Report of the Canadian Hypertension Society Consensus Conference: 3. Pharmacologic treatment of hypertensive disorders in pregnancy

OBJECTIVE: To provide Canadian physicians with evidence-based guidelines for the pharmacologic treatment of hypertensive disorders in pregnancy. OPTIONS: No medication, or treatment with antihypertensive or anticonvulsant drugs. OUTCOMES: Prevention of maternal complications, and prevention of perinatal complications and death. EVIDENCE: Pertinent articles published from 1962 to September 1996 retrieved from the Pregnancy and Childbirth Module of the Cochrane Database of Systematic Reviews and from MEDLINE; additional articles retrieved through a manual search of bibliographies; and expert opinion. Recommendations were graded according to levels of evidence. VALUES: Maternal and fetal well-being were equally valued, with the belief that treatment side effects should be minimized. BENEFITS, HARMS AND COSTS: Reduction in the rate of adverse perinatal outcomes, including death. Potential side effects of antihypertensive drugs include placental hypoperfusion, intrauterine growth retardation and long-term effects on the infant. RECOMMENDATIONS: A systolic blood pressure greater than 169 mm Hg or a diastolic pressure greater than 109 mm Hg in a pregnant woman should be considered an emergency and pharmacologic treatment with hydralazine, labetalol or nifedipine started. Otherwise, the thresholds at which to start antihypertensive treatment are a systolic pressure of 140 mm Hg or a diastolic pressure of 90 mm Hg in women with gestational hypertension without proteinuria or pre-existing hypertension before 28 weeks' gestation, those with gestational hypertension and proteinuria or symptoms at any time during the pregnancy, those with pre-existing hypertension and underlying conditions or target-organ damage, and those with pre-existing hypertension and superimposed gestational hypertension. The thresholds in other circumstances are a systolic pressure of 150 mm Hg or a diastolic pressure of 95 mm Hg. For nonsevere hypertension, methyldopa is the first-line drug; labetalol, pindolol, oxprenolol and nifedipine are second-line drugs. Fetal distress attributed to placental hypoperfusion is rare, and long-term effects on the infant are unknown. Magnesium sulfate is recommended for the prevention and treatment of seizures. VALIDATION: The guidelines are more precise but compatible with those from the US and Australia.     

Report of the Canadian Hypertension Society Consensus Conference: 4. Hypertension in the elderly.

Several knowledge gaps, which made evidence-based guidelines impossible in 1985, have since been filled. There is now unequivocal evidence that treatment of isolated systolic hypertension benefits elderly patients, as does treatment beyond the age of 75 years. Pseudohypertension, although occasionally problematic, is not common and is not a reason to neglect the treatment of elderly patients, including those with isolated systolic hypertension. In general, long-term antihypertensive treatment of the elderly is well tolerated and does not cause important decreases in mental function. Comparative drug studies continue to accumulate; most show no clinically significant general differences between drugs, aside from the somewhat decreased efficacy and tolerability of beta-blockade in elderly patients. As in the young, certain drugs may be preferred in the presence of other conditions--e.g., congestive heart failure or diabetes.     

Report of the Canadian Hypertension Society Consensus Conference: 2. Diagnosis of hypertension in adults.

OBJECTIVE: To update recommendations for the diagnosis of mild hypertension in adults and to assess the role of echocardiography, self-measurement of blood pressure and ambulatory blood pressure monitoring. DATA SOURCES: Literature reviews of previous consensus conferences were updated with searches of MEDLINE for the period Jan. 1, 1988, to Nov. 15, 1991, and supplemented by reference lists and personal files. STUDY SELECTION: Panel members selected relevant articles and rated them according to methodologic criteria. DATA EXTRACTION: The data extracted concerned the measurement of blood pressure, the diagnosis of hypertension, the treatment of mild hypertension, and the reliability and validity of echocardiography, self-measurement of blood pressure and ambulatory blood pressure monitoring in the diagnosis of mild hypertension. The recommendations made were graded according to the level of evidence available, circulated to many experts and approved at a consensus conference. MAIN RESULTS: Previous recommendations for the accurate measurement of blood pressure remain mostly unchanged. Antihypertensive treatment should be prescribed for patients (including the elderly) with an average diastolic blood pressure of at least 100 mm Hg, for those with isolated systolic hypertension (systolic blood pressure of at least 160 mm Hg and diastolic blood pressure of less than 90 mm Hg) and for patients with a diastolic blood pressure of 90 to 99 mm Hg and target-organ damage. Clinical judgement is required in treating patients with a diastolic blood pressure of 90 to 99 mm Hg without target-organ damage, and individual risk for cardiovascular disease must be taken into account. There is insufficient evidence to warrant the routine use of echocardiography, self-measurement of blood pressure or ambulatory blood pressure monitoring in diagnosis. CONCLUSIONS: Recent high-quality evidence supports several new recommendations for the diagnosis of mild hypertension in adults. Additional research is needed to determine the role of echocardiography, self-measurement of blood pressure and ambulatory blood pressure monitoring.     

Report of the Canadian Hypertension Society's consensus conference on the management of mild hypertension.

Since the publication in 1977 of joint recommendations by the Canadian Cardiovascular Society, the Canadian Heart Foundation and the Ontario Council of Health on the detection and management of hypertension in Canada, several clinical trials on the efficacy of antihypertensive drug treatment in patients with mild hypertension have been undertaken. The Canadian Hypertension Society (CHS) felt that the results of these trials should be reviewed to determine whether existing recommendations on treatment should be changed. Three expert panels appointed by the CHS reviewed evidence on the clinical efficacy of antihypertensive therapy, the diagnosis of hypertension and the treatment of mild hypertension, and formulated recommendations on the care of mildly hypertensive patients in Canada. A consensus conference of biomedical scientists, practising physicians and government representatives reviewed and reached agreement on the panels' recommendations. The final recommendations of the conference are presented in this report.     

Anticardiolipin and anti-beta2-glycoprotein-I antibodies in hypertensive disorders of pregnancy

BACKGROUND: This study was undertaken in order to determine the frequency of anticardiolipin (aCL) and anti-beta2-glycoprotein-I antibodies (anti-beta2 GP-I) in patients with hypertensive disorders of pregnancy. METHODS: We studied aCL (IgG and IgM) and IgG anti-beta 2 GP-I by ELISA in the serum and IgG aCL and anti-beta 2 GP-I in the urine of 125 women with hypertensive disorders of pregnancy (cases) (75 had preeclampsia, 25 had eclampsia, and 25 had chronic hypertension). One hundred and twenty seven normal women were used as controls. Antibody positivity was defined as above the 90(th) percentile of the controls. RESULTS: We found no differences in frequency of serum anti-beta 2 GP-I or serum and urinary aCL between cases and controls. In contrast, we found that frequency of IgG anti-beta 2 GP-I was higher in the urine of cases (26.1%) compared to controls (9.4%, p = 0.001). Strength of association was stronger for urinary anti-beta2-glycoprotein-I in women with preeclampsia (odds ratio [OR] = 4.3, 95% confidence limit [CI 95%] = 1.95-9.62, p <0.0001). Cases and the subgroup of preeclamptic patients also had higher titers of urinary IgG anti-beta 2 GP-I than control women (p <0.0001). CONCLUSIONS: Our work suggests that urine testing is necessary in order to ascertain whether antibodies to beta(2)GP-I are associated with preeclampsia.