Cardiac magnetic resonance-derived fibrosis, strain and molecular biomarkers of fibrosis in hypertensive heart disease.

AIMS: Myocardial fibrosis is a relevant component of hypertensive heart disease (HHD). Novel cardiovascular magnetic resonance (CMR) imaging techniques have shown potential in quantification of diffuse cardiac fibrosis, with T1 mapping, and estimating preclinical cardiac dysfunction, with strain analysis. Molecular biomarkers of fibrosis have been related with clinical outcomes and histologically proven myocardial fibrosis. The relationship between these CMR-imaging techniques and circulating biomarkers is not fully understood. METHODS AND RESULTS: CMR was performed on a 3T scanner in 36 individuals with HHD. Extracellular volume fraction (ECV) and the partition coefficient were assessed using the T1 mapping technique shMOLLI. Longitudinal, circumferential and radial strain was assessed using CMR-Feature Tracking. Molecular biomarkers of collagen synthesis (PICP and PIIINP) and collagen degradation (CITP and MMP-1) were measured in blood using commercial kits. Correlation models showed a significant relationship of T1 mapping measures with left atrial diameter, LV mass, LV posterior wall thickness, LV end-diastolic volume and longitudinal strain. In fully adjusted regression models, ECV was associated with left atrial diameter (ß=0.75, P = 0.005) and longitudinal strain (ß = 0.43, P = 0.030); the partition coefficient was associated with LV posterior wall thickness (ß = 0.53, P = 0.046). Strain measures were associated with cardiac geometry, and longitudinal strain was marginally associated with CITP. CONCLUSION: In individuals with HHD, CMR-derived measures of myocardial fibrosis and function are related and might be useful tools for the identification and characterization of preclinical cardiac dysfunction and diffuse myocardial fibrosis. Molecular biomarkers of fibrosis were marginally associated with myocardial strain, but not with the extension of CMR-measured cardiac fibrosis.

Pulse pressure amplification and its determinants.

BACKGROUND: Pulse pressure (PP) amplification expressed as the peripheral-to-central PP ratio has gained importance in the assessment of cardiovascular phenotypes and cardiovascular risk. The aim of the present study was to assess the relationship between PP amplification, large vessel parameters and peripheral blood pressure (BP) to gain insights into the amplification phenomenon. METHODS: Peripheral BP, central BP and carotid-femoral pulse wave velocity (cfPWV) were assessed using the OMRON M6, SphygmoCor and Complior devices, respectively, in 741 adults attending the hypertension outpatient clinic. Analysis of covariance, partial correlations and multiple linear regression models were performed to assess the relationship between PP amplification, peripheral BP and cfPWV. RESULTS: PP amplification was inversely related to BP group. Women showed lower PP amplification than men (1.24 ± 0.18 and 1.35 ± 0.18, respectively, p < 0.001). Age, female gender and mean arterial pressure were inversely associated with PP amplification (p < 0.001), whereas heart rate and body mass index showed positive associations (p < 0.001 and p = 0.049, respectively). cfPWV was a predictor of PP amplification in men but not in women (p = 0.006 and p = 0.424, respectively). CONCLUSIONS: PP amplification is related to BP: the higher the BP, the lower the PP amplification. Gender, age and body composition have a significant impact on PP amplification.

Carotid-femoral pulse wave velocity assessment by two different methods: implications for risk assessment.

