Gabriel Waisman

Magnesium Plus nifedipine: Potentiation of hypotensive effect in preeclampsia?

Two women with preeclampsia treated unsuccessfully with alpha-methyldopa and magnesium sulfate became profoundly hypotensive when oral nifedipine was added. Blood pressure returned to previous levels without changes in fetal vitality. Awareness of this potentiation is important because nifedipine is being used increasingly in the treatment of pregnancy-related hypertension.

Contribution of stroke volume to the change in pulse pressure pattern with age.

This study investigated the effect of age on pulse pressure and its underlying mechanisms in unmedicated hypertensive men with the same level of mean arterial pressure. We included 77 men 17 to 76 years old with daytime mean arterial pressure between 95 and 114 mm Hg. In the supine position, pulse pressure showed a significant widening in young (<30 years) and older (>/=60 years) patients. Pulse pressure decreased in parallel with stroke index from age >30 to 40 to 49 years. Upright posture, however, eliminated this difference through a larger orthostatic fall in stroke index and pulse pressure in the youngest patients. After age 50 years, pulse pressure exhibited a progressive widening despite the further age-related decrease in stroke index. Supine, upright, and 24-hour pulse pressure fitted a curvilinear correlation with age (r=0.55, 0.56, and 0.68, respectively, P<0.001), with a transition at age 50 years. Before age 50 years, 24-hour pulse pressure correlated positively with stroke volume (r=0.5, P<0.001) and negatively with arterial compliance (SV/PP ratio, r=-0.37, P<0.01). In contrast, in men >/=50 years old, 24-hour pulse pressure correlated negatively with the SV/PP ratio (r=-0.5; P<0.01), without significant influence of stroke volume. Thus, in hypertensive men, the age-related change in stroke volume significantly accounted for the change in clinic and ambulatory pulse pressure during young adulthood, but its contribution decreased after the fifth decade.

Diastolic Pressure Underestimates Age-Related Hemodynamic Impairment

It has been hypothesized that as large arteries become more rigid with age, the pattern of hypertension changes from diastolic to systolic. Thus, diastolic blood pressure (DBP) may lose its ability to reflect the increase in vascular resistance with age. To assess this, we studied the age-related changes in blood pressure pattern and its steady-state and pulsatile determinants. We performed an epidemiological analysis based on a national survey of 10,462 subjects from Argentina. A hemodynamic analysis (impedance cardiography) was then carried out in 636 consecutive hypertensive patients (age, 25 to 74 years). Whereas the rate of increment in the prevalence of mild to moderate hypertension (MMH) reached a plateau after the sixth decade, isolated and borderline systolic forms of hypertension began a steep and sustained rise. Among patients with MMH, DBP remained stable from the third to the seventh decade, whereas SBP maintained a sustained increase. Despite similar DBP, the systemic vascular resistance index increased 47% (P<.01) and the cardiac index decreased 27% (P<.01), whereas the ratio of stroke volume to pulse pressure, an index of arterial compliance, decreased 45% (P<.01). However, there were no significant differences between older patients with MMH and those with isolated systolic hypertension in the level of SBP, vascular resistance, stroke volume, and cardiac index. Compared with age-matched normotensive control subjects, the ratio of stroke volume to pulse pressure was much more reduced in isolated systolic hypertension (48%) than in MMH (30%). In summary, the present study, carried out in a large sample of hypertensive subjects with a wide age range, showed a simultaneous impairment in vascular resistance and arterial compliance associated with aging in different patterns of hypertension. The magnitude of these changes, with opposite effects on DBP but additive effects on SBP, suggests that a hemodynamic mechanism could determine the transition in the prevalence of diastolic hypertension toward a systolic pattern of hypertension with aging. Also, the results suggest that SBP, but not DBP, is a reliable indicator of the underlying hemodynamic abnormalities (high resistance and low arterial compliance) in the elderly.

