Optimal Antihypertensive Level for Improvement of Coronary Microvascular Dysfunction

Abstract

Abstract-Recently, coronary microvascular function was documented to be impaired even in patients with prehypertension. However, the impact of antihypertensive level on improvement of coronary microvascular dysfunction in hypertensive patients remains to be established. We investigated the optimal blood pressure achieved with treatment of antihypertensive agents for improvement of coronary microvascular dysfunction in hypertensive patients. We prospectively studied 108 untreated hypertensive patients. All patients were treated with antihypertensive agents for approximately 12 months. Coronary flow reserve (CFR) was measured before and after treatment. The patients were divided into hypertensive, prehypertensive, and normal groups based on their average blood pressure during the treatment period. Pretreatment CFR was similar among all groups. CFR increased significantly in the normal group during the treatment period, but decreased significantly in the prehypertensive and hypertensive groups. This decrease was significantly greater in the hypertensive group than in the prehypertensive group. Multivariate analysis showed lowering blood pressure to normal level to be an independent determinant of improvement in CFR. The normal group was divided into normal-higher and normal-lower subgroups based on their average diastolic blood pressure during the treatment period. Increase in CFR was significantly greater in the normal-higher group than in the normal-lower group. These findings indicate that lowering blood pressure to a normal level is necessary to improve coronary microvascular dysfunction in hypertensive patients. Furthermore, raising diastolic blood pressure to a higher level within normal range has the most beneficial effect. However, as this study is based on observational design, it may have several limitations. (Hypertension. 2012;60:326-332.) • Online Data Supplement Key Words: antihypertensive treatment Ⅲ blood pressure Ⅲ coronary microvascular dysfunction Ⅲ echocardiography Ⅲ hypertension I t is well known that hypertensive patients have a decreased coronary flow reserve (CFR), even if they have normal epicardial coronary arteries. 1 In the absence of epicardial coronary stenosis, CFR is considered to be a marker of coronary microvascular dysfunction. A recent study documented that coronary microvascular function was impaired even in patients with prehypertension. 2 Antihypertensive treatment has been shown to improve coronary microvascular dysfunction 3-5 ; however, the optimal level for therapeutically lowering blood pressure (BP) remains to be established, with no previous data existing regarding the impact of antihypertensive level on coronary microvascular dysfunction. Recently, it was reported that CFR measured by transthoracic Doppler echocardiography had an excellent correlation with that measured by positron emission tomography, which was validated as the reference standard for measuring CFR. 6 In the present study, we examined the optimal level for therapeutic lowering of BP with antihypertensi...

Ischemia and No Obstructive Coronary Artery Disease (INOCA)

“…Therapeutically lowering blood pressure can improve CFR, but excess lowering of diastolic blood pressure attenuates the benefit. 113 The insulin sensitizer metformin has been shown to improve endothelial function. 114 Lifestyle modifications include weight loss, 115 smoking cessation, high-fiber diet, fruits and vegetables consumption and regular physical activity.…”

Coronary Microvascular Dysfunction ― Epidemiology, Pathogenesis, Prognosis, Diagnosis, Risk Factors and Therapy ―

“…Therapeutically lowering blood pressure can improve CFR, but excess lowering of diastolic blood pressure attenuates the benefit. 83 Insulin sensitizer, metformin, has been shown to improve endothelial function. 84 Lifestyle modifications include weight loss, 85 smoking cessation, high-fiber diet, fruit and vegetable consumption, and regular physical activity.…”

Recent Clinical Trials of Hypertension Management

“…This debate will continue in the absence of a major contemporary trial specifically designed to address systolic BP targets and supported by further data on the relationship of BP to various target organ manifestations of hypertensive vascular disease. [30][31][32] The choice of thresholds for initiation of therapy and targets for BP lowering have far greater implications than the relatively small differences in efficacy and tolerability between drug classes. These recommendations vary considerably as authoritative international bodies examine the same evolving body of evidence.…”