Neeraj Prasad

Increased plasma levels of brain natriuretic peptide in patients with isolated diastolic dysfunction

nomegaly might have developed as a result of the ligation of the thoracic duct for treatment of chylopericardium. It appears that accumulation of chyle in the pleural space and spleen could depend on several factors: ligation of the thoracic duct with a resultant increase in pressure; failure to establish collateral lymph drainage to the right thoracic duct or lymphaticovenous connections to relieve the pressure; and reflux of chylous lymph through normal lymphatic channels. We should take into account these lethal complications that follow thoracic duct ligation for treatment of primary chylopericardium.

Predictors of angiographic restenosis after coronary intervention in patients with diabetes mellitus.

BACKGROUNDnPatients with diabetes mellitus are particularly prone to restenosis after percutaneous coronary intervention. An exploratory, nested, case-control study was undertaken to identify clinical, lesional, and procedural predictors of angiographic restenosis in these patients.nnnMETHODSnSeventy-five patients with diabetes mellitus with 86 coronary lesions were selected from a larger population of 217 patients who had undergone 6-month angiographic follow-up after a first, successful balloon angioplasty (PTCA) or stent implantation procedure. Data collection was by patient interview and review of hospital database and other medical records. All angiograms were analyzed with quantitative coronary angiography, and restenosis was defined as a >or=50% diameter reduction at the treated site. A multivariate analysis of 10 prespecified explanatory variables, derived from a literature review, was performed on a per-lesion basis.nnnRESULTSnThere were 45 patients (53 lesions) with restenosis and 30 patients (33 lesions) without restenosis. Univariate predictors of binary restenosis were periprocedural glycosylated hemoglobin level, vessel reference diameter, PTCA, and larger final balloon size to reference artery diameter ratio. Multiple logistic regression identified poor glycemic control (odds ratio [OR] 3.03, 95% CI 1.06-8.65, P =.038), small vessel reference diameter (OR 3.41, 95% CI 1.17-9.95, P =.025), and mode of intervention (OR 3.12, 95% CI 1.08-9.00, P =.036) as independent risk factors. Vessel reference diameter appeared to be an important effect modifier of the association between type of intervention and angiographic outcome, with stenting no longer superior to PTCA in patients with diabetes mellitus who had vessels <2.87 mm in diameter (P =.054).nnnCONCLUSIONnPoor glycemic control, vessel size, and PTCA were independent predictors of restenosis in patients with diabetes mellitus. It is possible that improved periprocedural glycemic control, in addition to stenting, may reduce the restenosis rate in these patients.

Elevated blood pressure during the first two hours of ambulatory blood pressure monitoring : a study comparing consecutive twenty-four-hour monitoring periods

Objective and design Ambulatory blood pressure monitoring is being used increasingly in clinical practice and hypertension research. We have noted elevated blood pressure during the initial hours of monitoring. The objective of the present study was to examine the consistency, magnitude and duration of this elevation, and to determine whether this effect causes significant differences in the mean ambulatory blood pressure monitoring values comparing the first (day 1) and second (day 2) consecutive 24-h periods of monitoring. Methods Fifty patients who were hypertensive based on repeated clinic readings were studied prospectively. Each underwent continuous 48-h ambulatory blood pressure monitoring with a SpaceLabs 90207 monitor. The device recorded blood pressure at 15-min intervals during the daytime (0600–2159 h) and at 30-min intervals at night-time (2200–0559 h). From these readings hourly means were calculated. Repeated-measures analysis of variance was performed to compare the hourly means of days 1 and 2. Results Repeated-measures analysis of variance indicated that a significant difference existed for both systolic and diastolic blood pressure between day 1 and day 2. Paired Students t-test revealed that this difference occurred during the first 2 h of monitoring. The daytime blood pressure was higher on day 1 as a result of the initial elevation of blood pressure at the onset of monitoring. The initial elevation of blood pressure was present both in white-coat hypertensives and in essential hypertensives. Conclusion The first 2 h of ambulatory blood pressure monitoring are associated with elevated blood pressure both in white-coat hypertensives and in essential hypertensives. This has a minor effect on mean daytime and 24-h ambulatory blood pressures. We propose that improved ambulatory blood pressure monitoring recordings would be obtained in clinical practice, and more particularly in research applications, if 26-h ambulatory blood pressure monitoring was carried out, excluding the first 2 h from the summary analyses.

