Peripheral Vascular Function in Dilated Cardiomyopathy of Different Etiology

Vascular function in dilated cardiomyopathy of different etiology has been poorly investigated. Moreover, reference values of flow-mediated dilation (FMD) in chronic heart failure (CHF) need to be updated according to the new standardized protocols. We characterized the vascular impairment in different stages of post-ischemic dilated cardiomyopathy (PI-DC) or idiopathic dilated cardiomyopathy (I-DC). Eighty consecutive outpatients with CHF in different New York Heart Association (NYHA) classes (45 PI-DC, 35 I-DC) and 50 control subjects underwent FMD and brachial distensibility coefficient measurement. Patients with CHF showed a marked impairment in FMD compared with controls that worsened from classes NYHA I-II to III-IV, independently of etiology ( P < .05). New York Heart Association I-II PI-DC patients showed a worse FMD compared with NYHA I-II I-DC patients ( P < .05). Brachial distensibility coefficient values were significantly lower in patients with CHF compared with controls ( P < .001) without differences between PI-DC and I-DC. In conclusion, advanced CHF is characterized by vascular impairment that is independent of etiology. In the early stages of CHF, endothelial dysfunction is more severe in patients with PI-DC compared with I-DC probably due to the high cardiovascular risk profile. In I-DC, vascular function impairment is independent of cardiovascular risk factors and could participate in the pathogenesis of I-DC.

Multiparametric Ultrasound to Assess Adult Carotid Arteries

The aim of the study was to assess the value of multiparametric ultrasound in atherosclerotic cardiovascular disease risk screening of the carotid artery. We performed ultrasonography of carotid arteries in 96 adults in 3 age groups: senior (age ≥65 years, n = 44), middle age (age 45-64 years, n = 31), and young adults (age 20-44 years, n = 21). The senior group was then divided into subgroups: athletes (n = 21) and non-athletes (n = 23). Ultrasound parameters included carotid intima-media thickness, distensibility coefficient, and presence of plaque(s). Statistical analyses included one-way analysis of variance with post hoc to analyze the differences in ultrasound parameters among the age groups; unpaired t-test to examine differences between hypertensive and normotensive participants, between seniors with and without plaque(s), and between senior athletes and non-athletes; Pearson correlation coefficient to analyze correlations of ultrasound parameters to age and blood pressure; and intraclass correlation coefficient to test intra- and inter-observer reliability in performing multiparametric ultrasound. Carotid intima-media thickness and distensibility coefficient significantly differed among the 3 age groups and between athletes and non-athletes ( P < .001). Senior athletes had greater distensibility than non-athletes (all Ps < .05). Carotid intima-media thickness was increased and distensibility was reduced with age and hypertension. Age and blood pressure positively correlated with carotid intima-media thickness (Pearson correlation coefficient, r > .21) and negatively with distensibility coefficient (Pearson correlation coefficient, r < –.48). Inter- and intra-observer reliability in performing multiparametric ultrasound was good (intraclass correlation coefficient, r > .81). Multiparametric ultrasound is a useful tool to assess carotid artery function and morphology comprehensively.

Derivation of the distensibility coefficient using tissue Doppler as a marker of arterial function

To date, the main cardiovascular application of TDI (tissue Doppler imaging) has been in myocardial evaluation. In the present study, we investigated the feasibility and reproducibility of assessing arterial elasticity using the DC (distensibility coefficient) measured by TDI, the correlation of this with the DC obtained by other methods and the DC in patients with various degrees of cardiovascular risk. We studied 450 subjects (256 men; age, 51±10 years) with and without risk factors of cardiovascular disease. Arterial displacement was measured from TDI, and B-mode and M-mode images of the common carotid artery in the longitudinal plane, and the DC with each method was compared. Linear regression showed a good correlation between all three methods. The results for TDI and B-mode were comparable [(21±10) compared with (21±10)×10−3/kPa respectively; P=not significant], but there were significant differences between TDI and M-mode [(21±10) compared with (31±13)×10−3/kPa respectively; P<0.0001] and between B-mode and M-mode [(21±10) compared with (31±13)×10−3/kPa respectively; P<0.0001]. Similarly, Bland–Altman analysis showed the least variability in the DC between TDI and B-mode, and there were no significant differences between the average measurements. The TDI DC also had the lowest paired difference for inter-observer variability [(−0.1±1.1)×10−3/kPa; P=not significant]. In conclusion, the results of the present study suggest that TDI of the carotid arteries is feasible, comparable with B-mode measurements, more robust than M-mode and less variable than the other methods.