INTRODUCTION: Several devices are available for carotid-femoral pulse wave velocity (cfPWV) measurement, and a cut-off value for reference cfPWV has been established. However, discrepancies between devices have been reported. OBJECTIVES: The aim of the study was to establish the concordance of two common techniques (Complior and SphygmoCor), taking into account the anatomical distance between the measurement sites, and to investigate the impact on cardiovascular risk stratification. METHODS: cfPWV, central and peripheral blood pressure were assessed in patients attending the hypertension outpatient clinic. The subtracted carotid-femoral distance was estimated both according to the manufacturer's recommendations and correcting the obtained values by 10.3%. Bland-Altman plots, Pearson's correlation coefficient, Lin's concordance correlation coefficient and multivariate models were used to investigate the difference in cfPWV. RESULTS: cfPWV assessed in 118 patients (age 55 ±â€Š12 years, 61% hypertensive patients, BMI 28.9 ±â€Š4.4  kg/m2) with the Complior device was lower than that assessed with the SphygmoCor device, regardless of correcting the subtracted carotid-femoral distance (8.7 vs. 10.3  m/s and 9.3  m/s, respectively; P value < 0.001). The average difference was -1.59 ±â€Š1.5 and -0.617 ±â€Š1.39  m/s for corrected and uncorrected SphygmoCor values, respectively, SBP, BMI and female being the main determinants of the difference. Cardiovascular risk stratification changed in up to 40% of the study population, depending on the device and the arterial distance estimation. CONCLUSION: The concordance between the Complior and the SphygmoCor device is poor when the anatomical artery length is controlled for and in the presence of cardiovascular risk factors, resulting in a difference in classification of cardiovascular risk.

Influence of obesity in central blood pressure.

BACKGROUND: Obesity is an important risk factor for cardiovascular disease and has become a major concern in healthcare due to its high prevalence worldwide. The aim of the present study was to investigate the impact of BMI on central blood pressure (BP) and pulse wave velocity (PWV) in normotensive and hypertensive patients. PATIENTS AND METHODS: Normotensive and hypertensive adult patients who attended the outpatient clinic of cardiovascular risk were included. Peripheral BP was obtained in the brachial artery by using an oscillometric device (OMRON M-6). Central aortic BP waveform was reconstructed from the radial artery pressure waveforms (SphygmoCor, AtCor Medical, Sydney, Australia) and central BP was calculated. Carotid-femoral PWV was measured by an automatic device (Complior, Artech, France). RESULTS: We examined a total of 351 patients [50.7% women; 77 patients normal-weight (BMI < 25 kg/m)], 274 patients overweight or obese (BMI ≥25 kg/m). Central SBP showed a positive association with male sex and mean BP, but a negative association with overweight/obesity. PWV was positively associated with age, male sex, central BP, peripheral BP and BP treatment, whereas BMI of at least 25 kg/m led to a decrease in PWV in patients with the same central SBP levels. Likewise, PWV was lower in the overweight/obese group compared to the normal-weight group at the same central SBP. CONCLUSION: Overweight and obesity tend to have lower central SBP as compared to lean patients, mainly in women. Further research is required to assess the interaction between body weight and vascular dynamics and their clinical implications.

Effects of nebivolol and atenolol on central aortic pressure in hypertensive patients: a multicenter, randomized, double-blind study.

INTRODUCTION: The main objective was to compare the mean change in augmentation index of hypertensive patients treated with nebivolol or atenolol. METHODS: Multicenter, double-blind randomized study conducted in six Spanish centers. We enrolled outpatients between the ages of 40 and 65 years with mild or moderate essential hypertension (systolic blood pressure, SBP ≥ 140 mmHg to ≤ 179 mmHg and diastolic blood pressure, DBP ≥ 90 mmHg to ≤ 109 mmHg after a 2-week run-in placebo period). Patients received nebivolol 5 mg or atenolol 50 mg once daily. At week 3, atenolol could be titrated up to 100 mg qd for non-responders. Additionally, patients not achieving normal blood pressure after 6 weeks could be treated with 25 mg hydrochlorothiazide. Follow-up visits were at 3, 6 and 10 weeks. RESULTS: The final study population of 138 patients (58% men; median age 52.6 years, range 40-67 years) was randomized into two groups of 69 patients each. Baseline characteristics of the two groups were similar. At the screening visit, 69% presented with mild hypertension. Nebivolol modified the mean augmentation index to a lesser extent than atenolol after 10 weeks (mean difference 3.1%, 95% CI 0.55-5.69; p = 0.027). A higher proportion of patients in the atenolol group required a diuretic. Reductions in central aortic pressure and peripheral arterial pressure were similar for both treatment groups. CONCLUSIONS: The study confirms that nebivolol produces a less pronounced impact on augmentation index than atenolol.