pectoris angina infarction myocardial months unstable starting prior acute drug heart uncontrolled failure congestive hypertension disease angina significant unstable symptomatic uncontrolled myocardial infarction angina congestive heart failure months cardiac unstable angioplasty stenting cardiac heart infarction myocardial angina unstable vascular cardiovascular angina myocardial infarction unstable months history prior day study enrollment angina unstable months prior entry intervention disease medical surgical study heart arterial thrombotic evidenced disease infarction myocardial measurement york unstable infarction myocardial cardiac months history prior entry stress study unstable angina new heart onset months cardiac rest anginal nyha infarction heart congestive myocardial failure infarction months unstable angina history cardiac