Data from the US has provided some new guidance on the management of hypertension in the elderly. 

For patients older than 70, a reduction in blood pressure is associated with a reduction in mortality, preliminary results from a new study have shown.¹

The study follows the recent publication of new recommendations from the US on the treatment of high blood pressure in adults age 65 and older.

In the study, on patients over 70, the lowest mortality rate during an eight-year period was found in those who achieved a systolic blood pressure between 130-139mmHg (16.7%), according to researchers at the Washington DC Veterans Affairs Medical Center. Mortality rates increased at both higher pressures and lower systolic pressures, a pattern also seen with diastolic pressure. The optimal diastolic pressure was 70-79mmHg, the recent American Society of Hypertension meeting in New York was told.

Aggressive treatment

Until recently, clinicians have often been wary of treating older patients aggressively because of a lack of outcome data and concerns about side-effects. However, the HYVET trial in 2008² showed that treating hypertensive patients 80 years and older to a target of 150/80mmHg led to significant reductions in stroke death, all-cause death and heart failure.

The findings led to an expert consensus document from the American College of Cardiology and the American Heart Association that was released recently, which included a recommendation for a general target of less than 140/90mmHg for patients 65 and older, although the authors acknowledged some uncertainty about whether patients 80 and older should have a slightly higher target.

To explore the effects of lowering blood pressure below the targets in the HYVET trial, the Washington researchers analysed data from 183,054 patients, aged 70 and up, who had treated hypertension and received care at one of 15 VA Medical Centers. The patients were followed from 2000 to 2007.

The researchers divided the patients into groups based on their achieved systolic blood pressure six months before death or the last available measurement: 150 and higher, 140-149, 130-139, 120-129, 110-119, 100-109, and less than 100mmHg.

During the study period, the rates of blood pressure control improved from 45% to 73% and that was consistent across age groups.

There were no additional side-effects seen in the older patients, despite concerns that if additional medications were added, the older patients might not tolerate this. 

Overall, about a quarter (24.6%) of the patients older than 70 died during follow-up. Compared with patients who achieved a systolic blood pressure of 130-139mmHg, those who achieved pressures of 140-149 or 150 and higher had significantly increased rates of all-cause death – relative increases of 17% and 40%, respectively (P < 0.001) – after adjustment for age, co-morbidities, and other risk factors.

Dropping lower than 130mmHg was also associated with higher mortality rates, ranging from relative increases of 22% to 408% for the lowest pressures (P < 0.001).

A similar J-shaped association between blood pressure and mortality was observed for diastolic pressure. 

Meanwhile, the collaborative efforts of nine health organisations have resulted in new recommendations on the treatment of high blood pressure in adults aged 65 and older.³

The authors of the document say target blood pressure should be less than 140/90mmHg, although a range of 140-145mmHg would be acceptable for individuals who are 80 years old. Among younger people, a normal blood pressure reading is considered to be less than 120/80mmHg.

Recommendations

The prevalence of high blood pressure among older adults is a concern: about two-thirds of men and three-quarters of women have hypertension, which is a significant risk factor for heart attack and stroke. In the document, the authors recommended the following:

• Clinicians should take at least three blood pressure readings over two or more office visits before they make a diagnosis of high blood pressure
• Certain patient populations, including individuals who have diabetes, chronic kidney disease, and coronary artery disease, should have a goal of 130/80mmHg rather than the general target of less than 140/90mmHg
• Among individuals who have mild hypertension, lifestyle changes, including stopping smoking, limiting salt intake, maintaining a healthy weight, increasing physical exercise, and limiting alcohol consumption to two or fewer drinks per day may be sufficient to lower blood pressure. If such efforts are not adequate, medication can be considered
• Patients should start with the lowest dose of a single drug, which can be increased gradually if the dose is inadequate. The recommended first-line of treatment should be thiazide diuretics, chlorthalidone, and bendroflumethiazide. If a diuretic is not used as the first drug, it is usually recommended as the second drug if the patient needs it
• In patients whose blood pressure is greater than 20/10mmHg over their goal, treatment can be initiated with two drugs
• Among patients who have coronary artery disease and stable angina or a history of myocardial infarction, the first drug to treat high blood pressure should be a beta-blocker (eg, atenolol, metoprolol). In patients whose pressure remains high or if angina persists, a long-acting dihydropyridine calcium antagonist should be added to the treatment plan.

The consensus document was developed by the American College of Cardiology Foundation and the American Heart Association, along with the American Academy of Neurology, the American Geriatrics Society, the American Society of Hypertension, the American Society of Nephrology, the American Society for Preventive Cardiology, the Association of Black Cardiologists, and the European Society of Hypertension.