Author + information
Patients with angina and coronary microvascular dysfunction (CMVD) in the absence of obstructive epicardial coronary artery disease (CAD) or structural heart disease (Type 1 CMVD) remain without evidence based treatment options. Ranolazine has been shown to reduce frequency of angina episodes among patients with Type 1 CMVD.
of this pilot project is to assess the impact of ranolazine on CMVD as measured by the index of microcirculatory resistance (IMR).
Patients referred for cardiac catheterization for angina who are found to have non-obstructive epicardial CAD underwent invasive coronary flow and pressure assessment including IMR (Mean distal pressure X hyperemic transit time). Patients with elevated resistance (IMR >20) at baseline were enrolled and treated with ranolazine 1000 mg BID for four weeks. Post treatment IMR was measured at the completion of 4 weeks. Primary outcome measure was change in IMR post treatment. Secondary outcome measure was change in exercise tolerance, activity status and change in Seattle Angina Questionnaire (SAQ) post treatment.
7 patients were enrolled. Mean age was 57.6±11.5 and less than 40% of patients were female. All patients had improvement in IMR after treatment (Table 1). This was mainly driven by improvement in mean aortic and distal perfusion pressure post treatment.
In this pilot proposal, among patients with angina and Type 1 CMVD, early data shows favorable changes in microcirculatory function, symptoms and activity status with ranolazine.
|Mean baseline transit time(sec)||1.7±0.39||1.5±0.29||NS|
|Mean hyperemic transit time(sec)||0.5±0.24||0.4±0.24||NS|
|Abnormal TIMI flow (%)||100||60|
|Mean Pressure (aortic)(mm hg)||79.6±23.2||59.4±22.4||0.04|
|Mean Pressure (distal) (mm hg)||72.7±28.38||50.6±20.64||0.03|
|LVEDP (mm hg)||13.6±4.0||12±6.9||NS|