Blood pressure level attainment among patients with coronary artery disease and uncontrolled blood pressure.

STUDY

OBJECTIVES

To determine the proportion of patients with coronary artery disease (CAD) and uncontrolled blood pressure who attained a blood pressure of less than 130/80 mm Hg, and to compare patient- and health system- specific characteristics and identify factors independently associated with attaining this blood pressure level.

DESIGN

Retrospective, longitudinal, cohort study.

SETTING

Health maintenance organization.

PATIENTS: A cohort of 1380 patients (14%) who had uncontrolled blood pressure out of 9785 adults with established CAD enrolled in the Clinical Pharmacy Cardiac Risk Service.

MEASUREMENTS AND MAIN

RESULTS

Uncontrolled hypertension was defined as a mean of two consecutive blood pressure readings of 140/90 mm Hg or higher in 2006 or 2007, most proximal to December 31, 2007 (baseline). The cohort was followed from January 1, 2008-June 30, 2009 (follow-up). The follow-up blood pressure level was the mean of the last two consecutive blood pressure readings most proximal to June 30, 2009. Of the 1380 patients, 34.9% (482 patients), 34.0% (469), and 31.1% (429) attained a blood pressure below 130/80, 130/80-139/89, and 140/90 mm Hg or higher, respectively, at follow-up. Significantly more patients in the less than 130/80 mm Hg group were male, had Medicare insurance, had lower baseline systolic and/or diastolic blood pressures, and had a higher Chronic Disease Score compared with the other groups. For every additional clinic visit, there was a 3% increased likelihood of attaining a blood pressure below 130/80 mm Hg (adjusted odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.04). Patients experiencing a cardiac event during the follow-up period were approximately twice as likely to attain a blood pressure below 130/80 mm Hg (OR 1.97, 95% CI 1.04-3.77) compared with those who did not have a subsequent event.

CONCLUSION

Despite systematic and aggressive treatment of blood pressure in patients with CAD and uncontrolled blood pressure, a minority of patients attained a blood pressure of less than 130/80 mm Hg. Considering that higher utilization of the health care system was associated with reaching this blood pressure level and that a similar number of therapeutic interventions in the groups resulted in variable success for blood pressure lowering, attaining a blood pressure level of less than 130/80 mm Hg may be difficult for some patients with CAD.