Response to Letter Regarding Article, "Surgical Ineligibility and Mortality Among Patients With Unprotected Left Main or Multivessel Coronary Artery Disease Undergoing Percutaneous Coronary Intervention". Issue 12 (22nd September 2015) - Waldo, Stephen W.; Secemsky, Eric A.; O'Brien, Cashel; Kennedy, Kevin F.; Pomerantsev, Eugene; Sundt, Thoralf M.; McNulty, Edward J.; Scirica, Benjamin M.; Yeh, Robert W.