BackgroundPast research has identified aortic stenosis (AS) as a major risk factor for adverse outcomes in noncardiac surgery; however, more contemporary studies have questioned the grave prognosis. To further our understanding of this, the risks of a 30-day major adverse cardiovascular event (MACE) and all-cause mortality were investigated in a contemporary Danish cohort. HypothesisAS is not an independent risk factor for adverse outcomes in noncardiac surgery. MethodsAll patients with and without diagnosed AS who underwent noncardiac surgery in 2005 to 2011 were identified through nationwide administrative registers. AS patients (n=2823; mean age, 75.5years, 53% female) were matched with patients without AS (n=2823) on propensity score for AS and surgery type. ResultsIn elective surgery, MACE (ie, nonfatal myocardial infarction, ischemic stroke, or cardiovascular death) occurred in 66/1772 (3.7%) of patients with AS and 52/1772 (2.9%) of controls (P=0.19), whereas mortality occurred in 67/1772 (3.8%) AS patients and 51/1772 (2.9%) controls (P=0.13). In emergency surgery, 163/1051 (15.5%) AS patients and 120/1051 (11.4%) controls had a MACE (P=0.006), whereas 225/1051 (21.4%) vs 179/1051 (17.0%) AS patients and controls died, respectively (P=0.01). Event rates were higher for those with symptoms (defined as use of nitrates, congestive heart failure, or use of loop diuretics), compared with those without symptoms (P<0.0001). ConclusionsAS is associated with high perioperative rates of MACE and mortality, but perhaps prognosis is, in practice, not much worse for patients with AS than for matched controls. Symptomatic patients and patients undergoing emergency surgery are at considerable risks of a MACE and mortality.