30-Day Cardiovascular Outcomes of Adult Patients Undergoing Non-cardiac Surgery at the University of Santo Tomas Hospital: A Prospective Cohort Study

Abstract

BACKGROUND: Approximately 3,500 non-cardiac surgeries are being performed each year in the University of Santo Tomas Hospital (Manila, Philippines). No study has yet been made to evaluate the cardiovascular outcomes of these surgical patients. This prospective cohort study was performed to determine the 30-day cardiovascular outcomes in patients undergoing non-cardiac surgery in the private and clinical divisions of this institution and to evaluate the utility of currently used risk scoring systems. METHODS: There were 159 adult patients admitted from July to September 2015 for non-cardiac surgery who consented for inclusion. Risk stratification was done using the Revised Cardiac Risk Index (RCRI) and the Gupta Perioperative Risk calculator. They were followed up for major adverse cardiovascular events (MACE) until 30 days after the surgery. RESULTS: Out of 159 cases, nine patients (5.7%) developed MACE, eight of whom had a cardiac arrest. All major events occurred within 16 days following surgery. The number of comorbidities, presence of chronic kidney disease and emergency surgery significantly predicted perioperative MACE. RCRI had a sensitivity of 88.89%, specificity of 78.37%, positive predictive value (PPV) of 20% and negative predictive value (NPV) of 99.15% for predicting MACE. Gupta Perioperative Risk had a sensitivity of 77.78%, specificity of 84.46%, PPV of 23.3% and NPV of 98.43%. When combined, the two risk scoring systems showed a sensitivity of 88.89%, specificity of 77.70%, PPV of 19.5% and NPV of 99.14%. CONCLUSIONS: The 5.7% incidence of perioperative cardiovascular complications for non-cardiac surgery was similar to that seen worldwide. Physicians must be vigilant for these complications in the first 16 days following the surgery especially in patients undergoing emergency surgery and who have comorbidities like chronic kidney disease. RCRI is more sensitive while the Gupta Perioperative Risk is more specific and has higher positive predictive value for the occurrence of a MACE. Both scoring indices were useful in risk-stratifying patients.