Influence of the angiotensin converting enzyme I/D gene polymorphisms on left ventricular diastolic filling in patients with essential hypertension

Background An insertion/deletion (I/D) polymorphism in the angiotensin converting enzyme (ACE) gene accounts for 50% of the variance in serum ACE activity. ACE is responsible for the generation of angiotensin II, which not only has pressor and mitogenic activities but also exerts effects on left ventricular diastolic performance. Objective To investigate the contribution of genetic polymorphisms at the ACE gene to the development of diastolic functional abnormalities in 100 patients with essential hypertension. Methods and results The left ventricular mass (LVMI) of each patient was assessed echocardiographically. We calculated peak and integral early: late left ventricular diastolic filling ratios (E: AP, and E: AI, respectively) and determined the ACE genotype from leukocyte DNA. There was no significant difference in age, sex, blood pressure and LVMI among genotype groups. Analysis of covariance modelled for indices of diastolic function, adjusted for age, sex, heart rate and LVMI, demonstrated that the E: AP interacted with age (P < 0.0001), heart rate (P < 0.001) and ACE genotype (P = 0.018). Similarly, the E: AI interacted with age (P < 0.001), heart rate (P = 0.025) and ACE genotype (P = 0.047). There was a strong correlation between the E: AP and the LVMI for the DD group (r = −0.81, P <0.0001) but not for the ID (r = −0.03, P = 0.83) and II (r = −0.23, P = 0.23) groups. Conclusions These findings suggest that the I/D polymorphism of the ACE gene influences the relationship between left ventricular mass and echocardiographic left ventricular diastolic filling abnormalities in patients with essential hypertension.

Raised plasma concentrations of brain natriuretic peptide in pulmonary arterial hypertension

N. PRASAD, C. C. LANG, H. M. MCALPINE, A-M. J. CHOY, T. M. MACDONALD AND A. D. STRUTHERS Department of Clinical Pharmacology and Cardiology, Ninewells Hospital and Medical School, Dundee, UK. Introduction Brain natriuretic peptide (BNP) is a relatively recent addition to the family of natriuretic peptides (1). Although originally isolated from the porcine brain, BNP, like atria1 natriuretic peptide (ANP), is a cardiac hormone which is synthesized and secreted into the circulation by the heart (1,2). Increased cardiac secretion of BNP has been reported in patients with predominant left-sided heart failure (2,3). No information is available for patients with haemodynamic alterations limited to the pulmonary circulation for BNP, although plasma ANP concen- trations have been shown to be elevated in pul- monary hypertension (4,5). We report measurement of plasma BNP concentrations in two patients with pulmonary hypertension undergoing right heart car- diac catheterizations. The patients were maintained on oxygen during the study as hypoxaemia can cause ANP release (6). We also report the effect of nifedipine, a calcium antagonist and potent vaso- dilator, on plasma BNP levels in one of these patients. Case 1 A 57-year-old female was referred to our hospital with a 3-yr history of progressive fatigue and increas- ing dyspnoea with recent onset of ankle swelling. Her medical history was unremarkable. Physical exami- nation revealed peripheral cyanosis, a right ventricu- lar heave and a loud pulmonary component to the second heart sound. Investigations included a normal

Safe withdrawal of monotherapy for hypertension is poorly effective and not likely to reduce health-care costs

