of de novo AF in HCM. METHODS: Consecutive patients with HCM underwent clinical assessment and 48-hour Holter electrocardiography to detect AF episodes. Left ventricular (LV) morphology, function and fibrosis, and the left atrium (LA) were characterized by cardiac magnetic resonance. Mitral valve, systolic pulmonary artery pressure, LV filling and maximum gradients were assessed by echocardiography. Patients with no previous history of AF were followed with Holter recordings. RESULTS: Two hundred and nine patients were included (mean age 53±16 years; 140 men), 46 (22%) of whom had a history of AF and a longer duration from HCM diagnosis, more frequent use of heart failure medication, a higher systolic pulmonary artery pressure, a lower LV ejection fraction, a higher extent of LV fibrosis and prevalence of fibrosis on right ventricular (RV)-LV insertions, a higher LA volume and lower LA phasic function. Patients with no AF at inclusion were followed for 26 (17-42) months, and 15 (9%) developed de novo AF. Among clinical characteristics, New York Heart Association class was the only significant AF predictor in the multivariable analysis (hazard ratio 2.65 per class, 95% confidence interval [CI] 1.15-6.10; P=0.02). Among imaging characteristics, two independent predictors were identified: myocardial fibrosis on RV insertions (hazard ratio 2.8, 95% CI 1.3-5.9; P=0.008); and LA volume (hazard ratio 1.03 per mL/m2, 95% CI 1.01-1.06; P=0.006). CONCLUSIONS: AF in HCM is predicted by New York Heart Association class, LA volume and LV fibrosis on RV-LV insertions on cardiac magnetic resonance imaging. The mechanisms relating the ventricular phenotype to AF should be clarified in future studies.

Characterization of hypertrophic cardiomyopathy according to global, regional, and multi-layer longitudinal strain analysis, and prediction of sudden cardiac death.

To evaluate the severity of hypertrophic cardiomyopathy (HCM) according to global, regional, and multi-layer longitudinal strain (LS) analysis using speckle-tracking echocardiography. From February 2007 to November 2014, we prospectively evaluated 375 consecutive HCM patients referred to our specialized cardiomyopathy center. Demographics, clinical, and rest and exercise echocardiographic parameters were collected according to a completely standardized protocol. Global, regional, and multilayer strain analyses were performed. Correlations between LS and other characteristics were evaluated, and we assessed their prognostic value to predict sudden cardiac death (SCD) or appropriate implantable cardioverter defibrillator (ICD) shocks during follow-up, using Cox proportional hazards analyses. We finally included 217 patients (50.1 ± 15.6 years, 67% male) but only 179 (82%) had LS analysis of sufficient quality. An inverse relation was observed between the mean basal left ventricular (LV) LS and diastolic parameters [E/Ea (r = - 0.30) and left atrium indexed volume (r = - 0.23)], as well as between the resting LV outflow-tract maximal gradient (r = - 0.26) or during peak exercise (r = - 0.20). Mean LS in the LV hypertrophic area was particularly related with maximal wall thickness (r = - 0.47) and transmural global LS with the degree of myocardial fibrosis in cardiac magnetic resonance (r = - 0.32). During a median follow-up of 2.8 ± 1.5 years, mean transmural LS in the hypertrophic area was predictor of SCD and appropriate ICD shock (10 events/179 patients, hazard ratio = 0.83 [95% CI 0.72-0.95], p = 0.01). Basal LS and hypertrophic area LS are valuable parameters to evaluate HCM severity. Mean hypertrophic area LS particularly seems predictive of SCD occurrence and appropriate ICD shocks.