Impact of ranolazine on coronary microvascular dysfunction (MICRO) study. Academic Article uri icon


  • Patients with angina and coronary microvascular dysfunction, without evidence of structural or epicardial coronary disease (Type I CMVD) remain without evidence based treatment options. Previous work has demonstrated that ranolazine can improve angina frequency and stability among patients with Type 1 CMVD; however, the mechanism remains unclear. Therefore, the objective of this pilot project was to assess the impact of ranolazine on Type I CMVD as measured using an invasive tool to measure global resistance (index of microcirculatory resistance (IMR)).Patients with Type 1 CMVD diagnosed using IMR were enrolled and treated with ranolazine 1000mg BID. Coronary angiography and IMR were performed at baseline and on treatment after four weeks. The primary outcome measure was change in IMR pre- and post-treatment. Secondary outcome measures, improvement in angina and activity level, were assessed using the Seattle Angina Questionnaire (SAQ), Duke Activity Status Index (DASI) and Metabolic equivalent for Task (MET) scores.A total of 7 patient were enrolled and completed the study. Mean age was 57.6±7.5, 43% were female and 43% were Hispanic. Mean baseline IMR was 37.25±16.27 which decreased to 19.48±5.69 (p=0.02; (-48% Δ) after treatment with ranolazine. Four of the five SAQ domains improved on treatment with significant improvement in physical limitation (p=0.001), angina frequency (p=0.04), angina stability (p=0.05) and disease perception (p=0.001). Non-significant improvements in activity were also seen in both the DASI and MET scores.Among patients with Type 1 CMVD, our pilot data suggest favorable changes in IMR, anginal symptoms and activity status with ranolazine treatment. These findings support further evaluation of the effects of ranolazine on microcirculatory function and angina symptoms in a larger cohort of patients with Type 1 CMVD.Copyright © 2017 Elsevier Inc. All rights reserved.

publication date

  • September 2017