Left ventricular apical aneurysms and outcomes in hypertrophic cardiomyopathy

Abstract

Abstract Background/Introduction The presence of left ventricular apical aneurysm (LVAA) has been shown to be associated with increased risk of adverse events in patients with hypertrophic cardiomyopathy (HCM). However, the between LVAA size and outcomes is uncertain. Purpose To explore associations between baseline LVAA diameter and progressive changes in LVAA size over time and poor outcomes in HCM patients. Methods Our HCM multimodality imaging database (transthoracic echocardiography (TTE) or cardiac magnetic resonance (CMR)) was retrospectively assessed for studies reporting LVAA, defined as one or more akinetic or dyskinetic apical segments. LVAA size (widest systolic diameter in millimetres in the transverse plane) was recorded at two time points: earliest identification and most recent imaging, with LVAA size progression (mm/year) calculated. Patients’ electronic records were reviewed for composite outcome including stroke, apical thrombus, death, and appropriate therapy from implantable cardioverter defibrillator (ICD). Continuous variables are presented as mean ± standard deviation (SD), categorical data numerically or as percentages. Comparisons between groups were made using Wilcoxon ranks sum and Fischer exact test for continuous and binary variables, respectively. Cox regression was used to assess independent associations with composite outcomes. A p value of <0.05 was considered statistically significant. Results A total of 106 patients were identified with LVAA and clinical follow-up (mean age 64.7±11.4 years, 70% male). Mean follow-up duration was 6.5±3.0 years. Baseline LVAA was confirmed by CMR and TTE in 70 and 30% of cases respectively. Mean LVAA size at baseline was 16.2±7.6 mm (range 6-56 mm). During multivariate Cox analysis, baseline LVAA size in mm was independently associated with the composite outcome (HR 1.04, 95% CIs 1.0 to 1.08, p=0.04). Mean duration between baseline and maximal LVAA size scan was 5.4±3.0 years. Median progression in LVAA size was 1.0 (IQR 0.6 to 1.8) mm per annum (range 0.0 to 8.1 mm). During multivariate analysis, LVAA progression rate in mm per year was independently associated with the composite outcome (HR 1.4 95% CIs 1.11 to 1.7, p=0.002). Conclusion(s) These data support the association between LVAA size and poor outcomes in HCM patients. We also demonstrate the progressive nature of LVAAs and indicate those more rapidly increasing in size are at highest risk of adverse events, with potential implications for management strategies.