Objective To carry out a population-based evaluation of withdrawal of treatment in primary care using repeated ambulatory blood pressure monitoring (ABPM) assessment to avoid subjecting patients to prolonged periods of excess risk. Method Patients from two community practices (total population 11 034 patients) being administered monotherapy for hypertension, were identified and invited to participate. Subjects were withdrawn from treatment if they had no significant co-morbidity and daytime ABPM blood pressure was ≤ 150/90 mmHg. Antihypertensive therapy was restarted if daytime ABPM blood pressure was >150/90 mmHg during weeks 4, 8, 12, 26, 39 and 52. Results Of 126 eligible patients 53 had a co-morbidity and 37 declined to participate. Of the 36 patients who entered the study 10 were excluded because they had elevated ABPM blood pressures during treatment and one because they had echocardiographic left ventricular hypertrophy. Of the 25 patients from whom monotherapy was withdrawn, we restarted treatment of 19 before week 52. If clinic blood pressure monitoring had been used instead of ABPM, different decisions would have been taken in eight of 25 cases. The costs of the ABPM-determined withdrawal of treatment programme were greater than the expected savings in drug costs, even assuming that all six patients from whom treatment was withdrawn remained without treatment for a further 9 years. This conclusion was not sensitive to reducing the number of ABPM measurements and to inflation in study-drug costs. However, if all patients had been treated with the most expensive drug, then even the full ABPM programme could have saved money within 9 years. Conclusions Antihypertensive therapy could be withdrawn from only a small proportion of patients in the community on the basis of ABPM. The costs of the programme are likely to exceed savings unless the cost of drugs administered is substantially higher than that observed in this study.

Left ventricular hypertrophy in hypertension--general and local trends in diagnosis and therapy.

LVH is a frequent echocardiographic finding in the general population but it should be regarded as an ominous predictor of future cardiovascular events rather than an innocent compensatory phenomenon. Echocardiography is the most sensitive and specific method for its detection but the ECG should not be regarded as superfluous since additional prognostic information and information about coexisting myocardial damage is present. The decreasing prevalence of LVH suggests that LVH can be prevented by control of hypertension and prevention of weight gain. Once LVH is present then antihypertensive drugs, weight reduction or salt restriction may promote its reversal, with early studies demonstrating associated improvement in mortality and morbidity.

729-3 Left Ventricular Hypertrophy in Essential Hypertension Depends on ACE Genotype

Introduction A deletion/insertion polymorphism in the ACE gene accounts for approximately 50% of the variance in plasma angiotensin converting enzyme (ACE) concentration, and may be linked to tissue ACE activity. The deletion allele (D) occurs with increased frequency in patients with hypertrophic and dilated cardiomyopathy. Left ventricular hypertrophy (LVH) is a recognised complication of essential hypertension, and is associated with increased morbidity and mortality. Angiotensin II, which is produced by ACE, promotes myocyte growth and collagen deposition, and has been causally linked with the development of LVH. Aim To examine the contribution of ACE genotype to the development of left ventricular hypertrophy in patients with essential hypertension. Method Eighty-five consecutive patients (58 males, [59.5%]; mean age 53.8 years) attending the out-patient hypertension clinic were studied. Blood pressure was measured using a semi-automatic sphygmomanometer. Echocardiography was performed and left ventricular mass (indexed for height and weight) was calculated from M-mode measurements according to the Penn convention. DNA was extracted from peripheral blood leucocytes by a commercially available method, and ACE genotype determined by the polymerase chain reaction using standard primers and conditions. Results DD (nxa0=xa025) ID (nxa0=xa041) II (nxa0=xa019) LVMI (g/M 2 ) † (27.5) 116.1 (42.9) 116.5 (48.2) 108.0 SBP (mmHg) † 149.2 (22.4) 159.1 (28.6) 156.3 (26.5) Relationship of LVMI to SBP pxa0lxa00.001 Pxa0=xa00.002 Pxa0=xa00.729 Dxa0=xa0ACE gene deletion allele; Ixa0=xa0ACE gene insertion allele. † Results expressed as meanxa0±xa0standard deviation Conclusion There is a significant correlation between LVM and SBP in patients with the deletion allele, but not in homozygotes for the insertion allele. The deletion homozygotes have a similar left ventricular mass to the heterozygotes, but for a lower mean SBP. These data suggest that systolic blood pressure is a major determinant of left ventricular mass in hypertension, but the relationship is expressed only in the presence of the deletion allele.