Effect of ACE-inhibition on coronary microvascular function and symptoms in normotensive women with microvascular angina: A randomized placebo-controlled trial

ObjectiveStudies have suggested a beneficial effect of angiotensin-converting enzyme (ACE) inhibition. To explore whether the ACE inhibitor ramipril has a direct effect on the microvasculature beyond the blood pressure (BP) lowering effect, we investigated whether ramipril improved coronary microvascular function in normotensive women with coronary microvascular dysfunction (CMD).MethodsWe included 63 normotensive women with angina, no epicardial stenosis>50% and CMD defined as a coronary flow velocity reserve (CFVR)ResultsFollow-up was available on 55 patients. BP remained unchanged during treatment in both groups. CFVR improved in both the ramipril (p = 0.004) and placebo group (p = 0.026) with no difference between groups (p = 0.63). Symptoms improved in both groups with no significant between-group differences. No changes were detected in parameters of systolic and diastolic function. No serious adverse reactions were reported.ConclusionsIn normotensive women with angina and CMD, treatment with ramipril had no significant effect on CFVR or symptoms compared with placebo. The effect of ACE inhibition previously reported may be mediated by blood pressure reduction.研究目的：已有研究提示血管紧张素转换酶（angiotensin-converting enzyme, ACE）抑制治疗具有有益效果。为探究血管紧张素转换酶抑制剂雷米普利（ramipril）是否可脱离其降压（blood pressure, BP）作用，直接对微血管系统产生影响，本研究针对血压正常且合并冠状动脉微血管功能障碍（coronary microvascular dysfunction, CMD）的女性患者，考察雷米普利能否改善其冠状动脉微血管功能。研究方法：本研究纳入63例存在心绞痛、无心外膜冠状动脉狭窄程度＞50%，且以冠状动脉血流速度储备（coronary flow velocity reserve, CFVR）定义为冠状动脉微血管功能障碍的血压正常女性受试者。研究结果：最终55例患者完成随访。两组患者治疗期间血压均无显著变化。雷米普利组（p=0.004）与安慰剂组（p=0.026）的冠状动脉血流速度储备均得到改善，且两组间差异无统计学意义（p=0.63）。两组患者的临床症状均有所改善，组间差异无统计学显著性。收缩及舒张心功能相关参数未出现明显改变。未报告严重不良反应事件。研究结论：对于合并心绞痛与冠状动脉微血管功能障碍的血压正常女性患者，与安慰剂相比，雷米普利治疗对冠状动脉血流速度储备及临床症状均无显著改善作用。既往报道的血管紧张素转换酶抑制疗法的获益效应，可能是通过降低血压实现的。