Other scoring systems can be applied to calculate no, mild, or moderate to severe frailty. Examples of major organ system compromise include cardiac dysfunction (severe LV systolic or diastolic dysfunction or RV dysfunction, fixed pulmonary hypertension); kidney dysfunction (chronic kidney disease, stage 3 or worse); pulmonary dysfunction (FEV1 <50% of predicted); central nervous system dysfunction (dementia, Alzheimer s disease, Parkinson s disease, cerebrovascular accident with persistent physical limitation); gastrointestinal dysfunction (Crohn s disease, ulcerative colitis, nutritional impairment, or serum albumin <3.0); cancer (active malignancy); and liver dysfunction (any history of cirrhosis, variceal bleeding, or elevated INR in the absence of VKA therapy). Examples of procedure-specific impediments include presence of tracheostomy, heavily calcified (porcelain) ascending aorta, chest malformation, arterial coronary graft adherent to posterior chest wall, and radiation damage. indicates diffusion capacity for carbon dioxide; FEV1 , forced expiratory volume in 1 s; INR, international normalized ratio; LV, left ventricular; MR, mitral regurgitation; RV, right ventricular; SAVR, surgical aortic valve replacement; STS, Society of Thoracic Surgeons; and VKA, vitamin K antagonist. CLINICAL STATEMENTS AND GUIDELINES Risk prediction tools for trans- catheter mitral valve repair are comparatively less The relationship between operator/ institutional case volume and outcomes has been explored for surgical20 aor- tic valve replacement (AVR), surgical mitral valve repair and replacement,24 32 and transcatheter mitral valve repair.33 Table 9 includes examples of several factors that impact outcomes but are not routinely captured in currently available risk scores. Perioperative mortality rates for 6 specific surgical procedures are shown in Table 10. The potential to return to activities of daily living after an intervention must be considered. 2.6. 