Lack of control of high blood pressure and treatment recommendations in Canada

BACKGROUND: Hypertension is a major risk factor for death that affects many Canadians, but only 16% of hypertensive Canadians are treated and have their hypertension controlled. While the control rate is very low, the 2001 Canadian Hypertension Recommendations do not recommend that low risk hypertensive patients be started on pharmacotherapy, and pharmacotherapy is not recommended for people for whom there is no demonstrable benefit from randomized, controlled trails. OBJECTIVES: To determine the proportion of hypertensive patients who are appropriately managed according to the 2001 Canadian Hypertension Recommendations. METHODS: Data from the Canadian Heart Health Survey, which surveyed a cross-sectional population (n=23,129) between 1986 and 1992, were used to determine the proportion of nondiabetic hypertensive patients who are managed according to the 2001 Canadian Hypertension Recommendations. Hypertensive patients not recommended to receive pharmacotherapy include those without risk factors and target organ damage, with a diastolic blood pressure of 90 to 99 mmHg and a systolic blood pressure of less than 160 mmHg. People with diastolic blood pressures of less than 90 mmHg who have systolic blood pressures of 140 to 159 mmHg are also not recommended to have pharmacotherapy. Patients prescribed antihypertensive therapy who had blood pressure controlled to less than 140/90 mmHg were assessed as having their hypertension managed appropriately, as were those who were not treated and were not recommended to be prescribed treatment. RESULTS: There were 58,813 (1.7%) hypertensive patients who did not have target organ damage or additional risk factors, and had a systolic blood pressure of less than 160 mmHg and a diastolic blood pressure between 90 and 99 mmHg. Twenty four per cent of hypertensive persons (831,787) had a systolic blood pressure of 140 to 160 mmHg and a diastolic blood pressure of less than 90 mmHg. About 25% (23.6%+1.7%) of hypertensive Canadians in the Canadian Heart Health Survey are not recommended to be prescribed antihypertensive therapy according to the 2001 Canadian Hypertension Recommendations. Sixteen per cent of hypertensive patients were treated and had their blood pressures controlled (blood pressure less than 140/90 mmHg). Therefore, about 41% (ie, 16%+25%) of hypertensive patients are appropriately managed according to the 2001 Canadian Hypertension Recommendations. CONCLUSIONS: The results of the Canadian Heart Health survey indicate that there are a striking number of Canadians with untreated high blood pressure (59%) who probably do not have their hypertension managed according to the 2001 Canadian Hypertension Recommendations. Greater efforts are required to identify people with hypertension, and to ensure that they are managed according to the best available evidence.