Results of antihypertensive treatment by primary and secondary care physicians as assessed by ambulatory blood pressure monitoring

Comparing the effects of white coat hypertension and sustained hypertension on mortality in a UK primary care setting

PURPOSE

We examined all-cause mortality within a primary care setting in patients with white coat hypertension or sustained hypertension in whom blood pressure (BP) monitoring was indicated.

METHODS

This prospective multicenter study of ambulatory BP monitoring included 48 family practices in the county of Oxfordshire, United Kingdom. Mortality was compared for patients having white coat hypertension (mean of 3 clinic BP readings >140/90 mm Hg and daytime ambulatory readings< or =135/85 mm Hg) and patients having sustained hypertension (mean of 3 clinic readings >140/90 mm Hg and daytime ambulatory readings >135/85 mm Hg).

RESULTS

A routine primary care cohort consisting of 5,182 patients chosen to undergo ambulatory BP monitoring by their family physician was followed up for a median of 7.3 years (interquartile range, 5.8-8.9). There were 335 deaths (6.5%), corresponding to a mortality rate of 8.9 deaths (95% confidence interval [CI], 8.0-9.9) per 1,000 years of follow-up. Patients with white coat hypertension (n = 1,117) were more likely to be female and were on average younger than patients with sustained hypertension (n = 4,065). The unadjusted rate of all-cause mortality in patients with white coat hypertension was lower, at 4.4 deaths per 1,000 years of follow-up (95% CI, 3.1-6.0) than that in patients with sustained hypertension, at 10.2 deaths per 1,000 years of follow-up (95% CI, 9.1-11.4). This reduction in all-cause mortality was still clinically significant after adjustment for age, sex, smoking, use of antihypertensive medication, and practice-clustering effects (hazard ratio = 0.64; 95% CI, 0.42-0.97; P=.04).

CONCLUSIONS

White coat hypertension (elevation of clinic BP only) confers significantly less risk of death than sustained hypertension (elevation of both clinic and ambulatory BPs). Trials are now needed to evaluate the risk reduction achievable in patients who have white coat hypertension and are receiving BP-lowering therapy.

Daytime ambulatory systolic blood pressure is more effective at predicting mortality than clinic blood pressure

OBJECTIVES

To assess the prognostic value of daytime ambulatory blood pressure compared with routine clinic blood pressure in determining mortality.

METHODS

Prospective multicentre study in 48 general practices in Oxfordshire, a hypertension clinic in Oxford and a hypertension clinic in London.

RESULTS

A cohort of 10 129 patients from Oxford and London was followed up for a median of 8.2 years. Nine hundred and one deaths were recorded (8.9%) corresponding to a mortality rate per 1000 years of follow-up of 10.8 (99% confidence interval 9.9-11.8). Comparing the highest quartile for systolic ambulatory blood pressure with the lowest (>or=160 vs. <135 mmHg) gives an estimated age sex-adjusted hazard ratio for mortality of 1.51 (95% confidence interval 1.25-1.83, P<0.001). The corresponding comparison for clinic systolic blood pressure (>or=174 vs. <148 mmHg) results in a hazard ratio of 1.02 (95% confidence interval 0.84-1.24, P=0.9). Comparing ambulatory versus clinic systolic blood pressure (10 mmHg groupings) using nested statistical modelling, removal of the ambulatory blood pressure term from the baseline Cox model (nine 10 mmHg categories) resulted in a highly significant likelihood ratio test statistic of 52.5 (df=8, P<0.0001). The corresponding result for removal of the clinic blood pressure term was 18.1 (df=8, P=0.02), thus reinforcing the finding that ambulatory blood pressure monitoring has greater prognostic significance. Ambulatory blood pressure was also a better predictor of all-cause mortality both in patients taking medication and those not taking medication at the time of monitoring.

CONCLUSION

Daytime ambulatory blood pressure monitoring is a much better prognostic indicator of all-cause mortality than clinic blood pressure.

Hypertension therapy: mixing, matching, and meeting targets

The inappropriate control of hypertension is a public health problem worldwide. It is notable that although there are several causes for this situation, lack of effective pharmacotherapy is not among them. It has long been known that combinations of antihypertensive drugs are highly effective in most patients; the problem is implementing treatment recommendation guidelines into clinical practice with the most effective and best tolerated therapies. The latest guidelines on therapies for hypertension from the World Health Organization/International Society of Hypertension, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (US), and the European Societies of Hypertension and Cardiology consistently emphasize this need of combination treatments in a large part of the hypertensive patient population. This review focuses on the combination of one of the oldest drugs, thiazide diuretics, with one of the youngest, angiotensin-receptor blockers, and analyzes the available literature regarding potential applications in specific populations. This represents one of the most widely used, rational and effective combination therapies, combining excellent control of blood pressure with unequalled tolerability. In addition, angiotensin-receptor blocker/diuretic combinations may have cardiovascular benefits beyond those from blood pressure lowering itself.