A steeper LV-aortic root angle independently predicts dynamic LVOT obstruction in patients with hypertrophic cardiomyopathy (beta = -0.34, p<0.001).
Cross-Sectional (n=257)
Does a steeper LV-aortic root angle predict dynamic LVOT obstruction in patients with hypertrophic cardiomyopathy independently of basal septal thickness?
A steeper LV-aortic root angle is independently associated with dynamic LVOT obstruction in patients with hypertrophic cardiomyopathy, offering a novel anatomical predictor beyond basal septal thickness.
Effect estimate: beta = -0.34
p-value: p=<0.001
BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) exhibit a difference in left ventricular outflow tract (LVOT) obstruction, independently of basal septal thickness (BST). Some patients with HCM have a steeper left ventricle to aortic root angle than controls. OBJECTIVE: To test the predictors of the LV-aortic root angle and the association between LV-aortic root angle and LVOT obstruction using three-dimensional imaging. PATIENTS: 153 consecutive patients with HCM (mean (SD) age 46 (14) years, 68% men) and 62 patients with hypertensive heart disease of the elderly (all >65 years of age, 73 (6) years, 34% men) who underwent whole-heart three-dimensional cardiac magnetic resonance (CMR) angiography (1.5 T) and Doppler echocardiography. Forty-two controls (age 43 (11) years, 38% men) who underwent contrast-enhanced multidetector computed tomography and were free of cardiovascular pathology were also studied. MAIN OUTCOMES: LV-aortic root angle, BST and maximal non-exercise LVOT gradient were measured in patients with HCM and in hypertensive-elderly patients. Additionally, LV-aortic root angle and BST were measured in controls. RESULTS: The mean (SD) LV-aortic root angle was significantly different (p<0.001) in the three groups: HCM (134 (10) degrees ), hypertensive-elderly (128 (10) degrees ), control (140 (7) degrees ). There was an inverse correlation between age and LV-aortic root angle in the three groups (all p<0.001): HCM (r = -0.56), hypertensive-elderly (r = -0.35), control (r = -0.48). On univariate analysis, in the HCM group, LV-aortic root angle (beta = -0.34, p<0.001), age (beta = 0.23, p = 0.01) and end-systolic volume index (beta = -0.20, p = 0.02), but not BST (beta = 0.02, p = 0.8), were associated with LVOT gradient. On multivariate analysis, only LV-aortic root angle was associated with LVOT gradient. CONCLUSIONS: Patients with HCM have a steeper LV-aortic root angle than controls. In patients with HCM, a steeper LV-aortic root angle predicts dynamic LVOT obstruction, independently of BST.
Kwon et al. (2009) conducted a cross-sectional in Hypertrophic cardiomyopathy (n=257). LV-aortic root angle vs. Controls and hypertensive elderly was evaluated on Association between LV-aortic root angle and LVOT gradient in HCM patients (beta = -0.34, p=<0.001). A steeper LV-aortic root angle independently predicts dynamic LVOT obstruction in patients with hypertrophic cardiomyopathy (beta = -0.34, p<0.001).