Recent Respiratory Infection Predicts Atherothrombotic Stroke: Case―Control Study in a Buenos Aires Healthcare System

Background and Purpose— Increasing evidence links infections to atherosclerosis. Case–control and cohort studies have found that infections, especially respiratory and dental, are associated with coronary heart disease. However, data on the association of infections with cerebrovascular disease are limited, especially beyond Europe and the United States. We assessed the relationship between recent infections and atherothrombotic disease in a South American cohort. Methods— We conducted a case–control study of 105 cases and 354 control subjects in a Buenos Aires healthcare system matched by age (mean age, 73.2±12.3 and 72.9±12.8 years), sex, and major cardiovascular risk factors. Cases were patients hospitalized with atherothrombotic ischemic stroke from December 2006 to October 2007. Control subjects were randomly assigned from an electronic outpatient database. Data from the preceding year on inpatient and ambulatory respiratory, urinary and abdominal infections as well as peripheral white blood cell count were collected. Results— Infections were more frequent in cases than control subjects (29% versus 13%; OR, 2.6; 95% CI, 1.4 to 4.5; P=0.0004); however, this was driven by community-acquired respiratory tract infections (19% versus 6%; OR, 3.9; 95% CI, 1.9 to 8; P<0.001) because there were no differences between cases and control subjects for other types of infection. Respiratory tract infections were the most prevalent type of infection during the 3 months before an atherothrombotic ischemic event, occurring more in cases compared with control subjects (17% versus 4%; OR, 5; 95% CI, 2.2 to 11.3; P<0.001). In multivariable analysis adjusting for major vascular risk factors, history of respiratory infection in the prior year was associated more with cases than control subjects (OR, 4.9; 95% CI, 2.3 to 10.2;P<0.001). White blood cell count was slightly higher in cases versus control subjects (7602±2058 versus 7121.6±1947, P=0.01). Conclusion— In this South American cohort, recent respiratory tract infections were significantly associated with atherothrombotic stroke, suggesting that prompt identification and treatment of individuals with or at risk for these infections may mitigate the burden from this type of stroke.

Twenty-four-hour ambulatory blood pressure profiles in liver transplant recipients

Abstract:  Twenty‐four‐hour ambulatory blood pressure monitoring (ABPM) has proven to have better reproducibility than office blood pressure (BP) and is increasingly used for the study of hypertension in children and adolescents. The aim of our study was to assess 24‐h BP profiles and to compare the results of office BP measurements with ABPM in stable liver transplant recipients transplanted before the age of 18 yr. ABPM was performed in 29 patients (nine males, 20 females), aged 3.9–24.8 yr (median 10.8 yr). The investigation was conducted 1.1–11.5 yr (median 5.1 yr) following transplantation. ABPM confirmed hypertension in one out of three office hypertensive patients. Seven patients (24%), whose office BP recordings were within the normotensive range, were reclassified as hypertensive. Non‐dippers (n = 17), arbitrarily defined as patients with less than 10% nocturnal fall in BP, were similarly distributed among patients with ambulatory normotension and ambulatory hypertension (χ2, p = 0.79). In addition, non‐dippers showed a negative correlation between 24‐h total urinary albumin excretion and both systolic and diastolic nocturnal decline in BP (Rho = −0.48, p < 0.05 and Rho = −0.86, p < 0.01, respectively). Our study found office BP readings to be poorly representative of 24‐h BP profile. Larger studies are needed to confirm our observations as well as to determine whether routine BP measurements in the follow‐up of paediatric liver transplant recipients should be based solely on office BP.

