Denis Clement

European Society of Hypertension Position Paper on Ambulatory Blood Pressure Monitoring

Ambulatory blood pressure monitoring (ABPM) is being used increasingly in both clinical practice and hypertension research. Although there are many guidelines that emphasize the indications for ABPM, there is no comprehensive guideline dealing with all aspects of the technique. It was agreed at a consensus meeting on ABPM in Milan in 2011 that the 34 attendees should prepare a comprehensive position paper on the scientific evidence for ABPM.This position paper considers the historical background, the advantages and limitations of ABPM, the threshold levels for practice, and the cost-effectiveness of the technique. It examines the need for selecting an appropriate device, the accuracy of devices, the additional information and indices that ABPM devices may provide, and the software requirements.At a practical level, the paper details the requirements for using ABPM in clinical practice, editing considerations, the number of measurements required, and the circumstances, such as obesity and arrhythmias, when particular care needs to be taken when using ABPM.The clinical indications for ABPM, among which white-coat phenomena, masked hypertension, and nocturnal hypertension appear to be prominent, are outlined in detail along with special considerations that apply in certain clinical circumstances, such as childhood, the elderly and pregnancy, and in cardiovascular illness, examples being stroke and chronic renal disease, and the place of home measurement of blood pressure in relation to ABPM is appraised.The role of ABPM in research circumstances, such as pharmacological trials and in the prediction of outcome in epidemiological studies is examined and finally the implementation of ABPM in practice is considered in relation to the issue of reimbursement in different countries, the provision of the technique by primary care practices, hospital clinics and pharmacies, and the growing role of registries of ABPM in many countries.

Daytime and Nighttime Blood Pressure as Predictors of Death and Cause-Specific Cardiovascular Events in Hypertension

Our aim was to assess the prognostic significance of nighttime and daytime ambulatory blood pressure and their ratio for mortality and cause-specific cardiovascular events in hypertensive patients without major cardiovascular disease at baseline. We performed a meta-analysis on individual data of 3468 patients from 4 prospective studies performed in Europe. Age of the subjects averaged 61±13 years, 45% were men, 13.7% smoked, 8.4% had diabetes, and 61% were under antihypertensive treatment at the time of ambulatory blood pressure monitoring. Office, daytime, and nighttime blood pressure averaged 159±20/91±12, 143±17/87±12, and 130±18/75±12 mm Hg. Total follow-up amounted to 23 164 patient-years. We used multivariable Cox regression analysis to assess the hazard ratios associated with 1 standard deviation higher blood pressure. Daytime and nighttime systolic blood pressure predicted all-cause and cardiovascular mortality, coronary heart disease, and stroke, independently from office blood pressure and confounding variables. When these blood pressures were entered simultaneously into the models, nighttime blood pressure predicted all outcomes, whereas daytime blood pressure did not add prognostic precision to nighttime pressure. Appropriate interaction terms indicated that the results were similar in men and women, in younger and older patients, and in treated and untreated patients The systolic night–day blood pressure ratio predicted all outcomes, which only persisted for all-cause mortality after adjustment for 24-hour blood pressure. In conclusion, nighttime blood pressure is in general a better predictor of outcome than daytime pressure in hypertensive patients, and the night–day blood pressure ratio predicts mortality, even after adjustment for 24-hour blood pressure.

Night-day blood pressure ratio and dipping pattern as predictors of death and cardiovascular events in hypertension

Our objective was to assess the prognostic significance of the night-time dipping pattern and the night–day blood pressure (BP) ratio for mortality and cardiovascular events in hypertensive patients without major cardiovascular disease at baseline. We performed a meta-analysis on individual data of 3468 patients from four prospective studies performed in Europe. Age of the subjects averaged 61±13 years; 45% were men and 61% were under antihypertensive treatment at the time of ambulatory BP monitoring. The night–day BP ratio and 24-h BP averaged, respectively, 0.907±0.085/0.866±0.095 and 138.1±16.4/82.3±11.0 mm Hg. Total follow-up time amounted to 23 164 patient-years. We used multivariable Cox regression analysis to assess the outcome of reverse dippers, non-dippers and extreme dippers vs dippers, and to assess the hazard ratios associated with 1 standard deviation higher night–day BP ratio. In comparison with dippers, and with adjustment for confounders and 24-h BP, the incidence of cardiovascular events was worse in reverse dippers (P⩽0.05), whereas mortality was lower in extreme dippers (P⩽0.01); outcome was similar in non-dippers and dippers. The systolic night–day BP ratio independently predicted all-cause mortality and cardiovascular events (P⩽0.001), which persisted after additional adjustment for 24-h BP (P⩽0.05); appropriate interaction terms indicated that the results were similar in men and women, in younger and older patients and in treated and untreated patients. In conclusion, the dipping pattern and the night–day BP ratio significantly and independently predict mortality and cardiovascular events in hypertensive patients without history of major cardiovascular disease, even after adjustment for 24-h BP.

