Noncardiac surgery and the risk of death and other cardiovascular events in patients with hypertrophic cardiomyopathy

Background: There is a paucity of reports evaluating the perioperative risk of noncardiac surgery in patients with hypertrophic cardiomyopathy (HCM). Hypothesis: The study was undertaken to evaluate the incidence of acute myocardial infarction (MI) and all-cause in hospital mortality following noncardiac surgery in patients with HCM. Methods: We searched the National Hospital Discharge Survey database for patients with a diagnosis of HCM who had undergone noncardiac surgery. Cases were matched by age, gender, and year of surgery. Death or acute MI were used as endpoints for analysis. Results: From 1996 to 2002, 227 patients with HCM were matched with 554 controls (representing national estimates of 25,874 HCM and 50,326 controls patients). Patients with HCM were more likely than controls to have a history of atrial fibrillation (22.7 vs. 10.6%, p < 0.001) and of congestive heart failure (CHF) (24.2 vs. 14.1%, p < 0.001). The in-hospital incidence of death or MI was higher in patients with HCM than in controls (6.7 vs. 2.5%, p < 0.001 for death and 2.2 vs. 0.3%, p < 0.001 for MI). After correcting for age, gender, race, presence of hypertension, diabetes mellitus, history of coronary artery-disease, history of CHF, atrial fibrillation, and ventricular arrhythmias in a multivatiate binary logistic regression model, the presence of HCM increased the odds of death by 61% (odds ratio [OR] = 1.61, 95% confidence interval [CI] 1.46-1.77, p < 0.001), and almost tripled the odds of the combined endpoint of death or MI (OR = 2.82, 95% CI 2.59-3.07, p < 0.001). Conclusion: The presence of HCM significantly increases the risk of death and MI associated with noncardiac surgery. Patients with HCM undergoing elective procedures may require more careful preoprative assessment and perioperative monitoring. The impact of the severity of HCM on outcomes of noncardiac surgery needs further study.