Non-dipper hypertension is associated with slow coronary flow among hypertensives with normal coronary angiogram
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Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
Published on: March 15, 2022
Ercan Aksit1, Erdal Gursul1, Fatih Aydin2
1Department of Cardiology, Biga State Hospital, Canakkale, Turkey.
Insights
Hypertensive non-dippers, patients with a smaller drop in nocturnal blood pressure, exhibit higher Thrombolysis in Myocardial Infarction (TIMI) frame counts, indicating microvascular dysfunction, compared to dippers. This suggests increased cardiovascular risk in non-dipper hypertensive individuals.
Area of Science:
- Cardiology
- Hypertension Research
- Vascular Biology
Background:
- Hypertension is a major risk factor for cardiovascular disease.
- Nocturnal blood pressure dipping patterns, specifically the 'dipper' and 'non-dipper' classifications, are associated with cardiovascular outcomes.
- Microvascular function, assessed by Thrombolysis in Myocardial Infarction (TIMI) frame count, plays a crucial role in cardiovascular health.
Purpose of the Study:
- To compare the microvascular function, using TIMI frame count, between dipper and non-dipper hypertensive patients with normal coronary arteries.
- To investigate the relationship between nocturnal blood pressure dipping status and coronary microvascular impairment in hypertensive individuals.
Main Methods:
- A retrospective study involving 60 hypertensive patients with normal coronary arteries.
- Patients were categorized into dipper (n=30) and non-dipper (n=30) groups based on ambulatory blood pressure monitoring.
- Coronary microvascular function was assessed using TIMI frame counts in all major coronary arteries.
Main Results:
- Non-dipper hypertensives showed significantly higher TIMI frame counts in all coronary arteries and mean TIMI frame count compared to dipper hypertensives (p < 0.001).
- Body Mass Index (BMI) was significantly higher in the non-dipper group (25.47 ± 2.92 kg/m²) than in the dipper group (23.79 ± 2.81 kg/m², p = 0.027).
Conclusions:
- TIMI frame count, a reliable indicator of microvascular changes, is elevated in non-dipper hypertensive patients.
- Non-dipper status in hypertension is associated with impaired coronary microvascular function, suggesting a higher risk profile.
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.
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