Objective: In hypertensive patients with typical chest pain but absence of coronary stenosis the coronary microcirculation may be impaired, thus, our study aimed to appraise, in these subjects, the role of the coronary microcirculation, assessed by Myocardial Blush Grade (MBG) and Thrombolysis in Myocardial Infarction (TIMI) Frame Count (TFC).
Methods: A total of 95 subjects with chest pain and uninjured coronary arteries were recruited into the study: 80 subjects were hypertensive while 15 subjects were normotensive. The hypertensive subjects were divided into two subgroups: hypertensive subjects with positive scintigraphy and hypertensive subjects with negative scintigraphy. The TFC, a quantitative method of assessing coronary artery flow, the MBG, an assessment of the level of tissue perfusion, and the Total Myocardial Blush Score (TMBS), the sum of the myocardial blush grades of each coronary territory, were evaluated on the coronary angiogram of every patient.
Results: The TFC was higher (p<0.05) in hypertensive subjects than in normotensive subjects. The MBG and the TMBS were lower (p<0.05) in hypertensive subjects than in normotensive subjects. The TFC was higher (p<0.05) in positive scintigraphy than in negative scintigraphy. The MBG was lower (p<0.05) in positive scintigraphy than in negative scintigraphy. The Spearman rank correlation test showed that the TFC and the MBG was inversely associated.
Conclusion: The hypertensive subjects had impaired coronary artery flow and myocardial perfusion, documented by the TFC, MBG and myocardial perfusion scintigraphy. These methods may be universally applicable, in fact they are validated and most catheterization laboratories have access to them.