Perioperative myocardial ischemia and isolated systolic hypertension in non-cardiac surgery

Abstract

To determine whether patients with isolated systolic hypertension (ISH) undergoing non-cardiac surgery have a higher incidence of perioperative myocardial ischemia than normotensive patients and hence a greater risk for perioperative adverse events. After obtaining Research Ethics Board approval, patients were recruited to either an ISH group (systolic blood pressure [SBP]>140mmHg with diastolic blood pressure [DBP]<90mmHg) or a normotensive group (SBP<140mmHg and DBP<90mmHg), according to their resting preoperative blood pressure. The primary outcome was the overall incidence of perioperative myocardial ischemia (PMI) as determined by 48-hr ambulatory Holter monitoring. P values≤0.05 were considered to be statistically significant. A total of 312 (150 ISH and 162 normotensive) patients completed the study. Orthopedic surgery was the most frequent surgical procedure in both groups. The overall incidence of PMI was 19.7% in the ISH group compared with 18.8% in the normotensive group (difference 0.9%; 95% confidence interval [CI], -7.9% to 9.8%). The overall incidence of adverse events was 4.0% in the ISH group compared with 1.9% in the normotensive group (difference 2.2%; 95% CI, -1.6% to 5.9%). In this study, we chose to examine ISH as potential cardiac risk factor for patients undergoing non-cardiac surgery. The incidence of myocardial ischemia, a surrogate outcome, was similar in the two groups. The relatively high incidence of myocardial ischemia (19.2%) was of particular interest in this relatively low cardiac risk surgical population. (ClinicalTrials.gov number, NCT01237652).