Predictors of Masked Hypertension Among Treated Hypertensive Patients: An Interesting Association With Orthostatic Hypertension

BACKGROUND Masked hypertension (MH) entails an increased cardiovascular risk. Therefore, it is important to identify those individuals who would benefit the most from out-of-office blood pressure (BP) measurement. We sought to determine the prevalence and identify predictors of MH among adult hypertensive patients under treatment. METHODS Treated hypertensive patients aged ≥ 18 years underwent office (duplicate sitting and standing BP in 1 visit) and home BP measurements (duplicate measurements for 4 days in the morning, afternoon, and evening; at least 16 measurements) and completed a questionnaire regarding risk factors and history of cardiovascular disease. MH was defined as normal office BP (<140/90mm Hg) with elevated home BP (≥135/85mm Hg, average of all readings discarding first day measurements). Patients with a systolic BP rise upon standing ≥5mm Hg were considered to have orthostatic hypertension (OHT). Variables indentified as relevant predictors of MH were entered into a multivariable logistic regression analysis model. RESULTS Three hundred and four patients were included (mean age = 66.7 ±13.8; 67.4% women). The prevalence of MH in the whole population was 12.4% and was 20.9% among patients with office-controlled hypertension. Factors independently associated with MH were age (odds ratio (OR) = 1.08, 95% confidence interval (CI) = 1.03-1.14), high-normal office systolic BP (OR = 5.61, 95% CI = 1.39-22.57), history of peripheral artery disease (PAD) (OR = 8.83, 95% CI = 1.5-51.84), moderate alcohol consumption (OR = 0.08, 95% CI = 0.01-0.73), and OHT (OR = 3.65, 95% CI = 1.27 to 10.51). CONCLUSIONS Easily measurable parameters such as age, office systolic BP, history of PAD, and OHT may help to detect a population at risk of MH that would benefit from home BP monitoring.

Lack of effective blood pressure control among an elder hypertensive population in Buenos Aires.

Our purpose was to determine the level of awareness, treatment, and control of hypertension in a population of subjects aged 65 or more. We studied a random sample from the national health care program in Buenos Aires. Letters were mailed to 1000 selected individuals. Among those eligible, 41.4% (n = 414) were enrolled. The mean age was 73.8 years and 68% were women. Prevalence of hypertension in our sample was 77.5% (n = 321). Awareness of hypertension was 60.7% (n = 195). Fifty-four percent (n = 173) of the hypertensive subjects were receiving pharmacologic treatment and only 18.5% (n = 32) of them were controlled. These results show that there is a low level of awareness, pharmacologic treatment, and control of hypertension in the studied elderly subjects.

Factors associated with nonattendance at clinical medicine scheduled outpatient appointments in a university general hospital

Introduction Nonattendance at scheduled outpatient appointments for primary care is a major health care problem worldwide. Our aim was to estimate the prevalence of nonattendance at scheduled appointments for outpatients seeking primary care, to identify associated factors and build a model that predicts nonattendance at scheduled appointments. Methods A cohort study of adult patients, who had a scheduled outpatient appointment for primary care, was conducted between January 2010 and July 2011, at the Italian Hospital of Buenos Aires. We evaluated the history and characteristics of these patients, and their scheduling and attendance at appointments. Patients were divided into two groups: those who attended their scheduled appointments, and those who did not. We estimated the odds ratios (OR) and corresponding 95% confidence intervals (95% CI), and generated a predictive model for nonattendance, with logistic regression, using factors associated with lack of attendance, and those considered clinically relevant. Alternative models were compared using Akaike’s Information Criterion. A generation cohort and a validation cohort were assigned randomly. Results Of 113,716 appointments included in the study, 25,687 were missed (22.7%; 95% CI: 22.34%–22.83%). We found a statistically significant association between nonattendance and age (OR: 0.99; 95% CI: 0.99–0.99), number of issues in the personal health record (OR: 0.98; 95% CI: 0.98–0.99), time between the request for and date of appointment (OR: 1; 95% CI: 1–1), history of nonattendance (OR: 1.07; 95% CI: 1.07–1.07), appointment scheduled later than 4 pm (OR: 1.30; 95% CI: 1.24–1.35), and specific days of the week (OR: 1.00; 95% CI: 1.06–1.1). The predictive model for nonattendance included characteristics of the patient requesting the appointment, the appointment request, and the actual appointment date. The area under the receiver operating characteristic curve of the predictive model in the generation cohort was 0.892 (95% CI: 0.890–0.894). Conclusion Evidence related to patient characteristics, and the identification of appointments with a higher likelihood of nonattendance, should promote guided strategies to reduce the rate of nonattendance, as well as to future research on this topic. The use of predictive models could further guide management strategies to reduce the rate of nonattendance.

