Angina, Stable/diagnostic imaging; Coronary Artery Disease/diagnostic imaging; Coronary Stenosis/diagnostic imaging; Coronary Vessels/diagnostic imaging; Fractional Flow Reserve, Myocardial; Ultrasonography, Interventional; Angina, Stable/mortality; Angina, Stable/physiopathology; Angina, Stable/therapy; Cardiac Catheterization; Cardiovascular Agents/therapeutic use; Chi-Square Distribution; Coronary Angiography; Coronary Artery Bypass; Coronary Artery Disease/mortality; Coronary Artery Disease/physiopathology; Coronary Artery Disease/therapy; Coronary Stenosis/mortality; Coronary Stenosis/physiopathology; Coronary Stenosis/therapy; Coronary Vessels/drug effects; Coronary Vessels/physiopathology; Female; Fractional Flow Reserve, Myocardial/drug effects; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Patient Selection; Percutaneous Coronary Intervention; Predictive Value of Tests; Risk Factors; Severity of Illness Index; Time Factors; Treatment Outcome