Serum Vitamin C Concentration Is Low in Peripheral Arterial Disease and Is Associated With Inflammation and Severity of Atherosclerosis

BackgroundPeripheral arterial disease (PAD) is a severe atherosclerotic condition frequently accompanied by inflammation and oxidative stress. We hypothesized that vitamin C antioxidant levels might be low in PAD and are related to inflammation and disease severity. Methods and ResultsWe investigated vitamin C (l-ascorbic acid) levels in 85 PAD patients, 106 hypertensives without PAD, and 113 healthy subjects. Serum l-ascorbic acid concentrations were low among PAD patients (median, 27.8 &mgr;mol/L) despite comparable smoking status and dietary intake with the other groups (P <0.0001). Subclinical vitamin C deficiency (<11.4 &mgr;mol/L), confirmed by low serum alkaline phosphatase activity, was found in 14% of the PAD patients but not in the other groups. Serum C-reactive protein (CRP) concentrations were significantly higher in PAD patients (P <0.0001) and negatively correlated with l-ascorbic acid levels (r =−0.742, P <0.0001). In stepwise multivariate analysis, low l-ascorbic acid concentration in PAD patients was associated with high CRP level (P =0.0001), smoking (P =0.0009), and shorter absolute claudication distance on a standardized graded treadmill test (P =0.029). ConclusionsVitamin C concentrations are lower in intermittent claudicant patients in association with higher CRP levels and severity of PAD. Future studies attempting to relate vitamin C levels to disease occurrence should include in their analysis an inflammatory marker such as CRP.

Short-term and long-term repeatability of the morning blood pressure in older patients with isolated systolic hypertension

Objective Using 24-h ambulatory blood pressure monitoring, we studied the repeatability of the morning blood pressure in older (≥60 years) patients with isolated systolic hypertension. Methods The sleep-through morning surge was the morning blood pressure minus the lowest nighttime blood pressure. The preawake morning surge was the morning blood pressure minus the preawake blood pressure. In addition, we determined the cusum plot height of blood pressure from 04:00 to 10:00 h from a plot of cumulative sums. Results In 173 patients with repeat recordings within 33 days (median), the short-term repeatability coefficients, expressed as percentages of maximal variation, ranged from 35 to 41% for the daytime and nighttime blood pressures and from 50 to 56% for the night-to-day blood pressure ratios. Short-term repeatability ranged from 52 to 75% for the sleep-through and the preawake morning surge, and from 51 to 62% for the cusum plot height. In 219 patients with repeat recordings within 10 months (median), the corresponding long-term estimates ranged from 45 to 64%, from 69 to 71%, from 76 to 83%, and from 50 to 78%, respectively. In categorical analyses of the short-term repeatability of the sleep-through morning surge and the preawake morning surge, using the 75th percentile as arbitrary cut-off, surging status changed in 28.0 and 26.8% of patients (κ-statistic ≤0.33). In the long-term interval, these proportions were 32.0 and 32.0%, respectively (κ-statistic ≤0.20). The κ-statistic threshold for moderate reproducibility is 0.4. Conclusion The morning surge of blood pressure is poorly reproducible, irrespective of whether it is analysed as continuous or categorical variable.

Relationship between arterial elasticity indices and carotid artery intima-media thickness

Functional and structural changes of the arterial wall appear to serve as early hallmarks of the hypertensive disease process. Structural vascular changes can be studied by the determination of the intima-media wall thickness (IMT) at the carotid artery. The elastic behavior of the proximal and distal parts of the arterial tree can be assessed from noninvasively recorded radial artery waveforms. The aim of the study was to compare large (proximal, C1) and small (distal, C2) artery elasticity indices in two age-matched study groups with high- and low-normal blood pressure (BP) and to assess the relation between elasticity indices and IMT. A total number of 22 subjects with high-normal BP (40 +/- 2 years; BP, 147 +/- 2.5/84 +/- 1.5 mm Hg) and 22 matched controls with low-normal BP (40 +/- 2 years; BP, 123 +/- 1.9/69 +/- 1.5 mm Hg) were enrolled. The IMT was echographically determined at the common carotid artery by the leading-edge technique. Large artery (C1) and small artery (C2) elasticity indices were calculated from a third-order, four-element model of the arterial circulation. In the group with high-normal BP large and small artery elasticity indices were significantly decreased versus controls with low-normal BP (C1: 1.63 +/- 0.08 v 1.99 +/- 0.09 mL/mm Hg, P < .01; C2: 0.059 +/- 0.005 v 0.076 +/- 0.007 mL/ mm Hg, P < .05) and IMT increased significantly (0.607 +/- 0.039 v 0.516 +/- 0.027 mm, P < .05). Moreover, there was an inverse relationship between IMT and small artery elasticity index (r = -0.60, P = .004). In subjects with a high-normal BP there is already a change in the IMT of the carotid artery versus normotension. The IMT is related to the small artery elasticity index (C2).

