Physiological Stratification of Patients With Angina Due to Coronary Microvascular Dysfunction

Figures

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  Figure 1. Final Studies Undertaken All patients with angina and no obstructive coronary disease (NOCAD) enrolled in the study had assessment of coronary flow reserve (n = 86). Cath Lab Exercise = invasive catheter laboratory exercise physiology; Vascular Study = forearm venous occlusion plethysmography.

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  Figure 2. Resting Physiological Abnormalities in CMD (Top) Patients with functional coronary microvascular dysfunction (CMD) have higher supply/demandEXT (average peak velocity/rate−pressure product, in cm/mm Hg × 10−2) than structural CMD and reference group patients. (Middle) Both functional and structural CMD have elevated nitric oxide synthase (NOS) activity calculated as resting forearm blood flow/forearm blood flow during infusion of NG-monomethyl-L-arginine. (Bottom) Both functional and structural CMD have increased resting wave energy calculated using wave intensity analysis. ∗Statistically significant different from reference group, where p < 0.05. Numbers depict mean values and error bars depict SD. BCW = backward compression wave; BEW = backward expansion wave; FCW = forward compression wave; FEW = forward expansion wave.

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  Figure 3. Changes in Coronary Wave Energies During Exercise in Reference Group Patients and in Patients With Functional and Structural CMD ∗Significant difference from reference group. †Significant difference between CMD endotypes, both p < 0.05. Numbers depict mean values and error bars depict SD. Abbreviations as in Figure 2.

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  Figure 4. Systemic Hemodynamic and Coronary Circulation Response to Stress Patients with structural CMD had varying hemodynamic responses to supine bicycle exercise and adenosine-induced hyperemia compared with those with functional CMD and those in the reference group. Numbers depict mean values. 1 min = after 1 min of exercise; 50% = 50% of maximal exercise time; hyperemia = adenosine-induced hyperemia; MR = microvascular resistance; peak = immediately before exercise was discontinued due to exhaustion; RPP = rate−pressure product.

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  Figure 5. Results From Venous Occlusion Plethysmography Both functional and structural CMD demonstrate greater vasoconstriction in response to NG-monomethyl-L-arginine (L-NMMA), whereas structural CMD also demonstrated reduced vasodilatation to acetylcholine (ACh) and adenosine (Ado). Numbers depict mean values.

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  Central Illustration. Coronary Microvascular Dysfunction Disease Endotypes Summary of distinct coronary, myocardium, and systemic changes associated with each disease endotype compared with the reference group of patients (3). CMD = coronary microvascular dysfunction; NT-proBNP = N-terminal pro–brain natriuretic peptide.