Hypertrophic and hypertensive hypertrophic cardiomyopathy--a true association?

Retrospective analysis of clinical phenotype and prognosis of hypertrophic cardiomyopathy complicated with hypertension

We here studied the clinical features, cardiac structure, and functional changes and prognosis of hypertrophic cardiomyopathy (HCM) patients with hypertension (HTN). A total of 90 HCM patients with HTN and 172 patients without HTN were divided into a hypertensive group and non-hypertensive group. The clinical characteristics, cardiac structure and function, and prognosis of the two groups were compared. Our study found that HCM patients with HTN had fewer syncope events in their medical histories (8% vs. 22%, P < 0.01) and sudden deaths in the family (3% vs. 10%, P < 0.05). The prevalence of apical hypertrophy (18% vs. 7%, P < 0.01) and midventricular obstruction (26% vs. 15%, P < 0.05) was higher in the HTN group. Besides, simple HCM patients had more pathogenic gene mutations, while those with HTN were more likely to have mutations of uncertain clinical significance (64% vs. 24%, P < 0.05). Evaluation of 5-year survival rate showed a trend for a worse prognosis in HCM patients with HTN, but the results were not statistically insignificant (P = 0.065). In conclusion, we found that the clinical phenotypes of HCM patients with HTN differed from those of patients with HCM alone, suggesting that HTN may play a pathogenic role in the pathogenesis of hypertensive hypertrophic cardiomyopathy patients.

The effect of hypertension on cardiac structure and function in different types of hypertrophic cardiomyopathy: A single-center retrospective study

OBJECTIVES

To determine whether hypertension (HTN) affects cardiac structure and function in different types of hypertrophic cardiomyopathy (HCM).

DESIGN

Patients with obstructive HCM (n = 40), septal HCM (n = 88), and apical HCM (n = 42) were separated into hypertensive and non-hypertensive subgroups, and echocardiographic parameters at baseline and at follow-up were compared between the subgroups.

RESULTS

At follow-up, hypertensive obstructive HCM patients showed a decrease in end-diastolic volume (from 93.87 ± 26.08 mL to 79.06 ± 20.07 mL; p= 0.045) and in left ventricular end-diastolic diameter (from 45.00 ± 5.32 mm to 41.83 ± 4.58 mm; p =0.042). Non-hypertensive obstructive HCM patients showed a decrease in maximum aortic velocity (from 2.01 ± 0.53 m/s to 1.28 ± 0.25 m/s; p= 0.011) and in aortic maximum pressure gradient (from 17.22 ± 9.57 mm Hg to 6.79 ± 2.44 mm Hg; p= 0.03). Hypertensive apical HCM patients showed an increase in end-diastolic volume (from 95.28 ± 16.54 mL to 119.74 ± 25.19 mL; p= 0.016) and in left ventricular end-diastolic diameter (from 45.28 ± 3.36 mm to 50.20 ± 4.56 mm; p= 0.007).

CONCLUSIONS

HTN can affect left ventricular capacity in obstructive HCM and apical HCM, causing a decrease in ventricular capacity in the former and increase in the latter; it has no significant effect on the size of the left ventricular cavity in septal HCM. HTN can lead to a poor therapeutic effect on aortic flow rate and pressure gradient in obstructive HCM patients.

Should there be sex-specific criteria for the diagnosis and treatment of heart failure?

All-cause mortality from cardiovascular disease is declining in the USA. However, there remains a significant difference in risk factors for disease and in mortality between men and women. For example, prevalence and outcomes for heart failure with preserved ejection fraction differ between men and women. The reasons for these differences are multifactorial, but reflect, in part, an incomplete understanding of sex differences in the etiology of cardiovascular diseases and a failure to account for sex differences in pre-clinical studies including those designed to develop new diagnostic and treatment modalities. This review focuses on the underlying physiology of these sex differences and provides evidence that inclusion of female animals in pre-clinical studies of heart failure and in development of imaging modalities to assess cardiac function might provide new information from which one could develop sex-specific diagnostic criteria and approaches to treatment.

Expression and distribution of Src in the nucleus of myocytes in cardiac hypertrophy

The Src kinase is involved in signaling events leading to cardiac hypertrophy. The exact effects of tyrosine phosphorylation and subnuclear distribution on cardiac hypertrophy and failure remain to be investigated. In this study, we examined the intranuclear expression and distribution of c-Src, Src phosphorylated at tyrosine 529 (Src[pY529]), Src phosphorylated at tyrosine 418 (Src[pY418]) and Src phosphorylated at tyrosine 215 (Src[pY215]) in the myocardial nuclei of the left ventricle (LV) from 2-, 6-, 12- and 18-month-old spontaneously hypertensive heart failure (SHHF) rats and age-matched Wistar-Kyoto (WKY) rats as normotensive controls by western blot analysis, immunofluorescent labeling and immunoprecipitation. Cellular Src (c-Src) expression in the myocardial nuclei of the LV of the 2-, 6-, 12- and 18-month-old SHHF rats was not significantly different from that in the myocardial nuclei of the LV of the age-matched WKY rats. Although there were no significant differences observed between the levels of Src[pY529] and Src[pY418] in the myocardial nuclei of the LV of the 2-month-old SHHF and WKY rats, the expression of Src[pY529] significantly decreased, while that of Src[pY418] significantly increased in the myocardial nuclei of the LV of the 6-, 12- and 18-month-old SHHF rats compared to the age-matched WKY controls. Furthermore, as demonstrated by double labeling with antibodies against fibrillarin and Src-associated in mitosis 68 kDa (Sam68), c-Src was co-localized with both Sam68 and fibrillarin in the nuclei; Src[pY529] co-localized with fibrillarin, but Src[pY418] co-localized with Sam68. The results from the present study suggest that the dephosphorylation of Src tyrosine kinase 529, the phosphorylation of tyrosine 418 and their subnuclear redistribution are involved in endonuclear signal transduction in cardiac myocytes, which regulates the development and progression of LV eccentric hypertrophy induced by hypertension.