Hypertension in Peripheral Arterial Disease

Peripheral arterial disease (PAD) of the lower limbs is associated with a high cardiovascular morbidity and mortality. Intermittent claudication is the most common symptomatic manifestation of PAD, but is in its own value an important predictor of cardiovascular death, increasing it by three-fold, and increasing all-cause mortality by two-to-five fold. Hypertension is a risk factor for vascular disorders, including PAD. Of hypertensives at presentation, about 2-5% have intermittent claudication, with increasing prevalence with age. Otherwise, 35-55% of patients with PAD at presentation also show hypertension. Patients who suffer from hypertension with PAD have a greatly increased risk of myocardial infarction and stroke. There is no consensus on the specific treatment of hypertension in PAD because of the limited controlled studies on antihypertensive therapy in such specific PAD population. There is an obvious need of such outcome studies, especially since the two conditions are frequently encountered together. However, as risk is high in all PAD patients, the most important goal remains to decrease the global cardiovascular risk in such patients rather than to focus on the control of blood pressure only and on the reduction of symptoms of PAD. Therefore, treatment with antiplatelet drugs, ACE-inhibitors and statins should be considered.

Prevalence of Potential Candidates for Biventricular Pacing Among Patients with Known Coronary Artery Disease: A Prospective Registry from a Single Center

A Prospective Registry from a Single Center. New forms of ventricular pacing are increasingly studied as an option in the management of patients with heart failure. Coronary artery disease (CAD) is the most frequent cause of heart failure, and patients with complete left or right bundle branch block (LBBB and RBBB) and a reduced left ventricular ejection fraction (LVEF) are the best candidates for this new therapy. However, the prevalence of this clinical presentation is uncertain. During a 1‐year period, 433 patients with documented CAD (mean age 64 ± 10 years, 79% men) who were referred for myocardial perfusion imaging were prospectively studied. All patients underwent a 2‐day stress‐rest gated 99mTc‐Tetrofosmin SPECT study with evaluation of resting LV enddiastolic (LVEDV) and endsystolic (LVESV) volumes and LVEF. The resting ECG was examined in all patients for the presence of complete LBBB or RBBB. Of the 433 patients with CAD 36 patients (8.3%) had LBBB (n = 14) or RBBB (n = 22) and a QRS width >120 ms. These 36 patients were in general older and more frequently had diabetes and atrial fibrillation. Patients with LBBB or RBBB had a significantly lower LVEF (41 ± 16%vs 48 ± 14%, P < 0.01) and significantly higher LV volumes compared to patients without LBBB or RBBB (177 ± 79 mL vs 131 ± 53 mL, P < 0.001 for LVEDV and 116 ± 76 mL vs 73 ± 49 mL, P < 0.001 for LVESV). In total, 112 /433 (26%) had an LVEF ≤ 40%; 16 had also a LBBB or RBBB (3.7% of the whole population, 14% of the patients with a LVEF ≤ 40%). Within the group of patients with a LVEF ≥ 40%, patients with BBB had comparable LVEF (26 ± 9% vs 30 ± 8%, P = NS) but significantly higher LVEDV and LVESV (230 ± 70 mL vs 190 ± 64 mL, P < 0.05 for LVEDV and 170 ± 65 mL vs 135 ± 56 mL, P < 0.05 for LVESV). In this prospective registry 3.7% of all patients with known CAD had LBBB or RBBB in combination with a LVEF ≤ 40%. This represented 14% of all patients with a LVEF ≥ 40%. These limited numbers should be kept in mind when considering biventricular pacing as a new therapeutic options in patients with heart failure.

Relationship between left ventricular mass and blood pressure in treated hypertension.

This study evaluated prospectively whether there is still a relationship between left ventricular mass and blood pressure once hypertension is treated and determined the relative importance of daytime vs night-time blood pressure, systolic vs diastolic blood pressure and office vs ambulatory blood pressure. A total of 649 patients (305 or 47% female) with essential hypertension, treated with antihypertensive drugs for at least 3 months, underwent office blood pressure measurement and both daytime and night-time ambulatory blood pressure measurement, electrocardiography and echocardiography. Correlations were made between blood pressure values and parameters of left ventricular mass. Electrocardiographic voltage criteria and even more so echocardiographic parameters correlate significantly albeit weakly (r ⩽ 0.28) with blood pressure in treated hypertension. Correlations are consistently higher when systolic blood pressure is considered. Overall, the best correlations are found between 24-h ambulatory systolic or night-time blood pressure and the Sokolow–Lyon voltage as well as the echocardiographic age and body mass index adjusted left ventricular mass. In conclusion, once hypertension is treated, the relationship between blood pressure and left ventricular mass is low. Nevertheless, in this the largest single centre study of its kind, echocardiographic parameters of left ventricular mass in treated hypertensive subjects correlate better with blood pressure than electrocardiographic parameters. Parameters of hypertrophy are more closely related to systolic blood pressure than to diastolic blood pressure. In accordance with the finding that dippers have a better prognosis than non-dippers, night-time blood pressure consistently correlates better with left ventricular mass than daytime blood pressure.

Efficacy of an implanted automatic defibrillator which had induced atrial fibrillation.

A 54 year old man with refractory life threatening ventricular tachycardia was given an automatic defibrillator. The initial system was a transvenous defibrillator coil electrode and this was later modified by implantation of two patch electrodes at thoracotomy. The modified system successfully controlled ventricular tachycardia. On one occasion reversion of ventricular tachycardia by the defibrillator precipitated atrial fibrillation, a previously unreported side effect.