Background. The differential diagnosis of chest pain in women is complex, ranging from atypical angina to chest pain in the absence of coronary artery disease (i.e., Syndrome X). The mechanism of these conditions remains unexplained. The purpose of this study was to examine coronary blood flow based on a new angiographic technique. Methods. Patients with chest pain were enrolled. In the new technique, as the contrast injection stopped, the blood in white color moved in and displaced the black contrast. Characteristics of blood flow could be observed and classified by type and time. The duration of the arterial phase was calculated and compared with the control. Results. Sixty patients were enrolled. Ten patients with normal coronary arteries and ventricular function; without chest pain served as controls. In the control group, the duration of the arterial phase in the RCA was 1.76 sec, while it was 3.76 sec for the syndrome X group (p<0.05). From the mMID segment to the distal segment, syndrome X patients had a much longer delay compared to control subjects (0.81 vs. 0.26 sec) (p<0.05). From the distal segment (bDIS) to the origin of the PDA, syndrome X patients had an average duration of 0.81 sec compared to 0.40 sec in controls (p<0.05). The largest difference was the period of time when the contrast left the PDA until flushed from the distal vasculature, which was 1.66 sec and 0.40 sec in syndrome X vs. control. Syndrome X patients with prolonged myocardial phase (1.89 sec) had dense and prolonged contrast retention at the myocardium. Conclusions. In patients with syndrome X, the prolonged arterial phase deprived the myocardium of highly oxygenated blood and triggered ischemia. This new imaging method allows for a better understanding of the mechanism of ischemia in Syndrome X patients.

Introduction: Many patients with acute coronary syndrome (ACS) presented with elevated troponin level and reversible changes in the thallium scan. When they patients underwent coronary angiogram, the results showed patent coronary arteries. WHY? Hypothesis: Could abnormal coronary flow explain ACS, abnormal thallium and patent coronary arteries? Methods: Patients with newly diagnosed ACS and abnormal Thallium scan underwent a new dynamic coronary angiogram. 10 patients without ACS, normal EF and no coronary artery disease served as control. In this new technique, the contrast and blood flow were recorded at 15 images per second. The first image was of the index artery completely filled with contrast. The subsequent images showed the blood in white color moving in over a background of black contrast. The arterial phase started when the blood began moving in and ended when the contrast disappeared from the distal arterial vasculature as the contrast was replaced by blood. The machine learning (ML) program had 2 models (built on Python). Model 1 was built based on U-net and Densenet-121 for vessel segmentation. Model 2 was used for classification of flow. The model 2 was trained based on the convolutional neural network. The data to be collected was the duration of the arterial phase and the recurrence of ACS within one year follow-up Results: 45 patients with ACS (elevated troponin level (50-100mg), reversible stress thallium), underwent coronary angiogram. The angiograms of 10 control patients showed a normal arterial phase (AP) of 1.56 sec. It was prolonged at 2.5sec in 45 patients with ACS (p<0.05). After 1 year follow-up, 35 patients had no further ACS if their LDL cholesterol was well controlled (<75mg%), blood pressure (BP<130mmHg) and the patients stopped smoking. In 10 patients who continued to have uncontrolled LDL, high BP and especially smoking, they developed ACS including death. Conclusions: In ACS patients, a prolonged arterial phase associated with reversible change in nuclear scan and normal coronary arteries identified the patients of high risk. Aggressive treatment of risk factors protected these patients of new ACS. Failure to control risk factors lead to repeat ACS. New trials are needed to confirm and guide new personalized medicine approach.

Introduction: As hypertension (HTN) is a strong risk factor of coronary artery disease (CAD), what is an optimal blood pressure (BP) which could preclude CAD? Hypothesis: In industrial piping, laminar flow preserves equipment service life while turbulent flow damages the inner surface of pipes and pumps. Based on the same hydraulic principles, our hypothesis is built on the observations that turbulent flow injures the intima and triggers atherosclerosis. In order to identify an optimal BP, at which BP level, could we evidence VISUALLY the abolishment of turbulent flow at the iliac artery as proof of correction of the injuring mechanism precipitated by HTN? Methods: 210 patients with uncontrolled HTN who underwent coronary intervention and a repeat diagnostic angiogram a few months later because of unstable angina were enrolled. At the end each coronary procedure, patients underwent iliac angiogram for deployment of closure device. In a new technique of dynamic angiography, the contrast was injected until the iliac artery was completely opacified. As the injection stopped, the blood flew down and displaced the contrast. The movements of the blood in white color above a black background could be clearly identified and analyzed. At the same time, Artificial Intelligence (Machine Learning algorithms) program had 2 models built on Python. Model 1 was based on U-net and Densenet-121 for vessel segmentation. Model 2 was used for classification and movement of flow. Model 2 was trained based on the convolutional neural network. The main measurements were the type of flow (turbulent), directions (antegrade versus retrograde) and presence of collision from slamming of the retrograde against antegrade flow. Results: At baseline, 98% patients had prolonged reversed flow with turbulence. At the 2nd iliac angiogram, if the systolic BP was <110mmHg, the rate of turbulence was 10%. If the systolic BP >130mmHg, the turbulence was present in 70% (p<0.05) Conclusions: With the uncontrolled BP imaged as collision at the iliac artery secondary to heightened distal vascular resistance, the abolishment of turbulence and return of laminar flow confirmed that the ideal systolic BP was <110mmH in the application of personalized medicine. Larger studies need to confirm the above result.

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