Antihypertensive benefits rapid and lasting in the very elderly
MedWire News: Very elderly patients with hypertension receive rapid protection against stroke and cardiovascular events when they are treated with an antihypertensive agent, show the results of the HYVET extension.
Of the 1882 patients who did not have a cardiovascular event during the main phase of HYVET (Hypertension in the Very Elderly Trial), 91% participated in the open-label, 1-year extension study. All patients were given 1.5 mg per day of extended-release indapamide, with perindopril 2-4 mg if needed to maintain patients' blood pressure below 150/80 mmHg (about three-quarters of patients required combination therapy).
"The fact that the differences in cardiovascular events overall between active treatment and placebo seen in the main trial were lost within 1 year of active antihypertensive treatment reinforces the suggestion that the over 80s should be screened regularly with a view to treatment if they have sustained blood pressures of 160 mmHg or above as they are likely to gain benefits from early detection," the investigators write in the BMJ.
At entry to the extension phase, patients' average sitting blood pressure was 159.3/80.8 mmHg among those who took placebo during the main trial compared with 145.0/75.8 mmHg among those given active treatment. By 6 months, blood pressure was an average of just 1.2/0.7 mmHg higher in patients who took placebo rather than active treatment in the main trial.
The main phase of HYVET was stopped early because of the significant reduction in stroke and heart failure seen with active versus placebo treatment.
During the 1-year extension study, fatal and nonfatal stroke occurred at rates of 5.18 per 1000 patient-years among patients previously taking placebo, and 9.89 per 1000 patient-years among those previously taking indapamide, which was not a significant difference.
There were also no significant differences between patients previously taking placebo or active treatment in the rates of heart failure (3.9 and 1.1 per 1000 patient-years, respectively) and all cardiovascular events (16.9 and 13.2 per 1000 patient-years, respectively).
However, patients previously taking placebo had significantly higher rates of cardiovascular mortality than those taking active treatment, at 11.6 versus 2.2 per 1000 patient-years, and of all-cause mortality, at 38.8 versus 18.6 per 1000 patient-years.
This shows that the beneficial effect of antihypertensive treatment on these endpoints takes some time to accrue, say Nigel Beckett (Imperial College London, UK) and team. They say that it highlights the importance of continuing antihypertensive therapy in elderly patients with hypertension.
The average blood pressure achieved after 6 months of treatment in the cohort as a whole was 146/76 mm Hg.
The team says: "These results do not answer the question of whether even lower achieved pressures would be more effective in this age group, and additional research is needed to determine this."
By Eleanor McDermid