Towards the quantification of perioperative cardiovascular risk in the African context: A sub-analysis of the South African Surgical Outcomes Study and the African Surgical Outcomes Study.

BACKGROUND: The burden of cardiovascular disease in patients requiring non-cardiac surgery in Africa is not known. These patients are at increased risk for postoperative cardiovascular complications. OBJECTIVES: In this sub-study, to use data on comorbidities and surgical outcomes from two large observational studies, the South African Surgical Outcomes Study (SASOS) and the African Surgical Outcomes Study (ASOS), to investigate the prevalence of cardiovascular disease in elective surgical patients and the risk of postoperative cardiovascular complications in this population. METHODS: SASOS and ASOS were both prospective, observational cohort studies that collected data over 1 week in each participating centre. The primary outcome was in-hospital postoperative complications, which included prespecified and defined cardiovascular complications. We defined the cardiovascular disease burden of patients aged ≥45 years presenting for surgery (main objective), determined the relative risk of developing postoperative cardiovascular complications (secondary objective) and assessed the utility of the Revised Cardiac Risk Index (RCRI) for preoperative cardiovascular risk stratification of elective, non-cardiac surgical patients in Africa (third objective). RESULTS: The primary outcome analysis of 3 045 patients showed that patients with major cardiac complications were significantly older, with a higher prevalence of hypertension, coronary artery disease or congestive cardiac failure, and had undergone major surgery. In-hospital mortality for the cohort was 1.2%. CONCLUSIONS: The substantial burden of cardiovascular disease in patients presenting for non-cardiac surgery in Africa is shown in the principal findings of this study. The RCRI has moderate discrimination for major cardiac complications and major adverse cardiac events in African patients undergoing non-cardiac surgery.

The African Surgical OutcomeS-2 (ASOS-2) Pilot Trial, a mixed-methods implementation study

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. The working hypothesis is that patients die as a result of failure to rescue following complications in the postoperative period. The African Surgical OutcomeS-2 (ASOS-2) Trial plans to test the efficacy of increased postoperative surveillance in high risk patients for decreasing perioperative morbidity and mortality. This pilot trial aimed i) to evaluate the adequacy of data produced by the data collection strategies of the ASOS-2 Trial, ii) to evaluate the fidelity of implementation of the increased postoperative surveillance intervention, and iii) to understand the acceptability, appropriateness and feasibility of the intervention and the trial processes. Methods: The ASOS-2 Pilot Trial was a mixed-methods (quantitative-qualitative) implementation study focusing on the intervention arm of the proposed ASOS-2 Trial. The intervention is increased postoperative surveillance for high-risk surgical patients. The intervention protocol was implemented at all sites for a seven-day period. A post pilot trial survey was used to collect data on the implementation outcomes. Results: 803 patients were recruited from 16 hospitals in eight African countries. The sampling and data collection strategies provided 98% complete data collection. Seventy-three percent of respondents believed that they truly provided increased postoperative surveillance to high risk patients. In reality 83/125 (66%) of high-risk patients received some form of increased postoperative surveillance. However, the individual components of the increased postoperative surveillance intervention were implemented in less than 50% of high-risk patients (excepting increasing nursing observations). The components most frequently unavailable were the ability to provide care in a higher care ward (32.1%) and assigning the patient to a bed in view of the nurses' station (28.4%). Failure to comply with available components of the intervention ranged from 27.5% to 54.3%. The post pilot survey had a response rate of 30/40 (75%). In Likert scale questions about acceptability, appropriateness, and feasibility of the ASOS-2 intervention, 63% to 87% of respondents indicated agreement. Respondents reported barriers related to resources, trial processes, teamwork and communication as reasons for disagreement. Conclusions: The proposed ASOS-2 Trial appears to be appropriate, acceptable and feasible in Africa. This pilot trial provides support for the proposed ASOS-2 Trial. It emphasises the need for establishing trial site teams which address the needs of all stakeholders during the trial. A concerted effort must be made to help participating hospitals to increase compliance with all the components of the proposed intervention of 'increased postoperative surveillance' during the ASOS-2 Trial