The effect of chronic steroid therapy on outcomes following cardiac surgery: a propensity-matched analysis.

OBJECTIVE: Steroids are beneficial in reducing the inflammatory response accompanying surgery with cardiopulmonary bypass. However, chronic steroid therapy has been implicated as a risk factor for abdominal complications and mortality following surgery. We assessed the impact of chronic steroid therapy had on outcome following cardiac surgery. METHODS: During the period January 1999 to March 2003 there were 98 patients on chronic steroid therapy (Group S) who underwent cardiac surgery at our institution. These patients were matched with a control group of 98 patients who were not on steroids (Group C). A propensity score was used to perform the matching. The C statistic for this model was 0.72. RESULTS: Ninety (93.7%) of the 98 patients in Group S had been on oral prednisolone for a median of 9.5 years (25th and 75th percentile of 5 and 12 years) with a median dose of 5mg (25th and 75th percentile of 4 and 8.75 mg). Preoperative characteristics were well matched between both groups. There was no difference in the post-operative outcome between the two groups with respect to mortality, stroke, renal failure, abdominal complications, wound infections, requirement for inotropic support and myocardial infarction. Patients in Group S were more likely to develop atrial arrhythmias and to require prolonged ventilation, although this did not reach statistical significance. CONCLUSIONS: Chronic steroid therapy was not associated with increased mortality or overall morbidity following cardiac surgery. However, patients on chronic steroids may be at greater risk of developing atrial arrhythmias or of requiring prolonged ventilation.

Timing of intra-aortic balloon pump support and 1-year survival.

OBJECTIVE: The relationship between the timing of intra-aortic balloon pump (IABP) support and surgical outcome remains a subject of debate. Peri-operative mechanical circulatory support is commenced either prophylactically or after increasing inotropic support has proved inadequate. This study evaluates the effect timing of IABP support on the 1-year survival of patients undergoing cardiac surgery. METHODS: From April 1997 to September 2002, 7698 consecutive cardiac surgical procedures were performed. This included 5678 isolated coronary artery bypasses (CABGs), 1245 isolated valve procedures and 775 simultaneous CABG and valve procedures. IABP support was required in 237 patients (3.1%). Twenty-seven patients (0.35%) were classed as high-risk and received preoperative IABP support, 25 patients (0.32%) were haemodynamically compromised and required preoperative IABP support, 120 patients (1.56%) required intra-operative IABP support, and 65 patients (0.84%) required post-operative IABP support. Multiple variables were offered to a Cox proportional hazards model and significant predictors of 1-year survival were identified. These were used to risk adjust Kaplan-Meier survival curves. RESULTS: 1-year follow-up was complete and 450 deaths (5.8%) were recorded. The significant independent predictors of increased mortality at 1-year (P<0.05, HR=hazard ratio) were post-operative renal failure (HR=3.5), increasing EuroSCORE (HR=1.2), post-operative myocardial infarction (HR=3.7), post-operative IABP (HR=4.1) intra-operative IABP (HR=2.8), post-operative stroke (HR=2.5), increasing number of valves (HR=1.6), ejection fraction <30% (HR=1.3) and triple-vessel disease (HR=1.3). After risk-adjustment, 1-year survival for patients who required intra-operative IABP support was significantly greater than for those patients who required IABP support in the post-operative period. CONCLUSIONS: Patients who warrant IABP support in the post-operative setting have a significantly increased mortality at 1-year when compared to any other group. Therefore, earlier IABP support as part of surgical strategy may help to improve the outcome.

Left internal mammary artery to the left anterior descending artery: effect on morbidity and mortality and reasons for nonusage.

BACKGROUND: The left internal mammary artery to the left anterior descending artery is recognized as the gold standard for revascularization. Several studies have shown the benefits of the left internal mammary artery. However, a substantial portion of patients undergoing coronary artery bypass grafting does not receive this conduit. We sought to identify reasons for nonusage of the left internal mammary artery to the left anterior descending artery, while evaluating short- and medium-term outcomes. METHODS: Between April 1997 and September 2001 a total of 4406 consecutive patients underwent coronary artery bypass grafting with revascularization to the left anterior descending artery. All data were collected prospectively except reasons for nonusage of the left internal mammary artery. Logistic regression and Cox proportional hazards analyses were used to adjust in-hospital and medium-term outcomes, respectively. Selection bias was controlled by constructing a propensity score. A case note review was carried out to determine reasons for nonusage. RESULTS: A total of 4047 patients (91.8%) received the left internal mammary artery to the left anterior descending artery leaving 359 patients (8.2%) who did not. We found no difference in hospital mortality or morbidity, however, patients receiving the left internal mammary artery had a survival advantage at 4 years. Reasons for not using the left internal mammary artery were damage to the conduit (n = 44), poor flow (n = 43), poor lung function (n = 45), unstable symptoms (n = 24), vascular problems (n = 12), and 19 patients with "other" reasons (previous radiotherapy, chest wall deformity, and obese patients). Case notes had no reason stated for 146 patients and reasons for 26 patients were unobtainable. CONCLUSIONS: Left internal mammary artery usage is not associated with any increase in hospital mortality and morbidity, but these patients have better medium-term survival. Injury on harvesting, poor flow, and poor lung function were the most common reasons for not using this conduit.