Perspective:

This interesting study benefits greatly from the existence of comprehensive administrative databases for the province of Alberta, allowing the investigators to make observations on population-wide cohorts for the entire province. This important study highlights the significant perioperative risk faced by patients with a diagnosis of HF or AF undergoing noncardiac surgery. This observation is based, however, on the inclusion of all subjects who had any diagnosis of either HF or AF—a clearly very heterogeneous group. Nonetheless, this serves to remind practitioners that these diagnoses (HF and AF) can be related to significant perioperative risk. The conclusion of this paper that patients with HF or AF face greater mortality risk than CAD patients undergoing noncardiac surgery may be somewhat misleading, however. Perioperative risk prediction models mostly identify only CAD patients who are actively symptomatic or have a history of myocardial infarction as being at increased risk for perioperative complications. This is clearly only a high-risk subset of all patients with an ICD-9 diagnosis of CAD, which was the cohort studied in this paper. Thus, it is not known if existing perioperative risk prediction models may identify patients with CAD-associated perioperative risk that exceeds that observed with a preoperative diagnosis of HF or AF. Further study is needed to parse out the relative incremental perioperative risk associated with additional diagnoses of HF or AF.