Home blood pressure monitoring improves the diagnosis of hypertension in hemodialysis patients

Abstract

Using interdialytic ambulatory blood pressure (BP) recordings as the reference standard, we compared the performance of routine, standardized and home BP monitoring in 104 predominantly black patients on chronic hemodialysis for at least 3 months. Dialysis unit BP recordings were averaged over 2 weeks and home BP over 1 week. Awake ambulatory BP of > or =135 mmHg systolic or > or =85 mmHg diastolic was taken as evidence of hypertension. Average awake ambulatory BP was 128.1+/-21.6/73.5+/-13.5 mmHg, home BP 141.3+/-21.9/78.7+/-11.9 mmHg, standardized pre-dialysis BP 141.7+/-22.6/74.2+/-13.5 mmHg and post-dialysis 119.9+/-20.5/69.1+/-13.1 mmHg, routine pre-dialysis 145.4+/-21.8/79.0+/-13.1 mmHg and post-dialysis 131.5+/-19.2/72.5+/-11.4 mmHg. Sixty-three percent of the patients had well-controlled BP by ambulatory BP monitoring and isolated diastolic hypertension was rare (3%). The standard deviation of the differences between ambulatory and routine pre-dialysis BP was 17.6 mmHg, routine post-dialysis was 16.1 mmHg, standardized pre-dialysis was 16.4 mmHg, standardized post-dialysis was 14.1 mmHg, and home BP was 14.2 mmHg. The area under receiver operating characteristic curves was similar for home and standardized BP but lower for routine BP. Home systolic BP of > or =150 mmHg averaged over 1 week had the best combination of sensitivity (80%) and specificity (84.1%) in diagnosing systolic hypertension--present in 94% of the hypertensive dialysis patients. Home BP monitoring is similar to standardized recording of BP in hemodialysis patients. A systolic BP threshold of 150 mmHg at home averaged over 1 week serves as a useful predictor of hypertension diagnosed by ambulatory BP monitoring.