Non-dipper hypertension is associated with slow coronary flow among hypertensives with normal coronary angiogram.

AIM: A person with a drop of more than 10% in nocturnal arterial blood pressure during the circadian rhythm is referred to as a dipper and one with a smaller decrease is referred to as a non-dipper. In our study, we aimed to compare the thrombolysis in myocardial infarction (TIMI) frame count in non-dipper and dipper hypertensive patient groups who had normal coronary artery angiography.

METHODS: Patients with normal coronary arteries and with ambulatory blood pressure monitoring follow ups were retrospectively investigated and 60 patients (35%, female) were included in our study. The patients were grouped as dipper (n = 30) and non-dipper (n = 30) hypertensives.

RESULTS: The TIMI frame counts in all three coronary arteries and the mean TIMI frame count in the dipper hypertensive patient group were significantly lower than those of the non-dipper hypertensives (right coronary artery TIMI frame count: 16.83 ± 3.70; 21.63 ± 3.44, p < 0.001; circumflex artery TIMI frame count: 21.28 ± 3.52; 25.65 ± 3.61, p < 0.001; left anterior descending artery TIMI frame count: 34.20 ± 2.80; 37.05 ± 3.30, p = 0.001; corrected left anterior descending artery TIMI frame count: 20.05 ± 1.63; 21.74 ± 1.95, p = 0.001; mean TIMI frame count: 19.31 ± 2.3; 22.94 ± 2.61, p < 0.001). The body mass index (BMI) was 23.79 ± 2.81 kg/m2 in the dipper patient group, while it was 25.47 ± 2.92 in the non-dippers. BMI was found to be significantly higher in the non-dipper group than in the dipper group (p = 0.027).

CONCLUSION: In this study, TIMI frame count, which is a simple, productive, objective and reproducible method for determination of microvascular changes, was found to be higher in non-dipper hypertensive patients than in the dipper patients.