Caroline Dore

Prediction of Coronary and Cerebrovascular Morbidity and Mortality by Direct Continuous Ambulatory Blood Pressure Monitoring in Essential Hypertension

BACKGROUND The goal of this study was to assess the prognostic value of ambulatory versus clinic blood pressure measurement and to relate cardiovascular risk to ambulatory systolic and diastolic blood pressure levels. METHODS AND RESULTS The study population consisted of 688 patients 51+/-11 years of age who had undergone pretreatment 24-hour intra-arterial ambulatory blood pressure monitoring on the basis of elevated clinic blood pressure. A total of 157 first events were recorded during a 9.2+/-4.1-year follow-up period. The predictive value of a regression model containing age, sex, race, body mass index, smoking, diabetes mellitus, fasting cholesterol level, and previous history of cardiovascular disease was significantly improved by the addition of any ambulatory systolic or diastolic blood pressure parameter (whether 24-hour, daytime, or nighttime mean) or pulse pressure, whereas inclusion of baseline clinic blood pressure variables did not enhance the prediction of events. The most predictive models contained the ambulatory systolic blood pressure parameters. In the model containing 24-hour mean ambulatory systolic blood pressure (P=0.001), age (P<0.001), male sex (P<0.001), South Asian origin (P=0.008), diabetes mellitus (P=0. 05), and previous cardiovascular disease (P<0.001) were additional independent predictors of events. Whereas 24-hour ambulatory systolic blood pressure was linearly related to the incidence of both coronary and cerebrovascular events, 24-hour ambulatory diastolic blood pressure exhibited a positive linear relationship with cerebrovascular events but a curvilinear relationship with coronary events. CONCLUSIONS Ambulatory blood pressure is superior to clinic measurement for the assessment of cardiovascular risk; there is no reduction in coronary risk at lower levels of ambulatory diastolic blood pressure.

Value of thallium-201 imaging in detecting adverse cardiac events after myocardial infarction and thrombolysis: A follow up of 100 consecutive patients

Abstract Objective: To determine the prognostic role of thallium-201 imaging compared with that of exercise electrocardiography in patients with acute myocardial infarction treated by thrombolysis. Design: Patients who remained free of adverse cardiac events six weeks after myocardial infarction had stress and rest 201Tl imaging and exercise electrocardiography and were followed up for 8–32 months. Adverse cardiac events (death, reinfarction, unstable angina, and congestive heart failure) were documented. Setting: Large district general hospital, Middlesex. Subjects: 100 consecutive male and female patients who were stable six weeks after thrombolysis for myocardial infarction. Main outcome measures: Prediction of occurrence of adverse cardiac events after myocardial infarction by exercise cardiography and 201Tl myocardial perfusion imaging. Results: Reversible ischaemia on 201Tl imaging predicted adverse cardiac events in 33 out of 37 patients with such events during follow up (hazard ratio 8.1 (95% confidence interval 2.7 to 23.8), P<0.001). Exercise electrocardiography showed reversible ischaemia in 33 patients, of whom 13 had subsequent events, and failed to predict events in 24 patients (hazard ratio 1.1 (0.56 to 2.2), P = 0.8). Conclusion: 201Tl imaging is a sensitive predictor of subsequent adverse cardiac events in patients who have received thrombolysis after acute myocardial infarction, whereas exercise electrocardiography fails to predict outcome. Key messages Exercise electrocardiography is a poor predictor of such events Presence of reversible ischaemia on 201Tl imaging identifies 89% of patients who subsequently have such events

Ambulatory intraarterial blood pressure in essential hypertension. Effects of age, sex, race, and body mass--the Northwick Park Hospital Database Study.

Twenty-four-hour recordings of intraarterial blood pressure (IABP) from 723 untreated hypertensive patients were analyzed for the effects of age, sex, race, and body mass index on the level of IABP and its circadian variation. Age had a highly significant positive relationship (P < .001) with the cuff systolic and diastolic blood pressures, with regression coefficients (SE) of +0.83 (0.07) and -0.24 (0.04) mm Hg/year, respectively. There was a similar (P < .001) positive relationship between age and 24-h mean systolic IABP, measuring +0.71 (0.07) mm Hg/year, but 24-h mean diastolic IABP did not increase significantly with age. There was a significant (P < .001) inverse relationship between age and 24-h mean heart rate (HR), at -0.17 (0.03) beats/min/year. Nocturnal fall in systolic and diastolic IABP, calculated as the difference between daytime and nighttime mean IABP, had a significant (P < .001) negative relationship with age. Nocturnal fall in HR, calculated similarly, also significantly (P < .001) decreased with age. Age did not affect long-term systolic and diastolic IABP variability but did decrease long-term HR variability significantly (P < .001). Hypertensive men and women of similar age, had comparable daytime mean systolic and diastolic IABP (P = .15 and P = .03 respectively), but women had significantly (P < .001) lower nighttime mean systolic and diastolic IABP than men. The nocturnal fall in systolic and diastolic IABP was significantly (P < .002) greater in women as compared to men. Women also had significantly (P < .01) greater long-term systolic and diastolic IABP variability than men. Women had significantly (P < .001) greater 24-h, daytime mean and nighttime mean HR than men. Twenty-four-hour, daytime and nighttime mean IABP were all significantly higher (P < .01) in Afro-Caribbeans as compared to whites and Asians. No significant differences were observed in the magnitude of nocturnal IABP fall or long-term IABP variability between the three races. Asians and Afro-Caribbeans had significantly (P < .001) lower nocturnal HR falls and long-term HR variability (P < .01) than whites. Body mass index (BMI) did not relate directly to the level of daytime blood pressure, clinic cuff, or daytime mean IABP, in either men or women. BMI did have a highly significant (P < .001) positive relationship with nighttime mean IABP in men, but not in women. The degree of nocturnal fall of IABP had a significant (P < .001) inverse relationship with BMI in hypertensive men.

