The Revised Cardiac Risk Index (RCRI) is widely used to estimate risk of cardiac complications after noncardiac surgery; its estimates do not capture myocardial injury after noncardiac surgery (MINS). We evaluated the incidence of cardiac complications including MINS across RCRI risk classes and the RCRI's ability to discriminate, before surgery, between patients who will experience these complications and those who will not.This was a secondary analysis of a prospective cohort study of 35,815 patients ≥ 45 years old who had elective inpatient noncardiac surgery from 2007 to 2013 at 28 centres in 14 countries. The primary outcome was a composite of MINS, myocardial infarction, nonfatal cardiac arrest, or cardiac death within 30 days after surgery. The secondary outcome was this composite without MINS.The primary outcome occurred in 4725 patients (13.2%); its incidences across RCRI classes I (no risk factors), II (1 risk factor), III (2 risk factors), and IV (≥ 3 risk factors) were, respectively, 8.2%, 15.4%, 26.6%, and 40.2% (C-statistic for discrimination 0.65 [95% confidence interval 0.62-0.68]). The secondary outcome occurred in 1174 patients (3.3%) with incidences of 1.6%, 4.0%, 7.9%, and 12.9%, respectively (C-statistic 0.69 [0.65-0.72]). Thirty-five percent of primary outcome events and 26.9% of secondary outcome events occurred in patients with no RCRI risk factors.The RCRI alone is not sufficient to guide postoperative cardiac monitoring because 1 in 12 patients ≥ 45 years of age without any RCRI risk factors have a cardiac complication after major noncardiac surgery, and most of them would be missed without systematic troponin testing.