Defining Thresholds for Home Blood Pressure Monitoring in Octogenarians

To generate outcome-driven thresholds for home blood pressure (BP) in the elderly, we analyzed 375 octogenarians (60.3% women; 83.0 years [mean]) enrolled in the International Database on home BP in relation to cardiovascular outcome. Over 5.5 years (median), 155 participants died, 76 from cardiovascular causes, whereas 104, 55, 36, and 51 experienced a cardiovascular, cardiac, coronary, or cerebrovascular event, respectively. In 202 untreated participants, home diastolic in the lowest fifth of the distribution (⩽65.1 mm Hg) compared with the multivariable-adjusted average risk was associated with increased risk of cardiovascular mortality and morbidity (hazard ratios [HRs], ≥1.96; P⩽0.022), whereas the HR for cardiovascular mortality in the top fifth (≥82.0 mm Hg) was 0.37 (P=0.034). Among 173 participants treated for hypertension, the HR for total mortality in the lowest fifth of systolic home BP (<126.9 mm Hg) was 2.09 (P=0.020). In further analyses of home BP as continuous variable (per 1-SD increment), higher diastolic BP predicted lower cardiovascular mortality and morbidity and cardiac and coronary risk (HR⩽0.65; P⩽0.039) in untreated participants. In those treated, cardiovascular morbidity was curvilinearly associated with systolic home BP with nadir at 148.6 mm Hg and with a 1.45 HR (P=0.046) for a 1-SD decrease below this threshold. In conclusion, in untreated octogenarians, systolic home BP ≥152.4 and diastolic BP ⩽65.1 mm Hg entails increased cardiovascular risk, whereas diastolic home BP ≥82 mm Hg minimizes risk. In those treated, systolic home BP <126.9 mm Hg was associated with increased total mortality with lowest risk at 148.6 mm Hg.

Postprandial hypotension detected through home blood pressure monitoring: a frequent phenomenon in elderly hypertensive patients

Postprandial hypotension (PPH) is a frequently under-recognized entity associated with increased morbidity and mortality. The prevalence of PPH detected through home blood pressure monitoring (HBPM) is unknown. To determine the prevalence and clinical predictors of PPH in hypertensive patients assessed through HBPM. Hypertensive patients of 18 years or older underwent home blood pressure (BP) measurements (duplicate measurements for 4 days: in the morning, 1 h before and 1 h after their usual lunch, and in the evening; OMRON 705 CP). PPH was defined as a meal-induced systolic BP decrease of ⩾20 mm Hg. Variables identified as relevant predictors of PPH were entered into a multivariate logistic regression analysis. In total, 230 patients were included in the analysis, with a median age of 73.6 (interquartile range 16.9) years, and 65.2% were female. The prevalence of PPH (at least one episode) was 27.4%. Four variables were independently associated with PPH: age of 80 years or older (odds ratio (OR) 3.45, 95% confidence interval (CI) 1.35–8.82), body mass index (BMI) (OR 0.88, 95%CI 0.81–0.96), office systolic BP (OR 1.03, 95%CI 1.01–1.05) and a history of cerebrovascular disease (OR 3.29, 95%CI 1.03–10.53). PPH after a typical meal is a frequent phenomenon that can be detected through HBPM. Easily measurable parameters in the office such as older age, higher systolic BP, lower BMI and a history of cerebrovascular disease may help to detect patients at risk of PPH who would benefit from HBPM.