Echocardiographic Predictors of Heart Failure in Hypertrophic Cardiomyopathy Secondary to Hypertension

Abstract

On Echocardiography (Echo), hypertension (HTN) is known to manifest as variable degrees and patterns of LV hypertrophy (hypertensive hypertrophic cardiomyopathy) in association with divergent degree of systolic, diastolic dysfunction, left sided chamber and aortic enlargement; However, Echo predictors of heart failure (HF) in hypertensive hypertrophic cardiomyopathy (HTN HCM) has not been well studied. Identifying the independent Echo predictors of HF in HTN HCM. From Echo laboratory, we identified 300 consecutive patients with LV hypertrophy (LVH) (100 each of mild, moderate and severe LVH). We excluded 82 LVH patients of non-hypertensive etiology. Control group included 100 age-matched subjects with no LVH. We examined patients’ demographics, comorbidities including a history of HF, EKG, laboratory values, and Echo variables including but not limited to chamber size, LV mass, LVH phenotype, LV diastolic function, LV EF and mitral annular systolic velocity by tissue Doppler imaging (S’), a surrogate marker of LV long axis (longitudinal) systolic function. Above variables were compared between the subjects of HTN HCM with HF from those without HF by using X2 and ANOVA. Multivariable regression analysis (MVA) was performed to identify the independent predictors. Among HTN HCM, 28% (n=62), 36% (n=78) and 36% (n=78) had mild, moderate and severe degree of LVH respectively. 57% (n=125) were females with a mean age of 59 ± 14 years. 39% (n=85) had HF among which 82 % had HFpEF (heart failure with preserved EF, >50%), 14 % had HFrEF (HF with reduced EF, <40%) and 4 % were HFbEF (HF with borderline EF, 40-50%). When HTN HCM with and without HF groups were compared, a significant difference was noted among 2 out of 14 Echo (diastolic dysfunction and S’) and 4 of 16 clinical parameters (Tobacco abuse, Methamphetamine use, Coronary artery disease, Chronic kidney disease). Of note, there was no difference noted in LVH phenotype and LVEF between the groups of HF and no HF. On MVA, advanced LV diastolic dysfunction (moderate to severe) and impaired longitudinal LV systolic function (S’ ≤6cm/sec) were noted to be the only independent predictors of HF among all the variables (Figure 1). HFpEF is the predominant form of HF in HTN HCM. Impaired longitudinal LV systolic function and advanced diastolic dysfunction on Echo are the independent predictors of HF in HTN HCM. These markers can provide guidance in HF management of HTN HCM.