Long-term (four years) follow-up of patients with treated nocturnal hypertension assessed by ambulatory blood pressure monitoring.

Study Objective: Nocturnal Hypertension (NH) is an independent risk factor for cardiovascular morbidity and mortality (M-M). However, an inappropriate decrease in diastolic BP during the night significantly increases morbidity. There are no prospective studies on the long-term consequences on M-M in treated NH. We accordingly studied M-M in 107 consecutive patients with treated NH, assessed by ambulatory blood pressure monitoring (ABPM), during a four-year follow-up.
Patients and Methods: From the initial 107 patients six died (5 from brain or cardiovascular causes). In 65 patients it was possible to repeat the ABPM during the follow-up period. They were hypertensive patients class I-II (JNC IV) 62 +/- 10 years old, 56 were male and were observed before and after starting treatment on a four-year follow-up period. We considered age, sex, body mass index, previous cerebral and cardiovascular accidents, type and number of drugs administered, smoking habits, plasma cholesterol, glycemia, and causal and ambulatory blood pressure monitoring (ABPM) (24 hr, 6 am-10 am, 10 pm-6 am and pulse pressure) before and after follow-up, dipper status and the period of follow-up.
Results: The patients whom died were older and had a significantly higher systolic blood pressure compared to the survivors. We considered two groups: with (A - n = 18) or without (B - n = 47) cerebral and cardiac morbidity. The A group had more previous cerebral and cardiovascular accidents (p = 0.05), a more intensive treatment (p = 0.02), and a greater fall in diastolic blood pressure (DBP) during the night in both absolute and percentage numbers, after treatment, than the B group. However, after regression analysis, the only independent risk marker differentiating between the two groups was the percentage fall in the DBP after treatment (dipper phenomenon) (p = 0.01).
Conclusions: In 65 treated hypertensive (NH) patients assessed by ABPM before and after treatment (four-year follow-up) we identified a group with cerebral and cardiovascular morbidity. These patients, in contrast with another group with no morbidity, had more previous cerebral and cardiovascular accidents, they were more intensively treated, and they had a greater fall in diastolic blood pressure after therapy (absolute and percentage values). However, after regression analysis the diastolic nocturnal blood pressure dipper phenomenon after treatment was the only risk marker associated with morbidity. In such cases it is possible that treatment guided by ABPM can decrease morbidity.