Guglielmo Benemio

Risk Stratification of Left Ventricular Hypertrophy in Systemic Hypertension Using Noninvasive Ambulatory Blood Pressure Monitoring

Twenty-four-hour noninvasive ambulatory blood pressure (BP) monitoring and echocardiography were performed in 165 consecutive untreated hypertensive patients and in 92 healthy subjects. In the hypertensive group, left ventricular (LV) mass index showed closer correlations (all p less than 0.01 in the comparisons between the r coefficients) with average 24-hour ambulatory systolic (r = 0.47) and diastolic (r = 0.33) BP than with casual systolic (r = 0.35) and diastolic (r = 0.28) BP. Hypertensive patients were classified according to the difference between their observed and predicted levels of ambulatory BP (the latter assessed by regressing the observed ambulatory BP on the casual BP). When compared to those with lower than predicted ambulatory BP (less than or equal to 10 mm Hg systolic, less than or equal to 6 mm Hg diastolic), patients with higher than predicted ambulatory BP (greater than or equal to 10 mm Hg systolic and greater than or equal to 6mm Hg diastolic) had higher values of LV mass index and other indexes of LV hypertrophy (all p less than 0.01) but had similar values of casual BP. Prevalence of LV hypertrophy was 6 to 10% in the former and 35 to 39% in the latter (p less than 0.001). None of the indexes of LV structure differed between the group with low ambulatory BP and the normotensive group. It is concluded that hypertensive patients whose ambulatory BP readings are notably higher than one would predict from clinical BP readings are at highest risk of LV hypertrophy, an independent prognostic marker.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved cardiovascular risk stratification by a simple ECG index in hypertension

BACKGROUND We determined the prognostic value of the Cornell/strain [C/S] index, a simple electrocardiographic (ECG) index for left ventricular hypertrophy (LVH) defined by the presence of either a classic strain pattern or a Cornell voltage (sum of R in aVL + S in V(3)) >2.0 mV in women or 2.4 mV in men, or both. METHODS In a prospective, cohort study, 2190 initially untreated subjects (age 51 [+/- 12], 47% women) with essential hypertension without prior events were followed for up to 14 years (median, 5 years). RESULTS Prevalence of LVH at entry was 16.3% by using the C/S index, which yielded 33.6% sensitivity and 91.0% specificity. Other ECG criteria for LVH including Sokolow-Lyon, Romhilt-Estes, Framingham, Cornell, and strain alone, achieved a lower sensitivity and prevalence. Over the subsequent follow-up, 244 patients experienced a first major cardiovascular event. Event rate (x 100 person-years) was 2.01 in those without and 4.44 in those with LVH by the C/S index (P <.001). After adjustment for age, sex, smoking, and other counfounders, the C/S index identified subjects at increased risk of events (relative risk 1.76; 95% confidence interval 1.32-2.33). The C/S index achieved the highest population-attributable risk (16.1%) for cardiovascular events. CONCLUSIONS A simple ECG index that can be quickly measured from nondigital machines and without algorithms identifies LVH in a consistent proportion (16.3%) of hypertensive subjects. The LVH defined by such technique allows identification of individuals at high risk for cardiovascular events.

Predictors of diurnal blood pressure changes in 2042 subjects with essential hypertension.

Objective To determine the independent predictors of day-night blood pressure changes in a large population of subjects with essential hypertension. Methods We studied 2042 white untreated subjects with essential hypertension (mean age 52 years, range 17-93, 1052 men) who underwent 24 h ambulatory blood pressure monitoring on an outpatient basis. Night-time workers were excluded from analysis. Results For both sexes, the changes in systolic and diastolic blood pressures from day to night decreased progressively with age and increased with the reported duration of sleep. The 1207 employed subjects who underwent ambulatory blood pressure monitoring during a usual working day had greater day-night blood pressure differences than did those who did not work (16.2 versus 14.0%). By using multiple regression analysis we assessed the independent association of several variables with the diurnal blood pressure changes. Age and diabetes for both sexes, and clinic blood pressure in men, were inversely associated with the nocturnal fall in blood pressure. The duration of sleep and the occurrence of blood pressure monitoring during a normal work day predicted a greater day-night blood pressure difference for both sexes; smoking predicted a greater nocturnal fall in blood pressure for women. Conclusions Age is associated with an important and progressive attenuation of the day-night blood pressure difference in untreated and unrestricted subjects with essential hypertension. Other factors influencing diurnal blood pressure variations include clinic blood pressure, diabetes, the reported duration of sleep, smoking habits and working activity during blood pressure monitoring. These factors should be treated as potential confounders in the analysis of the relationship between diurnal blood pressure changes and target organ damage or prognosis.

