Barriers to blood pressure control and angiotensin enzyme inhibitor use in Canadian patients with chronic renal insufficiency

Abstract

Background: Current recommendations for the management of chronic renal insufficiency (CRI) include the use of angiotensin-converting enzyme inhibitors (ACEI) and achieving target blood pressure control. We designed this study to describe the use of these therapeutic strategies, and to investigate barriers to their implementation.

Methods: This was a prospective study of 304 consecutive CRI patients, seen at follow-up in four nephrology clinics across Canada. The use of blood pressure control and antihypertensive medication (AHM) in each of these clinics was recorded, and a questionnaire was administered to nephrologists to determine the basis for decisions concerning AHM regimens and ACEI use/non-use.

Results: Mean age was 60.8+/-15.7 years, mean creatinine clearance was 30.3+/-18 ml/min, and underlying renal diseases were similar to registry data. Mean arterial pressure (MAP) achieved was 99.4+/-14.4 and 98.9+/-11.9 mmHg in individuals with >1 and </=1 g/day proteinuria, respectively. When similarly stratified by proteinuria, mean systolic blood pressures were 141.4+/-23.5 and 140.9+/-20.3 mmHg, and mean diastolic blood pressures were 78.4+/-14.0 and 77.9+/-11.4 mmHg, respectively. Blood pressure control, according to published guidelines, was achieved in 128 patients (42.1%). A further 86 (28.3%) patients had their AHM increased. The remaining 90 (29.6%) did not have their AHM increased. Of these, 40 were labelled 'at target blood pressure' (mean MAP 100.5+/-5.4 mmHg), 19 'office hypertension' and 11 'unfavourable risk/benefit ratios'. There were 108/304 (35.5%) patients who were not taking ACEI or ARB (angiotensin receptor antagonist): 34/108 (31%) had previous ACEI failure due to hyperkalaemia (21/108, 19%) or acute renal failure (17/108, 16%), and 61/108 (55%) were felt 'unlikely to benefit' (categories not mutually exclusive). Miscommunication with the primary physician and medication costs were not identified as significant barriers to improved blood pressure control or ACEI use.

Conclusions: Approximately 40% of CRI patients are achieving current blood pressure goals and 64% are prescribed ACEI/ARB in tertiary care nephrology clinics. Although the use of these strategies may be increasing, there remains room for improvement. Physicians should remain aware of the need to use these proven strategies in patients with CRI.