The impact of symptom severity on cardiac reoperative risk: early referral and reoperation is warranted

Abstract

Operative mortality is comparatively higher for coronary artery bypass grafting (CABG) or valve reoperations. Studies of reoperative risk have focussed on surgical techniques. We sought to determine the risk and predictors of poor outcome in current practice, and the influence of preoperative symptoms. For every redo patient (n=289), we selected the best-matched pair of patients who underwent a primary operation (n=578) between 1998 and 2006. Matching variables were age, gender, left ventricular ejection fraction (LVEF) and type of operation. Poor outcome was defined as operative mortality or major morbidity. Median age was 68 (interquartile range 62-73) years and 28% were female for both groups. Severe symptoms and cardiac morbidity dominated the presentation of redo patients. CABG (53%), valve repair/replacement (34%) and combined CABG and valve (12%) were performed with overall operative mortality of 6.6% (median additive EuroScore 7.0) for redo versus 1.6% (median additive EuroScore 4.0) for primary groups (p<.0001). Whereas no significant difference was observed between primary (1.6%) and redo CABG (3.9%, p=.19), valve reoperations had higher operative mortality (9.6% vs 1.5%, p<.0001). Major complications occurred more frequently after redo valve compared to primary valve operations (28% vs 14%, p=.001). Reoperation (odds ratio [OR] 1.26, 95% confidence interval [CI] 0.66-2.42, p=.48) was not a predictor of major adverse event after CABG or valve surgery. Determinants of poor outcome after valve reoperations were New York Heart Association class III/IV (OR 6.86, 95% CI 2.29-12.11, p=.03), duration of extracorporeal circulation (OR 1.17, 95% CI 1.02-1.35, p=.03) and mitral valve replacement (OR 4.07, 95% CI 1.83-36.01, p=.04). The predictors of major adverse events after redo CABG were congestive heart failure (OR 1.85, 95% CI 1.04-8.98, p=.006) chronic obstructive pulmonary disease (OR 17.5, 95% CI 1.87-35.21, p=.05) and interval from prior surgery (OR 1.37, 95% CI 1.09-1.92, p=.01). In the current era, redo CABG is nearly as safe as the primary operation. A valve reoperation, on the contrary, is higher risk due, partly, to severe symptoms at presentation. Patients should be referred and operated on early before they develop severe symptoms.