Clinical relevance of office underestimation of usual blood pressure in treated hypertension

Average 24-h blood pressure (BP) is more representative of usual BP than office BP. However, the clinical relevance of 24-h BP in treated hypertensive subjects is incompletely known. Thus, we studied 395 uncomplicated hypertensive subjects (209 men, 53+/-10 years) who were receiving antihypertensive drug therapy from >1 year. All subjects underwent 24-h ambulatory BP monitoring and M-mode echocardiography. Subjects were classified by tertile of the difference between observed and predicted 24-h systolic BP (the latter determined by regressing 24-h systolic BP on office systolic BP): higher-than-predicted (III tertile), around the regression line (II tertile), and lower-that-predicted (I tertile) 24-h BP. Despite similar office BP (144/89, 141/88, and 144/89 mm Hg in the III, II, and I tertile, P = not significant), age, body mass index, and duration of hypertension, left ventricular mass was greater in the subjects with higher-than-predicted 24-h systolic BP (50+/-14 g x m(-2.7)) than in the other two groups (46+/-13 g x m(-2.7) and 42+/-10 g x m(-2.7), both P < .05). The III tertile also showed a more concentric left ventricular geometric pattern (relative wall thickness was 0.42+/-0.08, 0.40+/-0.07, and 0.38+/-0.07 in the III, II, and I tertile, P < .001) and a reduced systolic function at the midwall level (16.8+/-3, 17.7+/-3, and 18.2+/-3, P < .001). In conclusion, treated hypertensive subjects whose 24-h BP is notably higher than one would predict from office BP are more likely to develop left ventricular hypertrophy, a strong adverse prognostic marker. In a sizable subset of treated hypertensive subjects, BP measured in the physicians office underestimates usual BP and its impact on left ventricular structure.

Day-to-day variability of electrocardiographic diagnosis of left ventricular hypertrophy in hypertensive patients. Influence of electrode placement.

Objective Although electrocardiography (ECG) is recommended in all subjects with hypertension, no information is available on the influence exerted by random changes in the placement of electrodes on the day-to-day variability of ECG criteria for diagnosis of left ventricular hypertrophy (LVH). Methods In a multicentre, randomized study, two standard 12-lead ECG were recorded, 24 h apart, from 276 consecutive hypertensive patients (mean age 65 ± 12 years, 49.6% men). Overall, 142 patients were randomized to ECG with the position of electrodes marked on the skin using a dermographic pen and 134 to traditional ECG without marking the position of electrodes. Day-to-day variability of ECG criteria for LVH was compared between the two groups. Results Coefficients of variation (SD of the difference between paired voltage measurements divided by the mean value) varied consistently among subjects randomized to ECG without dermographic pen, ranging from 30% (R wave in lead I) to 81% (R wave in lead V5). Dermographic pen led to a lesser variability of ECG voltages with consequent reduction in the coefficients of variation, which ranged from 26% (R-wave amplitude in lead I) to 43% (R-wave amplitude in lead V5). The proportion of subjects who changed classification status for LVH (‘reclassification rate’) from the first to the second ECG session (LVH present in session 1 and absent in session 2, or vice versa) decreased for effect of dermographic pen from 11 to 4% (P = 0.040) with the Cornell voltage, from 19 to 11% (P = 0.029) with the Sokolow–Lyon voltage, and from 18 to 7% with the Romhilt–Estes criterion (P = 0.018), but not with other criteria. In particular, the typical strain and the Cornell strain were associated with the lowest reclassification rates regardless of dermographic pen. Conclusions Random changes in the position of ECG electrodes strongly impair the day-to-day reproducibility of Cornell voltage, Sokolow–Lyon and Romhilt–Estes criteria for LVH. The typical strain and Cornell strain criteria showed a lesser spontaneous day-to-day variability.

long-term effects of losartan and enalapril, alone or with a diuretic, on ambulatory blood pressure and cardiac performance in hypertension: a case-control study

Background The long‐term effects of angiotensin‐converting enzyme inhibitors and angiotensin II receptor blockers on ambulatory blood pressure and cardiac performance have never been examined comparatively. Objective We compared losartan and enalapril in their long‐term effects on office and ambulatory blood pressure, cardiac structure and function, and routine biochemical tests. Design In the setting of the Progetto Ipertensione Umbria Monitoraggio Ambulatoriale (PIUMA) study, 22 hypertensive subjects were studied with ambulatory blood pressure monitoring and echocardiography before and after an average of 3.3 years of treatment with losartan 50 mg daily. These subjects were matched in a 1:3 ratio with a group of 66 subjects treated with enalapril 20 mg daily. Case‐control sampling was based on age (± 5 years), sex, pre‐treatment office blood pressure (± 5 mmHg) and ambulatory blood pressure (± 5 mmHg), and duration of treatment (± 6 months). An additional group of subjects who interrupted their treatment with enalapril (n = 18) or losartan (n = 2) because of unwanted effects before execution of the follow‐up study was not included in the analysis. Results Hydrochlorothiazide was added during follow‐up in order to optimize blood pressure control (office blood pressure < 140 mmHg systolic and 90 mmHg diastolic) in 10 subjects (45%) in the losartan group and 34 subjects (52%) in the enalapril group. Office and ambulatory blood pressures were lowered to a similar extent by losartan and enalapril. Left ventricular mass decreased from 98 to 87g/m2 with losartan (P < 0.01) and from 98 to 89g/m2 with enalapril (P < 0.01). The change in left ventricular mass over time was more closely associated with the change in ambulatory blood pressure than with office blood pressure in both groups. Left ventricular internal diameter did not change with either drug. The endocardial shortening fraction, mid‐wall shortening fraction and Doppler indexes of active diastolic relaxation did not change with either drug. None of the biochemical parameters showed a significant change. Serum uric acid showed a slight and non‐significant reduction only in the losartan group. Conclusion In this case‐control study in uncomplicated subjects with essential hypertension, losartan and enalapril, alone or combined with a diuretic, effectively and equally lowered office and ambulatory blood pressure and induced a significant reduction in left ventricular mass during long‐term treatment. Left ventricular systolic and diastolic function remained unchanged with either regimen.