Risks of untreated and treated isolated systolic hypertension in the elderly: meta-analysis of outcome trials

• Published in: The Lancet (British edition) 2000-03, Vol.355 (9207), p.865-872
• Main Authors: Staessen, Jan A, Gasowski, Jerzy, Wang, Ji G, Thijs, Lutgarde, Hond, Elly Den, Boissel, Jean-Pierre, Coope, John, Ekbom, Tork, Gueyffier, François, Liu, Lisheng, Kerlikowske, Karla, Pocock, Stuart, Fagard, Robert H
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Antihypertensive Agents - adverse effects; Antihypertensive Agents - therapeutic use; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; Blood pressure; Cardiology. Vascular system; Cause of Death; Clinical manifestations. Epidemiology. Investigative techniques. Etiology; Clinical trials; Clinical Trials as Topic; Female; Health risk assessment; Humans; Hypertension; Hypertension - drug therapy; Hypertension - mortality; Male; Medical sciences; Middle Aged; Older people; Risk Assessment; Survival Rate; Systematic review; Treatment Outcome
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(99)07330-4

Previous meta-analysis of outcome trials in hypertension have not specifically focused on isolated systolic hypertension or they have explained treatment benefit mainly in function of the achieved diastolic blood pressure reduction. We therefore undertook a quantitative overview of the trials to further evaluate the risks associated with systolic blood pressure in treated and untreated older patients with isolated systolic hypertension Patients were 60 years old or more. Systolic blood pressure was 160 mm Hg or greater and diastolic blood pressure was less than 95 mm Hg. We used non-parametric methods and Cox regression to model the risks associated with blood pressure and to correct for regression dilution bias. We calculated pooled effects of treatment from stratified 2 X 2 contingency tables after application of Zelen's test of heterogeneity. In eight trials 15 693 patients with isolated systolic hypertension were followed up for 3.8 years (median). After correction for regression dilution bias, sex, age, and diastolic blood pressure, the relative hazard rates associated with a 10 mm Hg higher initial systolic blood pressure were 1.26 (p=0.0001) for total mortality, 1.22 (p=0.02) for stroke, but only 1.07 (p=0.37) for coronary events. Independent of systolic blood pressure, diastolic blood pressure was inversely correlated with total mortality, highlighting the role of pulse pressure as risk factor. Active treatment reduced total mortality by 13% (95% Cl 2–22, p=0.02), cardiovascular mortality by 18%, all cardiovascular complications by 26%, stroke by 30%, and coronary events by 23%. The number of patients to treat for 5 years to prevent one major cardiovascular event was lower in men (18 vs 38), at or above age 70 (19 vs 39), and in patients with previous cardiovascular complications (16 vs 37). Drug treatment is justified in older patients with isolated systolic hypertension whose systolic blood pressure is 160 mm Hg or higher. Absolute benefit is larger in men, in patients aged 70 or more and in those with previous cardiovascular complications or wider pulse pressure. Treatment prevented stroke more effectively than coronary events. However, the absence of a relation between coronary events and systolic blood pressure in untreated patients suggests that the coronary protection may have been underestimated.