Aortic stiffness is increased in hypertrophic cardiomyopathy with myocardial fibrosis: novel insights in vascular function from magnetic resonance imaging

Abstract

Objectives: The aim of the study was to determine if patients with hypertrophic cardiomyopathy (HCM), both with and without myocardial fibrosis, have altered aortic stiffness as assessed by magnetic resonance imaging (MRI) pulse wave velocity (PWV) measurements.

Background: Abnormal aortic stiffness implies an unfavorable prognosis and has been established in a variety of aortic diseases and ischemic cardiomyopathy. However, the relationship between aortic stiffness and HCM has not been studied previously.

Methods: The study was institutional review board approved and Health Insurance Portability and Accountability Act of 1996 compliant. Velocity-encoded MRI was performed in 100 HCM and 35 normal control subjects. PWV was determined between the mid-ascending and -descending thoracic aorta. Delayed-enhancement MRI was acquired for identification of myocardial fibrosis.

Results: Mean age was 52.4 years in HCM and 45.3 years in control subjects. The prevalence of myocardial fibrosis in HCM was 70%. PWV was significantly higher in HCM patients compared with control subjects (8.72 +/- 5.83 m/s vs. 3.74 +/- 0.86 m/s, p < 0.0001). PWV was higher (i.e., increased aortic stiffness) in HCM patients with myocardial fibrosis than in those without (9.66 +/- 6.43 m/s vs. 6.51 +/- 3.25 m/s, p = 0.005).

Conclusions: Increased aortic stiffness, as indicated by increased PWV, is evident in HCM patients, and is more pronounced in those with myocardial fibrosis. Further, aortic stiffening may adversely affect left ventricular performance. In addition, increased aortic stiffness correlates with myocardial fibrosis, and may represent another potentially important parameter for risk stratification in HCM, warranting further study.