Graduated compression and its relation to venous refilling time

Graduated compression is important in improving venous function, but the pressure profiles of different brands of stockings in situ and effects on a direct measure of venous function have not been investigated. The pressure profiles of 15 different types of below knee compression stockings were established with a medical stocking tester in 13 healthy volunteers. Analysis of variance was performed for each stocking separately, considering the factors of size of stocking, site of measurement, and their interaction. The criteria used to define satisfactory function were that the stockings should have a significant linear trend with site--that is, graduation--and no other significant effects. Only five types of stockings met these standards. Venous function was then assessed by photoplethysmography in 19 patients with defined venous abnormalities. For each patient the effect on venous refilling time of three satisfactory and three unsatisfactory stockings was assessed. The three satisfactory stockings gave refilling times that were not significantly different from normal in patients with both superficial and deep vein incompetence, while refilling times with the three unsatisfactory stockings remained significantly below normal in all patients with deep vein incompetence; one stocking had no significant effect on refilling times in either group. Functional testing of compression hosiery should form part of future British Standards specifications.

Sperm size in patients with inflammatory bowel disease on sulfasalazine therapy.

The size of the heads of spermatozoa from eight men with chronic inflammatory bowel disease (IBD) treated with sulfasalazine (SS) were measured by image analysis. These were compared with the size of sperm heads from noncolitic men with normal semen indices and with the sperm head size of noncolitic oligospermic men. The patients on SS therapy had a significantly larger sperm head size for the 99th percentile than the noncolitic oligospermic men. After withdrawal of the drug, sperm head size increased further before becoming smaller. The size did not return to that of the sperm of men with normal semen indices during the period studied. Possible mechanisms for the increase in sperm size are discussed and its association with the reversible infertility caused by SS medication.

Comparison of diltiazem at two dose levels with propranolol for treatment of stable angina pectoris

Two dose levels of diltiazem with propranolol were compared in the management of chronic stable angina. Two groups of patients were treated for alternate periods of 4 weeks with each drug in a double-blind crossover with computer-assisted maximal treadmill tests and ambulatory ST-segment monitoring for evaluation of efficacy and safety. In 12 patients who received diltiazem, 180 mg/day, the time to development of angina increased from 5.9 +/- 0.7 minutes (+/- standard error of the mean) during placebo treatment to 8.3 +/- 0.8 minutes during diltiazem treatment and to 9.2 +/- 0.8 minutes with propranolol, 240 mg/day. Three patients became angina-free when they were treated with both drugs. Among 12 patients who received diltiazem, 360 mg/day, 1 patient became angina-free during treatment with both drugs and 1 became angina-free with diltiazem only. The mean exercise time increased from 5.8 +/- 0.7 minutes with placebo to 8.6 +/- 1.0 minutes with diltiazem, 360 mg/day, and to 8.2 +/- 0.6 minutes with propranolol, 240 mg/day. Analysis of variance showed no difference in efficacy between the 2 doses of diltiazem or between the 2 drugs. Ambulatory heart rate was reduced both during the day and at night with both drugs and significantly more with propranolol than with diltiazem treatment. Except for 1 patient in whom a rash developed when given diltiazem, 180 mg/day, and another who had both a rash and first-degree heart block with diltiazem, 360 mg/day, both drugs were well tolerated. Thus, diltiazem in a daily dose of 180 or 360 mg/day is as effective as propranolol for the treatment of chronic stable angina.

Variation of aortic blood velocity with age at rest and during exercise in normal subjects

The effect of age on aortic blood velocity signal and its derived indices of left ventricular function namely peak velocity, stroke distance (the velocity—time integral) and minute distance (stroke distance × heart rate) was studied at rest and at maximal-tolerated supine exercise using a 2-mHz continuous-wave Doppler ultrasound applied via the suprasternal notch in 66 normal healthy volunteers. The peak velocity, stroke distance and the minute distance, both at rest and at maximal exercise decreased with advancing age by 1–1.1% per annum between the ages of 20 and 70 years. Accordingly a method for age-adjustment of the peak velocity, stroke and minute distances was introduced for clinical use in assessing individual subjects. These results indicate that age is an important variable affecting aortic blood velocity and its derived variables as non-invasive measures of left ventricular function both at rest and with exercise. The relationship with age is an important consideration when assessing individual subjects.