Intensive versus conventional blood pressure monitoring in a general practice population. The Blood Pressure Reduction in Danish General Practice trial: a randomized controlled parallel group trial

Objective: To compare the effect of a conventional to an intensive blood pressure monitoring regimen on blood pressure in hypertensive patients in the general practice setting.

Design: Randomized controlled parallel group trial with 12-month follow-up.

Setting: One hundred and ten general practices in all regions of Denmark.

Participants: One thousand forty-eight patients with essential hypertension.

Intervention: Conventional blood pressure monitoring ('usual group') continued usual ad hoc blood pressure monitoring by office blood pressure measurements, while intensive blood pressure monitoring ('intensive group') supplemented this with frequent home blood pressure monitoring and 24-hour ambulatory blood pressure monitoring.

Primary outcome measures: Mean day- and night-time systolic and diastolic 24-hour ambulatory blood pressure.

Secondary outcome measures: Change in systolic and diastolic office blood pressure and change in cardiovascular risk profile.

Results: Of the patients, 515 (49%) were allocated to the usual group, and 533 (51%) to the intensive group. The reductions in day- and night-time 24-hour ambulatory blood pressure were similar (usual group: 4.6 ± 13.5/2.8 ± 82 mmHg; intensive group: 5.6 ± 13.0/3.5 ± 8.2 mmHg; P = 0.27/P = 0.20). Cardiovascular risk scores were reduced in both groups at follow-up, but more so in the intensive than in the usual group (P = 0.02).

Conclusion: An intensive blood pressure monitoring strategy led to a similar blood pressure reduction to conventional monitoring. However, the intensive strategy appeared to improve patients' cardiovascular risk profile through other effects than a reduction of blood pressure.

Trial registration: Clinical Trials NCT00244660.