PURPOSE: Prior studies have described worsening of renal function after cardiac surgery. We undertook this study to find the predictors of poor post-operative renal function.
METHODS: 180 consecutive patients who underwent coronary artery bypass and valve surgeries in 2008 were included in our study. Data were analyzed to find significant associations between various variables and post operative renal function.
RESULTS: Our sample had a mean age of 66 + 11 with 29% women. 37% patients had history of diabetes. Mean ejection fraction was 51% + 11%. Mean pre-operative creatinine was 1.16 + 0.69 ng/ml. Mean post operative creatinine was 1.40 + 0.81 ng/ml, whereas 3% patients were on hemodialysis. 64% were taking on Beta-Blockers and 64% patients were taking ACE inhibitors at the time of surgery. Using Pearson’s correlation, increasing age showed a positive correlation with post-operative rise in creatinine (R=0.22, p=0.003). Lower preoperative ejection fraction was also associated with greater rise in creatinine post-operatively (R= 0.17, p=0.54). Association persisted at borderline significance after adjusting for age and gender (R=0.18, p=0.07). Use of Beta-blockers pre-operatively was associated with no significant impact on post-operative creatinine (p=0.23), where ACE inhibitor’s use was associated with a greater rise in creatinine (p=0.01). Patients with diabetes had significantly higher post-operative creatinine (p=0.01). History of hypertension or variables such as cross-clamp time or perfusion time did not show any significant correlation with post-operative renal function (p=0.38, 0.73, and 0.33 respectively). After adjusting for age, gender, and pre-operative creatinine, ACE inhibitors maintained a borderline significance with post-operative rise in creatinine (R=0.18, p=0.06).
CONCLUSION: Increasing age, history of diabetes, lower pre-operative ejection fraction and use of ACE inhibitors is associated with worsening of renal function after heart surgery whereas factors such as hypertension, use of beta blockers, cross clamp time or perfusion time does not have any significant impact on renal function.
CLINICAL IMPLICATIONS: Risk factors modification and stopping ACE inhibitors before surgery may have a positive impact on post-operative renal function.
DISCLOSURE: Maryam Qadir, No Financial Disclosure Information; No Product/Research Disclosure Information